version 1.52

removed avg function because of hidden internal overflow issues

.gitignore

@@ -24,8 +24,6 @@ __pycache__/
 parser.out
 parsetab.py
 .pytest_cache/
-compiler/src/prog8_kotlin.jar
-compiler/src/compiled_java
 .attach_pid*
 
 .gradle

.idea/.gitignore

@@ -0,0 +1,2 @@
+# Default ignored files
+/shelf/

.idea/modules.xml

@@ -2,6 +2,7 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
+      <module fileurl="file://$PROJECT_DIR$/DeprecatedStackVm/DeprecatedStackVm.iml" filepath="$PROJECT_DIR$/DeprecatedStackVm/DeprecatedStackVm.iml" />
       <module fileurl="file://$PROJECT_DIR$/compiler/compiler.iml" filepath="$PROJECT_DIR$/compiler/compiler.iml" />
       <module fileurl="file://$PROJECT_DIR$/docs/docs.iml" filepath="$PROJECT_DIR$/docs/docs.iml" />
       <module fileurl="file://$PROJECT_DIR$/examples/examples.iml" filepath="$PROJECT_DIR$/examples/examples.iml" />

.travis.yml

@@ -1,11 +1,11 @@
 language: java
+sudo: false
 # jdk: openjdk8
 # dist: xenial
-# sudo: false
 
 before_install:
   - chmod +x gradlew
 
 script:
-  - ./gradlew test
+  - gradle test
 

DeprecatedStackVm/DeprecatedStackVm.iml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
+  </component>
+</module>

DeprecatedStackVm/src/compiler/intermediate/Instruction.kt

@@ -1,4 +1,4 @@
-package prog8.compiler.intermediate
+package compiler.intermediate
 
 import prog8.vm.RuntimeValue
 import prog8.vm.stackvm.Syscall
@@ -15,8 +15,8 @@ open class Instruction(val opcode: Opcode,
         val argStr = arg?.toString() ?: ""
         val result =
                 when {
-                    opcode==Opcode.LINE -> "_line  $callLabel"
-                    opcode==Opcode.INLINE_ASSEMBLY -> {
+                    opcode== Opcode.LINE -> "_line  $callLabel"
+                    opcode== Opcode.INLINE_ASSEMBLY -> {
                         // inline assembly is not written out (it can't be processed as intermediate language)
                         // instead, it is converted into a system call that can be intercepted by the vm
                         if(callLabel!=null)
@@ -24,10 +24,10 @@ open class Instruction(val opcode: Opcode,
                         else
                             "inline_assembly"
                     }
-                    opcode==Opcode.INCLUDE_FILE -> {
+                    opcode== Opcode.INCLUDE_FILE -> {
                         "include_file \"$callLabel\" $arg $arg2"
                     }
-                    opcode==Opcode.SYSCALL -> {
+                    opcode== Opcode.SYSCALL -> {
                         val syscall = Syscall.values().find { it.callNr==arg!!.numericValue() }
                         "syscall  $syscall"
                     }

DeprecatedStackVm/src/compiler/intermediate/IntermediateProgram.kt

@@ -1,58 +1,53 @@
-package prog8.compiler.intermediate
+package compiler.intermediate
 
 import prog8.ast.antlr.escape
 import prog8.ast.base.*
-import prog8.ast.base.printWarning
-import prog8.ast.expressions.LiteralValue
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.ReferenceLiteralValue
+import prog8.ast.statements.StructDecl
 import prog8.ast.statements.VarDecl
-import prog8.vm.RuntimeValue
+import prog8.ast.statements.ZeropageWish
 import prog8.compiler.CompilerException
 import prog8.compiler.HeapValues
 import prog8.compiler.Zeropage
 import prog8.compiler.ZeropageDepletedError
+import prog8.vm.RuntimeValue
 import java.io.PrintStream
 import java.nio.file.Path
 
 
 class IntermediateProgram(val name: String, var loadAddress: Int, val heap: HeapValues, val source: Path) {
 
+    class VariableParameters (val zp: ZeropageWish, val memberOfStruct: StructDecl?)
+    class Variable(val scopedname: String, val value: RuntimeValue, val params: VariableParameters)
+
     class ProgramBlock(val name: String,
                        var address: Int?,
                        val instructions: MutableList<Instruction> = mutableListOf(),
-                       val variables: MutableMap<String, RuntimeValue> = mutableMapOf(),           // names are fully scoped
+                       val variables: MutableList<Variable> = mutableListOf(),
                        val memoryPointers: MutableMap<String, Pair<Int, DataType>> = mutableMapOf(),
                        val labels: MutableMap<String, Instruction> = mutableMapOf(),        // names are fully scoped
                        val force_output: Boolean)
-    {
-        val numVariables: Int
-            get() { return variables.size }
-        val numInstructions: Int
-            get() { return instructions.filter { it.opcode!= Opcode.LINE }.size }
-        val variablesMarkedForZeropage: MutableSet<String> = mutableSetOf()
-    }
 
     val allocatedZeropageVariables = mutableMapOf<String, Pair<Int, DataType>>()
     val blocks = mutableListOf<ProgramBlock>()
     val memory = mutableMapOf<Int, List<RuntimeValue>>()
     private lateinit var currentBlock: ProgramBlock
 
-    val numVariables: Int
-        get() = blocks.sumBy { it.numVariables }
-    val numInstructions: Int
-        get() = blocks.sumBy { it.numInstructions }
-
-    fun allocateZeropage(zeropage: Zeropage) {
+    fun allocateZeropage(zeropage: Zeropage) {          // TODO not used anymore???
         // allocates all @zp marked variables on the zeropage (for all blocks, as long as there is space in the ZP)
         var notAllocated = 0
         for(block in blocks) {
-            val zpVariables = block.variables.filter { it.key in block.variablesMarkedForZeropage }
+            val zpVariables = block.variables.filter { it.params.zp==ZeropageWish.REQUIRE_ZEROPAGE || it.params.zp==ZeropageWish.PREFER_ZEROPAGE }
             if (zpVariables.isNotEmpty()) {
                 for (variable in zpVariables) {
+                    if(variable.params.zp==ZeropageWish.NOT_IN_ZEROPAGE || variable.params.memberOfStruct!=null)
+                        throw CompilerException("zp conflict")
                     try {
-                        val address = zeropage.allocate(variable.key, variable.value.type, null)
-                        allocatedZeropageVariables[variable.key] = Pair(address, variable.value.type)
+                        val address = zeropage.allocate(variable.scopedname, variable.value.type, null)
+                        allocatedZeropageVariables[variable.scopedname] = Pair(address, variable.value.type)
                     } catch (x: ZeropageDepletedError) {
-                        printWarning(x.toString() + " variable ${variable.key} type ${variable.value.type}")
+                        printWarning(x.toString() + " variable ${variable.scopedname} type ${variable.value.type}")
                         notAllocated++
                     }
                 }
@@ -90,7 +85,7 @@ class IntermediateProgram(val name: String, var loadAddress: Int, val heap: Heap
         val branchOpcodes = setOf(Opcode.JZ, Opcode.JNZ, Opcode.JZW, Opcode.JNZW)
         for(blk in blocks) {
             val instructionsToReplace = mutableMapOf<Int, Instruction>()
-            blk.instructions.asSequence().withIndex().filter {it.value.opcode!=Opcode.LINE}.windowed(2).toList().forEach {
+            blk.instructions.asSequence().withIndex().filter {it.value.opcode!= Opcode.LINE }.windowed(2).toList().forEach {
                 if (it[1].value.opcode in branchOpcodes) {
                     if (it[0].value.opcode in pushvalue) {
                         val value = it[0].value.arg!!.asBoolean
@@ -143,8 +138,8 @@ class IntermediateProgram(val name: String, var loadAddress: Int, val heap: Heap
         for(blk in blocks) {
             val instructionsToReplace = mutableMapOf<Int, Instruction>()
 
-            blk.instructions.asSequence().withIndex().filter {it.value.opcode!=Opcode.LINE}.windowed(2).toList().forEach {
-                if(it[0].value.opcode==Opcode.CALL && it[1].value.opcode==Opcode.RETURN) {
+            blk.instructions.asSequence().withIndex().filter {it.value.opcode!= Opcode.LINE }.windowed(2).toList().forEach {
+                if(it[0].value.opcode== Opcode.CALL && it[1].value.opcode== Opcode.RETURN) {
                     instructionsToReplace[it[1].index] = Instruction(Opcode.JUMP, callLabel = it[0].value.callLabel)
                     instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
                 }
@@ -320,12 +315,12 @@ class IntermediateProgram(val name: String, var loadAddress: Int, val heap: Heap
                     instructionsToReplace[index0] = ins
                     instructionsToReplace[index1] = Instruction(Opcode.NOP)
                 }
-                Opcode.CAST_B_TO_F, Opcode.CAST_UB_TO_F-> {
+                Opcode.CAST_B_TO_F, Opcode.CAST_UB_TO_F -> {
                     val ins = Instruction(Opcode.PUSH_FLOAT, RuntimeValue(DataType.FLOAT, ins0.arg!!.integerValue().toDouble()))
                     instructionsToReplace[index0] = ins
                     instructionsToReplace[index1] = Instruction(Opcode.NOP)
                 }
-                Opcode.CAST_W_TO_F, Opcode.CAST_UW_TO_F-> throw CompilerException("invalid conversion following a byte")
+                Opcode.CAST_W_TO_F, Opcode.CAST_UW_TO_F -> throw CompilerException("invalid conversion following a byte")
                 Opcode.DISCARD_BYTE -> {
                     instructionsToReplace[index0] = Instruction(Opcode.NOP)
                     instructionsToReplace[index1] = Instruction(Opcode.NOP)
@@ -393,39 +388,53 @@ class IntermediateProgram(val name: String, var loadAddress: Int, val heap: Heap
     fun variable(scopedname: String, decl: VarDecl) {
         when(decl.type) {
             VarDeclType.VAR -> {
+                // var decls that are defined inside of a StructDecl are skipped in the output
+                //   because every occurrence of the members will have a separate mangled vardecl for that occurrence
+                if(decl.parent is StructDecl)
+                    return
+
+                val valueparams = VariableParameters(decl.zeropage, decl.struct)
                 val value = when(decl.datatype) {
-                    in NumericDatatypes -> RuntimeValue(decl.datatype, (decl.value as LiteralValue).asNumericValue!!)
+                    in NumericDatatypes -> {
+                        RuntimeValue(decl.datatype, (decl.value as NumericLiteralValue).number)
+                    }
                     in StringDatatypes -> {
-                        val litval = (decl.value as LiteralValue)
+                        val litval = (decl.value as ReferenceLiteralValue)
                         if(litval.heapId==null)
                             throw CompilerException("string should already be in the heap")
                         RuntimeValue(decl.datatype, heapId = litval.heapId)
                     }
                     in ArrayDatatypes -> {
-                        val litval = (decl.value as LiteralValue)
-                        if(litval.heapId==null)
+                        val litval = (decl.value as? ReferenceLiteralValue)
+                        if(litval!=null && litval.heapId==null)
                             throw CompilerException("array should already be in the heap")
-                        RuntimeValue(decl.datatype, heapId = litval.heapId)
+                        if(litval!=null){
+                            RuntimeValue(decl.datatype, heapId = litval.heapId)
+                        } else {
+                            throw CompilerException("initialization value expected")
+                        }
+                    }
+                    DataType.STRUCT -> {
+                        // struct variables have been flattened already
+                        return
                     }
                     else -> throw CompilerException("weird datatype")
                 }
-                currentBlock.variables[scopedname] = value
-                if(decl.zeropage)
-                    currentBlock.variablesMarkedForZeropage.add(scopedname)
+                currentBlock.variables.add(Variable(scopedname, value, valueparams))
             }
             VarDeclType.MEMORY -> {
                 // note that constants are all folded away, but assembly code may still refer to them
-                val lv = decl.value as LiteralValue
+                val lv = decl.value as NumericLiteralValue
                 if(lv.type!= DataType.UWORD && lv.type!= DataType.UBYTE)
                     throw CompilerException("expected integer memory address $lv")
-                currentBlock.memoryPointers[scopedname] = Pair(lv.asIntegerValue!!, decl.datatype)
+                currentBlock.memoryPointers[scopedname] = Pair(lv.number.toInt(), decl.datatype)
             }
             VarDeclType.CONST -> {
                 // note that constants are all folded away, but assembly code may still refer to them (if their integers)
                 // floating point constants are not generated at all!!
-                val lv = decl.value as LiteralValue
+                val lv = decl.value as NumericLiteralValue
                 if(lv.type in IntegerDatatypes)
-                    currentBlock.memoryPointers[scopedname] = Pair(lv.asIntegerValue!!, decl.datatype)
+                    currentBlock.memoryPointers[scopedname] = Pair(lv.number.toInt(), decl.datatype)
             }
         }
     }
@@ -453,16 +462,20 @@ class IntermediateProgram(val name: String, var loadAddress: Int, val heap: Heap
     }
 
     fun newBlock(name: String, address: Int?, options: Set<String>) {
-        currentBlock = ProgramBlock(name, address, force_output="force_output" in options)
+        currentBlock = ProgramBlock(name, address, force_output = "force_output" in options)
         blocks.add(currentBlock)
     }
 
     fun writeCode(out: PrintStream, embeddedLabels: Boolean=true) {
         out.println("; stackVM program code for '$name'")
-        out.println("%memory")
-        if(memory.isNotEmpty())
-            TODO("add support for writing/reading initial memory values")
-        out.println("%end_memory")
+        writeMemory(out)
+        writeHeap(out)
+        for(blk in blocks) {
+            writeBlock(out, blk, embeddedLabels)
+        }
+    }
+
+    private fun writeHeap(out: PrintStream) {
         out.println("%heap")
         heap.allEntries().forEach {
             out.print("${it.key}  ${it.value.type.name.toLowerCase()}  ")
@@ -491,34 +504,45 @@ class IntermediateProgram(val name: String, var loadAddress: Int, val heap: Heap
             }
         }
         out.println("%end_heap")
-        for(blk in blocks) {
-            out.println("\n%block ${blk.name} ${blk.address?.toString(16) ?: ""}")
+    }
 
-            out.println("%variables")
-            for(variable in blk.variables) {
-                val valuestr = variable.value.toString()
-                out.println("${variable.key}  ${variable.value.type.name.toLowerCase()}  $valuestr")
-            }
-            out.println("%end_variables")
-            out.println("%memorypointers")
-            for(iconst in blk.memoryPointers) {
-                out.println("${iconst.key}  ${iconst.value.second.name.toLowerCase()}  uw:${iconst.value.first.toString(16)}")
-            }
-            out.println("%end_memorypointers")
-            out.println("%instructions")
-            val labels = blk.labels.entries.associateBy({it.value}) {it.key}
-            for(instr in blk.instructions) {
-                if(!embeddedLabels) {
-                    val label = labels[instr]
-                    if (label != null)
-                        out.println("$label:")
-                } else {
-                    out.println(instr)
-                }
-            }
-            out.println("%end_instructions")
+    private fun writeBlock(out: PrintStream, blk: ProgramBlock, embeddedLabels: Boolean) {
+        out.println("\n%block ${blk.name} ${blk.address?.toString(16) ?: ""}")
 
-            out.println("%end_block")
+        out.println("%variables")
+        for (variable in blk.variables) {
+            if(variable.params.zp==ZeropageWish.REQUIRE_ZEROPAGE)
+                throw CompilerException("zp conflict")
+            val valuestr = variable.value.toString()
+            val struct =  if(variable.params.memberOfStruct==null) "" else "struct=${variable.params.memberOfStruct.name}"
+            out.println("${variable.scopedname}  ${variable.value.type.name.toLowerCase()}  $valuestr  zp=${variable.params.zp} s=$struct")
         }
+        out.println("%end_variables")
+        out.println("%memorypointers")
+        for (iconst in blk.memoryPointers) {
+            out.println("${iconst.key}  ${iconst.value.second.name.toLowerCase()}  uw:${iconst.value.first.toString(16)}")
+        }
+        out.println("%end_memorypointers")
+        out.println("%instructions")
+        val labels = blk.labels.entries.associateBy({ it.value }) { it.key }
+        for (instr in blk.instructions) {
+            if (!embeddedLabels) {
+                val label = labels[instr]
+                if (label != null)
+                    out.println("$label:")
+            } else {
+                out.println(instr)
+            }
+        }
+        out.println("%end_instructions")
+
+        out.println("%end_block")
+    }
+
+    private fun writeMemory(out: PrintStream) {
+        out.println("%memory")
+        if (memory.isNotEmpty())
+            TODO("add support for writing/reading initial memory values")
+        out.println("%end_memory")
     }
 }

DeprecatedStackVm/src/compiler/intermediate/Opcode.kt

@@ -1,4 +1,4 @@
-package prog8.compiler.intermediate
+package compiler.intermediate
 
 enum class Opcode {
 

DeprecatedStackVm/src/compiler/target/c64/codegen/AsmGen.kt

@@ -1,4 +1,4 @@
-package prog8.compiler.target.c64
+package compiler.target.c64.codegen
 
 // note: to put stuff on the stack, we use Absolute,X  addressing mode which is 3 bytes / 4 cycles
 // possible space optimization is to use zeropage (indirect),Y  which is 2 bytes, but 5 cycles
@@ -6,9 +6,16 @@ package prog8.compiler.target.c64
 import prog8.ast.antlr.escape
 import prog8.ast.base.DataType
 import prog8.ast.base.initvarsSubName
-import prog8.vm.RuntimeValue
+import prog8.ast.statements.ZeropageWish
 import prog8.compiler.*
-import prog8.compiler.intermediate.*
+import prog8.compiler.intermediate.Instruction
+import prog8.compiler.intermediate.IntermediateProgram
+import prog8.compiler.intermediate.LabelInstr
+import prog8.compiler.intermediate.Opcode
+import prog8.compiler.target.c64.AssemblyProgram
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.target.c64.Petscii
+import prog8.vm.RuntimeValue
 import java.io.File
 import java.util.*
 import kotlin.math.abs
@@ -44,8 +51,7 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
         // Convert invalid label names (such as "<anon-1>") to something that's allowed.
         val newblocks = mutableListOf<IntermediateProgram.ProgramBlock>()
         for(block in program.blocks) {
-            val newvars = block.variables.map { symname(it.key, block) to it.value }.toMap().toMutableMap()
-            val newvarsZeropaged = block.variablesMarkedForZeropage.map{symname(it, block)}.toMutableSet()
+            val newvars = block.variables.map { IntermediateProgram.Variable(symname(it.scopedname, block), it.value, it.params) }.toMutableList()
             val newlabels = block.labels.map { symname(it.key, block) to it.value}.toMap().toMutableMap()
             val newinstructions = block.instructions.asSequence().map {
                 when {
@@ -66,8 +72,6 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
                     newMempointers,
                     newlabels,
                     force_output = block.force_output)
-            newblock.variablesMarkedForZeropage.clear()
-            newblock.variablesMarkedForZeropage.addAll(newvarsZeropaged)
             newblocks.add(newblock)
         }
         program.blocks.clear()
@@ -146,7 +150,7 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
         return name.replace("-", "")
     }
 
-    private fun makeFloatFill(flt: Mflpt5): String {
+    private fun makeFloatFill(flt: MachineDefinition.Mflpt5): String {
         val b0 = "$"+flt.b0.toString(16).padStart(2, '0')
         val b1 = "$"+flt.b1.toString(16).padStart(2, '0')
         val b2 = "$"+flt.b2.toString(16).padStart(2, '0')
@@ -164,7 +168,8 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
         out("\n.cpu  '6502'\n.enc  'none'\n")
 
         if(program.loadAddress==0)   // fix load address
-            program.loadAddress = if(options.launcher==LauncherType.BASIC) BASIC_LOAD_ADDRESS else RAW_LOAD_ADDRESS
+            program.loadAddress = if(options.launcher==LauncherType.BASIC)
+                MachineDefinition.BASIC_LOAD_ADDRESS else MachineDefinition.RAW_LOAD_ADDRESS
 
         when {
             options.launcher == LauncherType.BASIC -> {
@@ -220,7 +225,7 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
 
         // the global list of all floating point constants for the whole program
         for(flt in globalFloatConsts) {
-            val floatFill = makeFloatFill(Mflpt5.fromNumber(flt.key))
+            val floatFill = makeFloatFill(MachineDefinition.Mflpt5.fromNumber(flt.key))
             out("${flt.value}\t.byte  $floatFill  ; float ${flt.key}")
         }
     }
@@ -237,16 +242,17 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
 
         // deal with zeropage variables
         for(variable in blk.variables) {
-            val sym = symname(blk.name+"."+variable.key, null)
+            val sym = symname(blk.name+"."+variable.scopedname, null)
             val zpVar = program.allocatedZeropageVariables[sym]
             if(zpVar==null) {
                 // This var is not on the ZP yet. Attempt to move it there (if it's not a float, those take up too much space)
-                if(variable.value.type in zeropage.allowedDatatypes && variable.value.type != DataType.FLOAT) {
+                if(variable.params.zp != ZeropageWish.NOT_IN_ZEROPAGE &&
+                        variable.value.type in zeropage.allowedDatatypes
+                        && variable.value.type != DataType.FLOAT) {
                     try {
                         val address = zeropage.allocate(sym, variable.value.type, null)
-                        out("${variable.key} = $address\t; auto zp ${variable.value.type}")
+                        out("${variable.scopedname} = $address\t; auto zp ${variable.value.type}")
                         // make sure we add the var to the set of zpvars for this block
-                        blk.variablesMarkedForZeropage.add(variable.key)
                         program.allocatedZeropageVariables[sym] = Pair(address, variable.value.type)
                     } catch (x: ZeropageDepletedError) {
                         // leave it as it is.
@@ -255,7 +261,7 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
             }
             else {
                 // it was already allocated on the zp
-                out("${variable.key} = ${zpVar.first}\t; zp ${zpVar.second}")
+                out("${variable.scopedname} = ${zpVar.first}\t; zp ${zpVar.second}")
             }
         }
 
@@ -289,78 +295,98 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
     }
 
     private fun vardecls2asm(block: IntermediateProgram.ProgramBlock) {
-        // these are the non-zeropage variables
-        val sortedVars = block.variables.filter{it.key !in block.variablesMarkedForZeropage}.toList().sortedBy { it.second.type }
-        for (v in sortedVars) {
-            when (v.second.type) {
-                DataType.UBYTE -> out("${v.first}\t.byte  0")
-                DataType.BYTE -> out("${v.first}\t.char  0")
-                DataType.UWORD -> out("${v.first}\t.word  0")
-                DataType.WORD -> out("${v.first}\t.sint  0")
-                DataType.FLOAT -> out("${v.first}\t.byte  0,0,0,0,0  ; float")
-                DataType.STR, DataType.STR_S -> {
-                    val rawStr = heap.get(v.second.heapId!!).str!!
-                    val bytes = encodeStr(rawStr, v.second.type).map { "$" + it.toString(16).padStart(2, '0') }
-                    out("${v.first}\t; ${v.second.type} \"${escape(rawStr).replace("\u0000", "<NULL>")}\"")
-                    for (chunk in bytes.chunked(16))
-                        out("  .byte  " + chunk.joinToString())
-                }
-                DataType.ARRAY_UB -> {
-                    // unsigned integer byte arraysize
-                    val data = makeArrayFillDataUnsigned(v.second)
-                    if (data.size <= 16)
-                        out("${v.first}\t.byte  ${data.joinToString()}")
-                    else {
-                        out(v.first)
-                        for (chunk in data.chunked(16))
-                            out("  .byte  " + chunk.joinToString())
-                    }
-                }
-                DataType.ARRAY_B -> {
-                    // signed integer byte arraysize
-                    val data = makeArrayFillDataSigned(v.second)
-                    if (data.size <= 16)
-                        out("${v.first}\t.char  ${data.joinToString()}")
-                    else {
-                        out(v.first)
-                        for (chunk in data.chunked(16))
-                            out("  .char  " + chunk.joinToString())
-                    }
-                }
-                DataType.ARRAY_UW -> {
-                    // unsigned word arraysize
-                    val data = makeArrayFillDataUnsigned(v.second)
-                    if (data.size <= 16)
-                        out("${v.first}\t.word  ${data.joinToString()}")
-                    else {
-                        out(v.first)
-                        for (chunk in data.chunked(16))
-                            out("  .word  " + chunk.joinToString())
-                    }
-                }
-                DataType.ARRAY_W -> {
-                    // signed word arraysize
-                    val data = makeArrayFillDataSigned(v.second)
-                    if (data.size <= 16)
-                        out("${v.first}\t.sint  ${data.joinToString()}")
-                    else {
-                        out(v.first)
-                        for (chunk in data.chunked(16))
-                            out("  .sint  " + chunk.joinToString())
-                    }
-                }
-                DataType.ARRAY_F -> {
-                    // float arraysize
-                    val array = heap.get(v.second.heapId!!).doubleArray!!
-                    val floatFills = array.map { makeFloatFill(Mflpt5.fromNumber(it)) }
-                    out(v.first)
-                    for(f in array.zip(floatFills))
-                        out("  .byte  ${f.second}  ; float ${f.first}")
-                }
-            }
+        val uniqueNames = block.variables.map { it.scopedname }.toSet()
+        if (uniqueNames.size != block.variables.size)
+            throw AssemblyError("not all variables have unique names")
+
+        // these are the non-zeropage variables.
+        // first get all the flattened struct members, they MUST remain in order
+        out(";  flattened struct members")
+        val (structMembers, normalVars) = block.variables.partition { it.params.memberOfStruct!=null }
+        structMembers.forEach { vardecl2asm(it.scopedname, it.value, it.params) }
+
+        // sort the other variables by type
+        out(";  other variables sorted by type")
+        val sortedVars = normalVars.sortedBy { it.value.type }
+        for (variable in sortedVars) {
+            val sym = symname(block.name + "." + variable.scopedname, null)
+            if(sym in program.allocatedZeropageVariables)
+                continue  // skip the ones that already belong in the zero page
+            vardecl2asm(variable.scopedname, variable.value, variable.params)
         }
     }
 
+    private fun vardecl2asm(varname: String, value: RuntimeValue, parameters: IntermediateProgram.VariableParameters) {
+        when (value.type) {
+            DataType.UBYTE -> out("$varname\t.byte  0")
+            DataType.BYTE -> out("$varname\t.char  0")
+            DataType.UWORD -> out("$varname\t.word  0")
+            DataType.WORD -> out("$varname\t.sint  0")
+            DataType.FLOAT -> out("$varname\t.byte  0,0,0,0,0  ; float")
+            DataType.STR, DataType.STR_S -> {
+                val rawStr = heap.get(value.heapId!!).str!!
+                val bytes = encodeStr(rawStr, value.type).map { "$" + it.toString(16).padStart(2, '0') }
+                out("$varname\t; ${value.type} \"${escape(rawStr).replace("\u0000", "<NULL>")}\"")
+                for (chunk in bytes.chunked(16))
+                    out("  .byte  " + chunk.joinToString())
+            }
+            DataType.ARRAY_UB -> {
+                // unsigned integer byte arraysize
+                val data = makeArrayFillDataUnsigned(value)
+                if (data.size <= 16)
+                    out("$varname\t.byte  ${data.joinToString()}")
+                else {
+                    out(varname)
+                    for (chunk in data.chunked(16))
+                        out("  .byte  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_B -> {
+                // signed integer byte arraysize
+                val data = makeArrayFillDataSigned(value)
+                if (data.size <= 16)
+                    out("$varname\t.char  ${data.joinToString()}")
+                else {
+                    out(varname)
+                    for (chunk in data.chunked(16))
+                        out("  .char  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_UW -> {
+                // unsigned word arraysize
+                val data = makeArrayFillDataUnsigned(value)
+                if (data.size <= 16)
+                    out("$varname\t.word  ${data.joinToString()}")
+                else {
+                    out(varname)
+                    for (chunk in data.chunked(16))
+                        out("  .word  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_W -> {
+                // signed word arraysize
+                val data = makeArrayFillDataSigned(value)
+                if (data.size <= 16)
+                    out("$varname\t.sint  ${data.joinToString()}")
+                else {
+                    out(varname)
+                    for (chunk in data.chunked(16))
+                        out("  .sint  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_F -> {
+                // float arraysize
+                val array = heap.get(value.heapId!!).doubleArray!!
+                val floatFills = array.map { makeFloatFill(MachineDefinition.Mflpt5.fromNumber(it)) }
+                out(varname)
+                for (f in array.zip(floatFills))
+                    out("  .byte  ${f.second}  ; float ${f.first}")
+            }
+            DataType.STRUCT -> throw AssemblyError("vars of type STRUCT should have been removed because flattened")
+        }
+    }
+
+
     private fun encodeStr(str: String, dt: DataType): List<Short> {
         return when(dt) {
             DataType.STR -> {
@@ -510,7 +536,7 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
         }
 
         // add any matching patterns from the big list
-        for(pattern in patterns) {
+        for(pattern in Patterns.patterns) {
             if(pattern.sequence.size > segment.size || (pattern.altSequence!=null && pattern.altSequence.size > segment.size))
                 continue        //  don't accept patterns that don't fit
             val opcodesList = opcodes.subList(0, pattern.sequence.size)
@@ -537,31 +563,31 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
             Opcode.SHL_BYTE -> AsmFragment(" asl  $variable+$index", 8)
             Opcode.SHR_UBYTE -> AsmFragment(" lsr  $variable+$index", 8)
             Opcode.SHR_SBYTE -> AsmFragment(" lda  $variable+$index |  asl  a |  ror  $variable+$index")
-            Opcode.SHL_WORD -> AsmFragment(" asl  $variable+${index*2+1} |  rol  $variable+${index*2}", 8)
-            Opcode.SHR_UWORD -> AsmFragment(" lsr  $variable+${index*2+1} |  ror  $variable+${index*2}", 8)
-            Opcode.SHR_SWORD -> AsmFragment(" lda  $variable+${index*2+1} |  asl  a |  ror  $variable+${index*2+1} |  ror  $variable+${index*2}", 8)
+            Opcode.SHL_WORD -> AsmFragment(" asl  $variable+${index * 2 + 1} |  rol  $variable+${index * 2}", 8)
+            Opcode.SHR_UWORD -> AsmFragment(" lsr  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
+            Opcode.SHR_SWORD -> AsmFragment(" lda  $variable+${index * 2 + 1} |  asl  a |  ror  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
             Opcode.ROL_BYTE -> AsmFragment(" rol  $variable+$index", 8)
             Opcode.ROR_BYTE -> AsmFragment(" ror  $variable+$index", 8)
-            Opcode.ROL_WORD -> AsmFragment(" rol  $variable+${index*2+1} |  rol  $variable+${index*2}", 8)
-            Opcode.ROR_WORD -> AsmFragment(" ror  $variable+${index*2+1} |  ror  $variable+${index*2}", 8)
+            Opcode.ROL_WORD -> AsmFragment(" rol  $variable+${index * 2 + 1} |  rol  $variable+${index * 2}", 8)
+            Opcode.ROR_WORD -> AsmFragment(" ror  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
             Opcode.ROL2_BYTE -> AsmFragment(" lda  $variable+$index |  cmp  #\$80 |  rol  $variable+$index", 8)
             Opcode.ROR2_BYTE -> AsmFragment(" lda  $variable+$index |  lsr  a |  bcc  + |  ora  #\$80 |+ |  sta  $variable+$index", 10)
-            Opcode.ROL2_WORD -> AsmFragment(" asl  $variable+${index*2+1} |  rol  $variable+${index*2} |  bcc  + |  inc  $variable+${index*2+1} |+",20)
-            Opcode.ROR2_WORD -> AsmFragment(" lsr  $variable+${index*2+1} |  ror  $variable+${index*2} |  bcc  + |  lda  $variable+${index*2+1} |  ora  #\$80 |  sta  $variable+${index*2+1} |+", 30)
+            Opcode.ROL2_WORD -> AsmFragment(" asl  $variable+${index * 2 + 1} |  rol  $variable+${index * 2} |  bcc  + |  inc  $variable+${index * 2 + 1} |+", 20)
+            Opcode.ROR2_WORD -> AsmFragment(" lsr  $variable+${index * 2 + 1} |  ror  $variable+${index * 2} |  bcc  + |  lda  $variable+${index * 2 + 1} |  ora  #\$80 |  sta  $variable+${index * 2 + 1} |+", 30)
             Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB -> AsmFragment(" inc  $variable+$index", 2)
             Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB -> AsmFragment(" dec  $variable+$index", 5)
-            Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_UW -> AsmFragment(" inc  $variable+${index*2} |  bne  + |  inc  $variable+${index*2+1} |+")
-            Opcode.DEC_INDEXED_VAR_W, Opcode.DEC_INDEXED_VAR_UW -> AsmFragment(" lda  $variable+${index*2} |  bne  + |  dec  $variable+${index*2+1} |+ |  dec  $variable+${index*2}")
+            Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_UW -> AsmFragment(" inc  $variable+${index * 2} |  bne  + |  inc  $variable+${index * 2 + 1} |+")
+            Opcode.DEC_INDEXED_VAR_W, Opcode.DEC_INDEXED_VAR_UW -> AsmFragment(" lda  $variable+${index * 2} |  bne  + |  dec  $variable+${index * 2 + 1} |+ |  dec  $variable+${index * 2}")
             Opcode.INC_INDEXED_VAR_FLOAT -> AsmFragment(
-                """
-                lda  #<($variable+${index*Mflpt5.MemorySize})
-                ldy  #>($variable+${index*Mflpt5.MemorySize})
+                    """
+                lda  #<($variable+${index * MachineDefinition.Mflpt5.MemorySize})
+                ldy  #>($variable+${index * MachineDefinition.Mflpt5.MemorySize})
                 jsr  c64flt.inc_var_f
                 """)
             Opcode.DEC_INDEXED_VAR_FLOAT -> AsmFragment(
-                """
-                lda  #<($variable+${index*Mflpt5.MemorySize})
-                ldy  #>($variable+${index*Mflpt5.MemorySize})
+                    """
+                lda  #<($variable+${index * MachineDefinition.Mflpt5.MemorySize})
+                ldy  #>($variable+${index * MachineDefinition.Mflpt5.MemorySize})
                 jsr  c64flt.dec_var_f
                 """)
 
@@ -571,8 +597,8 @@ class AsmGen(private val options: CompilationOptions, private val program: Inter
 
     private fun sameIndexedVarOperation(variable: String, indexVar: String, ins: Instruction): AsmFragment? {
         // an in place operation that consists of a push-value / op / push-index-var / pop-into-indexed-var
-        val saveX = " stx  ${C64Zeropage.SCRATCH_B1} |"
-        val restoreX = " | ldx  ${C64Zeropage.SCRATCH_B1}"
+        val saveX = " stx  ${MachineDefinition.C64Zeropage.SCRATCH_B1} |"
+        val restoreX = " | ldx  ${MachineDefinition.C64Zeropage.SCRATCH_B1}"
         val loadXWord: String
         val loadX: String
 

DeprecatedStackVm/src/compiler/target/c64/codegen/SimpleAsm.kt

@@ -1,15 +1,24 @@
-package prog8.compiler.target.c64
+package compiler.target.c64.codegen
 
 import prog8.compiler.CompilerException
 import prog8.compiler.intermediate.Instruction
 import prog8.compiler.intermediate.IntermediateProgram
 import prog8.compiler.intermediate.LabelInstr
 import prog8.compiler.intermediate.Opcode
+import prog8.compiler.target.c64.MachineDefinition.C64Zeropage
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_PLUS1_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_PLUS1_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_PLUS2_HEX
 import prog8.compiler.toHex
 import prog8.vm.stackvm.Syscall
 import prog8.vm.stackvm.syscallsForStackVm
 
 
+// note: see https://wiki.nesdev.com/w/index.php/6502_assembly_optimisations
+
+
 private var breakpointCounter = 0
 
 internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.ProgramBlock): String? {
@@ -61,13 +70,32 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.RRESTOREX -> " sta  ${C64Zeropage.SCRATCH_REG} |  pla |  tax |  lda  ${C64Zeropage.SCRATCH_REG}"
         Opcode.DISCARD_BYTE -> " inx"
         Opcode.DISCARD_WORD -> " inx"
+        Opcode.DISCARD_FLOAT -> " inx |  inx |  inx"
         Opcode.DUP_B -> {
-            " dex | lda ${(ESTACK_LO+1).toHex()},x | sta ${ESTACK_LO.toHex()},x"
+            " lda $ESTACK_LO_PLUS1_HEX,x | sta $ESTACK_LO_HEX,x | dex | ;DUP_B "
         }
         Opcode.DUP_W -> {
-            " dex | lda ${(ESTACK_LO+1).toHex()},x | sta ${ESTACK_LO.toHex()},x | lda ${(ESTACK_HI+1).toHex()},x | sta ${ESTACK_HI.toHex()},x "
+            " lda $ESTACK_LO_PLUS1_HEX,x | sta $ESTACK_LO_HEX,x | lda $ESTACK_HI_PLUS1_HEX,x | sta $ESTACK_HI_HEX,x | dex "
         }
-        Opcode.DISCARD_FLOAT -> " inx |  inx |  inx"
+
+        Opcode.CMP_B, Opcode.CMP_UB -> {
+            " inx | lda $ESTACK_LO_HEX,x | cmp #${ins.arg!!.integerValue().toHex()} | ;CMP_B "
+        }
+
+        Opcode.CMP_W, Opcode.CMP_UW -> {
+            """
+            inx
+            lda   $ESTACK_HI_HEX,x
+            cmp   #>${ins.arg!!.integerValue().toHex()}
+            bne   +
+            lda   $ESTACK_LO_HEX,x
+            cmp   #<${ins.arg.integerValue().toHex()}
+            ; bne   +    not necessary?
+            ; lda   #0   not necessary?
++                           
+            """
+        }
+
         Opcode.INLINE_ASSEMBLY ->  "@inline@" + (ins.callLabel2 ?: "")      // All of the inline assembly is stored in the calllabel2 property. the '@inline@' is a special marker to accept it.
         Opcode.INCLUDE_FILE -> {
             val offset = if(ins.arg==null) "" else ", ${ins.arg.integerValue()}"
@@ -108,11 +136,11 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         }
 
         Opcode.PUSH_BYTE -> {
-            " lda  #${hexVal(ins)} |  sta  ${ESTACK_LO.toHex()},x |  dex"
+            " lda  #${hexVal(ins)} |  sta  $ESTACK_LO_HEX,x |  dex"
         }
         Opcode.PUSH_WORD -> {
             val value = hexVal(ins)
-            " lda  #<$value |  sta  ${ESTACK_LO.toHex()},x |  lda  #>$value |  sta  ${ESTACK_HI.toHex()},x |  dex"
+            " lda  #<$value |  sta  $ESTACK_LO_HEX,x |  lda  #>$value |  sta  $ESTACK_HI_HEX,x |  dex"
         }
         Opcode.PUSH_FLOAT -> {
             val floatConst = getFloatConst(ins.arg!!)
@@ -121,28 +149,28 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.PUSH_VAR_BYTE -> {
             when(ins.callLabel) {
                 "X" -> throw CompilerException("makes no sense to push X, it's used as a stack pointer itself. You should probably not use the X register (or only in trivial assignments)")
-                "A" -> " sta  ${ESTACK_LO.toHex()},x |  dex"
-                "Y" -> " tya |  sta  ${ESTACK_LO.toHex()},x |  dex"
-                else -> " lda  ${ins.callLabel} |  sta  ${ESTACK_LO.toHex()},x |  dex"
+                "A" -> " sta  $ESTACK_LO_HEX,x |  dex"
+                "Y" -> " tya |  sta  $ESTACK_LO_HEX,x |  dex"
+                else -> " lda  ${ins.callLabel} |  sta  $ESTACK_LO_HEX,x |  dex"
             }
         }
         Opcode.PUSH_VAR_WORD -> {
-            " lda  ${ins.callLabel} |  sta  ${ESTACK_LO.toHex()},x |  lda  ${ins.callLabel}+1 |    sta  ${ESTACK_HI.toHex()},x |  dex"
+            " lda  ${ins.callLabel} |  sta  $ESTACK_LO_HEX,x |  lda  ${ins.callLabel}+1 |    sta  $ESTACK_HI_HEX,x |  dex"
         }
         Opcode.PUSH_VAR_FLOAT -> " lda  #<${ins.callLabel} |  ldy  #>${ins.callLabel}|  jsr  c64flt.push_float"
         Opcode.PUSH_MEM_B, Opcode.PUSH_MEM_UB -> {
             """
                 lda  ${hexVal(ins)}
-                sta  ${ESTACK_LO.toHex()},x
+                sta  $ESTACK_LO_HEX,x
                 dex
                 """
         }
         Opcode.PUSH_MEM_W, Opcode.PUSH_MEM_UW -> {
             """
                 lda  ${hexVal(ins)}
-                sta  ${ESTACK_LO.toHex()},x
+                sta  $ESTACK_LO_HEX,x
                 lda  ${hexValPlusOne(ins)}
-                sta  ${ESTACK_HI.toHex()},x
+                sta  $ESTACK_HI_HEX,x
                 dex
                 """
         }
@@ -151,43 +179,43 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         }
         Opcode.PUSH_MEMREAD -> {
             """
-                lda  ${(ESTACK_LO+1).toHex()},x
+                lda  $ESTACK_LO_PLUS1_HEX,x
                 sta  (+) +1
-                lda  ${(ESTACK_HI+1).toHex()},x
+                lda  $ESTACK_HI_PLUS1_HEX,x
                 sta  (+) +2
 +               lda  65535    ; modified
-                sta  ${(ESTACK_LO+1).toHex()},x
+                sta  $ESTACK_LO_PLUS1_HEX,x
                 """
         }
 
         Opcode.PUSH_REGAY_WORD -> {
-            " sta  ${ESTACK_LO.toHex()},x |  tya |  sta  ${ESTACK_HI.toHex()},x |  dex "
+            " sta  $ESTACK_LO_HEX,x |  tya |  sta  $ESTACK_HI_HEX,x |  dex "
         }
         Opcode.PUSH_ADDR_HEAPVAR -> {
-            " lda  #<${ins.callLabel} |  sta  ${ESTACK_LO.toHex()},x |  lda  #>${ins.callLabel}  |  sta  ${ESTACK_HI.toHex()},x |  dex"
+            " lda  #<${ins.callLabel} |  sta  $ESTACK_LO_HEX,x |  lda  #>${ins.callLabel}  |  sta  $ESTACK_HI_HEX,x |  dex"
         }
         Opcode.POP_REGAX_WORD -> throw AssemblyError("cannot load X register from stack because it's used as the stack pointer itself")
         Opcode.POP_REGXY_WORD -> throw AssemblyError("cannot load X register from stack because it's used as the stack pointer itself")
         Opcode.POP_REGAY_WORD -> {
-            " inx |  lda  ${ESTACK_LO.toHex()},x |  ldy  ${ESTACK_HI.toHex()},x "
+            " inx |  lda  $ESTACK_LO_HEX,x |  ldy  $ESTACK_HI_HEX,x "
         }
 
         Opcode.READ_INDEXED_VAR_BYTE -> {
             """
-                ldy  ${(ESTACK_LO+1).toHex()},x
+                ldy  $ESTACK_LO_PLUS1_HEX,x
                 lda  ${ins.callLabel},y
-                sta  ${(ESTACK_LO+1).toHex()},x
+                sta  $ESTACK_LO_PLUS1_HEX,x
                 """
         }
         Opcode.READ_INDEXED_VAR_WORD -> {
             """
-                lda  ${(ESTACK_LO+1).toHex()},x
+                lda  $ESTACK_LO_PLUS1_HEX,x
                 asl  a
                 tay
                 lda  ${ins.callLabel},y
-                sta  ${(ESTACK_LO+1).toHex()},x
+                sta  $ESTACK_LO_PLUS1_HEX,x
                 lda  ${ins.callLabel}+1,y
-                sta  ${(ESTACK_HI+1).toHex()},x
+                sta  $ESTACK_HI_PLUS1_HEX,x
                 """
         }
         Opcode.READ_INDEXED_VAR_FLOAT -> {
@@ -200,22 +228,22 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.WRITE_INDEXED_VAR_BYTE -> {
             """
                 inx
-                ldy  ${ESTACK_LO.toHex()},x
+                ldy  $ESTACK_LO_HEX,x
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  ${ins.callLabel},y
                 """
         }
         Opcode.WRITE_INDEXED_VAR_WORD -> {
             """
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 asl  a
                 tay
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  ${ins.callLabel},y
-                lda  ${ESTACK_HI.toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 sta  ${ins.callLabel}+1,y
                 """
         }
@@ -229,16 +257,16 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.POP_MEM_BYTE -> {
             """
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  ${hexVal(ins)}
                 """
         }
         Opcode.POP_MEM_WORD -> {
             """
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  ${hexVal(ins)}
-                lda  ${ESTACK_HI.toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 sta  ${hexValPlusOne(ins)}
                 """
         }
@@ -248,12 +276,12 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.POP_MEMWRITE -> {
             """
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  (+) +1
-                lda  ${ESTACK_HI.toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 sta  (+) +2
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
 +               sta  65535       ; modified
                 """
         }
@@ -261,13 +289,13 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.POP_VAR_BYTE -> {
             when (ins.callLabel) {
                 "X" -> throw CompilerException("makes no sense to pop X, it's used as a stack pointer itself")
-                "A" -> " inx |  lda  ${ESTACK_LO.toHex()},x"
-                "Y" -> " inx |  ldy  ${ESTACK_LO.toHex()},x"
-                else -> " inx |  lda  ${ESTACK_LO.toHex()},x |  sta  ${ins.callLabel}"
+                "A" -> " inx |  lda  $ESTACK_LO_HEX,x"
+                "Y" -> " inx |  ldy  $ESTACK_LO_HEX,x"
+                else -> " inx |  lda  $ESTACK_LO_HEX,x |  sta  ${ins.callLabel}"
             }
         }
         Opcode.POP_VAR_WORD -> {
-            " inx |  lda  ${ESTACK_LO.toHex()},x |  ldy  ${ESTACK_HI.toHex()},x |  sta  ${ins.callLabel} |  sty  ${ins.callLabel}+1"
+            " inx |  lda  $ESTACK_LO_HEX,x |  ldy  $ESTACK_HI_HEX,x |  sta  ${ins.callLabel} |  sty  ${ins.callLabel}+1"
         }
         Opcode.POP_VAR_FLOAT -> {
             " lda  #<${ins.callLabel} |  ldy  #>${ins.callLabel} |  jsr  c64flt.pop_float"
@@ -294,9 +322,9 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.POP_INC_MEMORY -> {
             """
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  (+) +1
-                lda  ${ESTACK_HI.toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 sta  (+) +2
 +               inc  65535     ; modified
                 """
@@ -304,9 +332,9 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.POP_DEC_MEMORY -> {
             """
                 inx
-                lda  ${ESTACK_LO.toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 sta  (+) +1
-                lda  ${ESTACK_HI.toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 sta  (+) +2
 +               dec  65535     ; modified
                 """
@@ -331,8 +359,8 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         }
         Opcode.INC_MEMORY -> " inc  ${hexVal(ins)}"
         Opcode.DEC_MEMORY -> " dec  ${hexVal(ins)}"
-        Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB -> " inx |  txa |  pha |  lda  ${ESTACK_LO.toHex()},x |  tax |  inc  ${ins.callLabel},x |  pla |  tax"
-        Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB -> " inx |  txa |  pha |  lda  ${ESTACK_LO.toHex()},x |  tax |  dec  ${ins.callLabel},x |  pla |  tax"
+        Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB -> " inx |  txa |  pha |  lda  $ESTACK_LO_HEX,x |  tax |  inc  ${ins.callLabel},x |  pla |  tax"
+        Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB -> " inx |  txa |  pha |  lda  $ESTACK_LO_HEX,x |  tax |  dec  ${ins.callLabel},x |  pla |  tax"
 
         Opcode.NEG_B -> " jsr  prog8_lib.neg_b"
         Opcode.NEG_W -> " jsr  prog8_lib.neg_w"
@@ -343,9 +371,9 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.POW_F -> " jsr  c64flt.pow_f"
         Opcode.INV_BYTE -> {
             """
-                lda  ${(ESTACK_LO + 1).toHex()},x
+                lda  $ESTACK_LO_PLUS1_HEX,x
                 eor  #255
-                sta  ${(ESTACK_LO + 1).toHex()},x
+                sta  $ESTACK_LO_PLUS1_HEX,x
                 """
         }
         Opcode.INV_WORD -> " jsr  prog8_lib.inv_word"
@@ -387,7 +415,7 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
             val label = ins.callLabel ?: hexVal(ins)
             """
                 inx
-                lda  ${(ESTACK_LO).toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 beq  $label
                 """
         }
@@ -395,9 +423,9 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
             val label = ins.callLabel ?: hexVal(ins)
             """
                 inx
-                lda  ${(ESTACK_LO).toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 beq  $label
-                lda  ${(ESTACK_HI).toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 beq  $label
                 """
         }
@@ -405,7 +433,7 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
             val label = ins.callLabel ?: hexVal(ins)
             """
                 inx
-                lda  ${(ESTACK_LO).toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 bne  $label
                 """
         }
@@ -413,9 +441,9 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
             val label = ins.callLabel ?: hexVal(ins)
             """
                 inx
-                lda  ${(ESTACK_LO).toHex()},x
+                lda  $ESTACK_LO_HEX,x
                 bne  $label
-                lda  ${(ESTACK_HI).toHex()},x
+                lda  $ESTACK_HI_HEX,x
                 bne  $label
                 """
         }
@@ -431,31 +459,31 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.CAST_B_TO_F -> " jsr  c64flt.stack_b2float"
         Opcode.CAST_UW_TO_F -> " jsr  c64flt.stack_uw2float"
         Opcode.CAST_W_TO_F -> " jsr  c64flt.stack_w2float"
-        Opcode.CAST_F_TO_UB -> " jsr  c64flt.stack_float2uw"
-        Opcode.CAST_F_TO_B -> " jsr  c64flt.stack_float2w"
+        Opcode.CAST_F_TO_UB -> " jsr  c64flt.stack_float2ub"
+        Opcode.CAST_F_TO_B -> " jsr  c64flt.stack_float2b"
         Opcode.CAST_F_TO_UW -> " jsr  c64flt.stack_float2uw"
         Opcode.CAST_F_TO_W -> " jsr  c64flt.stack_float2w"
-        Opcode.CAST_UB_TO_UW, Opcode.CAST_UB_TO_W -> " lda  #0 |  sta  ${(ESTACK_HI+1).toHex()},x"     // clear the msb
-        Opcode.CAST_B_TO_UW, Opcode.CAST_B_TO_W -> " lda  ${(ESTACK_LO+1).toHex()},x |  ${signExtendA("${(ESTACK_HI+1).toHex()},x")}"     // sign extend the lsb
-        Opcode.MSB -> " lda  ${(ESTACK_HI+1).toHex()},x |  sta  ${(ESTACK_LO+1).toHex()},x"
-        Opcode.MKWORD -> " inx |  lda  ${ESTACK_LO.toHex()},x |  sta  ${(ESTACK_HI+1).toHex()},x "
+        Opcode.CAST_UB_TO_UW, Opcode.CAST_UB_TO_W -> " lda  #0 |  sta  $ESTACK_HI_PLUS1_HEX,x"     // clear the msb
+        Opcode.CAST_B_TO_UW, Opcode.CAST_B_TO_W -> " lda  $ESTACK_LO_PLUS1_HEX,x |  ${signExtendA("$ESTACK_HI_PLUS1_HEX,x")}"     // sign extend the lsb
+        Opcode.MSB -> " lda  $ESTACK_HI_PLUS1_HEX,x |  sta  $ESTACK_LO_PLUS1_HEX,x"
+        Opcode.MKWORD -> " inx |  lda  $ESTACK_LO_HEX,x |  sta  $ESTACK_HI_PLUS1_HEX,x "
 
         Opcode.ADD_UB, Opcode.ADD_B -> {        // TODO inline better (pattern with more opcodes)
             """
-                lda  ${(ESTACK_LO + 2).toHex()},x
+                lda  $ESTACK_LO_PLUS2_HEX,x
                 clc
-                adc  ${(ESTACK_LO + 1).toHex()},x
+                adc  $ESTACK_LO_PLUS1_HEX,x
                 inx
-                sta  ${(ESTACK_LO + 1).toHex()},x
+                sta  $ESTACK_LO_PLUS1_HEX,x
                 """
         }
         Opcode.SUB_UB, Opcode.SUB_B -> {        // TODO inline better (pattern with more opcodes)
             """
-                lda  ${(ESTACK_LO + 2).toHex()},x
+                lda  $ESTACK_LO_PLUS2_HEX,x
                 sec
-                sbc  ${(ESTACK_LO + 1).toHex()},x
+                sbc  $ESTACK_LO_PLUS1_HEX,x
                 inx
-                sta  ${(ESTACK_LO + 1).toHex()},x
+                sta  $ESTACK_LO_PLUS1_HEX,x
                 """
         }
         Opcode.ADD_W, Opcode.ADD_UW -> "  jsr  prog8_lib.add_w"
@@ -485,27 +513,27 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.BITOR_WORD -> "  jsr  prog8_lib.bitor_w"
         Opcode.BITXOR_WORD -> "  jsr  prog8_lib.bitxor_w"
 
-        Opcode.REMAINDER_UB -> "  jsr prog8_lib.remainder_ub"
-        Opcode.REMAINDER_UW -> "  jsr prog8_lib.remainder_uw"
+        Opcode.REMAINDER_UB -> "  jsr  prog8_lib.remainder_ub"
+        Opcode.REMAINDER_UW -> "  jsr  prog8_lib.remainder_uw"
 
-        Opcode.GREATER_B -> "  jsr prog8_lib.greater_b"
-        Opcode.GREATER_UB -> "  jsr prog8_lib.greater_ub"
-        Opcode.GREATER_W -> "  jsr prog8_lib.greater_w"
-        Opcode.GREATER_UW -> "  jsr prog8_lib.greater_uw"
-        Opcode.GREATER_F -> "  jsr c64flt.greater_f"
+        Opcode.GREATER_B -> "  jsr  prog8_lib.greater_b"
+        Opcode.GREATER_UB -> "  jsr  prog8_lib.greater_ub"
+        Opcode.GREATER_W -> "  jsr  prog8_lib.greater_w"
+        Opcode.GREATER_UW -> "  jsr  prog8_lib.greater_uw"
+        Opcode.GREATER_F -> "  jsr  c64flt.greater_f"
 
-        Opcode.GREATEREQ_B -> "  jsr prog8_lib.greatereq_b"
-        Opcode.GREATEREQ_UB -> "  jsr prog8_lib.greatereq_ub"
-        Opcode.GREATEREQ_W -> "  jsr prog8_lib.greatereq_w"
-        Opcode.GREATEREQ_UW -> "  jsr prog8_lib.greatereq_uw"
-        Opcode.GREATEREQ_F -> "  jsr c64flt.greatereq_f"
+        Opcode.GREATEREQ_B -> "  jsr  prog8_lib.greatereq_b"
+        Opcode.GREATEREQ_UB -> "  jsr  prog8_lib.greatereq_ub"
+        Opcode.GREATEREQ_W -> "  jsr  prog8_lib.greatereq_w"
+        Opcode.GREATEREQ_UW -> "  jsr  prog8_lib.greatereq_uw"
+        Opcode.GREATEREQ_F -> "  jsr  c64flt.greatereq_f"
 
-        Opcode.EQUAL_BYTE -> "  jsr prog8_lib.equal_b"
-        Opcode.EQUAL_WORD -> "  jsr prog8_lib.equal_w"
-        Opcode.EQUAL_F -> "  jsr c64flt.equal_f"
+        Opcode.EQUAL_BYTE -> "  jsr  prog8_lib.equal_b"
+        Opcode.EQUAL_WORD -> "  jsr  prog8_lib.equal_w"
+        Opcode.EQUAL_F -> "  jsr  c64flt.equal_f"
         Opcode.NOTEQUAL_BYTE -> "  jsr prog8_lib.notequal_b"
         Opcode.NOTEQUAL_WORD -> "  jsr prog8_lib.notequal_w"
-        Opcode.NOTEQUAL_F -> "  jsr c64flt.notequal_f"
+        Opcode.NOTEQUAL_F -> "  jsr  c64flt.notequal_f"
 
         Opcode.LESS_UB -> "  jsr  prog8_lib.less_ub"
         Opcode.LESS_B -> "  jsr  prog8_lib.less_b"
@@ -519,12 +547,12 @@ internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.Progra
         Opcode.LESSEQ_W -> "  jsr  prog8_lib.lesseq_w"
         Opcode.LESSEQ_F -> "  jsr  c64flt.lesseq_f"
 
-        Opcode.SHIFTEDL_BYTE -> "  asl  ${(ESTACK_LO+1).toHex()},x"
-        Opcode.SHIFTEDL_WORD -> "  asl  ${(ESTACK_LO+1).toHex()},x |  rol  ${(ESTACK_HI+1).toHex()},x"
-        Opcode.SHIFTEDR_SBYTE -> "  lda  ${(ESTACK_LO+1).toHex()},x |  asl  a |  ror  ${(ESTACK_LO+1).toHex()},x"
-        Opcode.SHIFTEDR_UBYTE -> "  lsr  ${(ESTACK_LO+1).toHex()},x"
-        Opcode.SHIFTEDR_SWORD -> "  lda  ${(ESTACK_HI+1).toHex()},x |  asl a  |  ror  ${(ESTACK_HI+1).toHex()},x |  ror  ${(ESTACK_LO+1).toHex()},x"
-        Opcode.SHIFTEDR_UWORD -> "  lsr  ${(ESTACK_HI+1).toHex()},x |  ror  ${(ESTACK_LO+1).toHex()},x"
+        Opcode.SHIFTEDL_BYTE -> "  asl  $ESTACK_LO_PLUS1_HEX,x"
+        Opcode.SHIFTEDL_WORD -> "  asl  $ESTACK_LO_PLUS1_HEX,x |  rol  $ESTACK_HI_PLUS1_HEX,x"
+        Opcode.SHIFTEDR_SBYTE -> "  lda  $ESTACK_LO_PLUS1_HEX,x |  asl  a |  ror  $ESTACK_LO_PLUS1_HEX,x"
+        Opcode.SHIFTEDR_UBYTE -> "  lsr  $ESTACK_LO_PLUS1_HEX,x"
+        Opcode.SHIFTEDR_SWORD -> "  lda  $ESTACK_HI_PLUS1_HEX,x |  asl a  |  ror  $ESTACK_HI_PLUS1_HEX,x |  ror  $ESTACK_LO_PLUS1_HEX,x"
+        Opcode.SHIFTEDR_UWORD -> "  lsr  $ESTACK_HI_PLUS1_HEX,x |  ror  $ESTACK_LO_PLUS1_HEX,x"
 
         else -> null
     }

DeprecatedStackVm/src/prog8/vm/stackvm/Program.kt

@@ -4,10 +4,13 @@ import prog8.ast.antlr.unescape
 import prog8.ast.base.*
 import prog8.ast.expressions.AddressOf
 import prog8.ast.expressions.IdentifierReference
-import prog8.vm.RuntimeValue
 import prog8.compiler.HeapValues
 import prog8.compiler.IntegerOrAddressOf
-import prog8.compiler.intermediate.*
+import prog8.compiler.intermediate.Instruction
+import prog8.compiler.intermediate.LabelInstr
+import prog8.compiler.intermediate.Opcode
+import prog8.compiler.intermediate.opcodesWithVarArgument
+import prog8.vm.RuntimeValue
 import java.io.File
 import java.util.*
 import java.util.regex.Pattern
@@ -226,18 +229,18 @@ class Program (val name: String,
                 if(valueStr[0] !='"' && ':' !in valueStr)
                     throw VmExecutionException("missing value type character")
                 val value = when(val type = DataType.valueOf(typeStr.toUpperCase())) {
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, valueStr.substring(3).toShort(16))
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, valueStr.substring(2).toShort(16))
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, valueStr.substring(3).toInt(16))
-                    DataType.WORD -> RuntimeValue(DataType.WORD, valueStr.substring(2).toInt(16))
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, valueStr.substring(2).toDouble())
+                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, valueStr.substring(3).substringBefore(' ').toShort(16))// TODO process ZP and struct info?
+                    DataType.BYTE -> RuntimeValue(DataType.BYTE, valueStr.substring(2).substringBefore(' ').toShort(16))// TODO process ZP and struct info?
+                    DataType.UWORD -> RuntimeValue(DataType.UWORD, valueStr.substring(3).substringBefore(' ').toInt(16))// TODO process ZP and struct info?
+                    DataType.WORD -> RuntimeValue(DataType.WORD, valueStr.substring(2).substringBefore(' ').toInt(16))// TODO process ZP and struct info?
+                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, valueStr.substring(2).substringBefore(' ').toDouble())// TODO process ZP and struct info?
                     in StringDatatypes -> {
                         if(valueStr.startsWith('"') && valueStr.endsWith('"'))
                             throw VmExecutionException("encountered a var with a string value, but all string values should already have been moved into the heap")
                         else if(!valueStr.startsWith("heap:"))
                             throw VmExecutionException("invalid string value, should be a heap reference")
                         else {
-                            val heapId = valueStr.substring(5).toInt()
+                            val heapId = valueStr.substring(5).substringBefore(' ').toInt()     // TODO process ZP and struct info?
                             RuntimeValue(type, heapId = heapId)
                         }
                     }
@@ -245,7 +248,7 @@ class Program (val name: String,
                         if(!valueStr.startsWith("heap:"))
                             throw VmExecutionException("invalid array value, should be a heap reference")
                         else {
-                            val heapId = valueStr.substring(5).toInt()
+                            val heapId = valueStr.substring(5).substringBefore(' ').toInt()     // TODO process ZP and struct info?
                             RuntimeValue(type, heapId = heapId)
                         }
                     }

DeprecatedStackVm/src/prog8/vm/stackvm/StackVm.kt

@@ -1,26 +1,22 @@
 package prog8.vm.stackvm
 
-import prog8.ast.base.DataType
-import prog8.ast.base.IterableDatatypes
-import prog8.ast.base.NumericDatatypes
-import prog8.ast.base.Register
-import prog8.ast.base.initvarsSubName
-import prog8.vm.astvm.BitmapScreenPanel
-import prog8.vm.astvm.Memory
-import prog8.vm.RuntimeValue
+import prog8.ast.base.*
 import prog8.compiler.HeapValues
 import prog8.compiler.IntegerOrAddressOf
 import prog8.compiler.intermediate.Instruction
 import prog8.compiler.intermediate.Opcode
 import prog8.compiler.target.c64.Petscii
 import prog8.compiler.toHex
+import prog8.vm.RuntimeValue
+import prog8.vm.astvm.BitmapScreenPanel
+import prog8.vm.astvm.Memory
 import java.io.File
 import java.io.PrintStream
 import java.util.*
 import kotlin.math.*
 
 
-enum class Syscall(val callNr: Short) {
+internal enum class Syscall(val callNr: Short) {
     VM_WRITE_MEMCHR(10),           // print a single char from the memory address popped from stack
     VM_WRITE_MEMSTR(11),           // print a 0-terminated petscii string from the memory address popped from stack
     VM_WRITE_NUM(12),              // pop from the evaluation stack and print it as a number
@@ -107,10 +103,9 @@ enum class Syscall(val callNr: Short) {
     SYSASM_c64flt_print_f(214),
 }
 
+internal val syscallNames = enumValues<Syscall>().map { it.name }.toSet()
 
-val syscallNames = enumValues<Syscall>().map { it.name }.toSet()
-
-val syscallsForStackVm = setOf(
+internal val syscallsForStackVm = setOf(
         Syscall.VM_WRITE_MEMCHR,
         Syscall.VM_WRITE_MEMSTR,
         Syscall.VM_WRITE_NUM,
@@ -123,13 +118,13 @@ val syscallsForStackVm = setOf(
         Syscall.VM_GFX_LINE
 )
 
-class VmExecutionException(msg: String?) : Exception(msg)
+internal class VmExecutionException(msg: String?) : Exception(msg)
 
-class VmTerminationException(msg: String?) : Exception(msg)
+internal class VmTerminationException(msg: String?) : Exception(msg)
 
-class VmBreakpointException : Exception("breakpoint")
+internal class VmBreakpointException : Exception("breakpoint")
 
-class MyStack<T> : Stack<T>() {
+internal class MyStack<T> : Stack<T>() {
     fun peek(amount: Int) : List<T> {
         return this.toList().subList(max(0, size-amount), size)
     }
@@ -141,7 +136,6 @@ class MyStack<T> : Stack<T>() {
     }
 }
 
-
 class StackVm(private var traceOutputFile: String?) {
     val mem = Memory(::memread, ::memwrite)
     var P_carry: Boolean = false
@@ -156,9 +150,9 @@ class StackVm(private var traceOutputFile: String?) {
         private set
     var memoryPointers = mutableMapOf<String, Pair<Int, DataType>>()        // all named pointers
         private set
-    var evalstack = MyStack<RuntimeValue>()
+    internal var evalstack = MyStack<RuntimeValue>()
         private set
-    var callstack = MyStack<Int>()
+    internal var callstack = MyStack<Int>()
         private set
     private var program = listOf<Instruction>()
     private var labels = emptyMap<String, Int>()
@@ -204,7 +198,7 @@ class StackVm(private var traceOutputFile: String?) {
             throw VmExecutionException("program contains variable(s) for the reserved registers A/X/Y")
         // define the 'registers'
         variables["A"] = RuntimeValue(DataType.UBYTE, 0)
-        variables["X"] = RuntimeValue(DataType.UBYTE, 0)
+        variables["X"] = RuntimeValue(DataType.UBYTE, 255)
         variables["Y"] = RuntimeValue(DataType.UBYTE, 0)
 
         initMemory(program.memory)
@@ -1865,8 +1859,8 @@ class StackVm(private var traceOutputFile: String?) {
             }
             Opcode.RRESTORE -> {
                 variables["A"] = evalstack.pop()
-                variables["X"] = evalstack.pop()
                 variables["Y"] = evalstack.pop()
+                variables["X"] = evalstack.pop()
                 P_carry = evalstack.pop().asBoolean
                 P_irqd = evalstack.pop().asBoolean
             }
@@ -1875,10 +1869,17 @@ class StackVm(private var traceOutputFile: String?) {
             Opcode.INLINE_ASSEMBLY -> throw VmExecutionException("stackVm doesn't support executing inline assembly code $ins")
             Opcode.INCLUDE_FILE -> throw VmExecutionException("stackVm doesn't support including a file $ins")
             Opcode.PUSH_ADDR_HEAPVAR -> {
-                val heapId = variables.getValue(ins.callLabel!!).heapId!!
-                if(heapId<0)
-                    throw VmExecutionException("expected variable on heap")
-                evalstack.push(RuntimeValue(DataType.UWORD, heapId))       // push the "address" of the string or array variable (this is taken care of properly in the assembly code generator)
+                val variable = variables.getValue(ins.callLabel!!)
+                if(variable.heapId!=null) {
+                    val heapId = variable.heapId
+                    if (heapId < 0)
+                        throw VmExecutionException("expected variable on heap")
+                    evalstack.push(RuntimeValue(DataType.UWORD, heapId))       // push the "address" of the string or array variable (this is taken care of properly in the assembly code generator)
+                } else {
+                    // hack: return hash of the name, so we have at least *a* value...
+                    val addr = ins.callLabel.hashCode() and 65535
+                    evalstack.push(RuntimeValue(DataType.UWORD, addr))
+                }
             }
             Opcode.CAST_UB_TO_B -> typecast(DataType.UBYTE, DataType.BYTE)
             Opcode.CAST_W_TO_B -> typecast(DataType.WORD, DataType.BYTE)
@@ -1928,7 +1929,7 @@ class StackVm(private var traceOutputFile: String?) {
                 }
                 "c64.CHROUT" -> {
                     val sc=variables.getValue("A").integerValue()
-                    canvas?.printChar(sc.toShort())
+                    canvas?.printPetscii(sc.toShort())
                     callstack.pop()
                 }
                 "c64.GETIN" -> {
@@ -2029,7 +2030,7 @@ class StackVm(private var traceOutputFile: String?) {
                 val color = evalstack.pop()
                 val (cy, cx) = evalstack.pop2()
                 val text = heap.get(textPtr)
-                canvas?.writeText(cx.integerValue(), cy.integerValue(), text.str!!, color.integerValue().toShort(), true)
+                canvas?.writeTextAt(cx.integerValue(), cy.integerValue(), text.str!!, color.integerValue().toShort(), true)
             }
             Syscall.FUNC_RND -> evalstack.push(RuntimeValue(DataType.UBYTE, rnd.nextInt() and 255))
             Syscall.FUNC_RNDW -> evalstack.push(RuntimeValue(DataType.UWORD, rnd.nextInt() and 65535))
@@ -2311,54 +2312,54 @@ class StackVm(private var traceOutputFile: String?) {
             Syscall.SYSASM_c64scr_print -> {
                 val straddr = variables.getValue("A").integerValue() + 256*variables.getValue("Y").integerValue()
                 val str = heap.get(straddr).str!!
-                canvas?.printText(str, 1, true)
+                canvas?.printText(str, true)
             }
             Syscall.SYSASM_c64scr_print_ub -> {
                 val num = variables.getValue("A").integerValue()
-                canvas?.printText(num.toString(), 1, true)
+                canvas?.printText(num.toString(), true)
             }
             Syscall.SYSASM_c64scr_print_ub0 -> {
                 val num = variables.getValue("A").integerValue()
-                canvas?.printText("%03d".format(num), 1, true)
+                canvas?.printText("%03d".format(num), true)
             }
             Syscall.SYSASM_c64scr_print_b -> {
                 val num = variables.getValue("A").integerValue()
                 if(num<=127)
-                    canvas?.printText(num.toString(), 1, true)
+                    canvas?.printText(num.toString(), true)
                 else
-                    canvas?.printText("-${256-num}", 1, true)
+                    canvas?.printText("-${256-num}", true)
             }
             Syscall.SYSASM_c64scr_print_uw -> {
                 val lo = variables.getValue("A").integerValue()
                 val hi = variables.getValue("Y").integerValue()
                 val number = lo+256*hi
-                canvas?.printText(number.toString(), 1, true)
+                canvas?.printText(number.toString(), true)
             }
             Syscall.SYSASM_c64scr_print_uw0 -> {
                 val lo = variables.getValue("A").integerValue()
                 val hi = variables.getValue("Y").integerValue()
                 val number = lo+256*hi
-                canvas?.printText("%05d".format(number), 1, true)
+                canvas?.printText("%05d".format(number), true)
             }
             Syscall.SYSASM_c64scr_print_uwhex -> {
                 val prefix = if(this.P_carry) "$" else ""
                 val lo = variables.getValue("A").integerValue()
                 val hi = variables.getValue("Y").integerValue()
                 val number = lo+256*hi
-                canvas?.printText("$prefix${number.toString(16).padStart(4, '0')}", 1, true)
+                canvas?.printText("$prefix${number.toString(16).padStart(4, '0')}", true)
             }
             Syscall.SYSASM_c64scr_print_w -> {
                 val lo = variables.getValue("A").integerValue()
                 val hi = variables.getValue("Y").integerValue()
                 val number = lo+256*hi
                 if(number<=32767)
-                    canvas?.printText(number.toString(), 1, true)
+                    canvas?.printText(number.toString(), true)
                 else
-                    canvas?.printText("-${65536-number}", 1, true)
+                    canvas?.printText("-${65536-number}", true)
             }
             Syscall.SYSASM_c64flt_print_f -> {
                 val number = variables.getValue("c64flt.print_f.value").numericValue()
-                canvas?.printText(number.toString(), 1, true)
+                canvas?.printText(number.toString(), true)
             }
             Syscall.SYSASM_c64scr_setcc -> {
                 val x = variables.getValue("c64scr.setcc.column").integerValue()
@@ -2412,12 +2413,12 @@ class StackVm(private var traceOutputFile: String?) {
             irqStoredCarry = P_carry
             irqStoredTraceOutputFile = traceOutputFile
 
-            if(irqStartInstructionPtr>=0)
-                currentInstructionPtr = irqStartInstructionPtr
+            currentInstructionPtr = if(irqStartInstructionPtr>=0)
+                irqStartInstructionPtr
             else {
                 if(program.last().opcode!=Opcode.RETURN)
                     throw VmExecutionException("last instruction in program should be RETURN for irq handler")
-                currentInstructionPtr = program.size-1
+                program.size-1
             }
             callstack = MyStack()
             evalstack = MyStack()

DeprecatedStackVm/test/StackVMOpcodeTests.kt

@@ -8,10 +8,10 @@ import prog8.ast.base.ByteDatatypes
 import prog8.ast.base.DataType
 import prog8.ast.base.IterableDatatypes
 import prog8.ast.base.WordDatatypes
-import prog8.vm.RuntimeValue
 import prog8.compiler.HeapValues
 import prog8.compiler.intermediate.Instruction
 import prog8.compiler.intermediate.Opcode
+import prog8.vm.RuntimeValue
 import prog8.vm.stackvm.*
 import kotlin.test.*
 
@@ -413,10 +413,10 @@ class TestStackVmOpcodes {
         testUnaryOperator(RuntimeValue(DataType.UBYTE, 123), Opcode.INV_BYTE, RuntimeValue(DataType.UBYTE, 0x84))
         testUnaryOperator(RuntimeValue(DataType.UWORD, 4044), Opcode.INV_WORD, RuntimeValue(DataType.UWORD, 0xf033))
         assertFailsWith<VmExecutionException> {
-            testUnaryOperator(RuntimeValue(DataType.BYTE, 123), Opcode.INV_BYTE, RuntimeValue(DataType.BYTE, 0x84))
+            testUnaryOperator(RuntimeValue(DataType.BYTE, 123), Opcode.INV_BYTE, RuntimeValue(DataType.BYTE, -124))
         }
         assertFailsWith<VmExecutionException> {
-            testUnaryOperator(RuntimeValue(DataType.WORD, 4044), Opcode.INV_WORD, RuntimeValue(DataType.WORD, 0xf033))
+            testUnaryOperator(RuntimeValue(DataType.WORD, 4044), Opcode.INV_WORD, RuntimeValue(DataType.WORD, -4043))
         }
     }
 

README.md

@@ -14,35 +14,40 @@ as used in many home computers from that era. It is a medium to low level progra
 which aims to provide many conveniences over raw assembly code (even when using a macro assembler):
 
 - reduction of source code length
-- easier program understanding (because it's higher level, and way more compact)
 - modularity, symbol scoping, subroutines
-- subroutines have enforced input- and output parameter definitions
-- various data types other than just bytes (16-bit words, floats, strings, 16-bit register pairs)
-- automatic variable allocations, automatic string variables and string sharing
-- constant folding in expressions (compile-time evaluation)
+- various data types other than just bytes (16-bit words, floats, strings)
+- automatic variable allocations, automatic string and array variables and string sharing
+- subroutines with a input- and output parameter signature
+- constant folding in expressions
 - conditional branches
-- automatic type conversions
-- floating point operations  (uses the C64 Basic ROM routines for this)
+- 'when' statement to provide a concise jump table alternative to if/elseif chains
+- structs to group together sets of variables and manipulate them at once
+- floating point operations  (requires the C64 Basic ROM routines for this)
 - abstracting away low level aspects such as ZeroPage handling, program startup, explicit memory addresses
-- various code optimizations (code structure, logical and numerical expressions, unused code removal...) 
+- various code optimizations (code structure, logical and numerical expressions, unused code removal...)
+- inline assembly allows you to have full control when every cycle or byte matters
+- many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``memset``, ``memcopy``
 
 Rapid edit-compile-run-debug cycle:
 
 - use modern PC to work on 
-- quick compilation times (less than 1 second)
+- quick compilation times (seconds)
 - option to automatically run the program in the Vice emulator  
 - breakpoints, that let the Vice emulator drop into the monitor if execution hits them
 - source code labels automatically loaded in Vice emulator so it can show them in disassembly
-
+- virtual machine that can execute compiled code directy on the host system,
+  without having to actually convert it to assembly to run on a real 6502 
 
 It is mainly targeted at the Commodore-64 machine at this time.
 Contributions to add support for other 8-bit (or other?!) machines are welcome.
 
-Documentation is online at https://prog8.readthedocs.io/
+Documentation/manual
+--------------------
+See https://prog8.readthedocs.io/
 
 
-Required tools:
----------------
+Required tools
+--------------
 
 [64tass](https://sourceforge.net/projects/tass64/) - cross assembler. Install this on your shell path.
 A recent .exe version of this tool for Windows can be obtained from my [clone](https://github.com/irmen/64tass/releases) of this project.
@@ -64,7 +69,7 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
     %import c64utils
     %zeropage basicsafe
 
-    ~ main {
+    main {
 
         ubyte[256] sieve
         ubyte candidate_prime = 2

compiler/build.gradle

@@ -22,8 +22,6 @@ repositories {
     jcenter()
 }
 
-sourceCompatibility = 1.8
-
 def prog8version = rootProject.file('compiler/res/version.txt').text.trim()
 
 dependencies {
@@ -49,6 +47,12 @@ compileKotlin {
     }
 }
 
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
 sourceSets {
     main {
         java {
@@ -76,17 +80,6 @@ artifacts {
     archives shadowJar
 }
 
-task p8vmScript(type: CreateStartScripts) {
-    mainClassName = "prog8.vm.stackvm.MainKt"
-    applicationName = "p8vm"
-    outputDir = new File(project.buildDir, 'scripts')
-    classpath = jar.outputs.files + project.configurations.runtime
-}
-
-applicationDistribution.into("bin") {
-    from(p8vmScript)
-    fileMode = 0755
-}
 
 // To create a fat-jar use the 'create_compiler_jar' script for now
 // @todo investigate https://imperceptiblethoughts.com/shadow/introduction/

compiler/compiler.iml

@@ -8,7 +8,7 @@
       <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build" />
     </content>
-    <orderEntry type="jdk" jdkName="1.8" jdkType="JavaSDK" />
+    <orderEntry type="jdk" jdkName="openjdk-11" jdkType="JavaSDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
     <orderEntry type="library" name="antlr-runtime-4.7.2" level="project" />

compiler/res/prog8lib/c64flt.p8

@@ -7,7 +7,7 @@
 %option enable_floats
 
 
-~ c64flt {
+c64flt {
 	; ---- this block contains C-64 floating point related functions ----
 
 		const  float  PI	= 3.141592653589793
@@ -52,7 +52,7 @@ asmsub	MOVMF		(uword mflpt @ XY) clobbers(A,Y)	= $bbd4		; store fac1 to memory
 
 ; fac1-> signed word in Y/A (might throw ILLEGAL QUANTITY)
 ; (tip: use c64flt.FTOSWRDAY to get A/Y output; lo/hi switched to normal little endian order)
-asmsub	FTOSWORDYA	() clobbers(X) -> ubyte @ Y, ubyte @ A  = $b1aa
+asmsub	FTOSWORDYA	() clobbers(X) -> ubyte @ Y, ubyte @ A  = $b1aa     ; note: calls AYINT.
 
 ; fac1 -> unsigned word in Y/A (might throw ILLEGAL QUANTITY) (result also in $14/15)
 ; (tip: use c64flt.GETADRAY to get A/Y output; lo/hi switched to normal little endian order)
@@ -196,8 +196,8 @@ sub  print_f  (float value) {
 	; ---- prints the floating point value (without a newline) using basic rom routines.
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
-		lda  #<print_f_value
-		ldy  #>print_f_value
+		lda  #<value
+		ldy  #>value
 		jsr  MOVFM		; load float into fac1
 		jsr  FOUT		; fac1 to string in A/Y
 		jsr  c64.STROUT			; print string in A/Y
@@ -310,7 +310,7 @@ stack_uw2float	.proc
 		jmp  push_fac1_as_result
 		.pend
 
-stack_float2w	.proc
+stack_float2w	.proc               ; also used for float2b
 		jsr  pop_float_fac1
 		stx  c64.SCRATCH_ZPREGX
 		jsr  AYINT
@@ -323,7 +323,7 @@ stack_float2w	.proc
 		rts
 		.pend
 
-stack_float2uw	.proc
+stack_float2uw	.proc               ; also used for float2ub
 		jsr  pop_float_fac1
 		stx  c64.SCRATCH_ZPREGX
 		jsr  GETADR
@@ -954,6 +954,16 @@ func_sum_f	.proc
 		bne  -
 +		jmp  push_fac1_as_result
 		.pend
+		
+sign_f		.proc
+		jsr  pop_float_fac1
+		jsr  SIGN
+		sta  c64.ESTACK_LO,x
+		dex
+		rts
+		.pend
+		
+
 }}
 
 }  ; ------ end of block c64flt

compiler/res/prog8lib/c64lib.p8

@@ -6,7 +6,7 @@
 ; indent format: TABS, size=8
 
 
-~ c64 {
+c64 {
 		const   uword  ESTACK_LO	= $ce00		; evaluation stack (lsb)
 		const   uword  ESTACK_HI	= $cf00		; evaluation stack (msb)
 		&ubyte  SCRATCH_ZPB1		= $02		; scratch byte 1 in ZP
@@ -21,7 +21,7 @@
 		&ubyte  TIME_LO			= $a2		;    .. lo byte. Updated by IRQ every 1/60 sec
 		&ubyte  STKEY			= $91		; various keyboard statuses (updated by IRQ)
 		&ubyte  SFDX			= $cb		; current key pressed (matrix value) (updated by IRQ)
-	
+
 		&ubyte  COLOR			= $0286		; cursor color
 		&ubyte  HIBASE			= $0288		; screen base address / 256 (hi-byte of screen memory address)
 		&uword  CINV			= $0314		; IRQ vector
@@ -202,12 +202,12 @@ asmsub	CINT     () clobbers(A,X,Y)			= $FF81		; (alias: SCINIT) initialize scree
 asmsub	IOINIT   () clobbers(A, X)			= $FF84		; initialize I/O devices (CIA, SID, IRQ)
 asmsub	RAMTAS   () clobbers(A,X,Y)			= $FF87		; initialize RAM, tape buffer, screen
 asmsub	RESTOR   () clobbers(A,X,Y)			= $FF8A		; restore default I/O vectors
-asmsub	VECTOR   (ubyte dir @ Pc, uword userptr @ XY) clobbers(A,Y)  = $FF8D		; read/set I/O vector table
+asmsub	VECTOR   (uword userptr @ XY, ubyte dir @ Pc) clobbers(A,Y)  = $FF8D		; read/set I/O vector table
 asmsub	SETMSG   (ubyte value @ A)			= $FF90		; set Kernal message control flag
 asmsub	SECOND   (ubyte address @ A) clobbers(A)	= $FF93		; (alias: LSTNSA) send secondary address after LISTEN
 asmsub	TKSA     (ubyte address @ A) clobbers(A)	= $FF96		; (alias: TALKSA) send secondary address after TALK
-asmsub	MEMTOP   (ubyte dir @ Pc, uword address @ XY) -> uword @ XY	= $FF99		; read/set top of memory  pointer
-asmsub	MEMBOT   (ubyte dir @ Pc, uword address @ XY) -> uword @ XY	= $FF9C		; read/set bottom of memory  pointer
+asmsub	MEMTOP   (uword address @ XY, ubyte dir @ Pc) -> uword @ XY	= $FF99		; read/set top of memory  pointer
+asmsub	MEMBOT   (uword address @ XY, ubyte dir @ Pc) -> uword @ XY	= $FF9C		; read/set bottom of memory  pointer
 asmsub	SCNKEY   () clobbers(A,X,Y)			= $FF9F		; scan the keyboard
 asmsub	SETTMO   (ubyte timeout @ A)			= $FFA2		; set time-out flag for IEEE bus
 asmsub	ACPTR    () -> ubyte @ A			= $FFA5		; (alias: IECIN) input byte from serial bus
@@ -235,7 +235,7 @@ asmsub	GETIN    () clobbers(X,Y) -> ubyte @ A		= $FFE4		; (via 810 ($32A)) get a
 asmsub	CLALL    () clobbers(A,X)			= $FFE7		; (via 812 ($32C)) close all files
 asmsub	UDTIM    () clobbers(A,X)			= $FFEA		; update the software clock
 asmsub	SCREEN   () -> ubyte @ X, ubyte @ Y		= $FFED		; read number of screen rows and columns
-asmsub	PLOT     (ubyte dir @ Pc, ubyte col @ Y, ubyte row @ X) -> ubyte @ X, ubyte @ Y	= $FFF0		; read/set position of cursor on screen.  Use c64scr.plot for a 'safe' wrapper that preserves X.
+asmsub	PLOT     (ubyte col @ Y, ubyte row @ X, ubyte dir @ Pc) -> ubyte @ X, ubyte @ Y	= $FFF0		; read/set position of cursor on screen.  Use c64scr.plot for a 'safe' wrapper that preserves X.
 asmsub	IOBASE   () -> uword @ XY			= $FFF3		; read base address of I/O devices
 
 ; ---- end of C64 kernal routines ----

compiler/res/prog8lib/c64utils.p8

@@ -9,7 +9,7 @@
 %import c64lib
 
 
-~ c64utils {
+c64utils {
 
 		const   uword  ESTACK_LO	= $ce00
 		const   uword  ESTACK_HI	= $cf00
@@ -461,7 +461,7 @@ _raster_irq_handler
 
 
 
-~ c64scr {
+c64scr {
 	; ---- this block contains (character) Screen and text I/O related functions ----
 
 
@@ -821,7 +821,7 @@ asmsub  print_b  (byte value @ A) clobbers(A,Y)  {
 }
 
 
-asmsub  print_ubhex  (ubyte prefix @ Pc, ubyte value @ A) clobbers(A,Y)  {
+asmsub  print_ubhex  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the ubyte in A in hex form (if Carry is set, a radix prefix '$' is printed as well)
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -840,7 +840,7 @@ asmsub  print_ubhex  (ubyte prefix @ Pc, ubyte value @ A) clobbers(A,Y)  {
 }
 
 
-asmsub  print_ubbin  (ubyte prefix @ Pc, ubyte value @ A) clobbers(A,Y)  {
+asmsub  print_ubbin  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the ubyte in A in binary form (if Carry is set, a radix prefix '%' is printed as well)
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -862,7 +862,7 @@ asmsub  print_ubbin  (ubyte prefix @ Pc, ubyte value @ A) clobbers(A,Y)  {
 }
 
 
-asmsub  print_uwbin  (ubyte prefix @ Pc, uword value @ AY) clobbers(A,Y)  {
+asmsub  print_uwbin  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the uword in A/Y in binary form (if Carry is set, a radix prefix '%' is printed as well)
 	%asm {{
 		pha
@@ -875,7 +875,7 @@ asmsub  print_uwbin  (ubyte prefix @ Pc, uword value @ AY) clobbers(A,Y)  {
 }
 
 
-asmsub print_uwhex  (ubyte prefix @ Pc, uword value @ AY) clobbers(A,Y)  {
+asmsub print_uwhex  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the uword in A/Y in hexadecimal form (4 digits)
 	;      (if Carry is set, a radix prefix '$' is printed as well)
 	%asm {{
@@ -1063,7 +1063,7 @@ _mod		lda  $ffff		; modified
 sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte color)  {
 	; ---- set char+color at the given position on the screen
 	%asm {{
-		lda  setcc_row
+		lda  row
 		asl  a
 		tay
 		lda  setchr._screenrows+1,y
@@ -1072,15 +1072,15 @@ sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte color)  {
 		sta  _colormod+2
 		lda  setchr._screenrows,y
 		clc
-		adc  setcc_column
+		adc  column
 		sta  _charmod+1
 		sta  _colormod+1
 		bcc  +
 		inc  _charmod+2
 		inc  _colormod+2
-+		lda  setcc_char
++		lda  char
 _charmod	sta  $ffff		; modified
-		lda  setcc_color
+		lda  color
 _colormod	sta  $ffff		; modified
 		rts
 	}}

compiler/res/prog8lib/math.asm

@@ -643,3 +643,40 @@ mul_word_40	.proc
 		sta  c64.ESTACK_HI+1,x
 		rts
 		.pend
+
+sign_b		.proc
+		lda  c64.ESTACK_LO+1,x
+		beq  _sign_zero
+		bmi  _sign_neg
+_sign_pos	lda  #1
+		sta  c64.ESTACK_LO+1,x
+		rts
+_sign_neg	lda  #-1
+_sign_zero	sta  c64.ESTACK_LO+1,x
+		rts
+		.pend
+
+sign_ub		.proc
+		lda  c64.ESTACK_LO+1,x
+		beq  sign_b._sign_zero
+		bne  sign_b._sign_pos
+		.pend
+
+sign_w		.proc
+		lda  c64.ESTACK_HI+1,x
+		bmi  sign_b._sign_neg
+		beq  sign_ub
+		bne  sign_b._sign_pos
+		.pend
+
+sign_uw		.proc
+		lda  c64.ESTACK_HI+1,x
+		beq  _sign_possibly_zero
+_sign_pos	lda  #1
+		sta  c64.ESTACK_LO+1,x
+		rts
+_sign_possibly_zero	lda  c64.ESTACK_LO+1,x
+		bne  _sign_pos
+		sta  c64.ESTACK_LO+1,x
+		rts
+		.pend

compiler/res/prog8lib/math.p8

@@ -6,6 +6,6 @@
 
 %import c64lib
 
-~ math {
+math {
 	%asminclude "library:math.asm", ""
 }

compiler/res/prog8lib/prog8lib.asm

@@ -36,6 +36,17 @@ init_system	.proc
 		.pend
 
 
+read_byte_from_address	.proc
+	; -- read the byte from the memory address on the top of the stack, return in A (stack remains unchanged)
+		lda  c64.ESTACK_LO+1,x
+		ldy  c64.ESTACK_HI+1,x
+		sta  (+) +1
+		sty  (+) +2
++		lda  $ffff		; modified
+		rts
+		.pend
+
+
 add_a_to_zpword	.proc
 	; -- add ubyte in A to the uword in c64.SCRATCH_ZPWORD1
 		clc
@@ -840,11 +851,12 @@ func_all_w	.proc
 		bne  +
 		iny
 		lda  (c64.SCRATCH_ZPWORD1),y
-		bne  +
+		bne  ++
 		lda  #0
 		sta  c64.ESTACK_LO+1,x
 		rts
 +		iny
++		iny
 _cmp_mod	cpy  #255		; modified
 		bne  -
 		lda  #1

compiler/res/prog8lib/prog8lib.p8

@@ -6,6 +6,6 @@
 
 %import c64lib
 
-~ prog8_lib {
+prog8_lib {
 	%asminclude "library:prog8lib.asm", ""
 }

compiler/res/version.txt

@@ -1 +1 @@
-1.9
+1.52

compiler/src/prog8/CompilerMain.kt

@@ -1,21 +1,20 @@
 package prog8
 
+import prog8.ast.base.AstException
+import prog8.compiler.CompilationResult
+import prog8.compiler.compileProgram
+import prog8.parser.ParsingFailedError
 import prog8.vm.astvm.AstVm
-import prog8.vm.stackvm.stackVmMain
-import prog8.compiler.*
+import java.nio.file.FileSystems
+import java.nio.file.Path
 import java.nio.file.Paths
+import java.nio.file.StandardWatchEventKinds
+import java.util.*
 import kotlin.system.exitProcess
 
 
 fun main(args: Array<String>) {
 
-    // check if the user wants to launch the VM instead
-    if("-vm" in args) {
-        val newArgs = args.toMutableList()
-        newArgs.remove("-vm")
-        return stackVmMain(newArgs.toTypedArray())
-    }
-
     printSoftwareHeader("compiler")
 
     if (args.isEmpty())
@@ -33,54 +32,93 @@ internal fun printSoftwareHeader(what: String) {
 private fun compileMain(args: Array<String>) {
     var emulatorToStart = ""
     var moduleFile = ""
-    var writeVmCode = false
     var writeAssembly = true
     var optimize = true
-    var optimizeInlining = true
     var launchAstVm = false
+    var watchMode = false
     for (arg in args) {
         if(arg=="-emu")
             emulatorToStart = "x64"
         else if(arg=="-emu2")
             emulatorToStart = "x64sc"
-        else if(arg=="-writevm")
-            writeVmCode = true
         else if(arg=="-noasm")
             writeAssembly = false
         else if(arg=="-noopt")
             optimize = false
-        else if(arg=="-nooptinline")
-            optimizeInlining = false
         else if(arg=="-avm")
             launchAstVm = true
+        else if(arg=="-watch")
+            watchMode = true
         else if(!arg.startsWith("-"))
             moduleFile = arg
         else
             usage()
     }
-    if(moduleFile.isBlank())
-        usage()
 
-    val filepath = Paths.get(moduleFile).normalize()
+    if(watchMode) {
+        if(moduleFile.isBlank())
+            usage()
 
-    val (programAst, programName) = compileProgram(filepath, optimize, optimizeInlining,
-            !launchAstVm, writeVmCode, writeAssembly)
+        val watchservice = FileSystems.getDefault().newWatchService()
 
-    if(launchAstVm) {
-        println("\nLaunching AST-based vm...")
-        val vm = AstVm(programAst)
-        vm.run()
-    }
+        while(true) {
+            val filepath = Paths.get(moduleFile).normalize()
+            println("Continuous watch mode active. Main module: $filepath")
 
-    if(emulatorToStart.isNotEmpty()) {
-        if(programName==null)
-            println("\nCan't start emulator because no program was assembled.")
-        else {
-            println("\nStarting C-64 emulator $emulatorToStart...")
-            val cmdline = listOf(emulatorToStart, "-silent", "-moncommands", "$programName.vice-mon-list",
-                    "-autostartprgmode", "1", "-autostart-warp", "-autostart", programName + ".prg")
-            val process = ProcessBuilder(cmdline).inheritIO().start()
-            process.waitFor()
+            try {
+                val compilationResult = compileProgram(filepath, optimize, writeAssembly)
+                println("Imported files (now watching:)")
+                for (importedFile in compilationResult.importedFiles) {
+                    print("  ")
+                    println(importedFile)
+                    importedFile.parent.register(watchservice, StandardWatchEventKinds.ENTRY_MODIFY)
+                }
+                println("${Date()}: Waiting for file changes.")
+                val event = watchservice.take()
+                for(changed in event.pollEvents()) {
+                    val changedPath = changed.context() as Path
+                    println("  change detected: $changedPath")
+                }
+                event.reset()
+                println("\u001b[H\u001b[2J")      // clear the screen
+            } catch (x: Exception) {
+                throw x
+            }
+        }
+
+    } else {
+        if(moduleFile.isBlank())
+            usage()
+
+        val filepath = Paths.get(moduleFile).normalize()
+        val compilationResult: CompilationResult
+
+        try {
+            compilationResult = compileProgram(filepath, optimize, writeAssembly)
+            if(!compilationResult.success)
+                exitProcess(1)
+        } catch (x: ParsingFailedError) {
+            exitProcess(1)
+        } catch (x: AstException) {
+            exitProcess(1)
+        }
+
+        if (launchAstVm) {
+            println("\nLaunching AST-based vm...")
+            val vm = AstVm(compilationResult.programAst)
+            vm.run()
+        }
+
+        if (emulatorToStart.isNotEmpty()) {
+            if (compilationResult.programName.isEmpty())
+                println("\nCan't start emulator because no program was assembled.")
+            else {
+                println("\nStarting C-64 emulator $emulatorToStart...")
+                val cmdline = listOf(emulatorToStart, "-silent", "-moncommands", "${compilationResult.programName}.vice-mon-list",
+                        "-autostartprgmode", "1", "-autostart-warp", "-autostart", compilationResult.programName + ".prg")
+                val process = ProcessBuilder(cmdline).inheritIO().start()
+                process.waitFor()
+            }
         }
     }
 }
@@ -88,14 +126,12 @@ private fun compileMain(args: Array<String>) {
 
 private fun usage() {
     System.err.println("Missing argument(s):")
+    System.err.println("    [-noasm]        don't create assembly code")
+    System.err.println("    [-noopt]        don't perform any optimizations")
     System.err.println("    [-emu]          auto-start the 'x64' C-64 emulator after successful compilation")
     System.err.println("    [-emu2]         auto-start the 'x64sc' C-64 emulator after successful compilation")
-    System.err.println("    [-writevm]      write intermediate vm code to a file as well")
-    System.err.println("    [-noasm]        don't create assembly code")
-    System.err.println("    [-vm]           launch the prog8 virtual machine instead of the compiler")
     System.err.println("    [-avm]          launch the prog8 ast-based virtual machine after compilation")
-    System.err.println("    [-noopt]        don't perform any optimizations")
-    System.err.println("    [-nooptinline]  don't perform subroutine inlining optimizations")
+    System.err.println("    [-watch]        continuous compilation mode (watches for file changes)")
     System.err.println("    modulefile      main module file to compile")
     exitProcess(1)
 }

compiler/src/prog8/ast/AstToSourceCode.kt

@@ -1,22 +1,22 @@
-package prog8.compiler
+package prog8.ast
 
 import prog8.ast.antlr.escape
-import prog8.ast.IFunctionCall
-import prog8.ast.IStatement
-import prog8.ast.Module
-import prog8.ast.Program
-import prog8.ast.base.*
+import prog8.ast.base.DataType
+import prog8.ast.base.NumericDatatypes
+import prog8.ast.base.StringDatatypes
+import prog8.ast.base.VarDeclType
 import prog8.ast.expressions.*
 import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
+import prog8.compiler.toHex
 
-class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
-    var scopelevel = 0
+class AstToSourceCode(val output: (text: String) -> Unit, val program: Program): IAstVisitor {
+    private var scopelevel = 0
 
-    fun indent(s: String) = "    ".repeat(scopelevel) + s
-    fun outputln(text: String) = output(text + "\n")
-    fun outputlni(s: Any) = outputln(indent(s.toString()))
-    fun outputi(s: Any) = output(indent(s.toString()))
+    private fun indent(s: String) = "    ".repeat(scopelevel) + s
+    private fun outputln(text: String) = output(text + "\n")
+    private fun outputlni(s: Any) = outputln(indent(s.toString()))
+    private fun outputi(s: Any) = output(indent(s.toString()))
 
     override fun visit(program: Program) {
         outputln("============= PROGRAM ${program.name} (FROM AST) ===============")
@@ -76,7 +76,7 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
         output("\n")
     }
 
-    fun datatypeString(dt: DataType): String {
+    private fun datatypeString(dt: DataType): String {
         return when(dt) {
             in NumericDatatypes -> dt.toString().toLowerCase()
             in StringDatatypes -> dt.toString().toLowerCase()
@@ -85,21 +85,30 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
             DataType.ARRAY_UW -> "uword["
             DataType.ARRAY_W -> "word["
             DataType.ARRAY_F -> "float["
-            else -> "?????"
+            DataType.STRUCT -> ""       // the name of the struct is enough
+            else -> "?????2"
         }
     }
 
-    override fun visit(decl: VarDecl) {
-        if(decl.autoGenerated) {
-            // skip autogenerated vardecl
-            return
+    override fun visit(structDecl: StructDecl) {
+        outputln("struct ${structDecl.name} {")
+        scopelevel++
+        for(decl in structDecl.statements) {
+            outputi("")
+            decl.accept(this)
+            output("\n")
         }
+        scopelevel--
+        outputlni("}")
+    }
 
+    override fun visit(decl: VarDecl) {
         when(decl.type) {
             VarDeclType.VAR -> {}
             VarDeclType.CONST -> output("const ")
             VarDeclType.MEMORY -> output("&")
         }
+        output(decl.struct?.name ?: "")
         output(datatypeString(decl.datatype))
         if(decl.arraysize!=null) {
             decl.arraysize!!.index.accept(this)
@@ -107,7 +116,7 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
         if(decl.isArray)
             output("]")
 
-        if(decl.zeropage)
+        if(decl.zeropage == ZeropageWish.REQUIRE_ZEROPAGE || decl.zeropage==ZeropageWish.PREFER_ZEROPAGE)
             output(" @zp")
         output(" ${decl.name} ")
         if(decl.value!=null) {
@@ -123,10 +132,10 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
             for(param in subroutine.parameters.zip(subroutine.asmParameterRegisters)) {
                 val reg =
                         when {
-                            true==param.second.stack -> "stack"
+                            param.second.stack -> "stack"
                             param.second.registerOrPair!=null -> param.second.registerOrPair.toString()
                             param.second.statusflag!=null -> param.second.statusflag.toString()
-                            else -> "?????"
+                            else -> "?????1"
                         }
                 output("${datatypeString(param.first.type)} ${param.first.name} @$reg")
                 if(param.first!==subroutine.parameters.last())
@@ -167,10 +176,10 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
         }
     }
 
-    private fun outputStatements(statements: List<IStatement>) {
+    private fun outputStatements(statements: List<Statement>) {
         for(stmt in statements) {
-            if(stmt is VarDecl && stmt.autoGenerated)
-                continue    // skip autogenerated decls
+            if(stmt is VarDecl && stmt.autogeneratedDontRemove)
+                continue    // skip autogenerated decls (to avoid generating a newline)
             outputi("")
             stmt.accept(this)
             output("\n")
@@ -243,27 +252,48 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
         output("${label.name}:")
     }
 
-    override fun visit(literalValue: LiteralValue) {
-        when {
-            literalValue.isNumeric -> output(literalValue.asNumericValue.toString())
-            literalValue.isString -> output("\"${escape(literalValue.strvalue!!)}\"")
-            literalValue.isArray -> {
-                if(literalValue.arrayvalue!=null) {
-                    output("[")
-                    for (v in literalValue.arrayvalue) {
-                        v.accept(this)
-                        if (v !== literalValue.arrayvalue.last())
-                            output(", ")
-                    }
-                    output("]")
-                }
+    override fun visit(numLiteral: NumericLiteralValue) {
+        output(numLiteral.number.toString())
+    }
+
+    override fun visit(string: StringLiteralValue) {
+        output("\"${escape(string.value)}\"")
+    }
+
+    override fun visit(array: ArrayLiteralValue) {
+        outputListMembers(array.value.asSequence(), '[', ']')
+    }
+
+    private fun outputListMembers(array: Sequence<Expression>, openchar: Char, closechar: Char) {
+        var counter = 0
+        output(openchar.toString())
+        scopelevel++
+        for (v in array) {
+            v.accept(this)
+            if (v !== array.last())
+                output(", ")
+            counter++
+            if (counter > 16) {
+                outputln("")
+                outputi("")
+                counter = 0
             }
         }
+        scopelevel--
+        output(closechar.toString())
     }
 
     override fun visit(assignment: Assignment) {
-        assignment.singleTarget!!.accept(this)
-        if(assignment.aug_op!=null)
+        if(assignment is VariableInitializationAssignment) {
+            val targetVar = assignment.target.identifier?.targetVarDecl(program.namespace)
+            if(targetVar?.struct != null) {
+                // skip STRUCT init assignments
+                return
+            }
+        }
+
+        assignment.target.accept(this)
+        if (assignment.aug_op != null)
             output(" ${assignment.aug_op} ")
         else
             output(" = ")
@@ -287,7 +317,7 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
         output("for ")
         if(forLoop.decltype!=null) {
             output(datatypeString(forLoop.decltype))
-            if (forLoop.zeropage)
+            if (forLoop.zeropage==ZeropageWish.REQUIRE_ZEROPAGE || forLoop.zeropage==ZeropageWish.PREFER_ZEROPAGE)
                 output(" @zp ")
             else
                 output(" ")
@@ -310,7 +340,7 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
     }
 
     override fun visit(repeatLoop: RepeatLoop) {
-        outputln("repeat ")
+        output("repeat ")
         repeatLoop.body.accept(this)
         output(" until ")
         repeatLoop.untilCondition.accept(this)
@@ -318,11 +348,7 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
 
     override fun visit(returnStmt: Return) {
         output("return ")
-        for(v in returnStmt.values) {
-            v.accept(this)
-            if(v!==returnStmt.values.last())
-                output(", ")
-        }
+        returnStmt.value?.accept(this)
     }
 
     override fun visit(arrayIndexedExpression: ArrayIndexedExpression) {
@@ -351,8 +377,9 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
     }
 
     override fun visit(typecast: TypecastExpression) {
+        output("(")
         typecast.expression.accept(this)
-        output(" as ${datatypeString(typecast.type)} ")
+        output(" as ${datatypeString(typecast.type)}) ")
     }
 
     override fun visit(memread: DirectMemoryRead) {
@@ -397,11 +424,16 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
     }
 
     override fun visit(whenChoice: WhenChoice) {
-        if(whenChoice.value==null)
+        val choiceValues = whenChoice.values
+        if(choiceValues==null)
             outputi("else -> ")
         else {
             outputi("")
-            whenChoice.value.accept(this)
+            for(value in choiceValues) {
+                value.accept(this)
+                if(value !== choiceValues.last())
+                    output(",")
+            }
             output(" -> ")
         }
         if(whenChoice.statements.statements.size==1)
@@ -410,7 +442,12 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
             whenChoice.statements.accept(this)
         outputln("")
     }
+
+    override fun visit(structLv: StructLiteralValue) {
+        outputListMembers(structLv.values.asSequence(), '{', '}')
+    }
+
     override fun visit(nopStatement: NopStatement) {
-        TODO("NOP???")
+        output("; NOP @ ${nopStatement.position}  $nopStatement")
     }
 }

compiler/src/prog8/ast/AstToplevel.kt

@@ -1,27 +1,178 @@
 package prog8.ast
 
-import prog8.ast.base.FatalAstException
-import prog8.ast.base.NameError
-import prog8.ast.base.ParentSentinel
-import prog8.ast.base.Position
-import prog8.ast.statements.Block
-import prog8.ast.statements.Label
-import prog8.ast.statements.Subroutine
-import prog8.ast.statements.VarDecl
+import prog8.ast.base.*
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.statements.*
 import prog8.compiler.HeapValues
 import prog8.functions.BuiltinFunctions
 import java.nio.file.Path
 
 
+interface Node {
+    val position: Position
+    var parent: Node             // will be linked correctly later (late init)
+    fun linkParents(parent: Node)
+
+    fun definingModule(): Module {
+        if(this is Module)
+            return this
+        return findParentNode<Module>(this)!!
+    }
+
+    fun definingSubroutine(): Subroutine?  = findParentNode<Subroutine>(this)
+
+    fun definingScope(): INameScope {
+        val scope = findParentNode<INameScope>(this)
+        if(scope!=null) {
+            return scope
+        }
+        if(this is Label && this.name.startsWith("builtin::")) {
+            return BuiltinFunctionScopePlaceholder
+        }
+        if(this is GlobalNamespace)
+            return this
+        throw FatalAstException("scope missing from $this")
+    }
+}
+
+interface IFunctionCall {
+    var target: IdentifierReference
+    var arglist: MutableList<Expression>
+}
+
+interface INameScope {
+    val name: String
+    val position: Position
+    val statements: MutableList<Statement>
+    val parent: Node
+
+    fun linkParents(parent: Node)
+
+    fun subScopes(): Map<String, INameScope> {
+        val subscopes = mutableMapOf<String, INameScope>()
+        for(stmt in statements) {
+            when(stmt) {
+                // NOTE: if other nodes are introduced that are a scope, or contain subscopes, they must be added here!
+                is ForLoop -> subscopes[stmt.body.name] = stmt.body
+                is RepeatLoop -> subscopes[stmt.body.name] = stmt.body
+                is WhileLoop -> subscopes[stmt.body.name] = stmt.body
+                is BranchStatement -> {
+                    subscopes[stmt.truepart.name] = stmt.truepart
+                    if(stmt.elsepart.containsCodeOrVars())
+                        subscopes[stmt.elsepart.name] = stmt.elsepart
+                }
+                is IfStatement -> {
+                    subscopes[stmt.truepart.name] = stmt.truepart
+                    if(stmt.elsepart.containsCodeOrVars())
+                        subscopes[stmt.elsepart.name] = stmt.elsepart
+                }
+                is WhenStatement -> {
+                    stmt.choices.forEach { subscopes[it.statements.name] = it.statements }
+                }
+                is INameScope -> subscopes[stmt.name] = stmt
+                else -> {}
+            }
+        }
+        return subscopes
+    }
+
+    fun getLabelOrVariable(name: String): Statement? {
+        // this is called A LOT and could perhaps be optimized a bit more,
+        // but adding a memoization cache didn't make much of a practical runtime difference
+        for (stmt in statements) {
+            if (stmt is VarDecl && stmt.name==name) return stmt
+            if (stmt is Label && stmt.name==name) return stmt
+            if (stmt is AnonymousScope) {
+                val sub = stmt.getLabelOrVariable(name)
+                if(sub!=null)
+                    return sub
+            }
+        }
+        return null
+    }
+
+    fun allDefinedSymbols(): List<Pair<String, Statement>>  {
+        return statements.mapNotNull {
+            when (it) {
+                is Label -> it.name to it
+                is VarDecl -> it.name to it
+                is Subroutine -> it.name to it
+                is Block -> it.name to it
+                else -> null
+            }
+        }
+    }
+
+    fun lookup(scopedName: List<String>, localContext: Node) : Statement? {
+        if(scopedName.size>1) {
+            // a scoped name can a) refer to a member of a struct, or b) refer to a name in another module.
+            // try the struct first.
+            val thing = lookup(scopedName.dropLast(1), localContext) as? VarDecl
+            val struct = thing?.struct
+            if (struct != null) {
+                if(struct.statements.any { (it as VarDecl).name == scopedName.last()}) {
+                    // return ref to the mangled name variable
+                    val mangled = mangledStructMemberName(thing.name, scopedName.last())
+                    return thing.definingScope().getLabelOrVariable(mangled)
+                }
+            }
+
+            // it's a qualified name, look it up from the root of the module's namespace (consider all modules in the program)
+            for(module in localContext.definingModule().program.modules) {
+                var scope: INameScope? = module
+                for(name in scopedName.dropLast(1)) {
+                    scope = scope?.subScopes()?.get(name)
+                    if(scope==null)
+                        break
+                }
+                if(scope!=null) {
+                    val result = scope.getLabelOrVariable(scopedName.last())
+                    if(result!=null)
+                        return result
+                    return scope.subScopes()[scopedName.last()] as Statement?
+                }
+            }
+            return null
+        } else {
+            // unqualified name, find the scope the localContext is in, look in that first
+            var statementScope = localContext
+            while(statementScope !is ParentSentinel) {
+                val localScope = statementScope.definingScope()
+                val result = localScope.getLabelOrVariable(scopedName[0])
+                if (result != null)
+                    return result
+                val subscope = localScope.subScopes()[scopedName[0]] as Statement?
+                if (subscope != null)
+                    return subscope
+                // not found in this scope, look one higher up
+                statementScope = statementScope.parent
+            }
+            return null
+        }
+    }
+
+    fun containsCodeOrVars() = statements.any { it !is Directive || it.directive == "%asminclude" || it.directive == "%asm"}
+    fun containsNoCodeNorVars() = !containsCodeOrVars()
+
+    fun remove(stmt: Statement) {
+        if(!statements.remove(stmt))
+            throw FatalAstException("stmt to remove wasn't found in scope")
+    }
+}
+
+
 /*********** Everything starts from here, the Program; zero or more modules *************/
 
 class Program(val name: String, val modules: MutableList<Module>) {
     val namespace = GlobalNamespace(modules)
     val heap = HeapValues()
 
-    val loadAddress: Int
+    val definedLoadAddress: Int
         get() = modules.first().loadAddress
 
+    var actualLoadAddress: Int = 0
+
     fun entrypoint(): Subroutine? {
         val mainBlocks = modules.flatMap { it.statements }.filter { b -> b is Block && b.name=="main" }.map { it as Block }
         if(mainBlocks.size > 1)
@@ -32,10 +183,12 @@ class Program(val name: String, val modules: MutableList<Module>) {
             mainBlocks[0].subScopes()["start"] as Subroutine?
         }
     }
+
+    fun allBlocks(): List<Block> = modules.flatMap { it.statements.filterIsInstance<Block>() }
 }
 
 class Module(override val name: String,
-             override var statements: MutableList<IStatement>,
+             override var statements: MutableList<Statement>,
              override val position: Position,
              val isLibraryModule: Boolean,
              val source: Path) : Node, INameScope {
@@ -59,14 +212,14 @@ class Module(override val name: String,
 class GlobalNamespace(val modules: List<Module>): Node, INameScope {
     override val name = "<<<global>>>"
     override val position = Position("<<<global>>>", 0, 0, 0)
-    override val statements = mutableListOf<IStatement>()
+    override val statements = mutableListOf<Statement>()
     override var parent: Node = ParentSentinel
 
     override fun linkParents(parent: Node) {
         modules.forEach { it.linkParents(this) }
     }
 
-    override fun lookup(scopedName: List<String>, localContext: Node): IStatement? {
+    override fun lookup(scopedName: List<String>, localContext: Node): Statement? {
         if (scopedName.size == 1 && scopedName[0] in BuiltinFunctions) {
             // builtin functions always exist, return a dummy localContext for them
             val builtinPlaceholder = Label("builtin::${scopedName.last()}", localContext.position)
@@ -74,6 +227,20 @@ class GlobalNamespace(val modules: List<Module>): Node, INameScope {
             return builtinPlaceholder
         }
 
+        if(scopedName.size>1) {
+            // a scoped name can a) refer to a member of a struct, or b) refer to a name in another module.
+            // try the struct first.
+            val thing = lookup(scopedName.dropLast(1), localContext) as? VarDecl
+            val struct = thing?.struct
+            if (struct != null) {
+                if(struct.statements.any { (it as VarDecl).name == scopedName.last()}) {
+                    // return ref to the mangled name variable
+                    val mangled = mangledStructMemberName(thing.name, scopedName.last())
+                    return thing.definingScope().getLabelOrVariable(mangled)
+                }
+            }
+        }
+        // lookup something from the module.
         val stmt = localContext.definingModule().lookup(scopedName, localContext)
         return when (stmt) {
             is Label, is VarDecl, is Block, is Subroutine -> stmt
@@ -86,7 +253,11 @@ class GlobalNamespace(val modules: List<Module>): Node, INameScope {
 object BuiltinFunctionScopePlaceholder : INameScope {
     override val name = "<<builtin-functions-scope-placeholder>>"
     override val position = Position("<<placeholder>>", 0, 0, 0)
-    override var statements = mutableListOf<IStatement>()
+    override var statements = mutableListOf<Statement>()
     override var parent: Node = ParentSentinel
     override fun linkParents(parent: Node) {}
 }
+
+
+// prefix for struct member variables
+internal fun mangledStructMemberName(varName: String, memberName: String) = "prog8struct_${varName}_$memberName"

compiler/src/prog8/ast/Interfaces.kt

@@ -1,197 +0,0 @@
-package prog8.ast
-
-import prog8.ast.base.*
-import prog8.ast.expressions.*
-import prog8.ast.processing.IAstModifyingVisitor
-import prog8.ast.processing.IAstVisitor
-import prog8.ast.statements.*
-
-interface Node {
-    val position: Position
-    var parent: Node             // will be linked correctly later (late init)
-    fun linkParents(parent: Node)
-
-    fun definingModule(): Module {
-        if(this is Module)
-            return this
-        return findParentNode<Module>(this)!!
-    }
-
-    fun definingSubroutine(): Subroutine?  = findParentNode<Subroutine>(this)
-
-    fun definingScope(): INameScope {
-        val scope = findParentNode<INameScope>(this)
-        if(scope!=null) {
-            return scope
-        }
-        if(this is Label && this.name.startsWith("builtin::")) {
-            return BuiltinFunctionScopePlaceholder
-        }
-        if(this is GlobalNamespace)
-            return this
-        throw FatalAstException("scope missing from $this")
-    }
-}
-
-interface IStatement : Node {
-    fun accept(visitor: IAstModifyingVisitor) : IStatement
-    fun accept(visitor: IAstVisitor)
-    fun makeScopedName(name: String): String {
-        // easy way out is to always return the full scoped name.
-        // it would be nicer to find only the minimal prefixed scoped name, but that's too much hassle for now.
-        // and like this, we can cache the name even,
-        // like in a lazy property on the statement object itself (label, subroutine, vardecl)
-        val scope = mutableListOf<String>()
-        var statementScope = this.parent
-        while(statementScope !is ParentSentinel && statementScope !is Module) {
-            if(statementScope is INameScope) {
-                scope.add(0, statementScope.name)
-            }
-            statementScope = statementScope.parent
-        }
-        if(name.isNotEmpty())
-            scope.add(name)
-        return scope.joinToString(".")
-    }
-
-    val expensiveToInline: Boolean
-
-    fun definingBlock(): Block {
-        if(this is Block)
-            return this
-        return findParentNode<Block>(this)!!
-    }
-}
-
-interface IFunctionCall {
-    var target: IdentifierReference
-    var arglist: MutableList<IExpression>
-}
-
-interface INameScope {
-    val name: String
-    val position: Position
-    val statements: MutableList<IStatement>
-    val parent: Node
-
-    fun linkParents(parent: Node)
-
-    fun subScopes(): Map<String, INameScope> {
-        val subscopes = mutableMapOf<String, INameScope>()
-        for(stmt in statements) {
-            when(stmt) {
-                is INameScope -> subscopes[stmt.name] = stmt
-                is ForLoop -> subscopes[stmt.body.name] = stmt.body
-                is RepeatLoop -> subscopes[stmt.body.name] = stmt.body
-                is WhileLoop -> subscopes[stmt.body.name] = stmt.body
-                is BranchStatement -> {
-                    subscopes[stmt.truepart.name] = stmt.truepart
-                    if(stmt.elsepart.containsCodeOrVars())
-                        subscopes[stmt.elsepart.name] = stmt.elsepart
-                }
-                is IfStatement -> {
-                    subscopes[stmt.truepart.name] = stmt.truepart
-                    if(stmt.elsepart.containsCodeOrVars())
-                        subscopes[stmt.elsepart.name] = stmt.elsepart
-                }
-            }
-        }
-        return subscopes
-    }
-
-    fun getLabelOrVariable(name: String): IStatement? {
-        // TODO this is called A LOT and could perhaps be optimized a bit more, but adding a cache didn't make much of a practical runtime difference
-        for (stmt in statements) {
-            if (stmt is VarDecl && stmt.name==name) return stmt
-            if (stmt is Label && stmt.name==name) return stmt
-        }
-        return null
-    }
-
-    fun allDefinedSymbols(): List<Pair<String, IStatement>>  {
-        return statements.mapNotNull {
-            when (it) {
-                is Label -> it.name to it
-                is VarDecl -> it.name to it
-                is Subroutine -> it.name to it
-                is Block -> it.name to it
-                else -> null
-            }
-        }
-    }
-
-    fun lookup(scopedName: List<String>, localContext: Node) : IStatement? {
-        if(scopedName.size>1) {
-            // it's a qualified name, look it up from the root of the module's namespace (consider all modules in the program)
-            for(module in localContext.definingModule().program.modules) {
-                var scope: INameScope? = module
-                for(name in scopedName.dropLast(1)) {
-                    scope = scope?.subScopes()?.get(name)
-                    if(scope==null)
-                        break
-                }
-                if(scope!=null) {
-                    val result = scope.getLabelOrVariable(scopedName.last())
-                    if(result!=null)
-                        return result
-                    return scope.subScopes()[scopedName.last()] as IStatement?
-                }
-            }
-            return null
-        } else {
-            // unqualified name, find the scope the localContext is in, look in that first
-            var statementScope = localContext
-            while(statementScope !is ParentSentinel) {
-                val localScope = statementScope.definingScope()
-                val result = localScope.getLabelOrVariable(scopedName[0])
-                if (result != null)
-                    return result
-                val subscope = localScope.subScopes()[scopedName[0]] as IStatement?
-                if (subscope != null)
-                    return subscope
-                // not found in this scope, look one higher up
-                statementScope = statementScope.parent
-            }
-            return null
-        }
-    }
-
-    fun containsCodeOrVars() = statements.any { it !is Directive || it.directive == "%asminclude" || it.directive == "%asm"}
-    fun containsNoCodeNorVars() = !containsCodeOrVars()
-
-    fun remove(stmt: IStatement) {
-        if(!statements.remove(stmt))
-            throw FatalAstException("stmt to remove wasn't found in scope")
-    }
-}
-
-interface IExpression: Node {
-    fun constValue(program: Program): LiteralValue?
-    fun accept(visitor: IAstModifyingVisitor): IExpression
-    fun accept(visitor: IAstVisitor)
-    fun referencesIdentifier(name: String): Boolean
-    fun inferType(program: Program): DataType?
-
-    infix fun isSameAs(other: IExpression): Boolean {
-        if(this===other)
-            return true
-        when(this) {
-            is RegisterExpr ->
-                return (other is RegisterExpr && other.register==register)
-            is IdentifierReference ->
-                return (other is IdentifierReference && other.nameInSource==nameInSource)
-            is PrefixExpression ->
-                return (other is PrefixExpression && other.operator==operator && other.expression isSameAs expression)
-            is BinaryExpression ->
-                return (other is BinaryExpression && other.operator==operator
-                        && other.left isSameAs left
-                        && other.right isSameAs right)
-            is ArrayIndexedExpression -> {
-                return (other is ArrayIndexedExpression && other.identifier.nameInSource == identifier.nameInSource
-                        && other.arrayspec.index isSameAs arrayspec.index)
-            }
-            is LiteralValue -> return (other is LiteralValue && other==this)
-        }
-        return false
-    }
-}

compiler/src/prog8/ast/antlr/Antr2Kotlin.kt

@@ -3,16 +3,16 @@ package prog8.ast.antlr
 import org.antlr.v4.runtime.IntStream
 import org.antlr.v4.runtime.ParserRuleContext
 import org.antlr.v4.runtime.tree.TerminalNode
-import prog8.ast.*
+import prog8.ast.Module
 import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
-import java.io.CharConversionException
-import java.io.File
-import java.nio.file.Path
 import prog8.compiler.target.c64.Petscii
 import prog8.parser.CustomLexer
 import prog8.parser.prog8Parser
+import java.io.CharConversionException
+import java.io.File
+import java.nio.file.Path
 
 
 /***************** Antlr Extension methods to create AST ****************/
@@ -39,7 +39,7 @@ private fun ParserRuleContext.toPosition() : Position {
 }
 
 
-private fun prog8Parser.ModulestatementContext.toAst(isInLibrary: Boolean) : IStatement {
+private fun prog8Parser.ModulestatementContext.toAst(isInLibrary: Boolean) : Statement {
     val directive = directive()?.toAst()
     if(directive!=null) return directive
 
@@ -50,74 +50,104 @@ private fun prog8Parser.ModulestatementContext.toAst(isInLibrary: Boolean) : ISt
 }
 
 
-private fun prog8Parser.BlockContext.toAst(isInLibrary: Boolean) : IStatement =
+private fun prog8Parser.BlockContext.toAst(isInLibrary: Boolean) : Statement =
         Block(identifier().text, integerliteral()?.toAst()?.number?.toInt(), statement_block().toAst(), isInLibrary, toPosition())
 
 
-private fun prog8Parser.Statement_blockContext.toAst(): MutableList<IStatement> =
+private fun prog8Parser.Statement_blockContext.toAst(): MutableList<Statement> =
         statement().asSequence().map { it.toAst() }.toMutableList()
 
 
-private fun prog8Parser.StatementContext.toAst() : IStatement {
-    vardecl()?.let {
-        return VarDecl(VarDeclType.VAR,
-                it.datatype().toAst(),
-                it.ZEROPAGE() != null,
-                it.arrayindex()?.toAst(),
-                it.identifier().text,
-                null,
-                it.ARRAYSIG() != null || it.arrayindex() != null,
-                false,
-                it.toPosition())
-    }
+private fun prog8Parser.StatementContext.toAst() : Statement {
+    vardecl()?.let { return it.toAst() }
 
     varinitializer()?.let {
         val vd = it.vardecl()
-        return VarDecl(VarDeclType.VAR,
-                vd.datatype().toAst(),
-                vd.ZEROPAGE() != null,
+        return VarDecl(
+                VarDeclType.VAR,
+                vd.datatype()?.toAst() ?: DataType.STRUCT,
+                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
                 vd.arrayindex()?.toAst(),
-                vd.identifier().text,
+                vd.varname.text,
+                null,
                 it.expression().toAst(),
                 vd.ARRAYSIG() != null || vd.arrayindex() != null,
                 false,
-                it.toPosition())
+                it.toPosition()
+        )
+    }
+
+    structvarinitializer()?.let {
+        val vd = it.structvardecl()
+        return VarDecl(
+                VarDeclType.VAR,
+                DataType.STRUCT,
+                ZeropageWish.NOT_IN_ZEROPAGE,
+                null,
+                vd.varname.text,
+                vd.structname.text,
+                it.expression().toAst(),
+                isArray = false,
+                autogeneratedDontRemove = false,
+                position = it.toPosition()
+        )
+    }
+
+    structvardecl()?.let {
+        return VarDecl(
+                VarDeclType.VAR,
+                DataType.STRUCT,
+                ZeropageWish.NOT_IN_ZEROPAGE,
+                null,
+                it.varname.text,
+                it.structname.text,
+                null,
+                isArray = false,
+                autogeneratedDontRemove = false,
+                position = it.toPosition()
+        )
     }
 
     constdecl()?.let {
         val cvarinit = it.varinitializer()
         val vd = cvarinit.vardecl()
-        return VarDecl(VarDeclType.CONST,
-                vd.datatype().toAst(),
-                vd.ZEROPAGE() != null,
+        return VarDecl(
+                VarDeclType.CONST,
+                vd.datatype()?.toAst() ?: DataType.STRUCT,
+                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
                 vd.arrayindex()?.toAst(),
-                vd.identifier().text,
+                vd.varname.text,
+                null,
                 cvarinit.expression().toAst(),
                 vd.ARRAYSIG() != null || vd.arrayindex() != null,
                 false,
-                cvarinit.toPosition())
+                cvarinit.toPosition()
+        )
     }
 
     memoryvardecl()?.let {
         val mvarinit = it.varinitializer()
         val vd = mvarinit.vardecl()
-        return VarDecl(VarDeclType.MEMORY,
-                vd.datatype().toAst(),
-                vd.ZEROPAGE() != null,
+        return VarDecl(
+                VarDeclType.MEMORY,
+                vd.datatype()?.toAst() ?: DataType.STRUCT,
+                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
                 vd.arrayindex()?.toAst(),
-                vd.identifier().text,
+                vd.varname.text,
+                null,
                 mvarinit.expression().toAst(),
                 vd.ARRAYSIG() != null || vd.arrayindex() != null,
                 false,
-                mvarinit.toPosition())
+                mvarinit.toPosition()
+        )
     }
 
     assignment()?.let {
-        return Assignment(it.assign_targets().toAst(), null, it.expression().toAst(), it.toPosition())
+        return Assignment(it.assign_target().toAst(), null, it.expression().toAst(), it.toPosition())
     }
 
     augassignment()?.let {
-        return Assignment(listOf(it.assign_target().toAst()),
+        return Assignment(it.assign_target().toAst(),
                 it.operator.text,
                 it.expression().toAst(),
                 it.toPosition())
@@ -175,13 +205,16 @@ private fun prog8Parser.StatementContext.toAst() : IStatement {
     val whenstmt = whenstmt()?.toAst()
     if(whenstmt!=null) return whenstmt
 
+    structdecl()?.let {
+        return StructDecl(it.identifier().text,
+                it.vardecl().map { vd->vd.toAst() }.toMutableList(),
+                toPosition())
+    }
+
     throw FatalAstException("unprocessed source text (are we missing ast conversion rules for parser elements?): $text")
 }
 
-private fun prog8Parser.Assign_targetsContext.toAst(): List<AssignTarget> = assign_target().map { it.toAst() }
-
-
-private fun prog8Parser.AsmsubroutineContext.toAst(): IStatement {
+private fun prog8Parser.AsmsubroutineContext.toAst(): Statement {
     val name = identifier().text
     val address = asmsub_address()?.address?.toAst()?.number?.toInt()
     val params = asmsub_params()?.toAst() ?: emptyList()
@@ -218,15 +251,19 @@ private fun prog8Parser.Asmsub_returnsContext.toAst(): List<AsmSubroutineReturn>
 
 private fun prog8Parser.Asmsub_paramsContext.toAst(): List<AsmSubroutineParameter>
         = asmsub_param().map {
-    AsmSubroutineParameter(it.vardecl().identifier().text, it.vardecl().datatype().toAst(),
-            it.registerorpair()?.toAst(), it.statusregister()?.toAst(), !it.stack?.text.isNullOrEmpty(), toPosition())
+    val vardecl = it.vardecl()
+    val datatype = vardecl.datatype()?.toAst() ?: DataType.STRUCT
+    AsmSubroutineParameter(vardecl.varname.text, datatype,
+            it.registerorpair()?.toAst(),
+            it.statusregister()?.toAst(),
+            !it.stack?.text.isNullOrEmpty(), toPosition())
 }
 
 
 private fun prog8Parser.StatusregisterContext.toAst() = Statusflag.valueOf(text)
 
 
-private fun prog8Parser.Functioncall_stmtContext.toAst(): IStatement {
+private fun prog8Parser.Functioncall_stmtContext.toAst(): Statement {
     val location = scoped_identifier().toAst()
     return if(expression_list() == null)
         FunctionCallStatement(location, mutableListOf(), toPosition())
@@ -249,8 +286,7 @@ private fun prog8Parser.InlineasmContext.toAst() =
 
 
 private fun prog8Parser.ReturnstmtContext.toAst() : Return {
-    val values = expression_list()
-    return Return(values?.toAst() ?: emptyList(), toPosition())
+    return Return(expression()?.toAst(), toPosition())
 }
 
 private fun prog8Parser.UnconditionaljumpContext.toAst(): Jump {
@@ -260,7 +296,7 @@ private fun prog8Parser.UnconditionaljumpContext.toAst(): Jump {
 }
 
 
-private fun prog8Parser.LabeldefContext.toAst(): IStatement =
+private fun prog8Parser.LabeldefContext.toAst(): Statement =
         Label(children[0].text, toPosition())
 
 
@@ -285,7 +321,8 @@ private fun prog8Parser.Sub_return_partContext.toAst(): List<DataType> {
 
 private fun prog8Parser.Sub_paramsContext.toAst(): List<SubroutineParameter> =
         vardecl().map {
-            SubroutineParameter(it.identifier().text, it.datatype().toAst(), it.toPosition())
+            val datatype = it.datatype()?.toAst() ?: DataType.STRUCT
+            SubroutineParameter(it.varname.text, datatype, it.toPosition())
         }
 
 
@@ -372,39 +409,43 @@ private fun prog8Parser.IntegerliteralContext.toAst(): NumericLiteral {
 }
 
 
-private fun prog8Parser.ExpressionContext.toAst() : IExpression {
+private fun prog8Parser.ExpressionContext.toAst() : Expression {
 
     val litval = literalvalue()
     if(litval!=null) {
         val booleanlit = litval.booleanliteral()?.toAst()
         return if(booleanlit!=null) {
-            LiteralValue.fromBoolean(booleanlit, litval.toPosition())
+            NumericLiteralValue.fromBoolean(booleanlit, litval.toPosition())
         }
         else {
             val intLit = litval.integerliteral()?.toAst()
             when {
                 intLit!=null -> when(intLit.datatype) {
-                    DataType.UBYTE -> LiteralValue(DataType.UBYTE, bytevalue = intLit.number.toShort(), position = litval.toPosition())
-                    DataType.BYTE -> LiteralValue(DataType.BYTE, bytevalue = intLit.number.toShort(), position = litval.toPosition())
-                    DataType.UWORD -> LiteralValue(DataType.UWORD, wordvalue = intLit.number.toInt(), position = litval.toPosition())
-                    DataType.WORD -> LiteralValue(DataType.WORD, wordvalue = intLit.number.toInt(), position = litval.toPosition())
-                    DataType.FLOAT -> LiteralValue(DataType.FLOAT, floatvalue = intLit.number.toDouble(), position = litval.toPosition())
+                    DataType.UBYTE -> NumericLiteralValue(DataType.UBYTE, intLit.number.toShort(), litval.toPosition())
+                    DataType.BYTE -> NumericLiteralValue(DataType.BYTE, intLit.number.toShort(), litval.toPosition())
+                    DataType.UWORD -> NumericLiteralValue(DataType.UWORD, intLit.number.toInt(), litval.toPosition())
+                    DataType.WORD -> NumericLiteralValue(DataType.WORD, intLit.number.toInt(), litval.toPosition())
+                    DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, intLit.number.toDouble(), litval.toPosition())
                     else -> throw FatalAstException("invalid datatype for numeric literal")
                 }
-                litval.floatliteral()!=null -> LiteralValue(DataType.FLOAT, floatvalue = litval.floatliteral().toAst(), position = litval.toPosition())
-                litval.stringliteral()!=null -> LiteralValue(DataType.STR, strvalue = unescape(litval.stringliteral().text, litval.toPosition()), position = litval.toPosition())
+                litval.floatliteral()!=null -> NumericLiteralValue(DataType.FLOAT, litval.floatliteral().toAst(), litval.toPosition())
+                litval.stringliteral()!=null -> StringLiteralValue(DataType.STR, unescape(litval.stringliteral().text, litval.toPosition()), position = litval.toPosition())
                 litval.charliteral()!=null -> {
                     try {
-                        LiteralValue(DataType.UBYTE, bytevalue = Petscii.encodePetscii(unescape(litval.charliteral().text, litval.toPosition()), true)[0], position = litval.toPosition())
+                        NumericLiteralValue(DataType.UBYTE, Petscii.encodePetscii(unescape(litval.charliteral().text, litval.toPosition()), true)[0], litval.toPosition())
                     } catch (ce: CharConversionException) {
                         throw SyntaxError(ce.message ?: ce.toString(), litval.toPosition())
                     }
                 }
                 litval.arrayliteral()!=null -> {
-                    val array = litval.arrayliteral()?.toAst()
+                    val array = litval.arrayliteral().toAst()
                     // the actual type of the arraysize can not yet be determined here (missing namespace & heap)
-                    // the ConstantFolder takes care of that and converts the type if needed.
-                    LiteralValue(DataType.ARRAY_UB, arrayvalue = array, position = litval.toPosition())
+                    // the ConstantFold takes care of that and converts the type if needed.
+                    ArrayLiteralValue(DataType.ARRAY_UB, array, position = litval.toPosition())
+                }
+                litval.structliteral()!=null -> {
+                    val values = litval.structliteral().expression().map { it.toAst() }
+                    StructLiteralValue(values, litval.toPosition())
                 }
                 else -> throw FatalAstException("invalid parsed literal")
             }
@@ -427,7 +468,7 @@ private fun prog8Parser.ExpressionContext.toAst() : IExpression {
     if(funcall!=null) return funcall
 
     if (rangefrom!=null && rangeto!=null) {
-        val step = rangestep?.toAst() ?: LiteralValue(DataType.UBYTE, 1, position = toPosition())
+        val step = rangestep?.toAst() ?: NumericLiteralValue(DataType.UBYTE, 1, toPosition())
         return RangeExpr(rangefrom.toAst(), rangeto.toAst(), step, toPosition())
     }
 
@@ -478,10 +519,9 @@ private fun prog8Parser.BooleanliteralContext.toAst() = when(text) {
 }
 
 
-private fun prog8Parser.ArrayliteralContext.toAst() : Array<IExpression> =
+private fun prog8Parser.ArrayliteralContext.toAst() : Array<Expression> =
         expression().map { it.toAst() }.toTypedArray()
 
-
 private fun prog8Parser.If_stmtContext.toAst(): IfStatement {
     val condition = expression().toAst()
     val trueStatements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
@@ -492,7 +532,7 @@ private fun prog8Parser.If_stmtContext.toAst(): IfStatement {
     return IfStatement(condition, trueScope, elseScope, toPosition())
 }
 
-private fun prog8Parser.Else_partContext.toAst(): MutableList<IStatement> {
+private fun prog8Parser.Else_partContext.toAst(): MutableList<Statement> {
     return statement_block()?.toAst() ?: mutableListOf(statement().toAst())
 }
 
@@ -513,7 +553,7 @@ private fun prog8Parser.BranchconditionContext.toAst() = BranchCondition.valueOf
 private fun prog8Parser.ForloopContext.toAst(): ForLoop {
     val loopregister = register()?.toAst()
     val datatype = datatype()?.toAst()
-    val zeropage = ZEROPAGE()!=null
+    val zeropage = if(ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE
     val loopvar = identifier()?.toAst()
     val iterable = expression()!!.toAst()
     val scope =
@@ -554,13 +594,28 @@ private fun prog8Parser.WhenstmtContext.toAst(): WhenStatement {
 }
 
 private fun prog8Parser.When_choiceContext.toAst(): WhenChoice {
-    val value = expression()?.toAst()
+    val values = expression_list()?.toAst()
     val stmt = statement()?.toAst()
-    val stmt_block = statement_block()?.toAst()?.toMutableList() ?: mutableListOf()
+    val stmtBlock = statement_block()?.toAst()?.toMutableList() ?: mutableListOf()
     if(stmt!=null)
-        stmt_block.add(stmt)
-    val scope = AnonymousScope(stmt_block, toPosition())
-    return WhenChoice(value, scope, toPosition())
+        stmtBlock.add(stmt)
+    val scope = AnonymousScope(stmtBlock, toPosition())
+    return WhenChoice(values, scope, toPosition())
+}
+
+private fun prog8Parser.VardeclContext.toAst(): VarDecl {
+    return VarDecl(
+            VarDeclType.VAR,
+            datatype()?.toAst() ?: DataType.STRUCT,
+            if(ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+            arrayindex()?.toAst(),
+            varname.text,
+            null,
+            null,
+            ARRAYSIG() != null || arrayindex() != null,
+            false,
+            toPosition()
+    )
 }
 
 internal fun escape(str: String) = str.replace("\t", "\\t").replace("\n", "\\n").replace("\r", "\\r")
@@ -588,3 +643,4 @@ internal fun unescape(str: String, position: Position): String {
     }
     return result.joinToString("")
 }
+

compiler/src/prog8/ast/base/Base.kt

@@ -1,22 +1,24 @@
 package prog8.ast.base
 
 import prog8.ast.Node
+import prog8.compiler.target.c64.MachineDefinition
 
 /**************************** AST Data classes ****************************/
 
 enum class DataType {
-    UBYTE,
-    BYTE,
-    UWORD,
-    WORD,
-    FLOAT,
-    STR,
-    STR_S,
-    ARRAY_UB,
-    ARRAY_B,
-    ARRAY_UW,
-    ARRAY_W,
-    ARRAY_F;
+    UBYTE,              // pass by value
+    BYTE,               // pass by value
+    UWORD,              // pass by value
+    WORD,               // pass by value
+    FLOAT,              // pass by value
+    STR,                // pass by reference
+    STR_S,              // pass by reference
+    ARRAY_UB,           // pass by reference
+    ARRAY_B,            // pass by reference
+    ARRAY_UW,           // pass by reference
+    ARRAY_W,            // pass by reference
+    ARRAY_F,            // pass by reference
+    STRUCT;             // pass by reference
 
     /**
      * is the type assignable to the given other type?
@@ -24,26 +26,43 @@ enum class DataType {
     infix fun isAssignableTo(targetType: DataType) =
             // what types are assignable to others without loss of precision?
             when(this) {
-                UBYTE -> targetType == UBYTE || targetType == UWORD || targetType==WORD || targetType == FLOAT
-                BYTE -> targetType == BYTE || targetType == UBYTE || targetType == UWORD || targetType==WORD || targetType == FLOAT
-                UWORD -> targetType == UWORD || targetType == FLOAT
-                WORD -> targetType == WORD || targetType==UWORD || targetType == FLOAT
+                UBYTE -> targetType in setOf(UBYTE, WORD, UWORD, FLOAT)
+                BYTE -> targetType in setOf(BYTE, WORD, FLOAT)
+                UWORD -> targetType in setOf(UWORD, FLOAT)
+                WORD -> targetType in setOf(WORD, FLOAT)
                 FLOAT -> targetType == FLOAT
                 STR -> targetType == STR || targetType==STR_S
                 STR_S -> targetType == STR || targetType==STR_S
-                in ArrayDatatypes -> targetType === this
+                in ArrayDatatypes -> targetType == this
                 else -> false
             }
 
 
     infix fun isAssignableTo(targetTypes: Set<DataType>) = targetTypes.any { this isAssignableTo it }
 
-    infix fun biggerThan(other: DataType) =
+    infix fun largerThan(other: DataType) =
             when(this) {
                 in ByteDatatypes -> false
                 in WordDatatypes -> other in ByteDatatypes
                 else -> true
             }
+
+    infix fun equalsSize(other: DataType) =
+            when(this) {
+                in ByteDatatypes -> other in ByteDatatypes
+                in WordDatatypes -> other in WordDatatypes
+                else -> false
+            }
+
+    fun memorySize(): Int {
+        return when(this) {
+            in ByteDatatypes -> 1
+            in WordDatatypes -> 2
+            FLOAT -> MachineDefinition.Mflpt5.MemorySize
+            in PassByReferenceDatatypes -> 2
+            else -> -9999999
+        }
+    }
 }
 
 enum class Register {
@@ -89,18 +108,22 @@ enum class VarDeclType {
     MEMORY
 }
 
-val IterableDatatypes = setOf(
-        DataType.STR, DataType.STR_S,
-        DataType.ARRAY_UB, DataType.ARRAY_B,
-        DataType.ARRAY_UW, DataType.ARRAY_W,
-        DataType.ARRAY_F)
 val ByteDatatypes = setOf(DataType.UBYTE, DataType.BYTE)
 val WordDatatypes = setOf(DataType.UWORD, DataType.WORD)
 val IntegerDatatypes = setOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD)
 val NumericDatatypes = setOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.FLOAT)
 val StringDatatypes = setOf(DataType.STR, DataType.STR_S)
 val ArrayDatatypes = setOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W, DataType.ARRAY_F)
+val IterableDatatypes = setOf(
+        DataType.STR, DataType.STR_S,
+        DataType.ARRAY_UB, DataType.ARRAY_B,
+        DataType.ARRAY_UW, DataType.ARRAY_W,
+        DataType.ARRAY_F)
+val PassByValueDatatypes = NumericDatatypes
+val PassByReferenceDatatypes = IterableDatatypes.plus(DataType.STRUCT)
 val ArrayElementTypes = mapOf(
+        DataType.STR to DataType.UBYTE,
+        DataType.STR_S to DataType.UBYTE,
         DataType.ARRAY_B to DataType.BYTE,
         DataType.ARRAY_UB to DataType.UBYTE,
         DataType.ARRAY_W to DataType.WORD,

compiler/src/prog8/ast/base/Errors.kt

@@ -10,13 +10,13 @@ class SyntaxError(override var message: String, val position: Position) : AstExc
     override fun toString() = "$position Syntax error: $message"
 }
 
-class NameError(override var message: String, val position: Position) : AstException(message) {
+open class NameError(override var message: String, val position: Position) : AstException(message) {
     override fun toString() = "$position Name error: $message"
 }
 
-open class ExpressionError(message: String, val position: Position) : AstException(message) {
+class ExpressionError(message: String, val position: Position) : AstException(message) {
     override fun toString() = "$position Error: $message"
 }
 
 class UndefinedSymbolError(symbol: IdentifierReference)
-    : ExpressionError("undefined symbol: ${symbol.nameInSource.joinToString(".")}", symbol.position)
+    : NameError("undefined symbol: ${symbol.nameInSource.joinToString(".")}", symbol.position)

compiler/src/prog8/ast/base/Extensions.kt

@@ -1,19 +1,21 @@
 package prog8.ast.base
 
-import prog8.ast.*
-import prog8.ast.expressions.IdentifierReference
+import prog8.ast.Module
+import prog8.ast.Program
 import prog8.ast.processing.*
-import prog8.ast.statements.Assignment
-import prog8.ast.statements.ForLoop
 import prog8.compiler.CompilationOptions
+import prog8.compiler.target.c64.codegen.AnonymousScopeVarsCleanup
+import prog8.optimizer.FlattenAnonymousScopesAndRemoveNops
 
 
 // the name of the subroutine that should be called for every block to initialize its variables
 internal const val initvarsSubName="prog8_init_vars"
 
 
-// prefix for literal values that are turned into a variable on the heap
-internal const val autoHeapValuePrefix = "auto_heap_value_"
+internal fun Program.removeNopsFlattenAnonScopes() {
+    val flattener = FlattenAnonymousScopesAndRemoveNops()
+    flattener.visit(this)
+}
 
 
 internal fun Program.checkValid(compilerOptions: CompilationOptions) {
@@ -23,14 +25,26 @@ internal fun Program.checkValid(compilerOptions: CompilationOptions) {
 }
 
 
+internal fun Program.anonscopeVarsCleanup() {
+    val mover = AnonymousScopeVarsCleanup(this)
+    mover.visit(this)
+    printErrors(mover.result(), name)
+}
+
+
 internal fun Program.reorderStatements() {
-    val initvalueCreator = VarInitValueAndAddressOfCreator(namespace)
+    val initvalueCreator = VarInitValueAndAddressOfCreator(this)
     initvalueCreator.visit(this)
 
     val checker = StatementReorderer(this)
     checker.visit(this)
 }
 
+internal fun Program.addTypecasts() {
+    val caster = TypecastsAdder(this)
+    caster.visit(this)
+}
+
 internal fun Module.checkImportedValid() {
     val checker = ImportedModuleDirectiveRemover()
     checker.visit(this)
@@ -45,40 +59,12 @@ internal fun Program.checkRecursion() {
 
 
 internal fun Program.checkIdentifiers() {
-    val checker = AstIdentifiersChecker(namespace)
+    val checker = AstIdentifiersChecker(this)
     checker.visit(this)
 
     if(modules.map {it.name}.toSet().size != modules.size) {
         throw FatalAstException("modules should all be unique")
     }
 
-    // add any anonymous variables for heap values that are used,
-    // and replace an iterable literalvalue by identifierref to new local variable
-    for (variable in checker.anonymousVariablesFromHeap.values) {
-        val scope = variable.first.definingScope()
-        scope.statements.add(variable.second)
-        val parent = variable.first.parent
-        when {
-            parent is Assignment && parent.value === variable.first -> {
-                val idref = IdentifierReference(listOf("$autoHeapValuePrefix${variable.first.heapId}"), variable.first.position)
-                idref.linkParents(parent)
-                parent.value = idref
-            }
-            parent is IFunctionCall -> {
-                val parameterPos = parent.arglist.indexOf(variable.first)
-                val idref = IdentifierReference(listOf("$autoHeapValuePrefix${variable.first.heapId}"), variable.first.position)
-                idref.linkParents(parent)
-                parent.arglist[parameterPos] = idref
-            }
-            parent is ForLoop -> {
-                val idref = IdentifierReference(listOf("$autoHeapValuePrefix${variable.first.heapId}"), variable.first.position)
-                idref.linkParents(parent)
-                parent.iterable = idref
-            }
-            else -> TODO("replace literalvalue by identifierref: $variable  (in $parent)")
-        }
-        variable.second.linkParents(scope as Node)
-    }
-
     printErrors(checker.result(), name)
 }

compiler/src/prog8/ast/expressions/InferredTypes.kt

@@ -0,0 +1,50 @@
+package prog8.ast.expressions
+
+import prog8.ast.base.DataType
+
+object InferredTypes {
+    class InferredType private constructor(val isUnknown: Boolean, val isVoid: Boolean, private var datatype: DataType?) {
+        init {
+            if(datatype!=null && (isUnknown || isVoid))
+                throw IllegalArgumentException("invalid combination of args")
+        }
+
+        val isKnown = datatype!=null
+        fun typeOrElse(alternative: DataType) = if(isUnknown || isVoid) alternative else datatype!!
+        infix fun istype(type: DataType): Boolean = if(isUnknown || isVoid) false else this.datatype==type
+
+        companion object {
+            fun unknown() = InferredType(isUnknown = true, isVoid = false, datatype = null)
+            fun void() = InferredType(isUnknown = false, isVoid = true, datatype = null)
+            fun known(type: DataType) = InferredType(isUnknown = false, isVoid = false, datatype = type)
+        }
+
+        override fun equals(other: Any?): Boolean {
+            if(other !is InferredType)
+                return false
+            return isVoid==other.isVoid && datatype==other.datatype
+        }
+    }
+
+    private val unknownInstance = InferredType.unknown()
+    private val voidInstance = InferredType.void()
+    private val knownInstances = mapOf(
+            DataType.UBYTE to InferredType.known(DataType.UBYTE),
+            DataType.BYTE to InferredType.known(DataType.BYTE),
+            DataType.UWORD to InferredType.known(DataType.UWORD),
+            DataType.WORD to InferredType.known(DataType.WORD),
+            DataType.FLOAT to InferredType.known(DataType.FLOAT),
+            DataType.STR to InferredType.known(DataType.STR),
+            DataType.STR_S to InferredType.known(DataType.STR_S),
+            DataType.ARRAY_UB to InferredType.known(DataType.ARRAY_UB),
+            DataType.ARRAY_B to InferredType.known(DataType.ARRAY_B),
+            DataType.ARRAY_UW to InferredType.known(DataType.ARRAY_UW),
+            DataType.ARRAY_W to InferredType.known(DataType.ARRAY_W),
+            DataType.ARRAY_F to InferredType.known(DataType.ARRAY_F),
+            DataType.STRUCT to InferredType.known(DataType.STRUCT)
+    )
+
+    fun void() = voidInstance
+    fun unknown() = unknownInstance
+    fun knownFor(type: DataType) = knownInstances.getValue(type)
+}

compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt

@@ -1,32 +1,44 @@
 package prog8.ast.processing
 
-import prog8.ast.*
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
 import prog8.ast.base.*
-import prog8.ast.base.autoHeapValuePrefix
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
+import prog8.compiler.HeapValues
+import prog8.compiler.target.c64.AssemblyProgram
 import prog8.functions.BuiltinFunctions
 
 
-internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstModifyingVisitor {
+internal class AstIdentifiersChecker(private val program: Program) : IAstModifyingVisitor {
+
     private val checkResult: MutableList<AstException> = mutableListOf()
 
-    private var blocks: MutableMap<String, Block> = mutableMapOf()
+    private var blocks = mutableMapOf<String, Block>()
+    private val vardeclsToAdd = mutableMapOf<INameScope, MutableList<VarDecl>>()
 
     internal fun result(): List<AstException> {
         return checkResult
     }
 
-    private fun nameError(name: String, position: Position, existing: IStatement) {
+    private fun nameError(name: String, position: Position, existing: Statement) {
         checkResult.add(NameError("name conflict '$name', also defined in ${existing.position.file} line ${existing.position.line}", position))
     }
 
     override fun visit(module: Module) {
+        vardeclsToAdd.clear()
         blocks.clear()  // blocks may be redefined within a different module
         super.visit(module)
+        // add any new vardecls to the various scopes
+        for((where, decls) in vardeclsToAdd) {
+            where.statements.addAll(0, decls)
+            decls.forEach { it.linkParents(where as Node) }
+        }
     }
 
-    override fun visit(block: Block): IStatement {
+    override fun visit(block: Block): Statement {
         val existing = blocks[block.name]
         if(existing!=null)
             nameError(block.name, block.position, existing)
@@ -36,7 +48,7 @@ internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstMo
         return super.visit(block)
     }
 
-    override fun visit(functionCall: FunctionCall): IExpression {
+    override fun visit(functionCall: FunctionCall): Expression {
         if(functionCall.target.nameInSource.size==1 && functionCall.target.nameInSource[0]=="lsb") {
             // lsb(...) is just an alias for type cast to ubyte, so replace with "... as ubyte"
             val typecast = TypecastExpression(functionCall.arglist.single(), DataType.UBYTE, false, functionCall.position)
@@ -46,7 +58,7 @@ internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstMo
         return super.visit(functionCall)
     }
 
-    override fun visit(decl: VarDecl): IStatement {
+    override fun visit(decl: VarDecl): Statement {
         // first, check if there are datatype errors on the vardecl
         decl.datatypeErrors.forEach { checkResult.add(it) }
 
@@ -55,25 +67,65 @@ internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstMo
             // the builtin functions can't be redefined
             checkResult.add(NameError("builtin function cannot be redefined", decl.position))
 
-        val existing = namespace.lookup(listOf(decl.name), decl)
+        if(decl.name in AssemblyProgram.opcodeNames)
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol", decl.position))
+
+        // is it a struct variable? then define all its struct members as mangled names,
+        //    and include the original decl as well.
+        if(decl.datatype==DataType.STRUCT) {
+            if(decl.structHasBeenFlattened)
+                return super.visit(decl)    // don't do this multiple times
+
+            if(decl.struct==null) {
+                checkResult.add(NameError("undefined struct type", decl.position))
+                return super.visit(decl)
+            }
+
+            if(decl.struct!!.statements.any { (it as VarDecl).datatype !in NumericDatatypes})
+                return super.visit(decl)     // a non-numeric member, not supported. proper error is given by AstChecker later
+
+            if(decl.value is NumericLiteralValue) {
+                checkResult.add(ExpressionError("you cannot initialize a struct using a single value", decl.position))
+                return super.visit(decl)
+            }
+
+            val decls = decl.flattenStructMembers()
+            decls.add(decl)
+            val result = AnonymousScope(decls, decl.position)
+            result.linkParents(decl.parent)
+            return result
+        }
+
+        val existing = program.namespace.lookup(listOf(decl.name), decl)
         if (existing != null && existing !== decl)
             nameError(decl.name, decl.position, existing)
 
         return super.visit(decl)
     }
 
-    override fun visit(subroutine: Subroutine): IStatement {
-        if(subroutine.name in BuiltinFunctions) {
+    override fun visit(subroutine: Subroutine): Statement {
+        if(subroutine.name in AssemblyProgram.opcodeNames) {
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol", subroutine.position))
+        } else if(subroutine.name in BuiltinFunctions) {
             // the builtin functions can't be redefined
             checkResult.add(NameError("builtin function cannot be redefined", subroutine.position))
         } else {
-            if (subroutine.parameters.any { it.name in BuiltinFunctions })
-                checkResult.add(NameError("builtin function name cannot be used as parameter", subroutine.position))
+            // already reported elsewhere:
+            // if (subroutine.parameters.any { it.name in BuiltinFunctions })
+            //    checkResult.add(NameError("builtin function name cannot be used as parameter", subroutine.position))
 
-            val existing = namespace.lookup(listOf(subroutine.name), subroutine)
+            val existing = program.namespace.lookup(listOf(subroutine.name), subroutine)
             if (existing != null && existing !== subroutine)
                 nameError(subroutine.name, subroutine.position, existing)
 
+            // does the parameter redefine a variable declared elsewhere?
+            for(param in subroutine.parameters) {
+                val existingVar = subroutine.lookup(listOf(param.name), subroutine)
+                if (existingVar != null && existingVar.parent !== subroutine) {
+                    nameError(param.name, param.position, existingVar)
+                }
+            }
+
             // check that there are no local variables, labels, or other subs that redefine the subroutine's parameters
             val symbolsInSub = subroutine.allDefinedSymbols()
             val namesInSub = symbolsInSub.map{ it.first }.toSet()
@@ -92,36 +144,42 @@ internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstMo
             // NOTE:
             // - numeric types BYTE and WORD and FLOAT are passed by value;
             // - strings, arrays, matrices are passed by reference (their 16-bit address is passed as an uword parameter)
-            // - do NOT do this is the statement can be transformed into an asm subroutine later!
-            if(subroutine.asmAddress==null && !subroutine.canBeAsmSubroutine) {
+            if(subroutine.asmAddress==null) {
                 if(subroutine.asmParameterRegisters.isEmpty()) {
                     subroutine.parameters
                             .filter { it.name !in namesInSub }
                             .forEach {
-                                val vardecl = VarDecl(VarDeclType.VAR, it.type, false, null, it.name, null,
-                                        isArray = false, autoGenerated = true, position = subroutine.position)
+                                val vardecl = VarDecl(VarDeclType.VAR, it.type, ZeropageWish.NOT_IN_ZEROPAGE, null, it.name, null, null,
+                                        isArray = false, autogeneratedDontRemove = true, position = subroutine.position)
                                 vardecl.linkParents(subroutine)
                                 subroutine.statements.add(0, vardecl)
                             }
                 }
             }
+
+            if(subroutine.isAsmSubroutine && subroutine.statements.any{it !is InlineAssembly}) {
+                checkResult.add(SyntaxError("asmsub can only contain inline assembly (%asm)", subroutine.position))
+            }
         }
         return super.visit(subroutine)
     }
 
-    override fun visit(label: Label): IStatement {
+    override fun visit(label: Label): Statement {
+        if(label.name in AssemblyProgram.opcodeNames)
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol", label.position))
+
         if(label.name in BuiltinFunctions) {
             // the builtin functions can't be redefined
             checkResult.add(NameError("builtin function cannot be redefined", label.position))
         } else {
-            val existing = namespace.lookup(listOf(label.name), label)
+            val existing = program.namespace.lookup(listOf(label.name), label)
             if (existing != null && existing !== label)
                 nameError(label.name, label.position, existing)
         }
         return super.visit(label)
     }
 
-    override fun visit(forLoop: ForLoop): IStatement {
+    override fun visit(forLoop: ForLoop): Statement {
         // If the for loop has a decltype, it means to declare the loopvar inside the loop body
         // rather than reusing an already declared loopvar from an outer scope.
         // For loops that loop over an interable variable (instead of a range of numbers) get an
@@ -131,30 +189,36 @@ internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstMo
                 checkResult.add(SyntaxError("register loop variables have a fixed implicit datatype", forLoop.position))
             if(forLoop.loopRegister == Register.X)
                 printWarning("writing to the X register is dangerous, because it's used as an internal pointer", forLoop.position)
-        } else if(forLoop.loopVar!=null) {
-            val varName = forLoop.loopVar.nameInSource.last()
-            if(forLoop.decltype!=null) {
-                val existing = if(forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(forLoop.loopVar.nameInSource, forLoop.body.statements.first())
-                if(existing==null) {
-                    // create the local scoped for loop variable itself
-                    val vardecl = VarDecl(VarDeclType.VAR, forLoop.decltype, forLoop.zeropage, null, varName, null,
-                            isArray = false, autoGenerated = true, position = forLoop.loopVar.position)
-                    vardecl.linkParents(forLoop.body)
-                    forLoop.body.statements.add(0, vardecl)
-                    forLoop.loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
+        } else {
+            val loopVar = forLoop.loopVar
+            if (loopVar != null) {
+                val varName = loopVar.nameInSource.last()
+                if (forLoop.decltype != null) {
+                    val existing = if (forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(loopVar.nameInSource, forLoop.body.statements.first())
+                    if (existing == null) {
+                        // create the local scoped for loop variable itself
+                        val vardecl = VarDecl(VarDeclType.VAR, forLoop.decltype, forLoop.zeropage, null, varName, null, null,
+                                isArray = false, autogeneratedDontRemove = true, position = loopVar.position)
+                        vardecl.linkParents(forLoop.body)
+                        forLoop.body.statements.add(0, vardecl)
+                        loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
+                    } else if(existing.parent!==forLoop && existing.parent.parent!==forLoop) {
+                        checkResult.add(NameError("for loop var was already defined at ${existing.position}", loopVar.position))
+                    }
                 }
 
-            }
-
-            if(forLoop.iterable !is RangeExpr) {
-                val existing = if(forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(listOf(ForLoop.iteratorLoopcounterVarname), forLoop.body.statements.first())
-                if(existing==null) {
-                    // create loop iteration counter variable (without value, to avoid an assignment)
-                    val vardecl = VarDecl(VarDeclType.VAR, DataType.UBYTE, true, null, ForLoop.iteratorLoopcounterVarname, null,
-                            isArray = false, autoGenerated = true, position = forLoop.loopVar.position)
-                    vardecl.linkParents(forLoop.body)
-                    forLoop.body.statements.add(0, vardecl)
-                    forLoop.loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
+                val validName = forLoop.body.name.replace("<", "").replace(">", "").replace("-", "")
+                val loopvarName = "prog8_loopvar_$validName"
+                if (forLoop.iterable !is RangeExpr) {
+                    val existing = if (forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(listOf(loopvarName), forLoop.body.statements.first())
+                    if (existing == null) {
+                        // create loop iteration counter variable (without value, to avoid an assignment)
+                        val vardecl = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.PREFER_ZEROPAGE, null, loopvarName, null, null,
+                                isArray = false, autogeneratedDontRemove = true, position = loopVar.position)
+                        vardecl.linkParents(forLoop.body)
+                        forLoop.body.statements.add(0, vardecl)
+                        loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
+                    }
                 }
             }
         }
@@ -167,50 +231,179 @@ internal class AstIdentifiersChecker(private val namespace: INameScope) : IAstMo
         return super.visit(assignTarget)
     }
 
-    override fun visit(returnStmt: Return): IStatement {
-        if(returnStmt.values.isNotEmpty()) {
+    override fun visit(returnStmt: Return): Statement {
+        if(returnStmt.value!=null) {
             // possibly adjust any literal values returned, into the desired returning data type
             val subroutine = returnStmt.definingSubroutine()!!
-            if(subroutine.returntypes.size!=returnStmt.values.size)
+            if(subroutine.returntypes.size!=1)
                 return returnStmt  // mismatch in number of return values, error will be printed later.
-            val newValues = mutableListOf<IExpression>()
-            for(returnvalue in returnStmt.values.zip(subroutine.returntypes)) {
-                val lval = returnvalue.first as? LiteralValue
-                if(lval!=null) {
-                    val adjusted = lval.cast(returnvalue.second)
-                    if(adjusted!=null && adjusted !== lval)
-                        newValues.add(adjusted)
-                    else
-                        newValues.add(lval)
-                }
-                else
-                    newValues.add(returnvalue.first)
+            val newValue: Expression
+            val lval = returnStmt.value as? NumericLiteralValue
+            if(lval!=null) {
+                newValue = lval.cast(subroutine.returntypes.single())
+            } else {
+                newValue = returnStmt.value!!
             }
-            returnStmt.values = newValues
+
+            returnStmt.value = newValue
         }
         return super.visit(returnStmt)
     }
 
-
-    internal val anonymousVariablesFromHeap = mutableMapOf<String, Pair<LiteralValue, VarDecl>>()
-
-
-    override fun visit(literalValue: LiteralValue): LiteralValue {
-        if(literalValue.heapId!=null && literalValue.parent !is VarDecl) {
-            // a literal value that's not declared as a variable, which refers to something on the heap.
-            // we need to introduce an auto-generated variable for this to be able to refer to the value!
-            val variable = VarDecl(VarDeclType.VAR, literalValue.type, false, null, "$autoHeapValuePrefix${literalValue.heapId}", literalValue,
-                    isArray = false, autoGenerated = false, position = literalValue.position)
-            anonymousVariablesFromHeap[variable.name] = Pair(literalValue, variable)
+    override fun visit(arrayLiteral: ArrayLiteralValue): Expression {
+        val array = super.visit(arrayLiteral)
+        if(array is ArrayLiteralValue) {
+            val vardecl = array.parent as? VarDecl
+            return if (vardecl!=null) {
+                fixupArrayDatatype(array, vardecl, program.heap)
+            } else {
+                // fix the datatype of the array (also on the heap) to the 'biggest' datatype in the array
+                // (we don't know the desired datatype here exactly so we guess)
+                val datatype = determineArrayDt(array.value)
+                val litval2 = array.cast(datatype)!!
+                litval2.parent = array.parent
+                // finally, replace the literal array by a identifier reference.
+                makeIdentifierFromRefLv(litval2)
+            }
         }
-        return super.visit(literalValue)
+        return array
     }
 
-    override fun visit(addressOf: AddressOf): IExpression {
-        // register the scoped name of the referenced identifier
-        val variable= addressOf.identifier.targetVarDecl(namespace) ?: return addressOf
-        addressOf.scopedname = variable.scopedname
-        return super.visit(addressOf)
+    override fun visit(stringLiteral: StringLiteralValue): Expression {
+        val string = super.visit(stringLiteral)
+        if(string is StringLiteralValue) {
+            val vardecl = string.parent as? VarDecl
+            // intern the string; move it into the heap
+            if (string.value.length !in 1..255)
+                checkResult.add(ExpressionError("string literal length must be between 1 and 255", string.position))
+            else {
+                string.addToHeap(program.heap)
+            }
+            return if (vardecl != null)
+                string
+            else
+                makeIdentifierFromRefLv(string)  // replace the literal string by a identifier reference.
+        }
+        return string
+    }
+
+    private fun determineArrayDt(array: Array<Expression>): DataType {
+        val datatypesInArray = array.map { it.inferType(program) }
+        if(datatypesInArray.isEmpty() || datatypesInArray.any { !it.isKnown })
+            throw IllegalArgumentException("can't determine type of empty array")
+        val dts = datatypesInArray.map { it.typeOrElse(DataType.STRUCT) }
+        return when {
+            DataType.FLOAT in dts -> DataType.ARRAY_F
+            DataType.WORD in dts -> DataType.ARRAY_W
+            DataType.UWORD in dts -> DataType.ARRAY_UW
+            DataType.BYTE in dts -> DataType.ARRAY_B
+            DataType.UBYTE in dts -> DataType.ARRAY_UB
+            else -> throw IllegalArgumentException("can't determine type of array")
+        }
+    }
+
+    private fun makeIdentifierFromRefLv(array: ArrayLiteralValue): IdentifierReference {
+        // a referencetype literal value that's not declared as a variable
+        // we need to introduce an auto-generated variable for this to be able to refer to the value
+        // note: if the var references the same literal value, it is not yet de-duplicated here.
+        array.addToHeap(program.heap)
+        val scope = array.definingScope()
+        val variable = VarDecl.createAuto(array)
+        return replaceWithIdentifier(variable, scope, array.parent)
+    }
+
+    private fun makeIdentifierFromRefLv(string: StringLiteralValue): IdentifierReference {
+        // a referencetype literal value that's not declared as a variable
+        // we need to introduce an auto-generated variable for this to be able to refer to the value
+        // note: if the var references the same literal value, it is not yet de-duplicated here.
+        string.addToHeap(program.heap)
+        val scope = string.definingScope()
+        val variable = VarDecl.createAuto(string)
+        return replaceWithIdentifier(variable, scope, string.parent)
+    }
+
+    private fun replaceWithIdentifier(variable: VarDecl, scope: INameScope, parent: Node): IdentifierReference {
+        val variable1 = addVarDecl(scope, variable)
+        // replace the reference literal by a identifier reference
+        val identifier = IdentifierReference(listOf(variable1.name), variable1.position)
+        identifier.parent = parent
+        return identifier
+    }
+
+    override fun visit(structDecl: StructDecl): Statement {
+        for(member in structDecl.statements){
+            val decl = member as? VarDecl
+            if(decl!=null && decl.datatype !in NumericDatatypes)
+                checkResult.add(SyntaxError("structs can only contain numerical types", decl.position))
+        }
+
+        return super.visit(structDecl)
+    }
+
+    override fun visit(expr: BinaryExpression): Expression {
+        return when {
+            expr.left is StringLiteralValue ->
+                processBinaryExprWithString(expr.left as StringLiteralValue, expr.right, expr)
+            expr.right is StringLiteralValue ->
+                processBinaryExprWithString(expr.right as StringLiteralValue, expr.left, expr)
+            else -> super.visit(expr)
+        }
+    }
+
+    private fun processBinaryExprWithString(string: StringLiteralValue, operand: Expression, expr: BinaryExpression): Expression {
+        val constvalue = operand.constValue(program)
+        if(constvalue!=null) {
+            if (expr.operator == "*") {
+                // repeat a string a number of times
+                val idt = string.inferType(program)
+                return StringLiteralValue(idt.typeOrElse(DataType.STR),
+                        string.value.repeat(constvalue.number.toInt()), null, expr.position)
+            }
+        }
+        if(expr.operator == "+" && operand is StringLiteralValue) {
+            // concatenate two strings
+            val idt = string.inferType(program)
+            return StringLiteralValue(idt.typeOrElse(DataType.STR),
+                    "${string.value}${operand.value}", null, expr.position)
+        }
+        return expr
+    }
+
+    private fun addVarDecl(scope: INameScope, variable: VarDecl): VarDecl {
+        if(scope !in vardeclsToAdd)
+            vardeclsToAdd[scope] = mutableListOf()
+        val declList = vardeclsToAdd.getValue(scope)
+        val existing = declList.singleOrNull { it.name==variable.name }
+        return if(existing!=null) {
+            existing
+        } else {
+            declList.add(variable)
+            variable
+        }
     }
 
 }
+
+internal fun fixupArrayDatatype(array: ArrayLiteralValue, vardecl: VarDecl, heap: HeapValues): ArrayLiteralValue {
+    if(array.heapId!=null) {
+        val arrayDt = array.type
+        if(arrayDt!=vardecl.datatype) {
+            // fix the datatype of the array (also on the heap) to match the vardecl
+            val litval2 =
+                    try {
+                        array.cast(vardecl.datatype)!!
+                    } catch(x: ExpressionError) {
+                        // couldn't cast permanently.
+                        // instead, simply adjust the array type and trust the AstChecker to report the exact error
+                        ArrayLiteralValue(vardecl.datatype, array.value, array.heapId, array.position)
+                    }
+            vardecl.value = litval2
+            litval2.linkParents(vardecl)
+            litval2.addToHeap(heap)
+            return litval2
+        }
+    } else {
+        array.addToHeap(heap)
+    }
+    return array
+}

compiler/src/prog8/ast/processing/AstRecursionChecker.kt

@@ -1,6 +1,6 @@
 package prog8.ast.processing
 
-import prog8.ast.*
+import prog8.ast.INameScope
 import prog8.ast.base.AstException
 import prog8.ast.expressions.FunctionCall
 import prog8.ast.statements.FunctionCallStatement

compiler/src/prog8/ast/processing/IAstModifyingVisitor.kt

@@ -1,6 +1,8 @@
 package prog8.ast.processing
 
-import prog8.ast.*
+import prog8.ast.Module
+import prog8.ast.Program
+import prog8.ast.base.FatalAstException
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
 
@@ -10,63 +12,67 @@ interface IAstModifyingVisitor {
     }
 
     fun visit(module: Module) {
-        module.statements = module.statements.asSequence().map { it.accept(this) }.toMutableList()
+        module.statements = module.statements.map { it.accept(this) }.toMutableList()
     }
 
-    fun visit(expr: PrefixExpression): IExpression {
+    fun visit(expr: PrefixExpression): Expression {
         expr.expression = expr.expression.accept(this)
         return expr
     }
 
-    fun visit(expr: BinaryExpression): IExpression {
+    fun visit(expr: BinaryExpression): Expression {
         expr.left = expr.left.accept(this)
         expr.right = expr.right.accept(this)
         return expr
     }
 
-    fun visit(directive: Directive): IStatement {
+    fun visit(directive: Directive): Statement {
         return directive
     }
 
-    fun visit(block: Block): IStatement {
-        block.statements = block.statements.asSequence().map { it.accept(this) }.toMutableList()
+    fun visit(block: Block): Statement {
+        block.statements = block.statements.map { it.accept(this) }.toMutableList()
         return block
     }
 
-    fun visit(decl: VarDecl): IStatement {
+    fun visit(decl: VarDecl): Statement {
         decl.value = decl.value?.accept(this)
         decl.arraysize?.accept(this)
         return decl
     }
 
-    fun visit(subroutine: Subroutine): IStatement {
-        subroutine.statements = subroutine.statements.asSequence().map { it.accept(this) }.toMutableList()
+    fun visit(subroutine: Subroutine): Statement {
+        subroutine.statements = subroutine.statements.map { it.accept(this) }.toMutableList()
         return subroutine
     }
 
-    fun visit(functionCall: FunctionCall): IExpression {
+    fun visit(functionCall: FunctionCall): Expression {
         val newtarget = functionCall.target.accept(this)
         if(newtarget is IdentifierReference)
             functionCall.target = newtarget
+        else
+            throw FatalAstException("cannot change class of function call target")
         functionCall.arglist = functionCall.arglist.map { it.accept(this) }.toMutableList()
         return functionCall
     }
 
-    fun visit(functionCallStatement: FunctionCallStatement): IStatement {
+    fun visit(functionCallStatement: FunctionCallStatement): Statement {
         val newtarget = functionCallStatement.target.accept(this)
         if(newtarget is IdentifierReference)
             functionCallStatement.target = newtarget
+        else
+            throw FatalAstException("cannot change class of function call target")
         functionCallStatement.arglist = functionCallStatement.arglist.map { it.accept(this) }.toMutableList()
         return functionCallStatement
     }
 
-    fun visit(identifier: IdentifierReference): IExpression {
+    fun visit(identifier: IdentifierReference): Expression {
         // note: this is an identifier that is used in an expression.
         // other identifiers are simply part of the other statements (such as jumps, subroutine defs etc)
         return identifier
     }
 
-    fun visit(jump: Jump): IStatement {
+    fun visit(jump: Jump): Statement {
         if(jump.identifier!=null) {
             val ident = jump.identifier.accept(this)
             if(ident is IdentifierReference && ident!==jump.identifier) {
@@ -76,107 +82,125 @@ interface IAstModifyingVisitor {
         return jump
     }
 
-    fun visit(ifStatement: IfStatement): IStatement {
+    fun visit(ifStatement: IfStatement): Statement {
         ifStatement.condition = ifStatement.condition.accept(this)
         ifStatement.truepart = ifStatement.truepart.accept(this) as AnonymousScope
         ifStatement.elsepart = ifStatement.elsepart.accept(this) as AnonymousScope
         return ifStatement
     }
 
-    fun visit(branchStatement: BranchStatement): IStatement {
+    fun visit(branchStatement: BranchStatement): Statement {
         branchStatement.truepart = branchStatement.truepart.accept(this) as AnonymousScope
         branchStatement.elsepart = branchStatement.elsepart.accept(this) as AnonymousScope
         return branchStatement
     }
 
-    fun visit(range: RangeExpr): IExpression {
+    fun visit(range: RangeExpr): Expression {
         range.from = range.from.accept(this)
         range.to = range.to.accept(this)
         range.step = range.step.accept(this)
         return range
     }
 
-    fun visit(label: Label): IStatement {
+    fun visit(label: Label): Statement {
         return label
     }
 
-    fun visit(literalValue: LiteralValue): LiteralValue {
-        if(literalValue.arrayvalue!=null) {
-            for(av in literalValue.arrayvalue.withIndex()) {
-                val newvalue = av.value.accept(this)
-                literalValue.arrayvalue[av.index] = newvalue
-            }
-        }
+    fun visit(literalValue: NumericLiteralValue): NumericLiteralValue {
         return literalValue
     }
 
-    fun visit(assignment: Assignment): IStatement {
-        assignment.targets = assignment.targets.map { it.accept(this) }
+    fun visit(stringLiteral: StringLiteralValue): Expression {
+        return stringLiteral
+    }
+
+    fun visit(arrayLiteral: ArrayLiteralValue): Expression {
+        for(av in arrayLiteral.value.withIndex()) {
+            val newvalue = av.value.accept(this)
+            arrayLiteral.value[av.index] = newvalue
+        }
+        return arrayLiteral
+    }
+
+    fun visit(assignment: Assignment): Statement {
+        assignment.target = assignment.target.accept(this)
         assignment.value = assignment.value.accept(this)
         return assignment
     }
 
-    fun visit(postIncrDecr: PostIncrDecr): IStatement {
+    fun visit(postIncrDecr: PostIncrDecr): Statement {
         postIncrDecr.target = postIncrDecr.target.accept(this)
         return postIncrDecr
     }
 
-    fun visit(contStmt: Continue): IStatement {
+    fun visit(contStmt: Continue): Statement {
         return contStmt
     }
 
-    fun visit(breakStmt: Break): IStatement {
+    fun visit(breakStmt: Break): Statement {
         return breakStmt
     }
 
-    fun visit(forLoop: ForLoop): IStatement {
-        forLoop.loopVar?.accept(this)
+    fun visit(forLoop: ForLoop): Statement {
+        val newloopvar = forLoop.loopVar?.accept(this)
+        when(newloopvar) {
+            is IdentifierReference -> forLoop.loopVar = newloopvar
+            null -> forLoop.loopVar = null
+            else -> throw FatalAstException("can't change class of loopvar")
+        }
         forLoop.iterable = forLoop.iterable.accept(this)
         forLoop.body = forLoop.body.accept(this) as AnonymousScope
         return forLoop
     }
 
-    fun visit(whileLoop: WhileLoop): IStatement {
+    fun visit(whileLoop: WhileLoop): Statement {
         whileLoop.condition = whileLoop.condition.accept(this)
         whileLoop.body = whileLoop.body.accept(this) as AnonymousScope
         return whileLoop
     }
 
-    fun visit(repeatLoop: RepeatLoop): IStatement {
+    fun visit(repeatLoop: RepeatLoop): Statement {
         repeatLoop.untilCondition = repeatLoop.untilCondition.accept(this)
         repeatLoop.body = repeatLoop.body.accept(this) as AnonymousScope
         return repeatLoop
     }
 
-    fun visit(returnStmt: Return): IStatement {
-        returnStmt.values = returnStmt.values.map { it.accept(this) }
+    fun visit(returnStmt: Return): Statement {
+        returnStmt.value = returnStmt.value?.accept(this)
         return returnStmt
     }
 
-    fun visit(arrayIndexedExpression: ArrayIndexedExpression): IExpression {
-        arrayIndexedExpression.identifier.accept(this)
+    fun visit(arrayIndexedExpression: ArrayIndexedExpression): ArrayIndexedExpression {
+        val ident = arrayIndexedExpression.identifier.accept(this)
+        if(ident is IdentifierReference)
+            arrayIndexedExpression.identifier = ident
         arrayIndexedExpression.arrayspec.accept(this)
         return arrayIndexedExpression
     }
 
     fun visit(assignTarget: AssignTarget): AssignTarget {
-        assignTarget.arrayindexed?.accept(this)
-        assignTarget.identifier?.accept(this)
+        val ident = assignTarget.identifier?.accept(this)
+        when (ident) {
+            is IdentifierReference -> assignTarget.identifier = ident
+            null -> assignTarget.identifier = null
+            else -> throw FatalAstException("can't change class of assign target identifier")
+        }
+        assignTarget.arrayindexed = assignTarget.arrayindexed?.accept(this)
         assignTarget.memoryAddress?.let { visit(it) }
         return assignTarget
     }
 
-    fun visit(scope: AnonymousScope): IStatement {
-        scope.statements = scope.statements.asSequence().map { it.accept(this) }.toMutableList()
+    fun visit(scope: AnonymousScope): Statement {
+        scope.statements = scope.statements.map { it.accept(this) }.toMutableList()
         return scope
     }
 
-    fun visit(typecast: TypecastExpression): IExpression {
+    fun visit(typecast: TypecastExpression): Expression {
         typecast.expression = typecast.expression.accept(this)
         return typecast
     }
 
-    fun visit(memread: DirectMemoryRead): IExpression {
+    fun visit(memread: DirectMemoryRead): Expression {
         memread.addressExpression = memread.addressExpression.accept(this)
         return memread
     }
@@ -185,35 +209,55 @@ interface IAstModifyingVisitor {
         memwrite.addressExpression = memwrite.addressExpression.accept(this)
     }
 
-    fun visit(addressOf: AddressOf): IExpression {
-        addressOf.identifier.accept(this)
+    fun visit(addressOf: AddressOf): Expression {
+        val ident = addressOf.identifier.accept(this)
+        if(ident is IdentifierReference)
+            addressOf.identifier = ident
+        else
+            throw FatalAstException("can't change class of addressof identifier")
         return addressOf
     }
 
-    fun visit(inlineAssembly: InlineAssembly): IStatement {
+    fun visit(inlineAssembly: InlineAssembly): Statement {
         return inlineAssembly
     }
 
-    fun visit(registerExpr: RegisterExpr): IExpression {
+    fun visit(registerExpr: RegisterExpr): Expression {
         return registerExpr
     }
 
-    fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder): IStatement {
+    fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder): Statement {
         return builtinFunctionStatementPlaceholder
     }
 
-    fun visit(nopStatement: NopStatement): IStatement {
+    fun visit(nopStatement: NopStatement): Statement {
         return nopStatement
     }
 
-    fun visit(whenStatement: WhenStatement): IStatement {
-        whenStatement.condition.accept(this)
+    fun visit(whenStatement: WhenStatement): Statement {
+        whenStatement.condition = whenStatement.condition.accept(this)
         whenStatement.choices.forEach { it.accept(this) }
         return whenStatement
     }
 
     fun visit(whenChoice: WhenChoice) {
-        whenChoice.value?.accept(this)
-        whenChoice.statements.accept(this)
+        whenChoice.values = whenChoice.values?.map { it.accept(this) }
+        val stmt = whenChoice.statements.accept(this)
+        if(stmt is AnonymousScope)
+            whenChoice.statements = stmt
+        else {
+            whenChoice.statements = AnonymousScope(mutableListOf(stmt), stmt.position)
+            whenChoice.statements.linkParents(whenChoice)
+        }
+    }
+
+    fun visit(structDecl: StructDecl): Statement {
+        structDecl.statements = structDecl.statements.map{ it.accept(this) }.toMutableList()
+        return structDecl
+    }
+
+    fun visit(structLv: StructLiteralValue): Expression {
+        structLv.values = structLv.values.map { it.accept(this) }
+        return structLv
     }
 }

compiler/src/prog8/ast/processing/IAstVisitor.kt

@@ -1,6 +1,7 @@
 package prog8.ast.processing
 
-import prog8.ast.*
+import prog8.ast.Module
+import prog8.ast.Program
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
 
@@ -75,12 +76,18 @@ interface IAstVisitor {
     fun visit(label: Label) {
     }
 
-    fun visit(literalValue: LiteralValue) {
-        literalValue.arrayvalue?.let { it.forEach { v->v.accept(this) }}
+    fun visit(numLiteral: NumericLiteralValue) {
+    }
+
+    fun visit(string: StringLiteralValue) {
+    }
+
+    fun visit(array: ArrayLiteralValue) {
+        array.value.forEach { v->v.accept(this) }
     }
 
     fun visit(assignment: Assignment) {
-        assignment.targets.forEach { it.accept(this) }
+        assignment.target.accept(this)
         assignment.value.accept(this)
     }
 
@@ -111,7 +118,7 @@ interface IAstVisitor {
     }
 
     fun visit(returnStmt: Return) {
-        returnStmt.values.forEach { it.accept(this) }
+        returnStmt.value?.accept(this)
     }
 
     fun visit(arrayIndexedExpression: ArrayIndexedExpression) {
@@ -163,7 +170,15 @@ interface IAstVisitor {
     }
 
     fun visit(whenChoice: WhenChoice) {
-        whenChoice.value?.accept(this)
+        whenChoice.values?.forEach { it.accept(this) }
         whenChoice.statements.accept(this)
     }
+
+    fun visit(structDecl: StructDecl) {
+        structDecl.statements.forEach { it.accept(this) }
+    }
+
+    fun visit(structLv: StructLiteralValue) {
+        structLv.values.forEach { it.accept(this) }
+    }
 }

compiler/src/prog8/ast/processing/ImportedModuleDirectiveRemover.kt

@@ -1,9 +1,10 @@
 package prog8.ast.processing
 
-import prog8.ast.*
+import prog8.ast.Module
 import prog8.ast.base.SyntaxError
 import prog8.ast.base.printWarning
 import prog8.ast.statements.Directive
+import prog8.ast.statements.Statement
 
 internal class ImportedModuleDirectiveRemover : IAstModifyingVisitor {
     private val checkResult: MutableList<SyntaxError> = mutableListOf()
@@ -17,7 +18,7 @@ internal class ImportedModuleDirectiveRemover : IAstModifyingVisitor {
      */
     override fun visit(module: Module) {
         super.visit(module)
-        val newStatements : MutableList<IStatement> = mutableListOf()
+        val newStatements : MutableList<Statement> = mutableListOf()
 
         val moduleLevelDirectives = listOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address")
         for (sourceStmt in module.statements) {

compiler/src/prog8/ast/processing/StatementReorderer.kt

@@ -1,16 +1,53 @@
 package prog8.ast.processing
 
-import kotlin.comparisons.nullsLast
-import prog8.ast.*
+import prog8.ast.Module
+import prog8.ast.Program
 import prog8.ast.base.DataType
 import prog8.ast.base.FatalAstException
 import prog8.ast.base.initvarsSubName
-import prog8.ast.base.printWarning
-import prog8.ast.expressions.BinaryExpression
-import prog8.ast.expressions.FunctionCall
-import prog8.ast.expressions.TypecastExpression
+import prog8.ast.expressions.*
+import prog8.ast.mangledStructMemberName
 import prog8.ast.statements.*
-import prog8.functions.BuiltinFunctions
+
+
+private fun flattenStructAssignmentFromIdentifier(structAssignment: Assignment, program: Program): List<Assignment> {
+    val identifier = structAssignment.target.identifier!!
+    val identifierName = identifier.nameInSource.single()
+    val targetVar = identifier.targetVarDecl(program.namespace)!!
+    val struct = targetVar.struct!!
+    when {
+        structAssignment.value is IdentifierReference -> {
+            val sourceVar = (structAssignment.value as IdentifierReference).targetVarDecl(program.namespace)!!
+            if (sourceVar.struct == null)
+                throw FatalAstException("can only assign arrays or structs to structs")
+            // struct memberwise copy
+            val sourceStruct = sourceVar.struct!!
+            if(sourceStruct!==targetVar.struct) {
+                // structs are not the same in assignment
+                return listOf()     // error will be printed elsewhere
+            }
+            return struct.statements.zip(sourceStruct.statements).map { member ->
+                val targetDecl = member.first as VarDecl
+                val sourceDecl = member.second as VarDecl
+                if(targetDecl.name != sourceDecl.name)
+                    throw FatalAstException("struct member mismatch")
+                val mangled = mangledStructMemberName(identifierName, targetDecl.name)
+                val idref = IdentifierReference(listOf(mangled), structAssignment.position)
+                val sourcemangled = mangledStructMemberName(sourceVar.name, sourceDecl.name)
+                val sourceIdref = IdentifierReference(listOf(sourcemangled), structAssignment.position)
+                val assign = Assignment(AssignTarget(null, idref, null, null, structAssignment.position),
+                        null, sourceIdref, member.second.position)
+                assign.linkParents(structAssignment)
+                assign
+            }
+        }
+        structAssignment.value is StructLiteralValue -> {
+            throw IllegalArgumentException("not going to flatten a structLv assignment here")
+        }
+        else -> throw FatalAstException("strange struct value")
+    }
+}
+
 
 internal class StatementReorderer(private val program: Program): IAstModifyingVisitor {
     // Reorders the statements in a way the compiler needs.
@@ -24,9 +61,6 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
     // - the 'start' subroutine in the 'main' block will be moved to the top immediately following the directives.
     // - all other subroutines will be moved to the end of their block.
     // - sorts the choices in when statement.
-    //
-    // Also, makes sure any value assignments get the proper type casts if needed to cast them into the target variable's type.
-    // (this includes function call arguments)
 
     private val directivesToMove = setOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address", "%option")
 
@@ -60,7 +94,7 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
         module.statements.addAll(0, directives)
     }
 
-    override fun visit(block: Block): IStatement {
+    override fun visit(block: Block): Statement {
 
         val subroutines = block.statements.filterIsInstance<Subroutine>()
         var numSubroutinesAtEnd = 0
@@ -91,7 +125,7 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
                         && stmtBeforeFirstSub !is Jump
                         && stmtBeforeFirstSub !is Subroutine
                         && stmtBeforeFirstSub !is BuiltinFunctionStatementPlaceholder) {
-                    val ret = Return(emptyList(), stmtBeforeFirstSub.position)
+                    val ret = Return(null, stmtBeforeFirstSub.position)
                     ret.linkParents(block)
                     block.statements.add(block.statements.size - numSubroutinesAtEnd, ret)
                 }
@@ -124,7 +158,7 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
         return super.visit(block)
     }
 
-    override fun visit(subroutine: Subroutine): IStatement {
+    override fun visit(subroutine: Subroutine): Statement {
         super.visit(subroutine)
 
         val varDecls = subroutine.statements.filterIsInstance<VarDecl>()
@@ -139,7 +173,7 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
             // and if an assembly block doesn't contain a rts/rti
             if(subroutine.asmAddress==null && subroutine.amountOfRtsInAsm()==0) {
                 if (subroutine.statements.lastOrNull {it !is VarDecl } !is Return) {
-                    val returnStmt = Return(emptyList(), subroutine.position)
+                    val returnStmt = Return(null, subroutine.position)
                     returnStmt.linkParents(subroutine)
                     subroutine.statements.add(returnStmt)
                 }
@@ -149,137 +183,55 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
         return subroutine
     }
 
-    override fun visit(expr: BinaryExpression): IExpression {
-        val leftDt = expr.left.inferType(program)
-        val rightDt = expr.right.inferType(program)
-        if(leftDt!=null && rightDt!=null && leftDt!=rightDt) {
-            // determine common datatype and add typecast as required to make left and right equal types
-            val (commonDt, toFix) = expr.commonDatatype(leftDt, rightDt, expr.left, expr.right)
-            if(toFix!=null) {
-                when {
-                    toFix===expr.left -> {
-                        expr.left = TypecastExpression(expr.left, commonDt, true, expr.left.position)
-                        expr.left.linkParents(expr)
-                    }
-                    toFix===expr.right -> {
-                        expr.right = TypecastExpression(expr.right, commonDt, true, expr.right.position)
-                        expr.right.linkParents(expr)
-                    }
-                    else -> throw FatalAstException("confused binary expression side")
+    override fun visit(assignment: Assignment): Statement {
+        val assg = super.visit(assignment)
+        if(assg !is Assignment)
+            return assg
+
+        // see if a typecast is needed to convert the value's type into the proper target type
+        val valueItype = assg.value.inferType(program)
+        val targetItype = assg.target.inferType(program, assg)
+
+        if(targetItype.isKnown && valueItype.isKnown) {
+            val targettype = targetItype.typeOrElse(DataType.STRUCT)
+            val valuetype = valueItype.typeOrElse(DataType.STRUCT)
+
+            // struct assignments will be flattened (if it's not a struct literal)
+            if (valuetype == DataType.STRUCT && targettype == DataType.STRUCT) {
+                if (assg.value is StructLiteralValue)
+                    return assg  // do NOT flatten it at this point!! (the compiler will take care if it, later, if needed)
+
+                val assignments = flattenStructAssignmentFromIdentifier(assg, program)    //   'structvar1 = structvar2'
+                return if (assignments.isEmpty()) {
+                    // something went wrong (probably incompatible struct types)
+                    // we'll get an error later from the AstChecker
+                    assg
+                } else {
+                    val scope = AnonymousScope(assignments.toMutableList(), assg.position)
+                    scope.linkParents(assg.parent)
+                    scope
                 }
             }
         }
-        return super.visit(expr)
-    }
 
-    override fun visit(assignment: Assignment): IStatement {
-        val target=assignment.singleTarget
-        if(target!=null) {
-            // see if a typecast is needed to convert the value's type into the proper target type
-            val valuetype = assignment.value.inferType(program)
-            val targettype = target.inferType(program, assignment)
-            if(targettype!=null && valuetype!=null && valuetype!=targettype) {
-                if(valuetype isAssignableTo targettype) {
-                    assignment.value = TypecastExpression(assignment.value, targettype, true, assignment.value.position)
-                    assignment.value.linkParents(assignment)
-                }
-                // if they're not assignable, we'll get a proper error later from the AstChecker
-            }
-        } else TODO("multi-target assign")
-
-        return super.visit(assignment)
-    }
-
-    override fun visit(functionCallStatement: FunctionCallStatement): IStatement {
-        checkFunctionCallArguments(functionCallStatement, functionCallStatement.definingScope())
-        return super.visit(functionCallStatement)
-    }
-
-    override fun visit(functionCall: FunctionCall): IExpression {
-        checkFunctionCallArguments(functionCall, functionCall.definingScope())
-        return super.visit(functionCall)
-    }
-
-    private fun checkFunctionCallArguments(call: IFunctionCall, scope: INameScope) {
-        // see if a typecast is needed to convert the arguments into the required parameter's type
-        when(val sub = call.target.targetStatement(scope)) {
-            is Subroutine -> {
-                for(arg in sub.parameters.zip(call.arglist.withIndex())) {
-                    val argtype = arg.second.value.inferType(program)
-                    if(argtype!=null) {
-                        val requiredType = arg.first.type
-                        if (requiredType != argtype) {
-                            if (argtype isAssignableTo requiredType) {
-                                val typecasted = TypecastExpression(arg.second.value, requiredType, true, arg.second.value.position)
-                                typecasted.linkParents(arg.second.value.parent)
-                                call.arglist[arg.second.index] = typecasted
-                            }
-                            // if they're not assignable, we'll get a proper error later from the AstChecker
-                        }
+        if(assg.aug_op!=null) {
+            // transform augmented assg into normal assg so we have one case less to deal with later
+            val newTarget: Expression =
+                    when {
+                        assg.target.register != null -> RegisterExpr(assg.target.register!!, assg.target.position)
+                        assg.target.identifier != null -> assg.target.identifier!!
+                        assg.target.arrayindexed != null -> assg.target.arrayindexed!!
+                        assg.target.memoryAddress != null -> DirectMemoryRead(assg.target.memoryAddress!!.addressExpression, assg.value.position)
+                        else -> throw FatalAstException("strange assg")
                     }
-                }
-            }
-            is BuiltinFunctionStatementPlaceholder -> {
-                // if(sub.name in setOf("lsl", "lsr", "rol", "ror", "rol2", "ror2", "memset", "memcopy", "memsetw", "swap"))
-                val func = BuiltinFunctions.getValue(sub.name)
-                if(func.pure) {
-                    // non-pure functions don't get automatic typecasts because sometimes they act directly on their parameters
-                    for (arg in func.parameters.zip(call.arglist.withIndex())) {
-                        val argtype = arg.second.value.inferType(program)
-                        if (argtype != null) {
-                            if (arg.first.possibleDatatypes.any { argtype == it })
-                                continue
-                            for (possibleType in arg.first.possibleDatatypes) {
-                                if (argtype isAssignableTo possibleType) {
-                                    val typecasted = TypecastExpression(arg.second.value, possibleType, true, arg.second.value.position)
-                                    typecasted.linkParents(arg.second.value.parent)
-                                    call.arglist[arg.second.index] = typecasted
-                                    break
-                                }
-                            }
-                        }
-                    }
-                }
-            }
-            null -> {}
-            else -> TODO("call to something weird $sub   ${call.target}")
-        }
-    }
 
-    private fun sortConstantAssignmentSequence(first: Assignment, stmtIter: MutableIterator<IStatement>): Pair<List<Assignment>, IStatement?> {
-        val sequence= mutableListOf(first)
-        var trailing: IStatement? = null
-        while(stmtIter.hasNext()) {
-            val next = stmtIter.next()
-            if(next is Assignment) {
-                val constValue = next.value.constValue(program)
-                if(constValue==null) {
-                    trailing = next
-                    break
-                }
-                sequence.add(next)
-            }
-            else {
-                trailing=next
-                break
-            }
+            val expression = BinaryExpression(newTarget, assg.aug_op.substringBeforeLast('='), assg.value, assg.position)
+            expression.linkParents(assg.parent)
+            val convertedAssignment = Assignment(assg.target, null, expression, assg.position)
+            convertedAssignment.linkParents(assg.parent)
+            return super.visit(convertedAssignment)
         }
-        val sorted = sequence.sortedWith(compareBy({it.value.inferType(program)}, {it.singleTarget?.shortString(true)}))
-        return Pair(sorted, trailing)
-    }
 
-    override fun visit(typecast: TypecastExpression): IExpression {
-        // warn about any implicit type casts to Float, because that may not be intended
-        if(typecast.implicit && typecast.type in setOf(DataType.FLOAT, DataType.ARRAY_F)) {
-            printWarning("byte or word value implicitly converted to float. Suggestion: use explicit cast as float, a float number, or revert to integer arithmetic", typecast.position)
-        }
-        return super.visit(typecast)
-    }
-
-    override fun visit(whenStatement: WhenStatement): IStatement {
-        // sort the choices in low-to-high value order
-        whenStatement.choices
-                .sortWith(compareBy<WhenChoice, Int?>(nullsLast(), {it.value?.constValue(program)?.asIntegerValue}))
-        return super.visit(whenStatement)
+        return assg
     }
 }

compiler/src/prog8/ast/processing/TypecastsAdder.kt

@@ -0,0 +1,198 @@
+package prog8.ast.processing
+
+import prog8.ast.IFunctionCall
+import prog8.ast.INameScope
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.FatalAstException
+import prog8.ast.base.printWarning
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.functions.BuiltinFunctions
+
+
+internal class TypecastsAdder(private val program: Program): IAstModifyingVisitor {
+    // Make sure any value assignments get the proper type casts if needed to cast them into the target variable's type.
+    // (this includes function call arguments)
+
+    override fun visit(expr: BinaryExpression): Expression {
+        val expr2 = super.visit(expr)
+        if(expr2 !is BinaryExpression)
+            return expr2
+        val leftDt = expr2.left.inferType(program)
+        val rightDt = expr2.right.inferType(program)
+        if(leftDt.isKnown && rightDt.isKnown && leftDt!=rightDt) {
+            // determine common datatype and add typecast as required to make left and right equal types
+            val (commonDt, toFix) = BinaryExpression.commonDatatype(leftDt.typeOrElse(DataType.STRUCT), rightDt.typeOrElse(DataType.STRUCT), expr2.left, expr2.right)
+            if(toFix!=null) {
+                when {
+                    toFix===expr2.left -> {
+                        expr2.left = TypecastExpression(expr2.left, commonDt, true, expr2.left.position)
+                        expr2.left.linkParents(expr2)
+                    }
+                    toFix===expr2.right -> {
+                        expr2.right = TypecastExpression(expr2.right, commonDt, true, expr2.right.position)
+                        expr2.right.linkParents(expr2)
+                    }
+                    else -> throw FatalAstException("confused binary expression side")
+                }
+            }
+        }
+        return expr2
+    }
+
+    override fun visit(assignment: Assignment): Statement {
+        val assg = super.visit(assignment)
+        if(assg !is Assignment)
+            return assg
+
+        // see if a typecast is needed to convert the value's type into the proper target type
+        val valueItype = assg.value.inferType(program)
+        val targetItype = assg.target.inferType(program, assg)
+
+        if(targetItype.isKnown && valueItype.isKnown) {
+            val targettype = targetItype.typeOrElse(DataType.STRUCT)
+            val valuetype = valueItype.typeOrElse(DataType.STRUCT)
+            if (valuetype != targettype) {
+                if (valuetype isAssignableTo targettype) {
+                    assg.value = TypecastExpression(assg.value, targettype, true, assg.value.position)
+                    assg.value.linkParents(assg)
+                }
+                // if they're not assignable, we'll get a proper error later from the AstChecker
+            }
+        }
+        return assg
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        checkFunctionCallArguments(functionCallStatement, functionCallStatement.definingScope())
+        return super.visit(functionCallStatement)
+    }
+
+    override fun visit(functionCall: FunctionCall): Expression {
+        checkFunctionCallArguments(functionCall, functionCall.definingScope())
+        return super.visit(functionCall)
+    }
+
+    private fun checkFunctionCallArguments(call: IFunctionCall, scope: INameScope) {
+        // see if a typecast is needed to convert the arguments into the required parameter's type
+        when(val sub = call.target.targetStatement(scope)) {
+            is Subroutine -> {
+                for(arg in sub.parameters.zip(call.arglist.withIndex())) {
+                    val argItype = arg.second.value.inferType(program)
+                    if(argItype.isKnown) {
+                        val argtype = argItype.typeOrElse(DataType.STRUCT)
+                        val requiredType = arg.first.type
+                        if (requiredType != argtype) {
+                            if (argtype isAssignableTo requiredType) {
+                                val typecasted = TypecastExpression(arg.second.value, requiredType, true, arg.second.value.position)
+                                typecasted.linkParents(arg.second.value.parent)
+                                call.arglist[arg.second.index] = typecasted
+                            }
+                            // if they're not assignable, we'll get a proper error later from the AstChecker
+                        }
+                    }
+                }
+            }
+            is BuiltinFunctionStatementPlaceholder -> {
+                val func = BuiltinFunctions.getValue(sub.name)
+                if(func.pure) {
+                    // non-pure functions don't get automatic typecasts because sometimes they act directly on their parameters
+                    for (arg in func.parameters.zip(call.arglist.withIndex())) {
+                        val argItype = arg.second.value.inferType(program)
+                        if (argItype.isKnown) {
+                            val argtype = argItype.typeOrElse(DataType.STRUCT)
+                            if (arg.first.possibleDatatypes.any { argtype == it })
+                                continue
+                            for (possibleType in arg.first.possibleDatatypes) {
+                                if (argtype isAssignableTo possibleType) {
+                                    val typecasted = TypecastExpression(arg.second.value, possibleType, true, arg.second.value.position)
+                                    typecasted.linkParents(arg.second.value.parent)
+                                    call.arglist[arg.second.index] = typecasted
+                                    break
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            null -> {}
+            else -> throw FatalAstException("call to something weird $sub   ${call.target}")
+        }
+    }
+
+    override fun visit(typecast: TypecastExpression): Expression {
+        // warn about any implicit type casts to Float, because that may not be intended
+        if(typecast.implicit && typecast.type in setOf(DataType.FLOAT, DataType.ARRAY_F)) {
+            printWarning("byte or word value implicitly converted to float. Suggestion: use explicit cast as float, a float number, or revert to integer arithmetic", typecast.position)
+        }
+        return super.visit(typecast)
+    }
+
+    override fun visit(memread: DirectMemoryRead): Expression {
+        // make sure the memory address is an uword
+        val dt = memread.addressExpression.inferType(program)
+        if(dt.isKnown && dt.typeOrElse(DataType.UWORD)!=DataType.UWORD) {
+            val literaladdr = memread.addressExpression as? NumericLiteralValue
+            if(literaladdr!=null) {
+                memread.addressExpression = literaladdr.cast(DataType.UWORD)
+            } else {
+                memread.addressExpression = TypecastExpression(memread.addressExpression, DataType.UWORD, true, memread.addressExpression.position)
+                memread.addressExpression.parent = memread
+            }
+        }
+        return super.visit(memread)
+    }
+
+    override fun visit(memwrite: DirectMemoryWrite) {
+        val dt = memwrite.addressExpression.inferType(program)
+        if(dt.isKnown && dt.typeOrElse(DataType.UWORD)!=DataType.UWORD) {
+            val literaladdr = memwrite.addressExpression as? NumericLiteralValue
+            if(literaladdr!=null) {
+                memwrite.addressExpression = literaladdr.cast(DataType.UWORD)
+            } else {
+                memwrite.addressExpression = TypecastExpression(memwrite.addressExpression, DataType.UWORD, true, memwrite.addressExpression.position)
+                memwrite.addressExpression.parent = memwrite
+            }
+        }
+        super.visit(memwrite)
+    }
+
+    override fun visit(structLv: StructLiteralValue): Expression {
+        val litval = super.visit(structLv)
+        if(litval !is StructLiteralValue)
+            return litval
+
+        val decl = litval.parent as? VarDecl
+        if(decl != null) {
+            val struct = decl.struct
+            if(struct != null) {
+                addTypecastsIfNeeded(litval, struct)
+            }
+        } else {
+            val assign = litval.parent as? Assignment
+            if (assign != null) {
+                val decl2 = assign.target.identifier?.targetVarDecl(program.namespace)
+                if(decl2 != null) {
+                    val struct = decl2.struct
+                    if(struct != null) {
+                        addTypecastsIfNeeded(litval, struct)
+                    }
+                }
+            }
+        }
+
+        return litval
+    }
+
+    private fun addTypecastsIfNeeded(structLv: StructLiteralValue, struct: StructDecl) {
+        structLv.values = struct.statements.zip(structLv.values).map {
+            val memberDt = (it.first as VarDecl).datatype
+            val valueDt = it.second.inferType(program)
+            if (valueDt.typeOrElse(memberDt) != memberDt)
+                TypecastExpression(it.second, memberDt, true, it.second.position)
+            else
+                it.second
+        }
+    }
+}

compiler/src/prog8/ast/processing/VarInitValueAndAddressOfCreator.kt

@@ -1,15 +1,18 @@
 package prog8.ast.processing
 
-import prog8.ast.*
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
 import prog8.ast.base.*
-import prog8.ast.base.autoHeapValuePrefix
-import prog8.ast.expressions.AddressOf
-import prog8.ast.expressions.FunctionCall
-import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.LiteralValue
+import prog8.ast.expressions.*
 import prog8.ast.statements.*
+import prog8.compiler.CompilerException
+import prog8.functions.BuiltinFunctions
+import prog8.functions.FunctionSignature
 
-internal class VarInitValueAndAddressOfCreator(private val namespace: INameScope): IAstModifyingVisitor {
+
+internal class VarInitValueAndAddressOfCreator(private val program: Program): IAstModifyingVisitor {
     // For VarDecls that declare an initialization value:
     // Replace the vardecl with an assignment (to set the initial value),
     // and add a new vardecl with the default constant value of that type (usually zero) to the scope.
@@ -21,22 +24,31 @@ internal class VarInitValueAndAddressOfCreator(private val namespace: INameScope
 
     // Also takes care to insert AddressOf (&) expression where required (string params to a UWORD function param etc).
 
-    private val vardeclsToAdd = mutableMapOf<INameScope, MutableMap<String, VarDecl>>()
+    private val vardeclsToAdd = mutableMapOf<INameScope, MutableList<VarDecl>>()
 
     override fun visit(module: Module) {
         vardeclsToAdd.clear()
         super.visit(module)
-
         // add any new vardecls to the various scopes
-        for(decl in vardeclsToAdd)
-            for(d in decl.value) {
-                d.value.linkParents(decl.key as Node)
-                decl.key.statements.add(0, d.value)
-            }
+        for((where, decls) in vardeclsToAdd) {
+            where.statements.addAll(0, decls)
+            decls.forEach { it.linkParents(where as Node) }
+        }
     }
 
-    override fun visit(decl: VarDecl): IStatement {
+    override fun visit(decl: VarDecl): Statement {
         super.visit(decl)
+
+        if(decl.isArray && decl.value==null) {
+            // array datatype without initialization value, add list of zeros
+            val arraysize = decl.arraysize!!.size()!!
+            val array = ArrayLiteralValue(decl.datatype,
+                    Array(arraysize) { NumericLiteralValue.optimalInteger(0, decl.position) },
+                    null, decl.position)
+            array.addToHeap(program.heap)
+            decl.value = array
+        }
+
         if(decl.type!= VarDeclType.VAR || decl.value==null)
             return decl
 
@@ -45,13 +57,11 @@ internal class VarInitValueAndAddressOfCreator(private val namespace: INameScope
             addVarDecl(scope, decl.asDefaultValueDecl(null))
             val declvalue = decl.value!!
             val value =
-                    if(declvalue is LiteralValue) {
-                        val converted = declvalue.cast(decl.datatype)
-                        converted ?: declvalue
-                    }
+                    if(declvalue is NumericLiteralValue)
+                        declvalue.cast(decl.datatype)
                     else
                         declvalue
-            val identifierName = listOf(decl.name)    //  // TODO this was: (scoped name) decl.scopedname.split(".")
+            val identifierName = listOf(decl.name)    // this was: (scoped name) decl.scopedname.split(".")
             return VariableInitializationAssignment(
                     AssignTarget(null, IdentifierReference(identifierName, decl.position), null, null, decl.position),
                     null,
@@ -59,68 +69,89 @@ internal class VarInitValueAndAddressOfCreator(private val namespace: INameScope
                     decl.position
             )
         }
+
         return decl
     }
 
-    override fun visit(functionCall: FunctionCall): IExpression {
-        val targetStatement = functionCall.target.targetSubroutine(namespace)
+    override fun visit(functionCall: FunctionCall): Expression {
+        var parentStatement: Node = functionCall
+        while(parentStatement !is Statement)
+            parentStatement = parentStatement.parent
+        val targetStatement = functionCall.target.targetSubroutine(program.namespace)
         if(targetStatement!=null) {
-            var node: Node = functionCall
-            while(node !is IStatement)
-                node=node.parent
-            addAddressOfExprIfNeeded(targetStatement, functionCall.arglist, node)
+            addAddressOfExprIfNeeded(targetStatement, functionCall.arglist, parentStatement)
+        } else {
+            val builtinFunc = BuiltinFunctions[functionCall.target.nameInSource.joinToString (".")]
+            if(builtinFunc!=null)
+                addAddressOfExprIfNeededForBuiltinFuncs(builtinFunc, functionCall.arglist, parentStatement)
         }
         return functionCall
     }
 
-    override fun visit(functionCallStatement: FunctionCallStatement): IStatement {
-        val targetStatement = functionCallStatement.target.targetSubroutine(namespace)
-        if(targetStatement!=null)
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        val targetStatement = functionCallStatement.target.targetSubroutine(program.namespace)
+        if(targetStatement!=null) {
             addAddressOfExprIfNeeded(targetStatement, functionCallStatement.arglist, functionCallStatement)
+        } else {
+            val builtinFunc = BuiltinFunctions[functionCallStatement.target.nameInSource.joinToString (".")]
+            if(builtinFunc!=null)
+                addAddressOfExprIfNeededForBuiltinFuncs(builtinFunc, functionCallStatement.arglist, functionCallStatement)
+        }
         return functionCallStatement
     }
 
-    private fun addAddressOfExprIfNeeded(subroutine: Subroutine, arglist: MutableList<IExpression>, parent: IStatement) {
+    private fun addAddressOfExprIfNeeded(subroutine: Subroutine, arglist: MutableList<Expression>, parent: Statement) {
         // functions that accept UWORD and are given an array type, or string, will receive the AddressOf (memory location) of that value instead.
         for(argparam in subroutine.parameters.withIndex().zip(arglist)) {
-            if(argparam.first.value.type== DataType.UWORD || argparam.first.value.type in StringDatatypes) {
+            if(argparam.first.value.type==DataType.UWORD || argparam.first.value.type in StringDatatypes) {
                 if(argparam.second is AddressOf)
                     continue
                 val idref = argparam.second as? IdentifierReference
-                val strvalue = argparam.second as? LiteralValue
+                val strvalue = argparam.second as? StringLiteralValue
                 if(idref!=null) {
-                    val variable = idref.targetVarDecl(namespace)
+                    val variable = idref.targetVarDecl(program.namespace)
                     if(variable!=null && (variable.datatype in StringDatatypes || variable.datatype in ArrayDatatypes)) {
                         val pointerExpr = AddressOf(idref, idref.position)
-                        pointerExpr.scopedname = parent.makeScopedName(idref.nameInSource.single())
                         pointerExpr.linkParents(arglist[argparam.first.index].parent)
                         arglist[argparam.first.index] = pointerExpr
                     }
                 }
                 else if(strvalue!=null) {
-                    if(strvalue.isString) {
-                        // replace the argument with &autovar
-                        val autoVarName = "$autoHeapValuePrefix${strvalue.heapId}"
-                        val autoHeapvarRef = IdentifierReference(listOf(autoVarName), strvalue.position)
-                        val pointerExpr = AddressOf(autoHeapvarRef, strvalue.position)
-                        pointerExpr.scopedname = parent.makeScopedName(autoVarName)
-                        pointerExpr.linkParents(arglist[argparam.first.index].parent)
-                        arglist[argparam.first.index] = pointerExpr
-                        // add a vardecl so that the autovar can be resolved in later lookups
-                        val variable = VarDecl(VarDeclType.VAR, strvalue.type, false, null, autoVarName, strvalue,
-                                isArray = false, autoGenerated = false, position = strvalue.position)
-                        addVarDecl(strvalue.definingScope(), variable)
-                        // println("MADE ANONVAR $variable")   // XXX
-                    }
+                    // add a vardecl so that the autovar can be resolved in later lookups
+                    val variable = VarDecl.createAuto(strvalue)
+                    addVarDecl(strvalue.definingScope(), variable)
+                    // replace the argument with &autovar
+                    val autoHeapvarRef = IdentifierReference(listOf(variable.name), strvalue.position)
+                    val pointerExpr = AddressOf(autoHeapvarRef, strvalue.position)
+                    pointerExpr.linkParents(arglist[argparam.first.index].parent)
+                    arglist[argparam.first.index] = pointerExpr
                 }
             }
         }
     }
 
+    private fun addAddressOfExprIfNeededForBuiltinFuncs(signature: FunctionSignature, args: MutableList<Expression>, parent: Statement) {
+        // val paramTypesForAddressOf = PassByReferenceDatatypes + DataType.UWORD
+        for(arg in args.withIndex().zip(signature.parameters)) {
+            val argvalue = arg.first.value
+            val argDt = argvalue.inferType(program)
+            if(argDt.typeOrElse(DataType.UBYTE) in PassByReferenceDatatypes && DataType.UWORD in arg.second.possibleDatatypes) {
+                if(argvalue !is IdentifierReference)
+                    throw CompilerException("pass-by-reference parameter isn't an identifier? $argvalue")
+                val addrOf = AddressOf(argvalue, argvalue.position)
+                args[arg.first.index] = addrOf
+                addrOf.linkParents(parent)
+            }
+        }
+    }
+
+
     private fun addVarDecl(scope: INameScope, variable: VarDecl) {
         if(scope !in vardeclsToAdd)
-            vardeclsToAdd[scope] = mutableMapOf()
-        vardeclsToAdd.getValue(scope)[variable.name]=variable
+            vardeclsToAdd[scope] = mutableListOf()
+        val declList = vardeclsToAdd.getValue(scope)
+        if(declList.all{it.name!=variable.name})
+            declList.add(variable)
     }
 
 }

compiler/src/prog8/ast/statements/AstStatements.kt

@@ -5,12 +5,40 @@ import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.processing.IAstModifyingVisitor
 import prog8.ast.processing.IAstVisitor
-import prog8.compiler.HeapValues
-import kotlin.math.max
-import kotlin.math.min
 
 
-class BuiltinFunctionStatementPlaceholder(val name: String, override val position: Position) : IStatement {
+sealed class Statement : Node {
+    abstract fun accept(visitor: IAstModifyingVisitor) : Statement
+    abstract fun accept(visitor: IAstVisitor)
+    fun makeScopedName(name: String): String {
+        // easy way out is to always return the full scoped name.
+        // it would be nicer to find only the minimal prefixed scoped name, but that's too much hassle for now.
+        // and like this, we can cache the name even,
+        // like in a lazy property on the statement object itself (label, subroutine, vardecl)
+        val scope = mutableListOf<String>()
+        var statementScope = this.parent
+        while(statementScope !is ParentSentinel && statementScope !is Module) {
+            if(statementScope is INameScope) {
+                scope.add(0, statementScope.name)
+            }
+            statementScope = statementScope.parent
+        }
+        if(name.isNotEmpty())
+            scope.add(name)
+        return scope.joinToString(".")
+    }
+
+    abstract val expensiveToInline: Boolean
+
+    fun definingBlock(): Block {
+        if(this is Block)
+            return this
+        return findParentNode<Block>(this)!!
+    }
+}
+
+
+class BuiltinFunctionStatementPlaceholder(val name: String, override val position: Position) : Statement() {
     override var parent: Node = ParentSentinel
     override fun linkParents(parent: Node) {}
     override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
@@ -20,14 +48,14 @@ class BuiltinFunctionStatementPlaceholder(val name: String, override val positio
 }
 
 
-data class RegisterOrStatusflag(val registerOrPair: RegisterOrPair?, val statusflag: Statusflag?, val stack: Boolean?)
+data class RegisterOrStatusflag(val registerOrPair: RegisterOrPair?, val statusflag: Statusflag?, val stack: Boolean)
 
 
 class Block(override val name: String,
             val address: Int?,
-            override var statements: MutableList<IStatement>,
+            override var statements: MutableList<Statement>,
             val isInLibrary: Boolean,
-            override val position: Position) : IStatement, INameScope {
+            override val position: Position) : Statement(), INameScope {
     override lateinit var parent: Node
     override val expensiveToInline
         get() = statements.any { it.expensiveToInline }
@@ -47,7 +75,7 @@ class Block(override val name: String,
     fun options() = statements.filter { it is Directive && it.directive == "%option" }.flatMap { (it as Directive).args }.map {it.name!!}.toSet()
 }
 
-data class Directive(val directive: String, val args: List<DirectiveArg>, override val position: Position) : IStatement {
+data class Directive(val directive: String, val args: List<DirectiveArg>, override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -68,7 +96,7 @@ data class DirectiveArg(val str: String?, val name: String?, val int: Int?, over
     }
 }
 
-data class Label(val name: String, override val position: Position) : IStatement {
+data class Label(val name: String, override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -82,28 +110,26 @@ data class Label(val name: String, override val position: Position) : IStatement
     override fun toString(): String {
         return "Label(name=$name, pos=$position)"
     }
-
-    val scopedname: String by lazy { makeScopedName(name) }
 }
 
-open class Return(var values: List<IExpression>, override val position: Position) : IStatement {
+open class Return(var value: Expression?, override val position: Position) : Statement() {
     override lateinit var parent: Node
-    override val expensiveToInline = values.any { it !is LiteralValue }
+    override val expensiveToInline = value!=null && value !is NumericLiteralValue
 
     override fun linkParents(parent: Node) {
         this.parent = parent
-        values.forEach {it.linkParents(this)}
+        value?.linkParents(this)
     }
 
     override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 
     override fun toString(): String {
-        return "Return(values: $values, pos=$position)"
+        return "Return($value, pos=$position)"
     }
 }
 
-class ReturnFromIrq(override val position: Position) : Return(emptyList(), position) {
+class ReturnFromIrq(override val position: Position) : Return(null, position) {
     override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 
@@ -112,7 +138,7 @@ class ReturnFromIrq(override val position: Position) : Return(emptyList(), posit
     }
 }
 
-class Continue(override val position: Position) : IStatement {
+class Continue(override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -124,7 +150,7 @@ class Continue(override val position: Position) : IStatement {
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 }
 
-class Break(override val position: Position) : IStatement {
+class Break(override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -136,18 +162,57 @@ class Break(override val position: Position) : IStatement {
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 }
 
+
+enum class ZeropageWish {
+    REQUIRE_ZEROPAGE,
+    PREFER_ZEROPAGE,
+    DONTCARE,
+    NOT_IN_ZEROPAGE
+}
+
 class VarDecl(val type: VarDeclType,
               private val declaredDatatype: DataType,
-              val zeropage: Boolean,
+              val zeropage: ZeropageWish,
               var arraysize: ArrayIndex?,
               val name: String,
-              var value: IExpression?,
+              private val structName: String?,
+              var value: Expression?,
               val isArray: Boolean,
-              val autoGenerated: Boolean,
-              override val position: Position) : IStatement {
+              val autogeneratedDontRemove: Boolean,
+              override val position: Position) : Statement() {
     override lateinit var parent: Node
+    var struct: StructDecl? = null        // set later (because at parse time, we only know the name)
+        private set
+    var structHasBeenFlattened = false      // set later
+        private set
+
     override val expensiveToInline
-            get() = value!=null && value !is LiteralValue
+            get() = value!=null && value !is NumericLiteralValue
+
+    // prefix for literal values that are turned into a variable on the heap
+
+    companion object {
+        private var autoHeapValueSequenceNumber = 0
+
+        fun createAuto(string: StringLiteralValue): VarDecl {
+            if(string.heapId==null)
+                throw FatalAstException("can only create autovar for a string that has a heapid  $string")
+            val autoVarName = "auto_heap_value_${++autoHeapValueSequenceNumber}"
+            return VarDecl(VarDeclType.VAR, string.type, ZeropageWish.NOT_IN_ZEROPAGE, null, autoVarName, null, string,
+                        isArray = false, autogeneratedDontRemove = true, position = string.position)
+        }
+
+        fun createAuto(array: ArrayLiteralValue): VarDecl {
+            if(array.heapId==null)
+                throw FatalAstException("can only create autovar for an array that has a heapid  $array")
+
+            val autoVarName = "auto_heap_value_${++autoHeapValueSequenceNumber}"
+            val declaredType = ArrayElementTypes.getValue(array.type)
+            val arraysize = ArrayIndex.forArray(array)
+            return VarDecl(VarDeclType.VAR, declaredType, ZeropageWish.NOT_IN_ZEROPAGE, arraysize, autoVarName, null, array,
+                    isArray = true, autogeneratedDontRemove = true, position = array.position)
+        }
+    }
 
     val datatypeErrors = mutableListOf<SyntaxError>()       // don't crash at init time, report them in the AstChecker
     val datatype =
@@ -160,7 +225,7 @@ class VarDecl(val type: VarDeclType,
                 DataType.FLOAT -> DataType.ARRAY_F
                 else -> {
                     datatypeErrors.add(SyntaxError("array can only contain bytes/words/floats", position))
-                    DataType.UBYTE
+                    DataType.ARRAY_UB
                 }
             }
 
@@ -168,6 +233,11 @@ class VarDecl(val type: VarDeclType,
         this.parent = parent
         arraysize?.linkParents(this)
         value?.linkParents(this)
+        if(structName!=null) {
+            val structStmt = definingScope().lookup(listOf(structName), this)
+            if(structStmt!=null)
+                struct = definingScope().lookup(listOf(structName), this) as StructDecl
+        }
     }
 
     override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
@@ -176,26 +246,47 @@ class VarDecl(val type: VarDeclType,
     val scopedname: String by lazy { makeScopedName(name) }
 
     override fun toString(): String {
-        return "VarDecl(name=$name, vartype=$type, datatype=$datatype, array=$isArray, value=$value, pos=$position)"
+        return "VarDecl(name=$name, vartype=$type, datatype=$datatype, struct=$structName, value=$value, pos=$position)"
     }
 
     fun asDefaultValueDecl(parent: Node?): VarDecl {
         val constValue = when(declaredDatatype) {
-            DataType.UBYTE -> LiteralValue(DataType.UBYTE, 0, position = position)
-            DataType.BYTE -> LiteralValue(DataType.BYTE, 0, position = position)
-            DataType.UWORD -> LiteralValue(DataType.UWORD, wordvalue = 0, position = position)
-            DataType.WORD -> LiteralValue(DataType.WORD, wordvalue = 0, position = position)
-            DataType.FLOAT -> LiteralValue(DataType.FLOAT, floatvalue = 0.0, position = position)
+            DataType.UBYTE -> NumericLiteralValue(DataType.UBYTE, 0,  position)
+            DataType.BYTE -> NumericLiteralValue(DataType.BYTE, 0,  position)
+            DataType.UWORD -> NumericLiteralValue(DataType.UWORD, 0, position)
+            DataType.WORD -> NumericLiteralValue(DataType.WORD, 0, position)
+            DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, 0.0, position)
             else -> throw FatalAstException("can only set a default value for a numeric type")
         }
-        val decl = VarDecl(type, declaredDatatype, zeropage, arraysize, name, constValue, isArray, true, position)
+        val decl = VarDecl(type, declaredDatatype, zeropage, arraysize, name, structName, constValue, isArray, false, position)
         if(parent!=null)
             decl.linkParents(parent)
         return decl
     }
+
+    fun flattenStructMembers(): MutableList<Statement> {
+        val result = struct!!.statements.withIndex().map {
+            val member = it.value as VarDecl
+            val initvalue = if(value!=null) (value as StructLiteralValue).values[it.index] else null
+            VarDecl(
+                    VarDeclType.VAR,
+                    member.datatype,
+                    ZeropageWish.NOT_IN_ZEROPAGE,
+                    member.arraysize,
+                    mangledStructMemberName(name, member.name),
+                    struct!!.name,
+                    initvalue,
+                    member.isArray,
+                    true,
+                    member.position
+            ) as Statement
+        }.toMutableList()
+        structHasBeenFlattened = true
+        return result
+    }
 }
 
-class ArrayIndex(var index: IExpression, override val position: Position) : Node {
+class ArrayIndex(var index: Expression, override val position: Position) : Node {
     override lateinit var parent: Node
 
     override fun linkParents(parent: Node) {
@@ -204,15 +295,15 @@ class ArrayIndex(var index: IExpression, override val position: Position) : Node
     }
 
     companion object {
-        fun forArray(v: LiteralValue, heap: HeapValues): ArrayIndex {
-            val arraySize = v.arrayvalue?.size ?: heap.get(v.heapId!!).arraysize
-            return ArrayIndex(LiteralValue.optimalNumeric(arraySize, v.position), v.position)
+        fun forArray(v: ArrayLiteralValue): ArrayIndex {
+            return ArrayIndex(NumericLiteralValue.optimalNumeric(v.value.size, v.position), v.position)
         }
     }
 
     fun accept(visitor: IAstModifyingVisitor) {
         index = index.accept(visitor)
     }
+
     fun accept(visitor: IAstVisitor) {
         index.accept(visitor)
     }
@@ -221,17 +312,17 @@ class ArrayIndex(var index: IExpression, override val position: Position) : Node
         return("ArrayIndex($index, pos=$position)")
     }
 
-    fun size() = (index as? LiteralValue)?.asIntegerValue
+    fun size() = (index as? NumericLiteralValue)?.number?.toInt()
 }
 
-open class Assignment(var targets: List<AssignTarget>, val aug_op : String?, var value: IExpression, override val position: Position) : IStatement {
+open class Assignment(var target: AssignTarget, val aug_op : String?, var value: Expression, override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline
-            get() = value !is LiteralValue
+            get() = value !is NumericLiteralValue
 
     override fun linkParents(parent: Node) {
         this.parent = parent
-        targets.forEach { it.linkParents(this) }
+        this.target.linkParents(this)
         value.linkParents(this)
     }
 
@@ -239,24 +330,19 @@ open class Assignment(var targets: List<AssignTarget>, val aug_op : String?, var
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 
     override fun toString(): String {
-        return("Assignment(augop: $aug_op, targets: $targets, value: $value, pos=$position)")
+        return("Assignment(augop: $aug_op, target: $target, value: $value, pos=$position)")
     }
-
-    val singleTarget: AssignTarget?
-        get() {
-            return targets.singleOrNull()  // common case
-        }
 }
 
 // This is a special class so the compiler can see if the assignments are for initializing the vars in the scope,
 // or just a regular assignment. It may optimize the initialization step from this.
-class VariableInitializationAssignment(target: AssignTarget, aug_op: String?, value: IExpression, position: Position)
-    : Assignment(listOf(target), aug_op, value, position)
+class VariableInitializationAssignment(target: AssignTarget, aug_op: String?, value: Expression, position: Position)
+    : Assignment(target, aug_op, value, position)
 
 data class AssignTarget(val register: Register?,
-                        val identifier: IdentifierReference?,
-                        val arrayindexed: ArrayIndexedExpression?,
-                        var memoryAddress: DirectMemoryWrite?,
+                        var identifier: IdentifierReference?,
+                        var arrayindexed: ArrayIndexedExpression?,
+                        val memoryAddress: DirectMemoryWrite?,
                         override val position: Position) : Node {
     override lateinit var parent: Node
 
@@ -271,7 +357,7 @@ data class AssignTarget(val register: Register?,
     fun accept(visitor: IAstVisitor) = visitor.visit(this)
 
     companion object {
-        fun fromExpr(expr: IExpression): AssignTarget {
+        fun fromExpr(expr: Expression): AssignTarget {
             return when (expr) {
                 is RegisterExpr -> AssignTarget(expr.register, null, null, null, expr.position)
                 is IdentifierReference -> AssignTarget(null, expr, null, null, expr.position)
@@ -282,53 +368,35 @@ data class AssignTarget(val register: Register?,
         }
     }
 
-    fun inferType(program: Program, stmt: IStatement): DataType? {
+    fun inferType(program: Program, stmt: Statement): InferredTypes.InferredType {
         if(register!=null)
-            return DataType.UBYTE
+            return InferredTypes.knownFor(DataType.UBYTE)
 
         if(identifier!=null) {
-            val symbol = program.namespace.lookup(identifier.nameInSource, stmt) ?: return null
-            if (symbol is VarDecl) return symbol.datatype
+            val symbol = program.namespace.lookup(identifier!!.nameInSource, stmt) ?: return InferredTypes.unknown()
+            if (symbol is VarDecl) return InferredTypes.knownFor(symbol.datatype)
         }
 
         if(arrayindexed!=null) {
-            val dt = arrayindexed.inferType(program)
-            if(dt!=null)
-                return dt
+            return arrayindexed!!.inferType(program)
         }
 
         if(memoryAddress!=null)
-            return DataType.UBYTE
+            return InferredTypes.knownFor(DataType.UBYTE)
 
-        return null
+        return InferredTypes.unknown()
     }
 
-    fun shortString(withTypePrefix: Boolean=false): String {
-        if(register!=null)
-            return (if(withTypePrefix) "0register::" else "") + register.name
-        if(identifier!=null)
-            return (if(withTypePrefix) "3identifier::" else "") + identifier.nameInSource.last()
-        if(arrayindexed!=null)
-            return (if(withTypePrefix) "2arrayidx::" else "") + arrayindexed.identifier.nameInSource.last()
-        val address = memoryAddress?.addressExpression
-        if(address is LiteralValue)
-            return (if(withTypePrefix) "1address::" else "") +address.asIntegerValue.toString()
-        return if(withTypePrefix) "???::???" else "???"
-    }
-
-    fun isMemoryMapped(namespace: INameScope): Boolean =
-            memoryAddress!=null || (identifier?.targetVarDecl(namespace)?.type== VarDeclType.MEMORY)
-
-    infix fun isSameAs(value: IExpression): Boolean {
+    infix fun isSameAs(value: Expression): Boolean {
         return when {
             this.memoryAddress!=null -> false
             this.register!=null -> value is RegisterExpr && value.register==register
-            this.identifier!=null -> value is IdentifierReference && value.nameInSource==identifier.nameInSource
+            this.identifier!=null -> value is IdentifierReference && value.nameInSource==identifier!!.nameInSource
             this.arrayindexed!=null -> value is ArrayIndexedExpression &&
-                    value.identifier.nameInSource==arrayindexed.identifier.nameInSource &&
+                    value.identifier.nameInSource==arrayindexed!!.identifier.nameInSource &&
                     value.arrayspec.size()!=null &&
-                    arrayindexed.arrayspec.size()!=null &&
-                    value.arrayspec.size()==arrayindexed.arrayspec.size()
+                    arrayindexed!!.arrayspec.size()!=null &&
+                    value.arrayspec.size()==arrayindexed!!.arrayspec.size()
             else -> false
         }
     }
@@ -339,16 +407,16 @@ data class AssignTarget(val register: Register?,
         if(this.register!=null && other.register!=null)
             return this.register==other.register
         if(this.identifier!=null && other.identifier!=null)
-            return this.identifier.nameInSource==other.identifier.nameInSource
+            return this.identifier!!.nameInSource==other.identifier!!.nameInSource
         if(this.memoryAddress!=null && other.memoryAddress!=null) {
-            val addr1 = this.memoryAddress!!.addressExpression.constValue(program)
-            val addr2 = other.memoryAddress!!.addressExpression.constValue(program)
+            val addr1 = this.memoryAddress.addressExpression.constValue(program)
+            val addr2 = other.memoryAddress.addressExpression.constValue(program)
             return addr1!=null && addr2!=null && addr1==addr2
         }
         if(this.arrayindexed!=null && other.arrayindexed!=null) {
-            if(this.arrayindexed.identifier.nameInSource == other.arrayindexed.identifier.nameInSource) {
-                val x1 = this.arrayindexed.arrayspec.index.constValue(program)
-                val x2 = other.arrayindexed.arrayspec.index.constValue(program)
+            if(this.arrayindexed!!.identifier.nameInSource == other.arrayindexed!!.identifier.nameInSource) {
+                val x1 = this.arrayindexed!!.arrayspec.index.constValue(program)
+                val x2 = other.arrayindexed!!.arrayspec.index.constValue(program)
                 return x1!=null && x2!=null && x1==x2
             }
         }
@@ -361,12 +429,12 @@ data class AssignTarget(val register: Register?,
         if(this.memoryAddress!=null)
             return false
         if(this.arrayindexed!=null) {
-            val targetStmt = this.arrayindexed.identifier.targetVarDecl(namespace)
+            val targetStmt = this.arrayindexed!!.identifier.targetVarDecl(namespace)
             if(targetStmt!=null)
                 return targetStmt.type!= VarDeclType.MEMORY
         }
         if(this.identifier!=null) {
-            val targetStmt = this.identifier.targetVarDecl(namespace)
+            val targetStmt = this.identifier!!.targetVarDecl(namespace)
             if(targetStmt!=null)
                 return targetStmt.type!= VarDeclType.MEMORY
         }
@@ -374,7 +442,7 @@ data class AssignTarget(val register: Register?,
     }
 }
 
-class PostIncrDecr(var target: AssignTarget, val operator: String, override val position: Position) : IStatement {
+class PostIncrDecr(var target: AssignTarget, val operator: String, override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -394,7 +462,7 @@ class PostIncrDecr(var target: AssignTarget, val operator: String, override val
 class Jump(val address: Int?,
            val identifier: IdentifierReference?,
            val generatedLabel: String?,             // used in code generation scenarios
-           override val position: Position) : IStatement {
+           override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -412,11 +480,11 @@ class Jump(val address: Int?,
 }
 
 class FunctionCallStatement(override var target: IdentifierReference,
-                            override var arglist: MutableList<IExpression>,
-                            override val position: Position) : IStatement, IFunctionCall {
+                            override var arglist: MutableList<Expression>,
+                            override val position: Position) : Statement(), IFunctionCall {
     override lateinit var parent: Node
     override val expensiveToInline
-            get() = arglist.any { it !is LiteralValue }
+            get() = arglist.any { it !is NumericLiteralValue }
 
     override fun linkParents(parent: Node) {
         this.parent = parent
@@ -432,7 +500,7 @@ class FunctionCallStatement(override var target: IdentifierReference,
     }
 }
 
-class InlineAssembly(val assembly: String, override val position: Position) : IStatement {
+class InlineAssembly(val assembly: String, override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = true
 
@@ -444,22 +512,22 @@ class InlineAssembly(val assembly: String, override val position: Position) : IS
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 }
 
-class AnonymousScope(override var statements: MutableList<IStatement>,
-                     override val position: Position) : INameScope, IStatement {
+class AnonymousScope(override var statements: MutableList<Statement>,
+                     override val position: Position) : INameScope, Statement() {
     override val name: String
     override lateinit var parent: Node
     override val expensiveToInline
         get() = statements.any { it.expensiveToInline }
 
+    companion object {
+        private var sequenceNumber = 1
+    }
+
     init {
         name = "<anon-$sequenceNumber>"     // make sure it's an invalid soruce code identifier so user source code can never produce it
         sequenceNumber++
     }
 
-    companion object {
-        private var sequenceNumber = 1
-    }
-
     override fun linkParents(parent: Node) {
         this.parent = parent
         statements.forEach { it.linkParents(this) }
@@ -469,7 +537,7 @@ class AnonymousScope(override var statements: MutableList<IStatement>,
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 }
 
-class NopStatement(override val position: Position): IStatement {
+class NopStatement(override val position: Position): Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = false
 
@@ -479,6 +547,14 @@ class NopStatement(override val position: Position): IStatement {
 
     override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    companion object {
+        fun insteadOf(stmt: Statement): NopStatement {
+            val nop = NopStatement(stmt.position)
+            nop.parent = stmt.parent
+            return nop
+        }
+    }
 }
 
 // the subroutine class covers both the normal user-defined subroutines,
@@ -492,8 +568,8 @@ class Subroutine(override val name: String,
                  val asmClobbers: Set<Register>,
                  val asmAddress: Int?,
                  val isAsmSubroutine: Boolean,
-                 override var statements: MutableList<IStatement>,
-                 override val position: Position) : IStatement, INameScope {
+                 override var statements: MutableList<Statement>,
+                 override val position: Position) : Statement(), INameScope {
 
     var keepAlways: Boolean = false
     override val expensiveToInline
@@ -523,40 +599,6 @@ class Subroutine(override val name: String,
             .filter { it is InlineAssembly }
             .map { (it as InlineAssembly).assembly }
             .count { " rti" in it || "\trti" in it || " rts" in it || "\trts" in it || " jmp" in it || "\tjmp" in it }
-
-    val canBeAsmSubroutine =false // TODO disabled for now, see below about problem with converting to asm subroutine
-//            !isAsmSubroutine
-//                    && ((parameters.size == 1 && parameters[0].type in setOf(DataType.BYTE, DataType.UBYTE, DataType.WORD, DataType.UWORD))
-//                    || (parameters.size == 2 && parameters.map { it.type }.all { it == DataType.BYTE || it == DataType.UBYTE }))
-
-    fun intoAsmSubroutine(): Subroutine {
-        // TODO turn subroutine into asm calling convention.   Requires rethinking of how parameters are handled (conflicts with local vardefs now, see AstIdentifierChecker...)
-        return this // TODO
-
-//        println("TO ASM   $this")  // TODO
-//        val paramregs = if (parameters.size == 1 && parameters[0].type in setOf(DataType.BYTE, DataType.UBYTE))
-//            listOf(RegisterOrStatusflag(RegisterOrPair.Y, null, null))
-//        else if (parameters.size == 1 && parameters[0].type in setOf(DataType.WORD, DataType.UWORD))
-//            listOf(RegisterOrStatusflag(RegisterOrPair.AY, null, null))
-//        else if (parameters.size == 2 && parameters.map { it.type }.all { it == DataType.BYTE || it == DataType.UBYTE })
-//            listOf(RegisterOrStatusflag(RegisterOrPair.A, null, null), RegisterOrStatusflag(RegisterOrPair.Y, null, null))
-//        else throw FatalAstException("cannot convert subroutine to asm parameters")
-//
-//        val asmsub=Subroutine(
-//                name,
-//                parameters,
-//                returntypes,
-//                paramregs,
-//                emptyList(),
-//                emptySet(),
-//                null,
-//                true,
-//                statements,
-//                position
-//        )
-//        asmsub.linkParents(parent)
-//        return asmsub
-    }
 }
 
 open class SubroutineParameter(val name: String,
@@ -569,10 +611,10 @@ open class SubroutineParameter(val name: String,
     }
 }
 
-class IfStatement(var condition: IExpression,
+class IfStatement(var condition: Expression,
                   var truepart: AnonymousScope,
                   var elsepart: AnonymousScope,
-                  override val position: Position) : IStatement {
+                  override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline: Boolean
         get() = truepart.expensiveToInline || elsepart.expensiveToInline
@@ -591,7 +633,7 @@ class IfStatement(var condition: IExpression,
 class BranchStatement(var condition: BranchCondition,
                       var truepart: AnonymousScope,
                       var elsepart: AnonymousScope,
-                      override val position: Position) : IStatement {
+                      override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline: Boolean
         get() = truepart.expensiveToInline || elsepart.expensiveToInline
@@ -608,11 +650,11 @@ class BranchStatement(var condition: BranchCondition,
 
 class ForLoop(val loopRegister: Register?,
               val decltype: DataType?,
-              val zeropage: Boolean,
-              val loopVar: IdentifierReference?,
-              var iterable: IExpression,
+              val zeropage: ZeropageWish,
+              var loopVar: IdentifierReference?,
+              var iterable: Expression,
               var body: AnonymousScope,
-              override val position: Position) : IStatement {
+              override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = true
 
@@ -629,15 +671,11 @@ class ForLoop(val loopRegister: Register?,
     override fun toString(): String {
         return "ForLoop(loopVar: $loopVar, loopReg: $loopRegister, iterable: $iterable, pos=$position)"
     }
-
-    companion object {
-        const val iteratorLoopcounterVarname = "prog8forloopcounter"
-    }
 }
 
-class WhileLoop(var condition: IExpression,
+class WhileLoop(var condition: Expression,
                 var body: AnonymousScope,
-                override val position: Position) : IStatement {
+                override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = true
 
@@ -652,8 +690,8 @@ class WhileLoop(var condition: IExpression,
 }
 
 class RepeatLoop(var body: AnonymousScope,
-                 var untilCondition: IExpression,
-                 override val position: Position) : IStatement {
+                 var untilCondition: Expression,
+                 override val position: Position) : Statement() {
     override lateinit var parent: Node
     override val expensiveToInline = true
 
@@ -667,9 +705,9 @@ class RepeatLoop(var body: AnonymousScope,
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
 }
 
-class WhenStatement(val condition: IExpression,
-                    val choices: MutableList<WhenChoice>,
-                    override val position: Position): IStatement {
+class WhenStatement(var condition: Expression,
+                    var choices: MutableList<WhenChoice>,
+                    override val position: Position): Statement() {
     override lateinit var parent: Node
     override val expensiveToInline: Boolean = true
 
@@ -679,35 +717,40 @@ class WhenStatement(val condition: IExpression,
         choices.forEach { it.linkParents(this) }
     }
 
-    fun choiceValues(program: Program): List<Pair<Int?, WhenChoice>> {
+    fun choiceValues(program: Program): List<Pair<List<Int>?, WhenChoice>> {
         // only gives sensible results when the choices are all valid (constant integers)
-        return choices
-                .map {
-                    val cv = it.value?.constValue(program)
-                    if(cv==null)
-                        null to it
-                    else
-                        cv.asNumericValue!!.toInt() to it
-                    }
+        val result = mutableListOf<Pair<List<Int>?, WhenChoice>>()
+        for(choice in choices) {
+            if(choice.values==null)
+                result.add(null to choice)
+            else {
+                val values = choice.values!!.map { it.constValue(program)?.number?.toInt() }
+                if(values.contains(null))
+                    result.add(null to choice)
+                else
+                    result.add(values.filterNotNull() to choice)
+            }
+        }
+        return result
     }
 
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
 }
 
-class WhenChoice(val value: IExpression?,           // if null,  this is the 'else' part
-                 val statements: AnonymousScope,
+class WhenChoice(var values: List<Expression>?,           // if null,  this is the 'else' part
+                 var statements: AnonymousScope,
                  override val position: Position) : Node {
     override lateinit var parent: Node
 
     override fun linkParents(parent: Node) {
-        value?.linkParents(this)
+        values?.forEach { it.linkParents(this) }
         statements.linkParents(this)
         this.parent = parent
     }
 
     override fun toString(): String {
-        return "Choice($value at $position)"
+        return "Choice($values at $position)"
     }
 
     fun accept(visitor: IAstVisitor) = visitor.visit(this)
@@ -715,7 +758,28 @@ class WhenChoice(val value: IExpression?,           // if null,  this is the 'el
 }
 
 
-class DirectMemoryWrite(var addressExpression: IExpression, override val position: Position) : Node {
+class StructDecl(override val name: String,
+                 override var statements: MutableList<Statement>,      // actually, only vardecls here
+                 override val position: Position): Statement(), INameScope {
+
+    override lateinit var parent: Node
+    override val expensiveToInline: Boolean = true
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        this.statements.forEach { it.linkParents(this) }
+    }
+
+    val numberOfElements: Int
+        get() = this.statements.size
+
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+
+    fun nameOfFirstMember() = (statements.first() as VarDecl).name
+}
+
+class DirectMemoryWrite(var addressExpression: Expression, override val position: Position) : Node {
     override lateinit var parent: Node
 
     override fun linkParents(parent: Node) {

compiler/src/prog8/compiler/Main.kt

@@ -1,13 +1,11 @@
 package prog8.compiler
 
+import prog8.ast.AstToSourceCode
 import prog8.ast.Program
 import prog8.ast.base.*
-import prog8.ast.base.checkIdentifiers
-import prog8.ast.base.checkValid
-import prog8.ast.base.reorderStatements
 import prog8.ast.statements.Directive
-import prog8.compiler.target.c64.AsmGen
-import prog8.compiler.target.c64.C64Zeropage
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.target.c64.codegen.AsmGen
 import prog8.optimizer.constantFold
 import prog8.optimizer.optimizeStatements
 import prog8.optimizer.simplifyExpressions
@@ -15,20 +13,25 @@ import prog8.parser.ParsingFailedError
 import prog8.parser.importLibraryModule
 import prog8.parser.importModule
 import prog8.parser.moduleName
-import java.io.File
-import java.io.PrintStream
-import java.lang.Exception
 import java.nio.file.Path
-import kotlin.system.exitProcess
 import kotlin.system.measureTimeMillis
 
+
+class CompilationResult(val success: Boolean,
+                        val programAst: Program,
+                        val programName: String,
+                        val importedFiles: List<Path>)
+
+
 fun compileProgram(filepath: Path,
-                   optimize: Boolean, optimizeInlining: Boolean,
-                   generateVmCode: Boolean, writeVmCode: Boolean,
-                   writeAssembly: Boolean): Pair<Program, String?> {
+                   optimize: Boolean,
+                   writeAssembly: Boolean): CompilationResult {
     lateinit var programAst: Program
     var programName: String? = null
 
+    var importedFiles: List<Path> = emptyList()
+    var success=false
+
     try {
         val totalTime = measureTimeMillis {
             // import main module and everything it needs
@@ -36,6 +39,8 @@ fun compileProgram(filepath: Path,
             programAst = Program(moduleName(filepath.fileName), mutableListOf())
             importModule(programAst, filepath)
 
+            importedFiles = programAst.modules.filter { !it.source.startsWith("@embedded@") }.map{ it.source }
+
             val compilerOptions = determineCompilationOptions(programAst)
             if (compilerOptions.launcher == LauncherType.BASIC && compilerOptions.output != OutputType.PRG)
                 throw ParsingFailedError("${programAst.modules.first().position} BASIC launcher requires output type PRG.")
@@ -63,7 +68,9 @@ fun compileProgram(filepath: Path,
             }
             //println(" time2: $time2")
             val time3 = measureTimeMillis {
-                programAst.reorderStatements()     // reorder statements and add type casts, to please the compiler later
+                programAst.removeNopsFlattenAnonScopes()
+                programAst.reorderStatements()
+                programAst.addTypecasts()
             }
             //println(" time3: $time3")
             val time4 = measureTimeMillis {
@@ -78,41 +85,28 @@ fun compileProgram(filepath: Path,
                 while (true) {
                     // keep optimizing expressions and statements until no more steps remain
                     val optsDone1 = programAst.simplifyExpressions()
-                    val optsDone2 = programAst.optimizeStatements(optimizeInlining)
+                    val optsDone2 = programAst.optimizeStatements()
                     if (optsDone1 + optsDone2 == 0)
                         break
                 }
             }
 
+            programAst.addTypecasts()
+            programAst.removeNopsFlattenAnonScopes()
             programAst.checkValid(compilerOptions)          // check if final tree is valid
             programAst.checkRecursion()         // check if there are recursive subroutine calls
 
             // printAst(programAst)
-            // namespace.debugPrint()
 
-            if(generateVmCode) {
-                // compile the syntax tree into stackvmProg form, and optimize that
-                val compiler = Compiler(programAst)
-                val intermediate = compiler.compile(compilerOptions)
-                if (optimize)
-                    intermediate.optimize()
-
-                if (writeVmCode) {
-                    val stackVmFilename = intermediate.name + ".vm.txt"
-                    val stackvmFile = PrintStream(File(stackVmFilename), "utf-8")
-                    intermediate.writeCode(stackvmFile)
-                    stackvmFile.close()
-                    println("StackVM program code written to '$stackVmFilename'")
-                }
-
-                if (writeAssembly) {
-                    val zeropage = C64Zeropage(compilerOptions)
-                    intermediate.allocateZeropage(zeropage)
-                    val assembly = AsmGen(compilerOptions, intermediate, programAst.heap, zeropage).compileToAssembly(optimize)
-                    assembly.assemble(compilerOptions)
-                    programName = assembly.name
-                }
+            if(writeAssembly) {
+                // asm generation directly from the Ast, no need for intermediate code
+                val zeropage = MachineDefinition.C64Zeropage(compilerOptions)
+                programAst.anonscopeVarsCleanup()
+                val assembly = AsmGen(programAst, compilerOptions, zeropage).compileToAssembly(optimize)
+                assembly.assemble(compilerOptions)
+                programName = assembly.name
             }
+            success = true
         }
         println("\nTotal compilation+assemble time: ${totalTime / 1000.0} sec.")
 
@@ -120,12 +114,10 @@ fun compileProgram(filepath: Path,
         System.err.print("\u001b[91m")  // bright red
         System.err.println(px.message)
         System.err.print("\u001b[0m")  // reset
-        exitProcess(1)
     } catch (ax: AstException) {
         System.err.print("\u001b[91m")  // bright red
         System.err.println(ax.toString())
         System.err.print("\u001b[0m")  // reset
-        exitProcess(1)
     } catch (x: Exception) {
         print("\u001b[91m")  // bright red
         println("\n* internal error *")
@@ -139,12 +131,12 @@ fun compileProgram(filepath: Path,
         System.out.flush()
         throw x
     }
-    return Pair(programAst, programName)
+    return CompilationResult(success, programAst, programName ?: "", importedFiles)
 }
 
 fun printAst(programAst: Program) {
     println()
-    val printer = AstToSourceCode(::print)
+    val printer = AstToSourceCode(::print, programAst)
     printer.visit(programAst)
     println()
 }

compiler/src/prog8/compiler/Zeropage.kt

@@ -1,7 +1,6 @@
 package prog8.compiler
 
 import prog8.ast.base.*
-import prog8.ast.base.printWarning
 
 
 class ZeropageDepletedError(message: String) : Exception(message)
@@ -14,11 +13,14 @@ abstract class Zeropage(protected val options: CompilationOptions) {
 
     val allowedDatatypes = NumericDatatypes
 
-    fun available() = free.size
+    fun available() = if(options.zeropage==ZeropageType.DONTUSE) 0 else free.size
 
     fun allocate(scopedname: String, datatype: DataType, position: Position?): Int {
         assert(scopedname.isEmpty() || !allocations.values.any { it.first==scopedname } ) {"isSameAs scopedname can't be allocated twice"}
 
+        if(options.zeropage==ZeropageType.DONTUSE)
+            throw CompilerException("zero page usage has been disabled")
+
         val size =
                 when (datatype) {
                     in ByteDatatypes -> 1

compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt

@@ -9,10 +9,25 @@ class AssemblyProgram(val name: String) {
     private val assemblyFile = "$name.asm"
     private val viceMonListFile = "$name.vice-mon-list"
 
+    companion object {
+        // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
+        val opcodeNames = setOf("adc", "ahx", "alr", "anc", "and", "ane", "arr", "asl", "asr", "axs", "bcc", "bcs",
+                "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
+                "cld", "cli", "clv", "cmp", "cpx", "cpy", "dcm", "dcp", "dec", "dex", "dey",
+                "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
+                "inc", "ins", "inx", "iny", "isb", "isc", "jam", "jmp", "jsr", "lae", "las",
+                "lax", "lda", "lds", "ldx", "ldy", "lsr", "lxa", "nop", "ora", "pha", "php",
+                "pla", "plp", "rla", "rol", "ror", "rra", "rti", "rts", "sax", "sbc", "sbx",
+                "sec", "sed", "sei", "sha", "shl", "shr", "shs", "shx", "shy", "slo", "sre",
+                "sta", "stx", "sty", "tas", "tax", "tay", "tsx", "txa", "txs", "tya", "xaa")
+    }
+
+
     fun assemble(options: CompilationOptions) {
         // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps
-        val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch", "-Wall", "-Wno-strict-bool",
-                "-Werror", "-Wno-error=long-branch", "--dump-labels", "--vice-labels", "-l", viceMonListFile, "--no-monitor")
+        val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                "-Wall", "-Wno-strict-bool", "-Wno-shadow", "-Werror", "-Wno-error=long-branch",
+                "--dump-labels", "--vice-labels", "-l", viceMonListFile, "--no-monitor")
 
         val outFile = when(options.output) {
             OutputType.PRG -> {
@@ -41,7 +56,7 @@ class AssemblyProgram(val name: String) {
     private fun generateBreakpointList() {
         // builds list of breakpoints, appends to monitor list file
         val breakpoints = mutableListOf<String>()
-        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that's generated for them
+        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that"s generated for them
         for(line in File(viceMonListFile).readLines()) {
             val match = pattern.matchEntire(line)
             if(match!=null)

compiler/src/prog8/compiler/target/c64/Commodore64.kt

@@ -1,242 +0,0 @@
-package prog8.compiler.target.c64
-
-import prog8.compiler.CompilationOptions
-import prog8.compiler.CompilerException
-import prog8.compiler.Zeropage
-import prog8.compiler.ZeropageType
-import java.awt.Color
-import java.awt.image.BufferedImage
-import javax.imageio.ImageIO
-import kotlin.math.absoluteValue
-import kotlin.math.pow
-
-
-// 5-byte cbm MFLPT format limitations:
-const val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
-const val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
-
-const val BASIC_LOAD_ADDRESS = 0x0801
-const val RAW_LOAD_ADDRESS = 0xc000
-
-// the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-const val ESTACK_LO = 0xce00        //  $ce00-$ceff inclusive
-const val ESTACK_HI = 0xcf00        //  $cf00-$cfff inclusive
-
-
-class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
-
-    companion object {
-        const val SCRATCH_B1 = 0x02
-        const val SCRATCH_REG = 0x03    // temp storage for a register
-        const val SCRATCH_REG_X = 0xfa    // temp storage for register X (the evaluation stack pointer)
-        const val SCRATCH_W1 = 0xfb     // $fb+$fc
-        const val SCRATCH_W2 = 0xfd     // $fd+$fe
-    }
-
-    override val exitProgramStrategy: ExitProgramStrategy = when(options.zeropage) {
-        ZeropageType.BASICSAFE -> ExitProgramStrategy.CLEAN_EXIT
-        ZeropageType.FLOATSAFE, ZeropageType.KERNALSAFE, ZeropageType.FULL -> ExitProgramStrategy.SYSTEM_RESET
-    }
-
-
-    init {
-        if(options.floats && options.zeropage!=ZeropageType.FLOATSAFE && options.zeropage!=ZeropageType.BASICSAFE)
-            throw CompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe'")
-
-        if(options.zeropage == ZeropageType.FULL) {
-            free.addAll(0x04 .. 0xf9)
-            free.add(0xff)
-            free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_REG_X, SCRATCH_W1, SCRATCH_W1+1, SCRATCH_W2, SCRATCH_W2+1))
-            free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
-        } else {
-            if(options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
-                free.addAll(listOf(0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
-                        0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
-                        0x22, 0x23, 0x24, 0x25,
-                        0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
-                        0x47, 0x48, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x51, 0x52, 0x53,
-                        0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
-                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
-                        0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
-                        0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c,
-                        0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a,
-                        0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xff
-                        // 0x90-0xfa is 'kernel work storage area'
-                ))
-            }
-
-            if(options.zeropage == ZeropageType.FLOATSAFE) {
-                // remove the zero page locations used for floating point operations from the free list
-                free.removeAll(listOf(
-                        0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
-                        0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
-                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
-                        0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
-                        0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xf
-                ))
-            }
-
-            // add the other free Zp addresses,
-            // these are valid for the C-64 (when no RS232 I/O is performed) but to keep BASIC running fully:
-            free.addAll(listOf(0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0d, 0x0e,
-                    0x94, 0x95, 0xa7, 0xa8, 0xa9, 0xaa,
-                    0xb5, 0xb6, 0xf7, 0xf8, 0xf9))
-        }
-        assert(SCRATCH_B1 !in free)
-        assert(SCRATCH_REG !in free)
-        assert(SCRATCH_REG_X !in free)
-        assert(SCRATCH_W1 !in free)
-        assert(SCRATCH_W2 !in free)
-
-        for(reserved in options.zpReserved)
-            reserve(reserved)
-    }
-}
-
-
-data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short) {
-
-    companion object {
-        const val MemorySize = 5
-
-        val zero = Mflpt5(0, 0,0,0,0)
-        fun fromNumber(num: Number): Mflpt5 {
-            // see https://en.wikipedia.org/wiki/Microsoft_Binary_Format
-            // and https://sourceforge.net/p/acme-crossass/code-0/62/tree/trunk/ACME_Lib/cbm/mflpt.a
-            // and https://en.wikipedia.org/wiki/IEEE_754-1985
-
-            val flt = num.toDouble()
-            if(flt < FLOAT_MAX_NEGATIVE || flt > FLOAT_MAX_POSITIVE)
-                throw CompilerException("floating point number out of 5-byte mflpt range: $this")
-            if(flt==0.0)
-                return zero
-
-            val sign = if(flt<0.0) 0x80L else 0x00L
-            var exponent = 128 + 32	// 128 is cbm's bias, 32 is this algo's bias
-            var mantissa = flt.absoluteValue
-
-            // if mantissa is too large, shift right and adjust exponent
-            while(mantissa >= 0x100000000) {
-                mantissa /= 2.0
-                exponent ++
-            }
-            // if mantissa is too small, shift left and adjust exponent
-            while(mantissa < 0x80000000) {
-                mantissa *= 2.0
-                exponent --
-            }
-
-            return when {
-                exponent<0 -> zero  // underflow, use zero instead
-                exponent>255 -> throw CompilerException("floating point overflow: $this")
-                exponent==0 -> zero
-                else -> {
-                    val mantLong = mantissa.toLong()
-                    Mflpt5(
-                            exponent.toShort(),
-                            (mantLong.and(0x7f000000L) ushr 24).or(sign).toShort(),
-                            (mantLong.and(0x00ff0000L) ushr 16).toShort(),
-                            (mantLong.and(0x0000ff00L) ushr 8).toShort(),
-                            (mantLong.and(0x000000ffL)).toShort())
-                }
-            }
-        }
-    }
-
-    fun toDouble(): Double {
-        if(this == zero) return 0.0
-        val exp = b0 - 128
-        val sign = (b1.toInt() and 0x80) > 0
-        val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
-        val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
-        return if(sign) -result else result
-    }
-}
-
-object Charset {
-    private val normalImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-normal.png"))
-    private val shiftedImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-shifted.png"))
-
-    private fun scanChars(img: BufferedImage): Array<BufferedImage> {
-
-        val transparent = BufferedImage(img.width, img.height, BufferedImage.TYPE_INT_ARGB)
-        transparent.createGraphics().drawImage(img, 0, 0, null)
-
-        val black = Color(0,0,0).rgb
-        val nopixel = Color(0,0,0,0).rgb
-        for(y in 0 until transparent.height) {
-            for(x in 0 until transparent.width) {
-                val col = transparent.getRGB(x, y)
-                if(col==black)
-                    transparent.setRGB(x, y, nopixel)
-            }
-        }
-
-        val numColumns = transparent.width / 8
-        val charImages = (0..255).map {
-            val charX = it % numColumns
-            val charY = it/ numColumns
-            transparent.getSubimage(charX*8, charY*8, 8, 8)
-        }
-        return charImages.toTypedArray()
-    }
-
-    val normalChars = scanChars(normalImg)
-    val shiftedChars = scanChars(shiftedImg)
-
-    private val coloredNormalChars = mutableMapOf<Short, Array<BufferedImage>>()
-
-    fun getColoredChar(screenCode: Short, color: Short): BufferedImage {
-        val colorIdx = (color % Colors.palette.size).toShort()
-        val chars = coloredNormalChars[colorIdx]
-        if(chars!=null)
-            return chars[screenCode.toInt()]
-
-        val coloredChars = mutableListOf<BufferedImage>()
-        val transparent = Color(0,0,0,0).rgb
-        val rgb = Colors.palette[colorIdx.toInt()].rgb
-        for(c in normalChars) {
-            val colored = c.copy()
-            for(y in 0 until colored.height)
-                for(x in 0 until colored.width) {
-                    if(colored.getRGB(x, y)!=transparent) {
-                        colored.setRGB(x, y, rgb)
-                    }
-                }
-            coloredChars.add(colored)
-        }
-        coloredNormalChars[colorIdx] = coloredChars.toTypedArray()
-        return coloredNormalChars.getValue(colorIdx)[screenCode.toInt()]
-    }
-
-}
-
-private fun BufferedImage.copy(): BufferedImage {
-    val bcopy = BufferedImage(this.width, this.height, this.type)
-    val g = bcopy.graphics
-    g.drawImage(this, 0, 0, null)
-    g.dispose()
-    return bcopy
-}
-
-
-object Colors {
-    val palette = listOf(         // this is Pepto's Commodore-64 palette  http://www.pepto.de/projects/colorvic/
-            Color(0x000000),  // 0 = black
-            Color(0xFFFFFF),  // 1 = white
-            Color(0x813338),  // 2 = red
-            Color(0x75cec8),  // 3 = cyan
-            Color(0x8e3c97),  // 4 = purple
-            Color(0x56ac4d),  // 5 = green
-            Color(0x2e2c9b),  // 6 = blue
-            Color(0xedf171),  // 7 = yellow
-            Color(0x8e5029),  // 8 = orange
-            Color(0x553800),  // 9 = brown
-            Color(0xc46c71),  // 10 = light red
-            Color(0x4a4a4a),  // 11 = dark grey
-            Color(0x7b7b7b),  // 12 = medium grey
-            Color(0xa9ff9f),  // 13 = light green
-            Color(0x706deb),  // 14 = light blue
-            Color(0xb2b2b2)   // 15 = light grey
-    )
-}

compiler/src/prog8/compiler/target/c64/MachineDefinition.kt

@@ -0,0 +1,255 @@
+package prog8.compiler.target.c64
+
+import prog8.compiler.CompilationOptions
+import prog8.compiler.CompilerException
+import prog8.compiler.Zeropage
+import prog8.compiler.ZeropageType
+import java.awt.Color
+import java.awt.image.BufferedImage
+import javax.imageio.ImageIO
+import kotlin.math.absoluteValue
+import kotlin.math.pow
+
+object MachineDefinition {
+
+    // 5-byte cbm MFLPT format limitations:
+    const val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
+    const val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
+
+    const val BASIC_LOAD_ADDRESS = 0x0801
+    const val RAW_LOAD_ADDRESS = 0xc000
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    // and some heavily used string constants derived from the two values above
+    const val ESTACK_LO_VALUE       = 0xce00        //  $ce00-$ceff inclusive
+    const val ESTACK_HI_VALUE       = 0xcf00        //  $cf00-$cfff inclusive
+    const val ESTACK_LO_HEX         = "\$ce00"
+    const val ESTACK_LO_PLUS1_HEX   = "\$ce01"
+    const val ESTACK_LO_PLUS2_HEX   = "\$ce02"
+    const val ESTACK_HI_HEX         = "\$cf00"
+    const val ESTACK_HI_PLUS1_HEX   = "\$cf01"
+    const val ESTACK_HI_PLUS2_HEX   = "\$cf02"
+
+
+    class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+        companion object {
+            const val SCRATCH_B1 = 0x02
+            const val SCRATCH_REG = 0x03    // temp storage for a register
+            const val SCRATCH_REG_X = 0xfa    // temp storage for register X (the evaluation stack pointer)
+            const val SCRATCH_W1 = 0xfb     // $fb+$fc
+            const val SCRATCH_W2 = 0xfd     // $fd+$fe
+        }
+
+        override val exitProgramStrategy: ExitProgramStrategy = when (options.zeropage) {
+            ZeropageType.BASICSAFE, ZeropageType.DONTUSE -> ExitProgramStrategy.CLEAN_EXIT
+            ZeropageType.FLOATSAFE, ZeropageType.KERNALSAFE, ZeropageType.FULL -> ExitProgramStrategy.SYSTEM_RESET
+        }
+
+
+        init {
+            if (options.floats && options.zeropage !in setOf(ZeropageType.FLOATSAFE, ZeropageType.BASICSAFE, ZeropageType.DONTUSE ))
+                throw CompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+            if (options.zeropage == ZeropageType.FULL) {
+                free.addAll(0x04..0xf9)
+                free.add(0xff)
+                free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_REG_X, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+                free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
+            } else {
+                if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
+                    free.addAll(listOf(0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
+                            0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
+                            0x22, 0x23, 0x24, 0x25,
+                            0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
+                            0x47, 0x48, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x51, 0x52, 0x53,
+                            0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
+                            0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+                            0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
+                            0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c,
+                            0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a,
+                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xff
+                            // 0x90-0xfa is 'kernel work storage area'
+                    ))
+                }
+
+                if (options.zeropage == ZeropageType.FLOATSAFE) {
+                    // remove the zero page locations used for floating point operations from the free list
+                    free.removeAll(listOf(
+                            0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
+                            0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
+                            0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+                            0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
+                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xf
+                    ))
+                }
+
+                if(options.zeropage!=ZeropageType.DONTUSE) {
+                    // add the other free Zp addresses,
+                    // these are valid for the C-64 (when no RS232 I/O is performed) but to keep BASIC running fully:
+                    free.addAll(listOf(0x04, 0x05, 0x06, 0x0a, 0x0e,
+                            0x94, 0x95, 0xa7, 0xa8, 0xa9, 0xaa,
+                            0xb5, 0xb6, 0xf7, 0xf8, 0xf9))
+                } else {
+                    // don't use the zeropage at all
+                    free.clear()
+                }
+            }
+            assert(SCRATCH_B1 !in free)
+            assert(SCRATCH_REG !in free)
+            assert(SCRATCH_REG_X !in free)
+            assert(SCRATCH_W1 !in free)
+            assert(SCRATCH_W2 !in free)
+
+            for (reserved in options.zpReserved)
+                reserve(reserved)
+        }
+    }
+
+
+    data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short) {
+
+        companion object {
+            const val MemorySize = 5
+
+            val zero = Mflpt5(0, 0, 0, 0, 0)
+            fun fromNumber(num: Number): Mflpt5 {
+                // see https://en.wikipedia.org/wiki/Microsoft_Binary_Format
+                // and https://sourceforge.net/p/acme-crossass/code-0/62/tree/trunk/ACME_Lib/cbm/mflpt.a
+                // and https://en.wikipedia.org/wiki/IEEE_754-1985
+
+                val flt = num.toDouble()
+                if (flt < FLOAT_MAX_NEGATIVE || flt > FLOAT_MAX_POSITIVE)
+                    throw CompilerException("floating point number out of 5-byte mflpt range: $this")
+                if (flt == 0.0)
+                    return zero
+
+                val sign = if (flt < 0.0) 0x80L else 0x00L
+                var exponent = 128 + 32    // 128 is cbm's bias, 32 is this algo's bias
+                var mantissa = flt.absoluteValue
+
+                // if mantissa is too large, shift right and adjust exponent
+                while (mantissa >= 0x100000000) {
+                    mantissa /= 2.0
+                    exponent++
+                }
+                // if mantissa is too small, shift left and adjust exponent
+                while (mantissa < 0x80000000) {
+                    mantissa *= 2.0
+                    exponent--
+                }
+
+                return when {
+                    exponent < 0 -> zero  // underflow, use zero instead
+                    exponent > 255 -> throw CompilerException("floating point overflow: $this")
+                    exponent == 0 -> zero
+                    else -> {
+                        val mantLong = mantissa.toLong()
+                        Mflpt5(
+                                exponent.toShort(),
+                                (mantLong.and(0x7f000000L) ushr 24).or(sign).toShort(),
+                                (mantLong.and(0x00ff0000L) ushr 16).toShort(),
+                                (mantLong.and(0x0000ff00L) ushr 8).toShort(),
+                                (mantLong.and(0x000000ffL)).toShort())
+                    }
+                }
+            }
+        }
+
+        fun toDouble(): Double {
+            if (this == zero) return 0.0
+            val exp = b0 - 128
+            val sign = (b1.toInt() and 0x80) > 0
+            val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
+            val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
+            return if (sign) -result else result
+        }
+    }
+
+    object Charset {
+        private val normalImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-normal.png"))
+        private val shiftedImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-shifted.png"))
+
+        private fun scanChars(img: BufferedImage): Array<BufferedImage> {
+
+            val transparent = BufferedImage(img.width, img.height, BufferedImage.TYPE_INT_ARGB)
+            transparent.createGraphics().drawImage(img, 0, 0, null)
+
+            val black = Color(0, 0, 0).rgb
+            val nopixel = Color(0, 0, 0, 0).rgb
+            for (y in 0 until transparent.height) {
+                for (x in 0 until transparent.width) {
+                    val col = transparent.getRGB(x, y)
+                    if (col == black)
+                        transparent.setRGB(x, y, nopixel)
+                }
+            }
+
+            val numColumns = transparent.width / 8
+            val charImages = (0..255).map {
+                val charX = it % numColumns
+                val charY = it / numColumns
+                transparent.getSubimage(charX * 8, charY * 8, 8, 8)
+            }
+            return charImages.toTypedArray()
+        }
+
+        val normalChars = scanChars(normalImg)
+        val shiftedChars = scanChars(shiftedImg)
+
+        private val coloredNormalChars = mutableMapOf<Short, Array<BufferedImage>>()
+
+        fun getColoredChar(screenCode: Short, color: Short): BufferedImage {
+            val colorIdx = (color % colorPalette.size).toShort()
+            val chars = coloredNormalChars[colorIdx]
+            if (chars != null)
+                return chars[screenCode.toInt()]
+
+            val coloredChars = mutableListOf<BufferedImage>()
+            val transparent = Color(0, 0, 0, 0).rgb
+            val rgb = colorPalette[colorIdx.toInt()].rgb
+            for (c in normalChars) {
+                val colored = c.copy()
+                for (y in 0 until colored.height)
+                    for (x in 0 until colored.width) {
+                        if (colored.getRGB(x, y) != transparent) {
+                            colored.setRGB(x, y, rgb)
+                        }
+                    }
+                coloredChars.add(colored)
+            }
+            coloredNormalChars[colorIdx] = coloredChars.toTypedArray()
+            return coloredNormalChars.getValue(colorIdx)[screenCode.toInt()]
+        }
+
+    }
+
+    private fun BufferedImage.copy(): BufferedImage {
+        val bcopy = BufferedImage(this.width, this.height, this.type)
+        val g = bcopy.graphics
+        g.drawImage(this, 0, 0, null)
+        g.dispose()
+        return bcopy
+    }
+
+
+    val colorPalette = listOf(         // this is Pepto's Commodore-64 palette  http://www.pepto.de/projects/colorvic/
+            Color(0x000000),  // 0 = black
+            Color(0xFFFFFF),  // 1 = white
+            Color(0x813338),  // 2 = red
+            Color(0x75cec8),  // 3 = cyan
+            Color(0x8e3c97),  // 4 = purple
+            Color(0x56ac4d),  // 5 = green
+            Color(0x2e2c9b),  // 6 = blue
+            Color(0xedf171),  // 7 = yellow
+            Color(0x8e5029),  // 8 = orange
+            Color(0x553800),  // 9 = brown
+            Color(0xc46c71),  // 10 = light red
+            Color(0x4a4a4a),  // 11 = dark grey
+            Color(0x7b7b7b),  // 12 = medium grey
+            Color(0xa9ff9f),  // 13 = light green
+            Color(0x706deb),  // 14 = light blue
+            Color(0xb2b2b2)   // 15 = light grey
+    )
+
+}

compiler/src/prog8/compiler/target/c64/codegen/AnonymousScopeVarsCleanup.kt

@@ -0,0 +1,48 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.AstException
+import prog8.ast.base.NameError
+import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.statements.AnonymousScope
+import prog8.ast.statements.Statement
+import prog8.ast.statements.VarDecl
+
+class AnonymousScopeVarsCleanup(val program: Program): IAstModifyingVisitor {
+    private val checkResult: MutableList<AstException> = mutableListOf()
+    private val varsToMove: MutableMap<AnonymousScope, List<VarDecl>> = mutableMapOf()
+
+    fun result(): List<AstException> {
+        return checkResult
+    }
+
+    override fun visit(program: Program) {
+        varsToMove.clear()
+        super.visit(program)
+        for((scope, decls) in varsToMove) {
+            val sub = scope.definingSubroutine()!!
+            val existingVariables = sub.statements.filterIsInstance<VarDecl>().associateBy { it.name }
+            var conflicts = false
+            decls.forEach {
+                val existing = existingVariables[it.name]
+                if (existing!=null) {
+                    checkResult.add(NameError("variable ${it.name} already defined in subroutine ${sub.name} at ${existing.position}", it.position))
+                    conflicts = true
+                }
+            }
+            if (!conflicts) {
+                decls.forEach { scope.remove(it) }
+                sub.statements.addAll(0, decls)
+                decls.forEach { it.parent = sub }
+            }
+        }
+    }
+
+    override fun visit(scope: AnonymousScope): Statement {
+        val scope2 = super.visit(scope) as AnonymousScope
+        val vardecls = scope2.statements.filterIsInstance<VarDecl>()
+        varsToMove[scope2] = vardecls
+        return scope2
+    }
+}
+

compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt

@@ -0,0 +1,879 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.antlr.escape
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.compiler.*
+import prog8.compiler.target.c64.AssemblyProgram
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.Petscii
+import prog8.functions.BuiltinFunctions
+import prog8.functions.FunctionSignature
+import java.io.File
+import java.math.RoundingMode
+import java.util.*
+import kotlin.math.absoluteValue
+
+
+internal class AssemblyError(msg: String) : RuntimeException(msg)
+
+
+internal class AsmGen(val program: Program,
+                      val options: CompilationOptions,
+                      val zeropage: Zeropage) {
+
+    private val assemblyLines = mutableListOf<String>()
+    private val globalFloatConsts = mutableMapOf<Double, String>()     // all float values in the entire program (value -> varname)
+    private val allocatedZeropageVariables = mutableMapOf<String, Pair<Int, DataType>>()
+    private val breakpointLabels = mutableListOf<String>()
+    private val builtinFunctionsAsmGen = BuiltinFunctionsAsmGen(program, this)
+    private val forloopsAsmGen = ForLoopsAsmGen(program, this)
+    private val postincrdecrAsmGen = PostIncrDecrAsmGen(program, this)
+    private val functioncallAsmGen = FunctionCallAsmGen(program, this)
+    private val assignmentAsmGen = AssignmentAsmGen(program, this)
+    private val expressionsAsmGen = ExpressionsAsmGen(program, this)
+    internal val loopEndLabels = Stack<String>()
+    internal val loopContinueLabels = Stack<String>()
+
+    internal fun compileToAssembly(optimize: Boolean): AssemblyProgram {
+        assemblyLines.clear()
+        loopEndLabels.clear()
+        loopContinueLabels.clear()
+
+        println("Generating assembly code... ")
+
+        header()
+        val allBlocks = program.allBlocks()
+        if(allBlocks.first().name != "main")
+            throw AssemblyError("first block should be 'main'")
+        for(b in program.allBlocks())
+            block2asm(b)
+        footer()
+
+        if(optimize) {
+            var optimizationsDone = 1
+            while (optimizationsDone > 0) {
+                optimizationsDone = optimizeAssembly(assemblyLines)
+            }
+        }
+
+        File("${program.name}.asm").printWriter().use {
+            for (line in assemblyLines) { it.println(line) }
+        }
+
+        return AssemblyProgram(program.name)
+    }
+
+    private fun header() {
+        val ourName = this.javaClass.name
+        out("; 6502 assembly code for '${program.name}'")
+        out("; generated by $ourName on ${Date()}")
+        out("; assembler syntax is for the 64tasm cross-assembler")
+        out("; output options: output=${options.output} launcher=${options.launcher} zp=${options.zeropage}")
+        out("\n.cpu  '6502'\n.enc  'none'\n")
+
+        program.actualLoadAddress = program.definedLoadAddress
+        if (program.actualLoadAddress == 0)   // fix load address
+            program.actualLoadAddress = if (options.launcher == LauncherType.BASIC)
+                MachineDefinition.BASIC_LOAD_ADDRESS else MachineDefinition.RAW_LOAD_ADDRESS
+
+        when {
+            options.launcher == LauncherType.BASIC -> {
+                if (program.actualLoadAddress != 0x0801)
+                    throw AssemblyError("BASIC output must have load address $0801")
+                out("; ---- basic program with sys call ----")
+                out("* = ${program.actualLoadAddress.toHex()}")
+                val year = Calendar.getInstance().get(Calendar.YEAR)
+                out("  .word  (+), $year")
+                out("  .null  $9e, format(' %d ', _prog8_entrypoint), $3a, $8f, ' prog8 by idj'")
+                out("+\t.word  0")
+                out("_prog8_entrypoint\t; assembly code starts here\n")
+                out("  jsr  prog8_lib.init_system")
+            }
+            options.output == OutputType.PRG -> {
+                out("; ---- program without basic sys call ----")
+                out("* = ${program.actualLoadAddress.toHex()}\n")
+                out("  jsr  prog8_lib.init_system")
+            }
+            options.output == OutputType.RAW -> {
+                out("; ---- raw assembler program ----")
+                out("* = ${program.actualLoadAddress.toHex()}\n")
+            }
+        }
+
+        if (zeropage.exitProgramStrategy != Zeropage.ExitProgramStrategy.CLEAN_EXIT) {
+            // disable shift-commodore charset switching and run/stop key
+            out("  lda  #$80")
+            out("  lda  #$80")
+            out("  sta  657\t; disable charset switching")
+            out("  lda  #239")
+            out("  sta  808\t; disable run/stop key")
+        }
+
+        out("  ldx  #\$ff\t; init estack pointer")
+
+        out("  ; initialize the variables in each block")
+        for (block in program.allBlocks()) {
+            val initVarsSub = block.statements.singleOrNull { it is Subroutine && it.name == initvarsSubName }
+            if(initVarsSub!=null)
+                out("  jsr  ${block.name}.$initvarsSubName")
+        }
+
+        out("  clc")
+        when (zeropage.exitProgramStrategy) {
+            Zeropage.ExitProgramStrategy.CLEAN_EXIT -> {
+                out("  jmp  main.start\t; jump to program entrypoint")
+            }
+            Zeropage.ExitProgramStrategy.SYSTEM_RESET -> {
+                out("  jsr  main.start\t; call program entrypoint")
+                out("  jmp  (c64.RESET_VEC)\t; cold reset")
+            }
+        }
+        out("")
+    }
+
+    private fun footer() {
+        // the global list of all floating point constants for the whole program
+        out("; global float constants")
+        for (flt in globalFloatConsts) {
+            val mflpt5 = MachineDefinition.Mflpt5.fromNumber(flt.key)
+            val floatFill = makeFloatFill(mflpt5)
+            val floatvalue = flt.key
+            out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
+        }
+    }
+
+    private fun block2asm(block: Block) {
+        out("\n; ---- block: '${block.name}' ----")
+        out("${block.name}\t" + (if("force_output" in block.options()) ".block\n" else ".proc\n"))
+
+        if(block.address!=null) {
+            out(".cerror * > ${block.address.toHex()}, 'block address overlaps by ', *-${block.address.toHex()},' bytes'")
+            out("* = ${block.address.toHex()}")
+        }
+
+        outputSourceLine(block)
+        zeropagevars2asm(block.statements)
+        memdefs2asm(block.statements)
+        vardecls2asm(block.statements)
+        out("\n; subroutines in this block")
+
+        // first translate regular statements, and then put the subroutines at the end.
+        val (subroutine, stmts) = block.statements.partition { it is Subroutine }
+        stmts.forEach { translate(it) }
+        subroutine.forEach { translateSubroutine(it as Subroutine) }
+
+        out(if("force_output" in block.options()) "\n\t.bend\n" else "\n\t.pend\n")
+    }
+
+    private var generatedLabelSequenceNumber: Int = 0
+
+    internal fun makeLabel(postfix: String): String {
+        generatedLabelSequenceNumber++
+        return "_prog8_label_${generatedLabelSequenceNumber}_$postfix"
+    }
+
+    private fun outputSourceLine(node: Node) {
+        out(" ;\tsrc line: ${node.position.file}:${node.position.line}")
+    }
+
+    internal fun out(str: String, splitlines: Boolean = true) {
+        val fragment = (if(" | " in str) str.replace("|", "\n") else str).trim('\n')
+
+        if (splitlines) {
+            for (line in fragment.split('\n')) {
+                val trimmed = if (line.startsWith(' ')) "\t" + line.trim() else line.trim()
+                // trimmed = trimmed.replace(Regex("^\\+\\s+"), "+\t")  // sanitize local label indentation
+                assemblyLines.add(trimmed)
+            }
+        } else assemblyLines.add(fragment)
+    }
+
+    private fun makeFloatFill(flt: MachineDefinition.Mflpt5): String {
+        val b0 = "$" + flt.b0.toString(16).padStart(2, '0')
+        val b1 = "$" + flt.b1.toString(16).padStart(2, '0')
+        val b2 = "$" + flt.b2.toString(16).padStart(2, '0')
+        val b3 = "$" + flt.b3.toString(16).padStart(2, '0')
+        val b4 = "$" + flt.b4.toString(16).padStart(2, '0')
+        return "$b0, $b1, $b2, $b3, $b4"
+    }
+
+    private fun encodeStr(str: String, dt: DataType): List<Short> {
+        return when(dt) {
+            DataType.STR -> {
+                val bytes = Petscii.encodePetscii(str, true)
+                bytes.plus(0)
+            }
+            DataType.STR_S -> {
+                val bytes = Petscii.encodeScreencode(str, true)
+                bytes.plus(0)
+            }
+            else -> throw AssemblyError("invalid str type")
+        }
+    }
+
+    private fun zeropagevars2asm(statements: List<Statement>) {
+        out("; vars allocated on zeropage")
+        val variables = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.VAR }
+        for(variable in variables) {
+            // should NOT allocate subroutine parameters on the zero page
+            val fullName = variable.scopedname
+            val zpVar = allocatedZeropageVariables[fullName]
+            if(zpVar==null) {
+                // This var is not on the ZP yet. Attempt to move it there (if it's not a float, those take up too much space)
+                if(variable.zeropage != ZeropageWish.NOT_IN_ZEROPAGE &&
+                        variable.datatype in zeropage.allowedDatatypes
+                        && variable.datatype != DataType.FLOAT
+                        && options.zeropage != ZeropageType.DONTUSE) {
+                    try {
+                        val address = zeropage.allocate(fullName, variable.datatype, null)
+                        out("${variable.name} = $address\t; auto zp ${variable.datatype}")
+                        // make sure we add the var to the set of zpvars for this block
+                        allocatedZeropageVariables[fullName] = Pair(address, variable.datatype)
+                    } catch (x: ZeropageDepletedError) {
+                        // leave it as it is.
+                    }
+                }
+            }
+        }
+    }
+
+    private fun vardecl2asm(decl: VarDecl) {
+        when (decl.datatype) {
+            DataType.UBYTE -> out("${decl.name}\t.byte  0")
+            DataType.BYTE -> out("${decl.name}\t.char  0")
+            DataType.UWORD -> out("${decl.name}\t.word  0")
+            DataType.WORD -> out("${decl.name}\t.sint  0")
+            DataType.FLOAT -> out("${decl.name}\t.byte  0,0,0,0,0  ; float")
+            DataType.STRUCT -> {}       // is flattened
+            DataType.STR, DataType.STR_S -> {
+                val string = (decl.value as StringLiteralValue).value
+                val encoded = encodeStr(string, decl.datatype)
+                outputStringvar(decl, encoded)
+            }
+            DataType.ARRAY_UB -> {
+                val data = makeArrayFillDataUnsigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.byte  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .byte  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_B -> {
+                val data = makeArrayFillDataSigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.char  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .char  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_UW -> {
+                val data = makeArrayFillDataUnsigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.word  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .word  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_W -> {
+                val data = makeArrayFillDataSigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.sint  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .sint  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_F -> {
+                val array = (decl.value as ArrayLiteralValue).value
+                val floatFills = array.map {
+                    val number = (it as NumericLiteralValue).number
+                    makeFloatFill(MachineDefinition.Mflpt5.fromNumber(number))
+                }
+                out(decl.name)
+                for (f in array.zip(floatFills))
+                    out("  .byte  ${f.second}  ; float ${f.first}")
+            }
+        }
+    }
+
+    private fun memdefs2asm(statements: List<Statement>) {
+        out("\n; memdefs and kernel subroutines")
+        val memvars = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.MEMORY || it.type==VarDeclType.CONST }
+        for(m in memvars) {
+            out("  ${m.name} = ${(m.value as NumericLiteralValue).number.toHex()}")
+        }
+        val asmSubs = statements.filterIsInstance<Subroutine>().filter { it.isAsmSubroutine }
+        for(sub in asmSubs) {
+            if(sub.asmAddress!=null) {
+                if(sub.statements.isNotEmpty())
+                    throw AssemblyError("kernel subroutine cannot have statements")
+                out("  ${sub.name} = ${sub.asmAddress.toHex()}")
+            }
+        }
+    }
+
+    private fun vardecls2asm(statements: List<Statement>) {
+        out("\n; non-zeropage variables")
+        val vars = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.VAR }
+
+        // first output the flattened struct member variables *in order*
+        // after that, the other variables sorted by their datatype
+
+        val (structMembers, normalVars) = vars.partition { it.struct!=null }
+        structMembers.forEach { vardecl2asm(it) }
+
+        // special treatment for string types: merge strings that are identical
+        val encodedstringVars = normalVars
+                .filter {it.datatype in StringDatatypes }
+                .map { it to encodeStr((it.value as StringLiteralValue).value, it.datatype) }
+                .groupBy({it.second}, {it.first})
+        for((encoded, variables) in encodedstringVars) {
+            variables.dropLast(1).forEach { out(it.name) }
+            val lastvar = variables.last()
+            outputStringvar(lastvar, encoded)
+        }
+
+        // non-string variables
+        normalVars.filter{ it.datatype !in StringDatatypes}.sortedBy { it.datatype }.forEach {
+            if(it.scopedname !in allocatedZeropageVariables)
+                vardecl2asm(it)
+        }
+    }
+
+    private fun outputStringvar(lastvar: VarDecl, encoded: List<Short>) {
+        val string = (lastvar.value as StringLiteralValue).value
+        out("${lastvar.name}\t; ${lastvar.datatype} \"${escape(string).replace("\u0000", "<NULL>")}\"")
+        val outputBytes = encoded.map { "$" + it.toString(16).padStart(2, '0') }
+        for (chunk in outputBytes.chunked(16))
+            out("  .byte  " + chunk.joinToString())
+    }
+
+    private fun makeArrayFillDataUnsigned(decl: VarDecl): List<String> {
+        val array = (decl.value as ArrayLiteralValue).value
+        return when {
+            decl.datatype == DataType.ARRAY_UB ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = (it as NumericLiteralValue).number.toInt()
+                    "$"+number.toString(16).padStart(2, '0')
+                }
+            decl.datatype== DataType.ARRAY_UW -> array.map {
+                if(it is NumericLiteralValue) {
+                    "$" + it.number.toInt().toString(16).padStart(4, '0')
+                } else {
+                    (it as AddressOf).identifier.nameInSource.joinToString(".")
+                }
+            }
+            else -> throw AssemblyError("invalid arraysize type")
+        }
+    }
+
+    private fun makeArrayFillDataSigned(decl: VarDecl): List<String> {
+        val array = (decl.value as ArrayLiteralValue).value
+
+        return when {
+            decl.datatype == DataType.ARRAY_UB ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = (it as NumericLiteralValue).number.toInt()
+                    val hexnum = number.toString(16).padStart(2, '0')
+                    "$$hexnum"
+                }
+            decl.datatype == DataType.ARRAY_B ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = (it as NumericLiteralValue).number.toInt()
+                    val hexnum = number.absoluteValue.toString(16).padStart(2, '0')
+                    if(number>=0)
+                        "$$hexnum"
+                    else
+                        "-$$hexnum"
+                }
+            decl.datatype== DataType.ARRAY_UW -> array.map {
+                val number = (it as NumericLiteralValue).number.toInt()
+                val hexnum = number.toString(16).padStart(4, '0')
+                "$$hexnum"
+            }
+            decl.datatype== DataType.ARRAY_W -> array.map {
+                val number = (it as NumericLiteralValue).number.toInt()
+                val hexnum = number.absoluteValue.toString(16).padStart(4, '0')
+                if(number>=0)
+                    "$$hexnum"
+                else
+                    "-$$hexnum"
+            }
+            else -> throw AssemblyError("invalid arraysize type ${decl.datatype}")
+        }
+    }
+
+    internal fun getFloatConst(number: Double): String {
+        // try to match the ROM float constants to save memory
+        val mflpt5 = MachineDefinition.Mflpt5.fromNumber(number)
+        val floatbytes = shortArrayOf(mflpt5.b0, mflpt5.b1, mflpt5.b2, mflpt5.b3, mflpt5.b4)
+        when {
+            floatbytes.contentEquals(shortArrayOf(0x00, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_ZERO"
+            floatbytes.contentEquals(shortArrayOf(0x82, 0x49, 0x0f, 0xda, 0xa1)) -> return "c64flt.FL_PIVAL"
+            floatbytes.contentEquals(shortArrayOf(0x90, 0x80, 0x00, 0x00, 0x00)) -> return "c64flt.FL_N32768"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_FONE"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x35, 0x04, 0xf3, 0x34)) -> return "c64flt.FL_SQRHLF"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x35, 0x04, 0xf3, 0x34)) -> return "c64flt.FL_SQRTWO"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x80, 0x00, 0x00, 0x00)) -> return "c64flt.FL_NEGHLF"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x31, 0x72, 0x17, 0xf8)) -> return "c64flt.FL_LOG2"
+            floatbytes.contentEquals(shortArrayOf(0x84, 0x20, 0x00, 0x00, 0x00)) -> return "c64flt.FL_TENC"
+            floatbytes.contentEquals(shortArrayOf(0x9e, 0x6e, 0x6b, 0x28, 0x00)) -> return "c64flt.FL_NZMIL"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_FHALF"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x38, 0xaa, 0x3b, 0x29)) -> return "c64flt.FL_LOGEB2"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x49, 0x0f, 0xda, 0xa2)) -> return "c64flt.FL_PIHALF"
+            floatbytes.contentEquals(shortArrayOf(0x83, 0x49, 0x0f, 0xda, 0xa2)) -> return "c64flt.FL_TWOPI"
+            floatbytes.contentEquals(shortArrayOf(0x7f, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_FR4"
+            else -> {
+                // attempt to correct for a few rounding issues
+                when (number.toBigDecimal().setScale(10, RoundingMode.HALF_DOWN).toDouble()) {
+                    3.1415926536 -> return "c64flt.FL_PIVAL"
+                    1.4142135624 -> return "c64flt.FL_SQRTWO"
+                    0.7071067812 -> return "c64flt.FL_SQRHLF"
+                    0.6931471806 -> return "c64flt.FL_LOG2"
+                    else -> {}
+                }
+
+                // no ROM float const for this value, create our own
+                val name = globalFloatConsts[number]
+                if(name!=null)
+                    return name
+                val newName = "prog8_float_const_${globalFloatConsts.size}"
+                globalFloatConsts[number] = newName
+                return newName
+            }
+        }
+    }
+
+    internal fun signExtendAtoMsb(destination: String) =
+            """
+        ora  #$7f
+        bmi  +
+        lda  #0
++       sta  $destination
+        """
+
+    internal fun asmIdentifierName(identifier: IdentifierReference): String {
+        val name = if(identifier.memberOfStruct(program.namespace)!=null) {
+            identifier.targetVarDecl(program.namespace)!!.name
+        } else {
+            identifier.nameInSource.joinToString(".")
+        }
+        return fixNameSymbols(name)
+    }
+
+    internal fun fixNameSymbols(name: String) = name.replace("<", "prog8_").replace(">", "")     // take care of the autogenerated invalid (anon) label names
+
+    private fun branchInstruction(condition: BranchCondition, complement: Boolean) =
+            if(complement) {
+                when (condition) {
+                    BranchCondition.CS -> "bcc"
+                    BranchCondition.CC -> "bcs"
+                    BranchCondition.EQ, BranchCondition.Z -> "beq"
+                    BranchCondition.NE, BranchCondition.NZ -> "bne"
+                    BranchCondition.VS -> "bvc"
+                    BranchCondition.VC -> "bvs"
+                    BranchCondition.MI, BranchCondition.NEG -> "bmi"
+                    BranchCondition.PL, BranchCondition.POS -> "bpl"
+                }
+            } else {
+                when (condition) {
+                    BranchCondition.CS -> "bcs"
+                    BranchCondition.CC -> "bcc"
+                    BranchCondition.EQ, BranchCondition.Z -> "beq"
+                    BranchCondition.NE, BranchCondition.NZ -> "bne"
+                    BranchCondition.VS -> "bvs"
+                    BranchCondition.VC -> "bvc"
+                    BranchCondition.MI, BranchCondition.NEG -> "bmi"
+                    BranchCondition.PL, BranchCondition.POS -> "bpl"
+                }
+            }
+
+    internal fun readAndPushArrayvalueWithIndexA(arrayDt: DataType, variable: IdentifierReference) {
+        val variablename = asmIdentifierName(variable)
+        when (arrayDt) {
+            DataType.STR, DataType.STR_S, DataType.ARRAY_UB, DataType.ARRAY_B ->
+                out("  tay |  lda  $variablename,y |  sta  $ESTACK_LO_HEX,x |  dex")
+            DataType.ARRAY_UW, DataType.ARRAY_W ->
+                out("  asl  a |  tay |  lda  $variablename,y |  sta  $ESTACK_LO_HEX,x |  lda  $variablename+1,y |  sta  $ESTACK_HI_HEX,x | dex")
+            DataType.ARRAY_F ->
+                // index * 5 is done in the subroutine that's called
+                out("""
+                    sta  $ESTACK_LO_HEX,x
+                    dex
+                    lda  #<$variablename
+                    ldy  #>$variablename
+                    jsr  c64flt.push_float_from_indexed_var
+                """)
+            else ->
+                throw AssemblyError("weird array type")
+        }
+    }
+
+    internal fun saveRegister(register: Register) {
+        when(register) {
+            Register.A -> out("  pha")
+            Register.X -> out("  txa | pha")
+            Register.Y -> out("  tya | pha")
+        }
+    }
+
+    internal fun restoreRegister(register: Register) {
+        when(register) {
+            Register.A -> out("  pla")
+            Register.X -> out("  pla | tax")
+            Register.Y -> out("  pla | tay")
+        }
+    }
+
+    private fun translateSubroutine(sub: Subroutine) {
+        out("")
+        outputSourceLine(sub)
+
+        if(sub.isAsmSubroutine) {
+            if(sub.asmAddress!=null)
+                return  // already done at the memvars section
+
+            // asmsub with most likely just an inline asm in it
+            out("${sub.name}\t.proc")
+            sub.statements.forEach{ translate(it) }
+            out("  .pend\n")
+        } else {
+            // regular subroutine
+            out("${sub.name}\t.proc")
+            zeropagevars2asm(sub.statements)
+            memdefs2asm(sub.statements)
+            out("; statements")
+            sub.statements.forEach{ translate(it) }
+            out("; variables")
+            vardecls2asm(sub.statements)
+            out("  .pend\n")
+        }
+    }
+
+    internal fun translate(stmt: Statement) {
+        outputSourceLine(stmt)
+        when(stmt) {
+            is VarDecl, is StructDecl, is NopStatement -> {}
+            is Directive -> translate(stmt)
+            is Return -> translate(stmt)
+            is Subroutine -> translateSubroutine(stmt)
+            is InlineAssembly -> translate(stmt)
+            is FunctionCallStatement -> {
+                val functionName = stmt.target.nameInSource.last()
+                val builtinFunc = BuiltinFunctions[functionName]
+                if(builtinFunc!=null) {
+                    builtinFunctionsAsmGen.translateFunctioncallStatement(stmt, builtinFunc)
+                } else {
+                    functioncallAsmGen.translateFunctionCall(stmt)
+                    // discard any results from the stack:
+                    val sub = stmt.target.targetSubroutine(program.namespace)!!
+                    val returns = sub.returntypes.zip(sub.asmReturnvaluesRegisters)
+                    for((t, reg) in returns) {
+                        if(reg.stack) {
+                            if (t in IntegerDatatypes || t in PassByReferenceDatatypes) out("  inx")
+                            else if (t == DataType.FLOAT) out("  inx |  inx |  inx")
+                        }
+                    }
+                }
+            }
+            is Assignment -> assignmentAsmGen.translate(stmt)
+            is Jump -> translate(stmt)
+            is PostIncrDecr -> postincrdecrAsmGen.translate(stmt)
+            is Label -> translate(stmt)
+            is BranchStatement -> translate(stmt)
+            is IfStatement -> translate(stmt)
+            is ForLoop -> forloopsAsmGen.translate(stmt)
+            is Continue -> out("  jmp  ${loopContinueLabels.peek()}")
+            is Break -> out("  jmp  ${loopEndLabels.peek()}")
+            is WhileLoop -> translate(stmt)
+            is RepeatLoop -> translate(stmt)
+            is WhenStatement -> translate(stmt)
+            is BuiltinFunctionStatementPlaceholder -> throw AssemblyError("builtin function should not have placeholder anymore?")
+            is AnonymousScope -> translate(stmt)
+            is Block -> throw AssemblyError("block should have been handled elsewhere")
+        }
+    }
+
+    private fun translate(stmt: IfStatement) {
+        expressionsAsmGen.translateExpression(stmt.condition)
+        translateTestStack(stmt.condition.inferType(program).typeOrElse(DataType.STRUCT))
+        val elseLabel = makeLabel("if_else")
+        val endLabel = makeLabel("if_end")
+        out("  beq  $elseLabel")
+        translate(stmt.truepart)
+        out("  jmp  $endLabel")
+        out(elseLabel)
+        translate(stmt.elsepart)
+        out(endLabel)
+    }
+
+    private fun translateTestStack(dataType: DataType) {
+        when(dataType) {
+            in ByteDatatypes -> out("  inx |  lda  $ESTACK_LO_HEX,x")
+            in WordDatatypes -> out("  inx |  lda  $ESTACK_LO_HEX,x |  ora  $ESTACK_HI_HEX,x")
+            DataType.FLOAT -> throw AssemblyError("conditional value should be an integer (boolean)")
+            else -> throw AssemblyError("non-numerical dt")
+        }
+    }
+
+    private fun translate(stmt: WhileLoop) {
+        val whileLabel = makeLabel("while")
+        val endLabel = makeLabel("whileend")
+        loopEndLabels.push(endLabel)
+        loopContinueLabels.push(whileLabel)
+        out(whileLabel)
+        // TODO optimize for the simple cases, can we avoid stack use?
+        expressionsAsmGen.translateExpression(stmt.condition)
+        val conditionDt = stmt.condition.inferType(program)
+        if(!conditionDt.isKnown)
+            throw AssemblyError("unknown condition dt")
+        if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes) {
+            out("  inx |  lda  $ESTACK_LO_HEX,x  |  beq  $endLabel")
+        } else {
+            out("""
+                inx
+                lda  $ESTACK_LO_HEX,x
+                bne  +
+                lda  $ESTACK_HI_HEX,x
+                beq  $endLabel
++  """)
+        }
+        translate(stmt.body)
+        out("  jmp  $whileLabel")
+        out(endLabel)
+        loopEndLabels.pop()
+        loopContinueLabels.pop()
+    }
+
+    private fun translate(stmt: RepeatLoop) {
+        val repeatLabel = makeLabel("repeat")
+        val endLabel = makeLabel("repeatend")
+        loopEndLabels.push(endLabel)
+        loopContinueLabels.push(repeatLabel)
+        out(repeatLabel)
+        // TODO optimize this for the simple cases, can we avoid stack use?
+        translate(stmt.body)
+        expressionsAsmGen.translateExpression(stmt.untilCondition)
+        val conditionDt = stmt.untilCondition.inferType(program)
+        if(!conditionDt.isKnown)
+            throw AssemblyError("unknown condition dt")
+        if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes) {
+            out("  inx |  lda  $ESTACK_LO_HEX,x  |  beq  $repeatLabel")
+        } else {
+            out("""
+                inx
+                lda  $ESTACK_LO_HEX,x
+                bne  +
+                lda  $ESTACK_HI_HEX,x
+                beq  $repeatLabel
++ """)
+        }
+        out(endLabel)
+        loopEndLabels.pop()
+        loopContinueLabels.pop()
+    }
+
+    private fun translate(stmt: WhenStatement) {
+        expressionsAsmGen.translateExpression(stmt.condition)
+        val endLabel = makeLabel("choice_end")
+        val choiceBlocks = mutableListOf<Pair<String, AnonymousScope>>()
+        val conditionDt = stmt.condition.inferType(program)
+        if(!conditionDt.isKnown)
+            throw AssemblyError("unknown condition dt")
+        if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes)
+            out("  inx |  lda  $ESTACK_LO_HEX,x")
+        else
+            out("  inx |  lda  $ESTACK_LO_HEX,x |  ldy  $ESTACK_HI_HEX,x")
+        for(choice in stmt.choices) {
+            val choiceLabel = makeLabel("choice")
+            if(choice.values==null) {
+                // the else choice
+                translate(choice.statements)
+                out("  jmp  $endLabel")
+            } else {
+                choiceBlocks.add(Pair(choiceLabel, choice.statements))
+                for (cv in choice.values!!) {
+                    val value = (cv as NumericLiteralValue).number.toInt()
+                    if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes) {
+                        out("  cmp  #${value.toHex()} |  beq  $choiceLabel")
+                    } else {
+                        out("""
+                            cmp  #<${value.toHex()}
+                            bne  +
+                            cpy  #>${value.toHex()}
+                            beq  $choiceLabel
++                            
+                            """)
+                    }
+                }
+            }
+        }
+        for(choiceBlock in choiceBlocks) {
+            out(choiceBlock.first)
+            translate(choiceBlock.second)
+            out("  jmp  $endLabel")
+        }
+        out(endLabel)
+    }
+
+    private fun translate(stmt: Label) {
+        out(stmt.name)
+    }
+
+    private fun translate(scope: AnonymousScope) {
+        // note: the variables defined in an anonymous scope have been moved to their defining subroutine's scope
+        scope.statements.forEach{ translate(it) }
+    }
+
+    private fun translate(stmt: BranchStatement) {
+        if(stmt.truepart.containsNoCodeNorVars() && stmt.elsepart.containsCodeOrVars())
+            throw AssemblyError("only else part contains code, shoud have been switched already")
+
+        val jump = stmt.truepart.statements.first() as? Jump
+        if(jump!=null) {
+            // branch with only a jump
+            val instruction = branchInstruction(stmt.condition, false)
+            out("  $instruction  ${getJumpTarget(jump)}")
+            translate(stmt.elsepart)
+        } else {
+            if(stmt.elsepart.containsNoCodeNorVars()) {
+                val instruction = branchInstruction(stmt.condition, true)
+                val elseLabel = makeLabel("branch_else")
+                out("  $instruction  $elseLabel")
+                translate(stmt.truepart)
+                out(elseLabel)
+            } else {
+                val instruction = branchInstruction(stmt.condition, false)
+                val trueLabel = makeLabel("branch_true")
+                val endLabel = makeLabel("branch_end")
+                out("  $instruction  $trueLabel")
+                translate(stmt.elsepart)
+                out("  jmp  $endLabel")
+                out(trueLabel)
+                translate(stmt.truepart)
+                out(endLabel)
+            }
+        }
+    }
+
+    private fun translate(stmt: Directive) {
+        when(stmt.directive) {
+            "%asminclude" -> {
+                val sourcecode = loadAsmIncludeFile(stmt.args[0].str!!, stmt.definingModule().source)
+                val scopeprefix = stmt.args[1].str ?: ""
+                if(!scopeprefix.isBlank())
+                    out("$scopeprefix\t.proc")
+                assemblyLines.add(sourcecode.trimEnd().trimStart('\n'))
+                if(!scopeprefix.isBlank())
+                    out("  .pend\n")
+            }
+            "%asmbinary" -> {
+                val offset = if(stmt.args.size>1) ", ${stmt.args[1].int}" else ""
+                val length = if(stmt.args.size>2) ", ${stmt.args[2].int}" else ""
+                out("  .binary \"${stmt.args[0].str}\" $offset $length")
+            }
+            "%breakpoint" -> {
+                val label = "_prog8_breakpoint_${breakpointLabels.size+1}"
+                breakpointLabels.add(label)
+                out("$label\tnop")
+            }
+        }
+    }
+
+    private fun translate(jmp: Jump) {
+        out("  jmp  ${getJumpTarget(jmp)}")
+    }
+
+    private fun getJumpTarget(jmp: Jump): String {
+        return when {
+            jmp.identifier!=null -> asmIdentifierName(jmp.identifier)
+            jmp.generatedLabel!=null -> jmp.generatedLabel
+            jmp.address!=null -> jmp.address.toHex()
+            else -> "????"
+        }
+    }
+
+    private fun translate(ret: Return) {
+        ret.value?.let { expressionsAsmGen.translateExpression(it) }
+        out("  rts")
+    }
+
+    private fun translate(asm: InlineAssembly) {
+        val assembly = asm.assembly.trimEnd().trimStart('\n')
+        assemblyLines.add(assembly)
+    }
+
+    internal fun translateArrayIndexIntoA(expr: ArrayIndexedExpression) {
+        val index = expr.arrayspec.index
+        when (index) {
+            is NumericLiteralValue -> throw AssemblyError("this should be optimized directly")
+            is RegisterExpr -> {
+                when (index.register) {
+                    Register.A -> {}
+                    Register.X -> out("  txa")
+                    Register.Y -> out("  tya")
+                }
+            }
+            is IdentifierReference -> {
+                val indexName = asmIdentifierName(index)
+                out("  lda  $indexName")
+            }
+            else -> {
+                expressionsAsmGen.translateExpression(index)
+                out("  inx |  lda  $ESTACK_LO_HEX,x")
+            }
+        }
+    }
+
+    internal fun translateExpression(expression: Expression) =
+            expressionsAsmGen.translateExpression(expression)
+
+    internal fun translateFunctioncallExpression(functionCall: FunctionCall, signature: FunctionSignature) =
+            builtinFunctionsAsmGen.translateFunctioncallExpression(functionCall, signature)
+
+    internal fun translateFunctionCall(functionCall: FunctionCall) =
+            functioncallAsmGen.translateFunctionCall(functionCall)
+
+    internal fun assignFromEvalResult(target: AssignTarget) =
+            assignmentAsmGen.assignFromEvalResult(target)
+
+    fun assignFromByteConstant(target: AssignTarget, value: Short) =
+            assignmentAsmGen.assignFromByteConstant(target, value)
+
+    fun assignFromWordConstant(target: AssignTarget, value: Int) =
+            assignmentAsmGen.assignFromWordConstant(target, value)
+
+    fun assignFromFloatConstant(target: AssignTarget, value: Double) =
+            assignmentAsmGen.assignFromFloatConstant(target, value)
+
+    fun assignFromByteVariable(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromByteVariable(target, variable)
+
+    fun assignFromWordVariable(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromWordVariable(target, variable)
+
+    fun assignFromFloatVariable(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromFloatVariable(target, variable)
+
+    fun assignFromRegister(target: AssignTarget, register: Register) =
+            assignmentAsmGen.assignFromRegister(target, register)
+
+    fun assignFromMemoryByte(target: AssignTarget, address: Int?, identifier: IdentifierReference?) =
+            assignmentAsmGen.assignFromMemoryByte(target, address, identifier)
+}

compiler/src/prog8/compiler/target/c64/codegen/AsmOptimizer.kt

@@ -1,6 +1,11 @@
-package prog8.compiler.target.c64
+package prog8.compiler.target.c64.codegen
+
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_PLUS1_HEX
+
+
+// note: see https://wiki.nesdev.com/w/index.php/6502_assembly_optimisations
 
-import prog8.compiler.toHex
 
 fun optimizeAssembly(lines: MutableList<String>): Int {
 
@@ -24,10 +29,19 @@ fun optimizeAssembly(lines: MutableList<String>): Int {
         numberOfOptimizations++
     }
 
+    removeLines = optimizeCmpSequence(linesByFour)
+    if(removeLines.isNotEmpty()) {
+        for (i in removeLines.reversed())
+            lines.removeAt(i)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
     removeLines = optimizeStoreLoadSame(linesByFour)
     if(removeLines.isNotEmpty()) {
         for (i in removeLines.reversed())
             lines.removeAt(i)
+        linesByFour = getLinesBy(lines, 4)
         numberOfOptimizations++
     }
 
@@ -36,24 +50,45 @@ fun optimizeAssembly(lines: MutableList<String>): Int {
     if(removeLines.isNotEmpty()) {
         for (i in removeLines.reversed())
             lines.removeAt(i)
+        linesByFourteen = getLinesBy(lines, 14)
         numberOfOptimizations++
     }
 
-    // TODO more assembly optimizations?
+    // TODO more assembly optimizations
 
     return numberOfOptimizations
 }
 
+fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
+    // the when statement (on bytes) generates a sequence of:
+    //	 lda $ce01,x
+    //	 cmp #$20
+    //	 beq  check_prog8_s72choice_32
+    //	 lda $ce01,x
+    //	 cmp #$21
+    //	 beq  check_prog8_s73choice_33
+    // the repeated lda can be removed
+    val removeLines = mutableListOf<Int>()
+    for(lines in linesByFour) {
+        if(lines[0].value.trim()=="lda  $ESTACK_LO_PLUS1_HEX,x" &&
+                lines[1].value.trim().startsWith("cmp ") &&
+                lines[2].value.trim().startsWith("beq ") &&
+                lines[3].value.trim()=="lda  $ESTACK_LO_PLUS1_HEX,x") {
+            removeLines.add(lines[3].index) // remove the second lda
+        }
+    }
+    return removeLines
+}
+
 fun optimizeUselessStackByteWrites(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
     // sta on stack, dex, inx, lda from stack -> eliminate this useless stack byte write
     // this is a lot harder for word values because the instruction sequence varies.
     val removeLines = mutableListOf<Int>()
     for(lines in linesByFour) {
-        if(lines[0].value.trim()=="sta  ${ESTACK_LO.toHex()},x" &&
+        if(lines[0].value.trim()=="sta  $ESTACK_LO_HEX,x" &&
                 lines[1].value.trim()=="dex" &&
                 lines[2].value.trim()=="inx" &&
-                lines[3].value.trim()=="lda  ${ESTACK_LO.toHex()},x") {
-            removeLines.add(lines[0].index)
+                lines[3].value.trim()=="lda  $ESTACK_LO_HEX,x") {
             removeLines.add(lines[1].index)
             removeLines.add(lines[2].index)
             removeLines.add(lines[3].index)
@@ -66,7 +101,7 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
 
     // optimize sequential assignments of the isSameAs value to various targets (bytes, words, floats)
     // the float one is the one that requires 2*7=14 lines of code to check...
-    // @todo a better place to do this is in the Compiler instead and work on opcodes, and never even create the inefficient asm...
+    // @todo a better place to do this is in the Compiler instead and transform the Ast, and never even create the inefficient asm in the first place...
 
     val removeLines = mutableListOf<Int>()
     for (pair in linesByFourteen) {
@@ -128,7 +163,7 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
 }
 
 private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
-// all lines (that aren't empty or comments) in sliding pairs of 2
+// all lines (that aren't empty or comments) in sliding windows of certain size
         lines.withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
 
 private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>): List<Int> {

compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt

@@ -0,0 +1,745 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.DirectMemoryWrite
+import prog8.ast.statements.VarDecl
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.toHex
+
+internal class AssignmentAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translate(assign: Assignment) {
+        if(assign.aug_op!=null)
+            throw AssemblyError("aug-op assignments should have been transformed to normal ones")
+
+        when(assign.value) {
+            is NumericLiteralValue -> {
+                val numVal = assign.value as NumericLiteralValue
+                when(numVal.type) {
+                    DataType.UBYTE, DataType.BYTE -> assignFromByteConstant(assign.target, numVal.number.toShort())
+                    DataType.UWORD, DataType.WORD -> assignFromWordConstant(assign.target, numVal.number.toInt())
+                    DataType.FLOAT -> assignFromFloatConstant(assign.target, numVal.number.toDouble())
+                    else -> throw AssemblyError("weird numval type")
+                }
+            }
+            is RegisterExpr -> {
+                assignFromRegister(assign.target, (assign.value as RegisterExpr).register)
+            }
+            is IdentifierReference -> {
+                val type = assign.target.inferType(program, assign).typeOrElse(DataType.STRUCT)
+                when(type) {
+                    DataType.UBYTE, DataType.BYTE -> assignFromByteVariable(assign.target, assign.value as IdentifierReference)
+                    DataType.UWORD, DataType.WORD -> assignFromWordVariable(assign.target, assign.value as IdentifierReference)
+                    DataType.FLOAT -> assignFromFloatVariable(assign.target, assign.value as IdentifierReference)
+                    else -> throw AssemblyError("unsupported assignment target type $type")
+                }
+            }
+            is AddressOf -> {
+                val identifier = (assign.value as AddressOf).identifier
+                assignFromAddressOf(assign.target, identifier)
+            }
+            is DirectMemoryRead -> {
+                val read = (assign.value as DirectMemoryRead)
+                when(read.addressExpression) {
+                    is NumericLiteralValue -> {
+                        val address = (read.addressExpression as NumericLiteralValue).number.toInt()
+                        assignFromMemoryByte(assign.target, address, null)
+                    }
+                    is IdentifierReference -> {
+                        assignFromMemoryByte(assign.target, null, read.addressExpression as IdentifierReference)
+                    }
+                    else -> {
+                        asmgen.translateExpression(read.addressExpression)
+                        TODO("read memory byte from result and put that in ${assign.target}")
+                    }
+                }
+            }
+            is PrefixExpression -> {
+                // TODO optimize common cases
+                asmgen.translateExpression(assign.value as PrefixExpression)
+                assignFromEvalResult(assign.target)
+            }
+            is BinaryExpression -> {
+                // TODO optimize common cases
+                asmgen.translateExpression(assign.value as BinaryExpression)
+                assignFromEvalResult(assign.target)
+            }
+            is ArrayIndexedExpression -> {
+                // TODO optimize common cases
+                val arrayExpr = assign.value as ArrayIndexedExpression
+                val arrayDt = arrayExpr.identifier.targetVarDecl(program.namespace)!!.datatype
+                val index = arrayExpr.arrayspec.index
+                if(index is NumericLiteralValue) {
+                    // constant array index value
+                    val arrayVarName = asmgen.asmIdentifierName(arrayExpr.identifier)
+                    val indexValue = index.number.toInt() * ArrayElementTypes.getValue(arrayDt).memorySize()
+                    when (arrayDt) {
+                        DataType.STR, DataType.STR_S, DataType.ARRAY_UB, DataType.ARRAY_B ->
+                            asmgen.out("  lda  $arrayVarName+$indexValue |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+                        DataType.ARRAY_UW, DataType.ARRAY_W ->
+                            asmgen.out("  lda  $arrayVarName+$indexValue |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  lda  $arrayVarName+$indexValue+1 |  sta  ${MachineDefinition.ESTACK_HI_HEX},x | dex")
+                        DataType.ARRAY_F ->
+                            asmgen.out("  lda  #<$arrayVarName+$indexValue |  ldy  #>$arrayVarName+$indexValue |  jsr  c64flt.push_float")
+                        else ->
+                            throw AssemblyError("weird array type")
+                    }
+                } else {
+                    asmgen.translateArrayIndexIntoA(arrayExpr)
+                    asmgen.readAndPushArrayvalueWithIndexA(arrayDt, arrayExpr.identifier)
+                }
+                assignFromEvalResult(assign.target)
+            }
+            is TypecastExpression -> {
+                val cast = assign.value as TypecastExpression
+                val sourceType = cast.expression.inferType(program)
+                val targetType = assign.target.inferType(program, assign)
+                if(sourceType.isKnown && targetType.isKnown &&
+                        (sourceType.typeOrElse(DataType.STRUCT) in ByteDatatypes && targetType.typeOrElse(DataType.STRUCT) in ByteDatatypes) ||
+                        (sourceType.typeOrElse(DataType.STRUCT) in WordDatatypes && targetType.typeOrElse(DataType.STRUCT) in WordDatatypes)) {
+                    // no need for a type cast
+                    assign.value = cast.expression
+                    translate(assign)
+                } else {
+                    asmgen.translateExpression(assign.value as TypecastExpression)
+                    assignFromEvalResult(assign.target)
+                }
+            }
+            is FunctionCall -> {
+                asmgen.translateExpression(assign.value as FunctionCall)
+                assignFromEvalResult(assign.target)
+            }
+            is ArrayLiteralValue, is StringLiteralValue -> TODO("string/array/struct assignment?")
+            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened")
+            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
+        }
+    }
+
+    internal fun assignFromEvalResult(target: AssignTarget) {
+        val targetIdent = target.identifier
+        when {
+            target.register!=null -> {
+                if(target.register== Register.X)
+                    throw AssemblyError("can't pop into X register - use variable instead")
+                asmgen.out(" inx | ld${target.register.name.toLowerCase()}  ${MachineDefinition.ESTACK_LO_HEX},x ")
+            }
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                val targetDt = targetIdent.inferType(program).typeOrElse(DataType.STRUCT)
+                when(targetDt) {
+                    DataType.UBYTE, DataType.BYTE -> {
+                        asmgen.out(" inx | lda  ${MachineDefinition.ESTACK_LO_HEX},x  | sta  $targetName")
+                    }
+                    DataType.UWORD, DataType.WORD -> {
+                        asmgen.out("""
+                            inx
+                            lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                            sta  $targetName
+                            lda  ${MachineDefinition.ESTACK_HI_HEX},x
+                            sta  $targetName+1
+                        """)
+                    }
+                    DataType.FLOAT -> {
+                        asmgen.out("""
+                            lda  #<$targetName
+                            ldy  #>$targetName
+                            jsr  c64flt.pop_float
+                        """)
+                    }
+                    else -> throw AssemblyError("weird target variable type $targetDt")
+                }
+            }
+            target.memoryAddress!=null -> {
+                asmgen.out("  inx  | ldy  ${MachineDefinition.ESTACK_LO_HEX},x")
+                storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+            }
+            target.arrayindexed!=null -> {
+                val arrayDt = target.arrayindexed!!.identifier.targetVarDecl(program.namespace)!!.datatype
+                val arrayVarName = asmgen.asmIdentifierName(target.arrayindexed!!.identifier)
+                asmgen.translateExpression(target.arrayindexed!!.arrayspec.index)
+                asmgen.out("  inx |  lda  ${MachineDefinition.ESTACK_LO_HEX},x")
+                popAndWriteArrayvalueWithIndexA(arrayDt, arrayVarName)
+            }
+            else -> throw AssemblyError("weird assignment target $target")
+        }
+    }
+
+    internal fun assignFromAddressOf(target: AssignTarget, name: IdentifierReference) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        val struct = name.memberOfStruct(program.namespace)
+        val sourceName = if(struct!=null) {
+            // take the address of the first struct member instead
+            val decl = name.targetVarDecl(program.namespace)!!
+            val firstStructMember = struct.nameOfFirstMember()
+            // find the flattened var that belongs to this first struct member
+            val firstVarName = listOf(decl.name, firstStructMember)
+            val firstVar = name.definingScope().lookup(firstVarName, name) as VarDecl
+            firstVar.name
+        } else {
+            asmgen.fixNameSymbols(name.nameInSource.joinToString ("."))
+        }
+
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                        lda  #<$sourceName
+                        ldy  #>$sourceName
+                        sta  $targetName
+                        sty  $targetName+1
+                    """)
+            }
+            target.memoryAddress!=null -> {
+                TODO("assign address $sourceName to memory word $target")
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                TODO("assign address $sourceName to array $targetName [ $index ]")
+            }
+            else -> TODO("assign address $sourceName to $target")
+        }
+    }
+
+    internal fun assignFromWordVariable(target: AssignTarget, variable: IdentifierReference) {
+        val sourceName = asmgen.asmIdentifierName(variable)
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                    lda  $sourceName
+                    ldy  $sourceName+1
+                    sta  $targetName
+                    sty  $targetName+1
+                """)
+            }
+            target.memoryAddress!=null -> {
+                TODO("assign wordvar $sourceName to memory ${target.memoryAddress}")
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                asmgen.out("  lda  $sourceName |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  lda  $sourceName+1 |  sta  ${MachineDefinition.ESTACK_HI_HEX},x |  dex")
+                asmgen.translateExpression(index)
+                asmgen.out("  inx |  lda  ${MachineDefinition.ESTACK_LO_HEX},x")
+                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
+                popAndWriteArrayvalueWithIndexA(arrayDt, targetName)
+            }
+            else -> TODO("assign wordvar to $target")
+        }
+    }
+
+    internal fun assignFromFloatVariable(target: AssignTarget, variable: IdentifierReference) {
+        val sourceName = asmgen.asmIdentifierName(variable)
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                    lda  $sourceName
+                    sta  $targetName
+                    lda  $sourceName+1
+                    sta  $targetName+1
+                    lda  $sourceName+2
+                    sta  $targetName+2
+                    lda  $sourceName+3
+                    sta  $targetName+3
+                    lda  $sourceName+4
+                    sta  $targetName+4
+                """)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                asmgen.out("  lda  #<$sourceName |  ldy  #>$sourceName |  jsr  c64flt.push_float")
+                asmgen.translateExpression(index)
+                asmgen.out("  lda  #<$targetName |  ldy  #>$targetName |  jsr  c64flt.pop_float_to_indexed_var")
+            }
+            else -> TODO("assign floatvar to $target")
+        }
+    }
+
+    internal fun assignFromByteVariable(target: AssignTarget, variable: IdentifierReference) {
+        val sourceName = asmgen.asmIdentifierName(variable)
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            target.register!=null -> {
+                asmgen.out("  ld${target.register.name.toLowerCase()}  $sourceName")
+            }
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                    lda  $sourceName
+                    sta  $targetName
+                    """)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
+                asmgen.out("  lda  $sourceName |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+                asmgen.translateExpression(index)
+                asmgen.out("  inx |  lda  ${MachineDefinition.ESTACK_LO_HEX},x")
+                popAndWriteArrayvalueWithIndexA(arrayDt, targetName)
+            }
+            target.memoryAddress != null -> {
+                val addressExpr = target.memoryAddress.addressExpression
+                val addressLv = addressExpr as? NumericLiteralValue
+                when {
+                    addressLv != null -> asmgen.out("  lda  $sourceName |  sta  ${addressLv.number.toHex()}")
+                    addressExpr is IdentifierReference -> {
+                        val targetName = asmgen.asmIdentifierName(addressExpr)
+                        asmgen.out("  lda  $sourceName |  sta  $targetName")
+                    }
+                    else -> {
+                        asmgen.translateExpression(addressExpr)
+                        asmgen.out("""
+     inx
+     lda  ${MachineDefinition.ESTACK_LO_HEX},x
+     ldy  ${MachineDefinition.ESTACK_HI_HEX},x
+     sta  (+) +1
+     sty  (+) +2
+     lda  $sourceName
++    sta  ${65535.toHex()}      ; modified              
+                            """)
+                    }
+                }
+            }
+            else -> TODO("assign bytevar to $target")
+        }
+    }
+
+    internal fun assignFromRegister(target: AssignTarget, register: Register) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("  st${register.name.toLowerCase()}  $targetName")
+            }
+            target.register!=null -> {
+                when(register) {
+                    Register.A -> when(target.register) {
+                        Register.A -> {}
+                        Register.X -> asmgen.out("  tax")
+                        Register.Y -> asmgen.out("  tay")
+                    }
+                    Register.X -> when(target.register) {
+                        Register.A -> asmgen.out("  txa")
+                        Register.X -> {}
+                        Register.Y -> asmgen.out("  txy")
+                    }
+                    Register.Y -> when(target.register) {
+                        Register.A -> asmgen.out("  tya")
+                        Register.X -> asmgen.out("  tyx")
+                        Register.Y -> {}
+                    }
+                }
+            }
+            target.memoryAddress!=null -> {
+                storeRegisterInMemoryAddress(register, target.memoryAddress)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                when (index) {
+                    is NumericLiteralValue -> {
+                        val memindex = index.number.toInt()
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  $targetName+$memindex")
+                            Register.X -> asmgen.out("  stx  $targetName+$memindex")
+                            Register.Y -> asmgen.out("  sty  $targetName+$memindex")
+                        }
+                    }
+                    is RegisterExpr -> {
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                            Register.X -> asmgen.out("  stx  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                            Register.Y -> asmgen.out("  sty  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                        }
+                        when(index.register) {
+                            Register.A -> {}
+                            Register.X -> asmgen.out("  txa")
+                            Register.Y -> asmgen.out("  tya")
+                        }
+                        asmgen.out("""
+                            tay
+                            lda  ${MachineDefinition.C64Zeropage.SCRATCH_B1}
+                            sta  $targetName,y
+                            """)
+                    }
+                    is IdentifierReference -> {
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                            Register.X -> asmgen.out("  stx  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                            Register.Y -> asmgen.out("  sty  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                        }
+                        asmgen.out("""
+                            lda  ${asmgen.asmIdentifierName(index)}
+                            tay
+                            lda  ${MachineDefinition.C64Zeropage.SCRATCH_B1}
+                            sta  $targetName,y
+                        """)
+                    }
+                    else -> {
+                        asmgen.saveRegister(register)
+                        asmgen.translateExpression(index)
+                        asmgen.restoreRegister(register)
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                            Register.X -> asmgen.out("  stx  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                            Register.Y -> asmgen.out("  sty  ${MachineDefinition.C64Zeropage.SCRATCH_B1}")
+                        }
+                        asmgen.out("""
+                            inx
+                            lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                            tay
+                            lda  ${MachineDefinition.C64Zeropage.SCRATCH_B1}
+                            sta  $targetName,y  
+                        """)
+                    }
+                }
+            }
+            else -> TODO("assign register $register to $target")
+        }
+    }
+
+    private fun storeRegisterInMemoryAddress(register: Register, memoryAddress: DirectMemoryWrite) {
+        val addressExpr = memoryAddress.addressExpression
+        val addressLv = addressExpr as? NumericLiteralValue
+        val registerName = register.name.toLowerCase()
+        when {
+            addressLv != null -> asmgen.out("  st$registerName  ${addressLv.number.toHex()}")
+            addressExpr is IdentifierReference -> {
+                val targetName = asmgen.asmIdentifierName(addressExpr)
+                when(register) {
+                    Register.A -> asmgen.out("""
+                        ldy  $targetName
+                        sty  ${MachineDefinition.C64Zeropage.SCRATCH_W1}
+                        ldy  $targetName+1
+                        sty  ${MachineDefinition.C64Zeropage.SCRATCH_W1+1}
+                        ldy  #0
+                        sta  (${MachineDefinition.C64Zeropage.SCRATCH_W1}),y
+                        """)
+                    Register.X -> asmgen.out("""
+                        txa
+                        ldy  $targetName
+                        sty  ${MachineDefinition.C64Zeropage.SCRATCH_W1}
+                        ldy  $targetName+1
+                        sty  ${MachineDefinition.C64Zeropage.SCRATCH_W1+1}
+                        ldy  #0
+                        sta  (${MachineDefinition.C64Zeropage.SCRATCH_W1}),y
+                        """)
+                    Register.Y -> asmgen.out("""
+                        tya
+                        ldy  $targetName
+                        sty  ${MachineDefinition.C64Zeropage.SCRATCH_W1}
+                        ldy  $targetName+1
+                        sty  ${MachineDefinition.C64Zeropage.SCRATCH_W1+1}
+                        ldy  #0
+                        sta  (${MachineDefinition.C64Zeropage.SCRATCH_W1}),y
+                        """)
+                }
+            }
+            else -> {
+                asmgen.saveRegister(register)
+                asmgen.translateExpression(addressExpr)
+                asmgen.restoreRegister(register)
+                when (register) {
+                    Register.A -> asmgen.out("  tay")
+                    Register.X -> throw AssemblyError("can't use X register here")
+                    Register.Y -> {}
+                }
+                asmgen.out("""
+     inx
+     lda  ${MachineDefinition.ESTACK_LO_HEX},x
+     sta  (+) +1
+     lda  ${MachineDefinition.ESTACK_HI_HEX},x
+     sta  (+) +2
++    sty  ${65535.toHex()}      ; modified              
+                            """)
+            }
+        }
+    }
+
+    internal fun assignFromWordConstant(target: AssignTarget, word: Int) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                if(word ushr 8 == word and 255) {
+                    // lsb=msb
+                    asmgen.out("""
+                    lda  #${(word and 255).toHex()}
+                    sta  $targetName
+                    sta  $targetName+1
+                """)
+                } else {
+                    asmgen.out("""
+                    lda  #<${word.toHex()}
+                    ldy  #>${word.toHex()}
+                    sta  $targetName
+                    sty  $targetName+1
+                """)
+                }
+            }
+            target.memoryAddress!=null -> {
+                TODO("assign word $word to memory ${target.memoryAddress}")
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                // TODO optimize common cases
+                asmgen.translateExpression(index)
+                asmgen.out("""
+                    inx
+                    lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                    asl  a
+                    tay
+                    lda  #<${word.toHex()}
+                    sta  $targetName,y
+                    lda  #>${word.toHex()}
+                    sta  $targetName+1,y
+                """)
+            }
+            else -> TODO("assign word $word to $target")
+        }
+    }
+
+    internal fun assignFromByteConstant(target: AssignTarget, byte: Short) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            target.register!=null -> {
+                asmgen.out("  ld${target.register.name.toLowerCase()}  #${byte.toHex()}")
+            }
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out(" lda  #${byte.toHex()} |  sta  $targetName ")
+            }
+            target.memoryAddress!=null -> {
+                asmgen.out("  ldy  #${byte.toHex()}")
+                storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                // TODO optimize common cases
+                asmgen.translateExpression(index)
+                asmgen.out("""
+                    inx
+                    ldy  ${MachineDefinition.ESTACK_LO_HEX},x
+                    lda  #${byte.toHex()}
+                    sta  $targetName,y
+                """)
+            }
+            else -> TODO("assign byte $byte to $target")
+        }
+    }
+
+    internal fun assignFromFloatConstant(target: AssignTarget, float: Double) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        if(float==0.0) {
+            // optimized case for float zero
+            when {
+                targetIdent != null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                            lda  #0
+                            sta  $targetName
+                            sta  $targetName+1
+                            sta  $targetName+2
+                            sta  $targetName+3
+                            sta  $targetName+4
+                        """)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    if(index is NumericLiteralValue) {
+                        val indexValue = index.number.toInt() * MachineDefinition.Mflpt5.MemorySize
+                        asmgen.out("""
+                            lda  #0
+                            sta  $targetName+$indexValue
+                            sta  $targetName+$indexValue+1
+                            sta  $targetName+$indexValue+2
+                            sta  $targetName+$indexValue+3
+                            sta  $targetName+$indexValue+4
+                        """)
+                    } else {
+                        asmgen.translateExpression(index)
+                        asmgen.out("""
+                        inx
+                        lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                        asl  a
+                        asl  a
+                        clc
+                        adc  ${MachineDefinition.ESTACK_LO_HEX},x
+                        tay
+                        lda  #0
+                        sta  $targetName,y
+                        sta  $targetName+1,y
+                        sta  $targetName+2,y
+                        sta  $targetName+3,y
+                        sta  $targetName+4,y
+                    """) // TODO use a subroutine for this
+                    }
+                }
+                else -> TODO("assign float 0.0 to $target")
+            }
+        } else {
+            // non-zero value
+            val constFloat = asmgen.getFloatConst(float)
+            when {
+                targetIdent != null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                            lda  $constFloat
+                            sta  $targetName
+                            lda  $constFloat+1
+                            sta  $targetName+1
+                            lda  $constFloat+2
+                            sta  $targetName+2
+                            lda  $constFloat+3
+                            sta  $targetName+3
+                            lda  $constFloat+4
+                            sta  $targetName+4
+                        """)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val arrayVarName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    if(index is NumericLiteralValue) {
+                        val indexValue = index.number.toInt() * MachineDefinition.Mflpt5.MemorySize
+                        asmgen.out("""
+                            lda  $constFloat
+                            sta  $arrayVarName+$indexValue
+                            lda  $constFloat+1
+                            sta  $arrayVarName+$indexValue+1
+                            lda  $constFloat+2
+                            sta  $arrayVarName+$indexValue+2
+                            lda  $constFloat+3
+                            sta  $arrayVarName+$indexValue+3
+                            lda  $constFloat+4
+                            sta  $arrayVarName+$indexValue+4
+                        """)
+                    } else {
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        asmgen.out("""
+                            sta  ${MachineDefinition.C64Zeropage.SCRATCH_REG}
+                            asl  a
+                            asl  a
+                            clc
+                            adc  ${MachineDefinition.C64Zeropage.SCRATCH_REG}
+                            tay
+                            lda  $constFloat
+                            sta  $arrayVarName,y
+                            lda  $constFloat+1
+                            sta  $arrayVarName+1,y
+                            lda  $constFloat+2
+                            sta  $arrayVarName+2,y
+                            lda  $constFloat+3
+                            sta  $arrayVarName+3,y
+                            lda  $constFloat+4
+                            sta  $arrayVarName+4,y
+                        """)        // TODO use a subroutine for this
+                    }
+                }
+                else -> TODO("assign float $float to $target")
+            }
+        }
+    }
+
+    internal fun assignFromMemoryByte(target: AssignTarget, address: Int?, identifier: IdentifierReference?) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        if(address!=null) {
+            when {
+                target.register!=null -> {
+                    asmgen.out("  ld${target.register.name.toLowerCase()}  ${address.toHex()}")
+                }
+                targetIdent!=null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                        lda  ${address.toHex()}
+                        sta  $targetName
+                        """)
+                }
+                target.memoryAddress!=null -> {
+                    asmgen.out("  ldy  ${address.toHex()}")
+                    storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    TODO("assign memory byte at $address to array $targetName [ $index ]")
+                }
+                else -> TODO("assign memory byte $target")
+            }
+        }
+        else if(identifier!=null) {
+            val sourceName = asmgen.asmIdentifierName(identifier)
+            when {
+                target.register!=null -> {
+                    asmgen.out("""
+                        ldy  #0
+                        lda  ($sourceName),y
+                    """)
+                    when(target.register){
+                        Register.A -> {}
+                        Register.X -> asmgen.out("  tax")
+                        Register.Y -> asmgen.out("  tay")
+                    }
+                }
+                targetIdent!=null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                        ldy  #0
+                        lda  ($sourceName),y
+                        sta  $targetName
+                    """)
+                }
+                target.memoryAddress!=null -> {
+                    asmgen.out("  ldy  $sourceName")
+                    storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    TODO("assign memory byte $sourceName to array $targetName [ $index ]")
+                }
+                else -> TODO("assign memory byte $target")
+            }
+        }
+    }
+
+    private fun popAndWriteArrayvalueWithIndexA(arrayDt: DataType, variablename: String) {
+        when (arrayDt) {
+            DataType.STR, DataType.STR_S, DataType.ARRAY_UB, DataType.ARRAY_B ->
+                asmgen.out("  tay |  inx |  lda  ${MachineDefinition.ESTACK_LO_HEX},x  | sta  $variablename,y")
+            DataType.ARRAY_UW, DataType.ARRAY_W ->
+                asmgen.out("  asl  a |  tay |  inx |  lda  ${MachineDefinition.ESTACK_LO_HEX},x |  sta  $variablename,y |  lda  ${MachineDefinition.ESTACK_HI_HEX},x |  sta $variablename+1,y")
+            DataType.ARRAY_F ->
+                // index * 5 is done in the subroutine that's called
+                asmgen.out("""
+                    sta  ${MachineDefinition.ESTACK_LO_HEX},x
+                    dex
+                    lda  #<$variablename
+                    ldy  #>$variablename
+                    jsr  c64flt.pop_float_to_indexed_var
+                """)
+            else ->
+                throw AssemblyError("weird array type")
+        }
+    }
+}

compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt

@@ -0,0 +1,341 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.IFunctionCall
+import prog8.ast.Program
+import prog8.ast.base.ByteDatatypes
+import prog8.ast.base.DataType
+import prog8.ast.base.Register
+import prog8.ast.base.WordDatatypes
+import prog8.ast.expressions.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.FunctionCallStatement
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_PLUS1_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_PLUS1_HEX
+import prog8.compiler.toHex
+import prog8.functions.FunctionSignature
+
+internal class BuiltinFunctionsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateFunctioncallExpression(fcall: FunctionCall, func: FunctionSignature) {
+        translateFunctioncall(fcall, func, false)
+    }
+
+    internal fun translateFunctioncallStatement(fcall: FunctionCallStatement, func: FunctionSignature) {
+        translateFunctioncall(fcall, func, true)
+    }
+
+    private fun translateFunctioncall(fcall: IFunctionCall, func: FunctionSignature, discardResult: Boolean) {
+        val functionName = fcall.target.nameInSource.last()
+        if (discardResult) {
+            if (func.pure)
+                return  // can just ignore the whole function call altogether
+            else if (func.returntype != null)
+                throw AssemblyError("discarding result of non-pure function $fcall")
+        }
+
+        when (functionName) {
+            "msb" -> {
+                val arg = fcall.arglist.single()
+                if (arg.inferType(program).typeOrElse(DataType.STRUCT) !in WordDatatypes)
+                    throw AssemblyError("msb required word argument")
+                if (arg is NumericLiteralValue)
+                    throw AssemblyError("should have been const-folded")
+                if (arg is IdentifierReference) {
+                    val sourceName = asmgen.asmIdentifierName(arg)
+                    asmgen.out("  lda  $sourceName+1 |  sta  $ESTACK_LO_HEX,x |  dex")
+                } else {
+                    asmgen.translateExpression(arg)
+                    asmgen.out("  lda  $ESTACK_HI_PLUS1_HEX,x |  sta  $ESTACK_LO_PLUS1_HEX,x")
+                }
+            }
+            "mkword" -> {
+                translateFunctionArguments(fcall.arglist, func)
+                asmgen.out("  inx | lda  $ESTACK_LO_HEX,x  | sta  $ESTACK_HI_PLUS1_HEX,x")
+            }
+            "abs" -> {
+                translateFunctionArguments(fcall.arglist, func)
+                val dt = fcall.arglist.single().inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.abs_b")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.abs_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  c64flt.abs_f")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "swap" -> {
+                val first = fcall.arglist[0]
+                val second = fcall.arglist[1]
+                asmgen.translateExpression(first)
+                asmgen.translateExpression(second)
+                // pop in reverse order
+                val firstTarget = AssignTarget.fromExpr(first)
+                val secondTarget = AssignTarget.fromExpr(second)
+                asmgen.assignFromEvalResult(firstTarget)
+                asmgen.assignFromEvalResult(secondTarget)
+            }
+            "strlen" -> {
+                outputPushAddressOfIdentifier(fcall.arglist[0])
+                asmgen.out("  jsr  prog8_lib.func_strlen")
+            }
+            "min", "max", "sum" -> {
+                outputPushAddressAndLenghtOfArray(fcall.arglist[0])
+                val dt = fcall.arglist.single().inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.ARRAY_UB, DataType.STR_S, DataType.STR -> asmgen.out("  jsr  prog8_lib.func_${functionName}_ub")
+                    DataType.ARRAY_B -> asmgen.out("  jsr  prog8_lib.func_${functionName}_b")
+                    DataType.ARRAY_UW -> asmgen.out("  jsr  prog8_lib.func_${functionName}_uw")
+                    DataType.ARRAY_W -> asmgen.out("  jsr  prog8_lib.func_${functionName}_w")
+                    DataType.ARRAY_F -> asmgen.out("  jsr  c64flt.func_${functionName}_f")
+                    else -> throw AssemblyError("weird type $dt")
+                }
+            }
+            "any", "all" -> {
+                outputPushAddressAndLenghtOfArray(fcall.arglist[0])
+                val dt = fcall.arglist.single().inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.ARRAY_B, DataType.ARRAY_UB, DataType.STR_S, DataType.STR -> asmgen.out("  jsr  prog8_lib.func_${functionName}_b")
+                    DataType.ARRAY_UW, DataType.ARRAY_W -> asmgen.out("  jsr  prog8_lib.func_${functionName}_w")
+                    DataType.ARRAY_F -> asmgen.out("  jsr  c64flt.func_${functionName}_f")
+                    else -> throw AssemblyError("weird type $dt")
+                }
+            }
+            "sgn" -> {
+                translateFunctionArguments(fcall.arglist, func)
+                val dt = fcall.arglist.single().inferType(program)
+                when(dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> asmgen.out("  jsr  math.sign_ub")
+                    DataType.BYTE -> asmgen.out("  jsr  math.sign_b")
+                    DataType.UWORD -> asmgen.out("  jsr  math.sign_uw")
+                    DataType.WORD -> asmgen.out("  jsr  math.sign_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  c64flt.sign_f")
+                    else -> throw AssemblyError("weird type $dt")
+                }
+            }
+            "sin", "cos", "tan", "atan",
+            "ln", "log2", "sqrt", "rad",
+            "deg", "round", "floor", "ceil",
+            "rdnf" -> {
+                translateFunctionArguments(fcall.arglist, func)
+                asmgen.out("  jsr  c64flt.func_$functionName")
+            }
+/*
+        TODO this was the old code for bit rotations:
+            Opcode.SHL_BYTE -> AsmFragment(" asl  $variable+$index", 8)
+            Opcode.SHR_UBYTE -> AsmFragment(" lsr  $variable+$index", 8)
+            Opcode.SHR_SBYTE -> AsmFragment(" lda  $variable+$index |  asl  a |  ror  $variable+$index")
+            Opcode.SHL_WORD -> AsmFragment(" asl  $variable+${index * 2 + 1} |  rol  $variable+${index * 2}", 8)
+            Opcode.SHR_UWORD -> AsmFragment(" lsr  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
+            Opcode.SHR_SWORD -> AsmFragment(" lda  $variable+${index * 2 + 1} |  asl  a |  ror  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
+            Opcode.ROL_BYTE -> AsmFragment(" rol  $variable+$index", 8)
+            Opcode.ROR_BYTE -> AsmFragment(" ror  $variable+$index", 8)
+            Opcode.ROL_WORD -> AsmFragment(" rol  $variable+${index * 2 + 1} |  rol  $variable+${index * 2}", 8)
+            Opcode.ROR_WORD -> AsmFragment(" ror  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
+            Opcode.ROL2_BYTE -> AsmFragment(" lda  $variable+$index |  cmp  #\$80 |  rol  $variable+$index", 8)
+            Opcode.ROR2_BYTE -> AsmFragment(" lda  $variable+$index |  lsr  a |  bcc  + |  ora  #\$80 |+ |  sta  $variable+$index", 10)
+            Opcode.ROL2_WORD -> AsmFragment(" asl  $variable+${index * 2 + 1} |  rol  $variable+${index * 2} |  bcc  + |  inc  $variable+${index * 2 + 1} |+", 20)
+            Opcode.ROR2_WORD -> AsmFragment(" lsr  $variable+${index * 2 + 1} |  ror  $variable+${index * 2} |  bcc  + |  lda  $variable+${index * 2 + 1} |  ora  #\$80 |  sta  $variable+${index * 2 + 1} |+", 30)
+
+ */
+            "lsl" -> {
+                // in-place
+                val what = fcall.arglist.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    in ByteDatatypes -> {
+                        when (what) {
+                            is RegisterExpr -> {
+                                when (what.register) {
+                                    Register.A -> asmgen.out("  asl  a")
+                                    Register.X -> asmgen.out("  txa  |  asl  a |  tax")
+                                    Register.Y -> asmgen.out("  tya  |  asl  a |  tay")
+                                }
+                            }
+                            is IdentifierReference -> asmgen.out("  asl  ${asmgen.asmIdentifierName(what)}")
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    asmgen.out("  asl  ${(what.addressExpression as NumericLiteralValue).number.toHex()}")
+                                } else {
+                                    TODO("lsl memory byte $what")
+                                }
+                            }
+                            is ArrayIndexedExpression -> {
+                                TODO("lsl byte array $what")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    in WordDatatypes -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> TODO("lsl sbyte $what")
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out(" asl  $variable |  rol  $variable+1")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "lsr" -> {
+                // in-place
+                val what = fcall.arglist.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        when (what) {
+                            is RegisterExpr -> {
+                                when (what.register) {
+                                    Register.A -> asmgen.out("  lsr  a")
+                                    Register.X -> asmgen.out("  txa  |  lsr  a |  tax")
+                                    Register.Y -> asmgen.out("  tya  |  lsr  a |  tay")
+                                }
+                            }
+                            is IdentifierReference -> asmgen.out("  lsr  ${asmgen.asmIdentifierName(what)}")
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    asmgen.out("  lsr  ${(what.addressExpression as NumericLiteralValue).number.toHex()}")
+                                } else {
+                                    TODO("lsr memory byte $what")
+                                }
+                            }
+                            is ArrayIndexedExpression -> {
+                                TODO("lsr byte array $what")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.BYTE -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> TODO("lsr sbyte $what")
+                            is DirectMemoryRead -> TODO("lsr sbyte $what")
+                            is RegisterExpr -> TODO("lsr sbyte $what")
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lda  $variable |  asl  a |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.UWORD -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> TODO("lsr uword $what")
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out(" lsr  $variable+1 |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.WORD -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> TODO("lsr sword $what")
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lda  $variable+1 |  asl a  |  ror  $variable+1 |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "rol" -> {
+                // in-place
+                val what = fcall.arglist.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        TODO("rol ubyte")
+                    }
+                    DataType.UWORD -> {
+                        TODO("rol uword")
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "rol2" -> {
+                // in-place
+                val what = fcall.arglist.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        TODO("rol2 ubyte")
+                    }
+                    DataType.UWORD -> {
+                        TODO("rol2 uword")
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "ror" -> {
+                // in-place
+                val what = fcall.arglist.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        TODO("ror ubyte")
+                    }
+                    DataType.UWORD -> {
+                        TODO("ror uword")
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "ror2" -> {
+                // in-place
+                val what = fcall.arglist.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        TODO("ror2 ubyte")
+                    }
+                    DataType.UWORD -> {
+                        TODO("ror2 uword")
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            else -> {
+                translateFunctionArguments(fcall.arglist, func)
+                asmgen.out("  jsr  prog8_lib.func_$functionName")
+            }
+        }
+    }
+
+    private fun outputPushAddressAndLenghtOfArray(arg: Expression) {
+        arg as IdentifierReference
+        val identifierName = asmgen.asmIdentifierName(arg)
+        val size = arg.targetVarDecl(program.namespace)!!.arraysize!!.size()!!
+        asmgen.out("""
+                    lda  #<$identifierName
+                    sta  $ESTACK_LO_HEX,x
+                    lda  #>$identifierName
+                    sta  $ESTACK_HI_HEX,x
+                    dex
+                    lda  #$size
+                    sta  $ESTACK_LO_HEX,x
+                    dex
+                    """)
+    }
+
+    private fun outputPushAddressOfIdentifier(arg: Expression) {
+        val identifierName = asmgen.asmIdentifierName(arg as IdentifierReference)
+        asmgen.out("""
+                    lda  #<$identifierName
+                    sta  $ESTACK_LO_HEX,x
+                    lda  #>$identifierName
+                    sta  $ESTACK_HI_HEX,x
+                    dex
+                    """)
+    }
+
+    private fun translateFunctionArguments(args: MutableList<Expression>, signature: FunctionSignature) {
+        args.forEach {
+            asmgen.translateExpression(it)
+        }
+    }
+
+}

compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt

@@ -0,0 +1,430 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.toHex
+import prog8.functions.BuiltinFunctions
+import kotlin.math.absoluteValue
+
+internal class ExpressionsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateExpression(expression: Expression) {
+        when(expression) {
+            is PrefixExpression -> translateExpression(expression)
+            is BinaryExpression -> translateExpression(expression)
+            is ArrayIndexedExpression -> translatePushFromArray(expression)
+            is TypecastExpression -> translateExpression(expression)
+            is AddressOf -> translateExpression(expression)
+            is DirectMemoryRead -> translateExpression(expression)
+            is NumericLiteralValue -> translateExpression(expression)
+            is RegisterExpr -> translateExpression(expression)
+            is IdentifierReference -> translateExpression(expression)
+            is FunctionCall -> {
+                val functionName = expression.target.nameInSource.last()
+                val builtinFunc = BuiltinFunctions[functionName]
+                if(builtinFunc!=null) {
+                    asmgen.translateFunctioncallExpression(expression, builtinFunc)
+                } else {
+                    asmgen.translateFunctionCall(expression)
+                    val sub = expression.target.targetSubroutine(program.namespace)!!
+                    val returns = sub.returntypes.zip(sub.asmReturnvaluesRegisters)
+                    for((_, reg) in returns) {
+                        if(!reg.stack) {
+                            // result value in cpu or status registers, put it on the stack
+                            if(reg.registerOrPair!=null) {
+                                when(reg.registerOrPair) {
+                                    RegisterOrPair.A -> asmgen.out("  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+                                    RegisterOrPair.Y -> asmgen.out("  tya |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+                                    RegisterOrPair.AY -> asmgen.out("  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  tya |  sta  ${MachineDefinition.ESTACK_HI_HEX},x |  dex")
+                                    RegisterOrPair.X, RegisterOrPair.AX, RegisterOrPair.XY -> throw AssemblyError("can't push X register - use a variable")
+                                }
+                            }
+                            // return value from a statusregister is not put on the stack, it should be acted on via a conditional branch such as if_cc
+                        }
+                    }
+                }
+            }
+            is ArrayLiteralValue, is StringLiteralValue -> TODO("string/array/struct assignment?")
+            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened")
+            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
+        }
+    }
+
+    private fun translateExpression(expr: TypecastExpression) {
+        translateExpression(expr.expression)
+        when(expr.expression.inferType(program).typeOrElse(DataType.STRUCT)) {
+            DataType.UBYTE -> {
+                when(expr.type) {
+                    DataType.UBYTE, DataType.BYTE -> {}
+                    DataType.UWORD, DataType.WORD -> asmgen.out("  lda  #0  |  sta  ${MachineDefinition.ESTACK_HI_PLUS1_HEX},x")
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_ub2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.BYTE -> {
+                when(expr.type) {
+                    DataType.UBYTE, DataType.BYTE -> {}
+                    DataType.UWORD, DataType.WORD -> asmgen.out("  lda  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x  |  ${asmgen.signExtendAtoMsb("${MachineDefinition.ESTACK_HI_PLUS1_HEX},x")}")
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_b2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.UWORD -> {
+                when(expr.type) {
+                    DataType.BYTE, DataType.UBYTE -> {}
+                    DataType.WORD, DataType.UWORD -> {}
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_uw2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.WORD -> {
+                when(expr.type) {
+                    DataType.BYTE, DataType.UBYTE -> {}
+                    DataType.WORD, DataType.UWORD -> {}
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_w2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.FLOAT -> {
+                when(expr.type) {
+                    DataType.UBYTE -> asmgen.out(" jsr  c64flt.stack_float2uw")
+                    DataType.BYTE -> asmgen.out(" jsr  c64flt.stack_float2w")
+                    DataType.UWORD -> asmgen.out(" jsr  c64flt.stack_float2uw")
+                    DataType.WORD -> asmgen.out(" jsr  c64flt.stack_float2w")
+                    DataType.FLOAT -> {}
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            in PassByReferenceDatatypes -> throw AssemblyError("cannot case a pass-by-reference datatypes into something else")
+            else -> throw AssemblyError("weird type")
+        }
+    }
+
+    private fun translateExpression(expr: AddressOf) {
+        val name = asmgen.asmIdentifierName(expr.identifier)
+        asmgen.out("  lda  #<$name |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  lda  #>$name  |  sta  ${MachineDefinition.ESTACK_HI_HEX},x  | dex")
+    }
+
+    private fun translateExpression(expr: DirectMemoryRead) {
+        when(expr.addressExpression) {
+            is NumericLiteralValue -> {
+                val address = (expr.addressExpression as NumericLiteralValue).number.toInt()
+                asmgen.out("  lda  ${address.toHex()} |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+            }
+            is IdentifierReference -> {
+                val sourceName = asmgen.asmIdentifierName(expr.addressExpression as IdentifierReference)
+                asmgen.out("  lda  $sourceName |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+            }
+            else -> {
+                translateExpression(expr.addressExpression)
+                asmgen.out("  jsr  prog8_lib.read_byte_from_address")
+                asmgen.out("  sta  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x")
+            }
+        }
+    }
+
+    private fun translateExpression(expr: NumericLiteralValue) {
+        when(expr.type) {
+            DataType.UBYTE, DataType.BYTE -> asmgen.out(" lda  #${expr.number.toHex()}  | sta  ${MachineDefinition.ESTACK_LO_HEX},x  | dex")
+            DataType.UWORD, DataType.WORD -> asmgen.out("""
+                lda  #<${expr.number.toHex()}
+                sta  ${MachineDefinition.ESTACK_LO_HEX},x
+                lda  #>${expr.number.toHex()}
+                sta  ${MachineDefinition.ESTACK_HI_HEX},x
+                dex
+            """)
+            DataType.FLOAT -> {
+                val floatConst = asmgen.getFloatConst(expr.number.toDouble())
+                asmgen.out(" lda  #<$floatConst |  ldy  #>$floatConst |  jsr  c64flt.push_float")
+            }
+            else -> throw AssemblyError("weird type")
+        }
+    }
+
+    private fun translateExpression(expr: RegisterExpr) {
+        when(expr.register) {
+            Register.A -> asmgen.out(" sta  ${MachineDefinition.ESTACK_LO_HEX},x | dex")
+            Register.X -> throw AssemblyError("cannot push X - use a variable instead of the X register")
+            Register.Y -> asmgen.out(" tya |  sta  ${MachineDefinition.ESTACK_LO_HEX},x | dex")
+        }
+    }
+
+    private fun translateExpression(expr: IdentifierReference) {
+        val varname = asmgen.asmIdentifierName(expr)
+        when(expr.inferType(program).typeOrElse(DataType.STRUCT)) {
+            DataType.UBYTE, DataType.BYTE -> {
+                asmgen.out("  lda  $varname  |  sta  ${MachineDefinition.ESTACK_LO_HEX},x  |  dex")
+            }
+            DataType.UWORD, DataType.WORD, in ArrayDatatypes, in StringDatatypes -> {
+                // (for arrays and strings, push their address)
+                asmgen.out("  lda  $varname  |  sta  ${MachineDefinition.ESTACK_LO_HEX},x  |  lda  $varname+1 |  sta  ${MachineDefinition.ESTACK_HI_HEX},x |  dex")
+            }
+            DataType.FLOAT -> {
+                asmgen.out(" lda  #<$varname |  ldy  #>$varname|  jsr  c64flt.push_float")
+            }
+            else -> throw AssemblyError("stack push weird variable type $expr")
+        }
+    }
+
+    private val optimizedByteMultiplications = setOf(3,5,6,7,9,10,11,12,13,14,15,20,25,40)
+    private val optimizedWordMultiplications = setOf(3,5,6,7,9,10,12,15,20,25,40)
+    private val powerOfTwos = setOf(0,1,2,4,8,16,32,64,128,256)
+
+    private fun translateExpression(expr: BinaryExpression) {
+        val leftIDt = expr.left.inferType(program)
+        val rightIDt = expr.right.inferType(program)
+        if(!leftIDt.isKnown || !rightIDt.isKnown)
+            throw AssemblyError("can't infer type of both expression operands")
+
+        val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
+        val rightDt = rightIDt.typeOrElse(DataType.STRUCT)
+        // see if we can apply some optimized routines
+        when(expr.operator) {
+            ">>" -> {
+                // bit-shifts are always by a constant number (for now)
+                translateExpression(expr.left)
+                val amount = expr.right.constValue(program)!!.number.toInt()
+                when (leftDt) {
+                    DataType.UBYTE -> repeat(amount) { asmgen.out("  lsr  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x") }
+                    DataType.BYTE -> repeat(amount) { asmgen.out("  lda  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x |  asl  a |  ror  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x") }
+                    DataType.UWORD -> repeat(amount) { asmgen.out("  lsr  ${MachineDefinition.ESTACK_HI_PLUS1_HEX},x |  ror  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x") }
+                    DataType.WORD -> repeat(amount) { asmgen.out("  lda  ${MachineDefinition.ESTACK_HI_PLUS1_HEX},x |  asl a  |  ror  ${MachineDefinition.ESTACK_HI_PLUS1_HEX},x |  ror  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x") }
+                    else -> throw AssemblyError("weird type")
+                }
+                return
+            }
+            "<<" -> {
+                // bit-shifts are always by a constant number (for now)
+                translateExpression(expr.left)
+                val amount = expr.right.constValue(program)!!.number.toInt()
+                if (leftDt in ByteDatatypes)
+                    repeat(amount) { asmgen.out("  asl  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x") }
+                else
+                    repeat(amount) { asmgen.out("  asl  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x |  rol  ${MachineDefinition.ESTACK_HI_PLUS1_HEX},x") }
+                return
+            }
+            "*" -> {
+                val value = expr.right.constValue(program)
+                if(value!=null) {
+                    if(rightDt in IntegerDatatypes) {
+                        val amount = value.number.toInt()
+                        if(amount in powerOfTwos)
+                            printWarning("${expr.right.position} multiplication by power of 2 should have been optimized into a left shift instruction: $amount")
+                        when(rightDt) {
+                            DataType.UBYTE -> {
+                                if(amount in optimizedByteMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_byte_$amount")
+                                    return
+                                }
+                            }
+                            DataType.BYTE -> {
+                                if(amount in optimizedByteMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_byte_$amount")
+                                    return
+                                }
+                                if(amount.absoluteValue in optimizedByteMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  prog8_lib.neg_b |  jsr  math.mul_byte_${amount.absoluteValue}")
+                                    return
+                                }
+                            }
+                            DataType.UWORD -> {
+                                if(amount in optimizedWordMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_word_$amount")
+                                    return
+                                }
+                            }
+                            DataType.WORD -> {
+                                if(amount in optimizedWordMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_word_$amount")
+                                    return
+                                }
+                                if(amount.absoluteValue in optimizedWordMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  prog8_lib.neg_w |  jsr  math.mul_word_${amount.absoluteValue}")
+                                    return
+                                }
+                            }
+                            else -> {}
+                        }
+                    }
+                }
+            }
+        }
+
+        // the general, non-optimized cases
+        translateExpression(expr.left)
+        translateExpression(expr.right)
+        if(leftDt!=rightDt)
+            throw AssemblyError("binary operator ${expr.operator} left/right dt not identical")     // is this strictly required always?
+        when (leftDt) {
+            in ByteDatatypes -> translateBinaryOperatorBytes(expr.operator, leftDt)
+            in WordDatatypes -> translateBinaryOperatorWords(expr.operator, leftDt)
+            DataType.FLOAT -> translateBinaryOperatorFloats(expr.operator)
+            else -> throw AssemblyError("non-numerical datatype")
+        }
+    }
+
+    private fun translateExpression(expr: PrefixExpression) {
+        translateExpression(expr.expression)
+        val type = expr.inferType(program).typeOrElse(DataType.STRUCT)
+        when(expr.operator) {
+            "+" -> {}
+            "-" -> {
+                when(type) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.neg_b")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.neg_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  c64flt.neg_f")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "~" -> {
+                when(type) {
+                    in ByteDatatypes ->
+                        asmgen.out("""
+                            lda  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x
+                            eor  #255
+                            sta  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x
+                            """)
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.inv_word")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "not" -> {
+                when(type) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.not_byte")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.not_word")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            else -> throw AssemblyError("invalid prefix operator ${expr.operator}")
+        }
+    }
+
+
+    private fun translatePushFromArray(arrayExpr: ArrayIndexedExpression) {
+        // assume *reading* from an array
+        val index = arrayExpr.arrayspec.index
+        val arrayDt = arrayExpr.identifier.targetVarDecl(program.namespace)!!.datatype
+        val arrayVarName = asmgen.asmIdentifierName(arrayExpr.identifier)
+        if(index is NumericLiteralValue) {
+            val elementDt = ArrayElementTypes.getValue(arrayDt)
+            val indexValue = index.number.toInt() * elementDt.memorySize()
+            when(elementDt) {
+                in ByteDatatypes -> {
+                    asmgen.out("  lda  $arrayVarName+$indexValue |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  dex")
+                }
+                in WordDatatypes -> {
+                    asmgen.out("  lda  $arrayVarName+$indexValue |  sta  ${MachineDefinition.ESTACK_LO_HEX},x |  lda  $arrayVarName+$indexValue+1 |  sta  ${MachineDefinition.ESTACK_HI_HEX},x |  dex")
+                }
+                DataType.FLOAT -> {
+                    asmgen.out("  lda  #<$arrayVarName+$indexValue |  ldy  #>$arrayVarName+$indexValue |  jsr  c64flt.push_float")
+                }
+                else -> throw AssemblyError("weird type")
+            }
+        } else {
+            asmgen.translateArrayIndexIntoA(arrayExpr)
+            asmgen.readAndPushArrayvalueWithIndexA(arrayDt, arrayExpr.identifier)
+        }
+    }
+
+    private fun translateBinaryOperatorBytes(operator: String, types: DataType) {
+        when(operator) {
+            "**" -> throw AssemblyError("** operator requires floats")
+            "*" -> asmgen.out("  jsr  prog8_lib.mul_byte")  //  the optimized routines should have been checked earlier
+            "/" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.idiv_ub" else "  jsr  prog8_lib.idiv_b")
+            "%" -> {
+                if(types==DataType.BYTE)
+                    throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
+                asmgen.out("  jsr prog8_lib.remainder_ub")
+            }
+            "+" -> asmgen.out("""
+                lda  ${MachineDefinition.ESTACK_LO_PLUS2_HEX},x
+                clc
+                adc  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x
+                inx
+                sta  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x
+                """)
+            "-" -> asmgen.out("""
+                lda  ${MachineDefinition.ESTACK_LO_PLUS2_HEX},x
+                sec
+                sbc  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x
+                inx
+                sta  ${MachineDefinition.ESTACK_LO_PLUS1_HEX},x
+                """)
+            "<<", ">>" -> throw AssemblyError("bit-shifts not via stack")
+            "<" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.less_ub" else "  jsr  prog8_lib.less_b")
+            ">" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.greater_ub" else "  jsr  prog8_lib.greater_b")
+            "<=" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.lesseq_ub" else "  jsr  prog8_lib.lesseq_b")
+            ">=" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.greatereq_ub" else "  jsr  prog8_lib.greatereq_b")
+            "==" -> asmgen.out("  jsr  prog8_lib.equal_b")
+            "!=" -> asmgen.out("  jsr  prog8_lib.notequal_b")
+            "&" -> asmgen.out("  jsr  prog8_lib.bitand_b")
+            "^" -> asmgen.out("  jsr  prog8_lib.bitxor_b")
+            "|" -> asmgen.out("  jsr  prog8_lib.bitor_b")
+            "and" -> asmgen.out("  jsr  prog8_lib.and_b")
+            "or" -> asmgen.out("  jsr  prog8_lib.or_b")
+            "xor" -> asmgen.out("  jsr  prog8_lib.xor_b")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateBinaryOperatorWords(operator: String, types: DataType) {
+        when(operator) {
+            "**" -> throw AssemblyError("** operator requires floats")
+            "*" -> asmgen.out("  jsr  prog8_lib.mul_word")
+            "/" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.idiv_uw" else "  jsr  prog8_lib.idiv_w")
+            "%" -> {
+                if(types==DataType.WORD)
+                    throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
+                asmgen.out("  jsr prog8_lib.remainder_uw")
+            }
+            "+" -> asmgen.out("  jsr  prog8_lib.add_w")
+            "-" -> asmgen.out("  jsr  prog8_lib.sub_w")
+            "<<" -> throw AssemblyError("<< should not operate via stack")
+            ">>" -> throw AssemblyError(">> should not operate via stack")
+            "<" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.less_uw" else "  jsr  prog8_lib.less_w")
+            ">" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.greater_uw" else "  jsr  prog8_lib.greater_w")
+            "<=" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.lesseq_uw" else "  jsr  prog8_lib.lesseq_w")
+            ">=" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.greatereq_uw" else "  jsr  prog8_lib.greatereq_w")
+            "==" -> asmgen.out("  jsr  prog8_lib.equal_w")
+            "!=" -> asmgen.out("  jsr  prog8_lib.notequal_w")
+            "&" -> asmgen.out("  jsr  prog8_lib.bitand_w")
+            "^" -> asmgen.out("  jsr  prog8_lib.bitxor_w")
+            "|" -> asmgen.out("  jsr  prog8_lib.bitor_w")
+            "and" -> asmgen.out("  jsr  prog8_lib.and_w")
+            "or" -> asmgen.out("  jsr  prog8_lib.or_w")
+            "xor" -> asmgen.out("  jsr  prog8_lib.xor_w")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateBinaryOperatorFloats(operator: String) {
+        when(operator) {
+            "**" -> asmgen.out(" jsr  c64flt.pow_f")
+            "*" -> asmgen.out("  jsr  c64flt.mul_f")
+            "/" -> asmgen.out("  jsr  c64flt.div_f")
+            "+" -> asmgen.out("  jsr  c64flt.add_f")
+            "-" -> asmgen.out("  jsr  c64flt.sub_f")
+            "<" -> asmgen.out("  jsr  c64flt.less_f")
+            ">" -> asmgen.out("  jsr  c64flt.greater_f")
+            "<=" -> asmgen.out("  jsr  c64flt.lesseq_f")
+            ">=" -> asmgen.out("  jsr  c64flt.greatereq_f")
+            "==" -> asmgen.out("  jsr  c64flt.equal_f")
+            "!=" -> asmgen.out("  jsr  c64flt.notequal_f")
+            "%", "<<", ">>", "&", "^", "|", "and", "or", "xor" -> throw AssemblyError("requires integer datatype")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+}

compiler/src/prog8/compiler/target/c64/codegen/ForLoopsAsmGen.kt

@@ -0,0 +1,561 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.Register
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.expressions.RangeExpr
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.ForLoop
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.toHex
+import kotlin.math.absoluteValue
+
+
+internal class ForLoopsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translate(stmt: ForLoop) {
+        val iterableDt = stmt.iterable.inferType(program)
+        if(!iterableDt.isKnown)
+            throw AssemblyError("can't determine iterable dt")
+        when(stmt.iterable) {
+            is RangeExpr -> {
+                val range = (stmt.iterable as RangeExpr).toConstantIntegerRange()
+                if(range==null) {
+                    translateForOverNonconstRange(stmt, iterableDt.typeOrElse(DataType.STRUCT), stmt.iterable as RangeExpr)
+                } else {
+                    if (range.isEmpty())
+                        throw AssemblyError("empty range")
+                    translateForOverConstRange(stmt, iterableDt.typeOrElse(DataType.STRUCT), range)
+                }
+            }
+            is IdentifierReference -> {
+                translateForOverIterableVar(stmt, iterableDt.typeOrElse(DataType.STRUCT), stmt.iterable as IdentifierReference)
+            }
+            else -> throw AssemblyError("can't iterate over ${stmt.iterable}")
+        }
+    }
+
+    private fun translateForOverNonconstRange(stmt: ForLoop, iterableDt: DataType, range: RangeExpr) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val continueLabel = asmgen.makeLabel("for_continue")
+        val counterLabel = asmgen.makeLabel("for_counter")
+        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopContinueLabels.push(continueLabel)
+        val stepsize=range.step.constValue(program)?.number
+        when (stepsize) {
+            1 -> {
+                when(iterableDt) {
+                    DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                        if (stmt.loopRegister != null) {
+                            // loop register over range
+                            if(stmt.loopRegister!= Register.A)
+                                throw AssemblyError("can only use A")
+                            asmgen.translateExpression(range.to)
+                            asmgen.translateExpression(range.from)
+                            asmgen.out("""
+                inx
+                lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                sta  $loopLabel+1
+                inx
+                lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                sec
+                sbc  $loopLabel+1
+                adc  #0
+                sta  $counterLabel
+$loopLabel      lda  #0                 ; modified""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                inc  $loopLabel+1
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        } else {
+                            // loop over byte range via loopvar
+                            val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                            asmgen.translateExpression(range.to)
+                            asmgen.translateExpression(range.from)
+                            asmgen.out("""
+                inx
+                lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                sta  $varname
+                inx
+                lda  ${MachineDefinition.ESTACK_LO_HEX},x
+                sec
+                sbc  $varname
+                adc  #0
+                sta  $counterLabel
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                inc  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                    }
+                    DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                        asmgen.translateExpression(range.to)
+                        asmgen.out("  inc  ${MachineDefinition.ESTACK_LO_HEX}+1,x |  bne  + |  inc  ${MachineDefinition.ESTACK_HI_HEX}+1,x |+  ")
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        val assignLoopvar = Assignment(AssignTarget(null, stmt.loopVar, null, null, stmt.loopVar!!.position),
+                                null, range.from, range.position)
+                        assignLoopvar.linkParents(stmt)
+                        asmgen.translate(assignLoopvar)
+                        asmgen.out(loopLabel)
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+                inc  $varname
+                bne  +
+                inc  $varname+1            
++               lda  ${MachineDefinition.ESTACK_HI_HEX}+1,x
+                cmp  $varname+1
+                bne  +
+                lda  ${MachineDefinition.ESTACK_LO_HEX}+1,x
+                cmp  $varname
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel       inx""")
+                    }
+                    else -> throw AssemblyError("range expression can only be byte or word")
+                }
+            }
+            -1 -> {
+                when(iterableDt){
+                    DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                        if (stmt.loopRegister != null) {
+                            // loop register over range
+                            if(stmt.loopRegister!= Register.A)
+                                throw AssemblyError("can only use A")
+                            asmgen.translateExpression(range.from)
+                            asmgen.translateExpression(range.to)
+                            asmgen.out("""
+                inx
+                lda  ${MachineDefinition.ESTACK_LO_HEX}+1,x
+                sta  $loopLabel+1
+                sec
+                sbc  ${MachineDefinition.ESTACK_LO_HEX},x
+                adc  #0
+                sta  $counterLabel
+                inx
+$loopLabel      lda  #0                 ; modified""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                dec  $loopLabel+1
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        } else {
+                            // loop over byte range via loopvar
+                            val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                            asmgen.translateExpression(range.from)
+                            asmgen.translateExpression(range.to)
+                            asmgen.out("""
+                inx
+                lda  ${MachineDefinition.ESTACK_LO_HEX}+1,x
+                sta  $varname
+                sec
+                sbc  ${MachineDefinition.ESTACK_LO_HEX},x
+                adc  #0
+                sta  $counterLabel
+                inx
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                dec  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                    }
+                    DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                        asmgen.translateExpression(range.to)
+                        asmgen.out("""
+                lda  ${MachineDefinition.ESTACK_LO_HEX}+1,x
+                bne  +
+                dec  ${MachineDefinition.ESTACK_HI_HEX}+1,x
++               dec  ${MachineDefinition.ESTACK_LO_HEX}+1,x                            
+                        """)
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        val assignLoopvar = Assignment(AssignTarget(null, stmt.loopVar, null, null, stmt.loopVar!!.position),
+                                null, range.from, range.position)
+                        assignLoopvar.linkParents(stmt)
+                        asmgen.translate(assignLoopvar)
+                        asmgen.out(loopLabel)
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+                lda  $varname
+                bne  +
+                dec  $varname+1
++               dec  $varname                
+                lda  ${MachineDefinition.ESTACK_HI_HEX}+1,x
+                cmp  $varname+1
+                bne  +
+                lda  ${MachineDefinition.ESTACK_LO_HEX}+1,x
+                cmp  $varname
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel       inx""")
+                    }
+                    else -> throw AssemblyError("range expression can only be byte or word")
+                }
+            }
+            else -> when (iterableDt) {
+                DataType.ARRAY_UB, DataType.ARRAY_B -> TODO("non-const forloop bytes, step >1: $stepsize")
+                DataType.ARRAY_UW, DataType.ARRAY_W -> TODO("non-const forloop words, step >1: $stepsize")
+                else -> throw AssemblyError("range expression can only be byte or word")
+            }
+        }
+        asmgen.loopEndLabels.pop()
+        asmgen.loopContinueLabels.pop()
+    }
+
+    private fun translateForOverIterableVar(stmt: ForLoop, iterableDt: DataType, ident: IdentifierReference) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val continueLabel = asmgen.makeLabel("for_continue")
+        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopContinueLabels.push(continueLabel)
+        val iterableName = asmgen.asmIdentifierName(ident)
+        val decl = ident.targetVarDecl(program.namespace)!!
+        when(iterableDt) {
+            DataType.STR, DataType.STR_S -> {
+                if(stmt.loopRegister!=null && stmt.loopRegister!= Register.A)
+                    throw AssemblyError("can only use A")
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $loopLabel+1
+                    sty  $loopLabel+2
+$loopLabel          lda  ${65535.toHex()}       ; modified
+                    beq  $endLabel""")
+                if(stmt.loopVar!=null)
+                    asmgen.out("  sta  ${asmgen.asmIdentifierName(stmt.loopVar!!)}")
+                asmgen.translate(stmt.body)
+                asmgen.out("""
+$continueLabel      inc  $loopLabel+1
+                    bne  $loopLabel
+                    inc  $loopLabel+2
+                    bne  $loopLabel
+$endLabel""")
+            }
+            DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                // TODO: optimize loop code when the length of the array is < 256, don't need a separate counter in such cases
+                val length = decl.arraysize!!.size()!!
+                if(stmt.loopRegister!=null && stmt.loopRegister!= Register.A)
+                    throw AssemblyError("can only use A")
+                val counterLabel = asmgen.makeLabel("for_counter")
+                val modifiedLabel = asmgen.makeLabel("for_modified")
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $modifiedLabel+1
+                    sty  $modifiedLabel+2
+                    ldy  #0
+$loopLabel          sty  $counterLabel
+$modifiedLabel      lda  ${65535.toHex()},y       ; modified""")
+                if(stmt.loopVar!=null)
+                    asmgen.out("  sta  ${asmgen.asmIdentifierName(stmt.loopVar!!)}")
+                asmgen.translate(stmt.body)
+                asmgen.out("""
+$continueLabel      ldy  $counterLabel
+                    iny
+                    cpy  #${length and 255}
+                    beq  $endLabel
+                    jmp  $loopLabel
+$counterLabel       .byte  0
+$endLabel""")
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                // TODO: optimize loop code when the length of the array is < 256, don't need a separate counter in such cases
+                val length = decl.arraysize!!.size()!! * 2
+                if(stmt.loopRegister!=null)
+                    throw AssemblyError("can't use register to loop over words")
+                val counterLabel = asmgen.makeLabel("for_counter")
+                val modifiedLabel = asmgen.makeLabel("for_modified")
+                val modifiedLabel2 = asmgen.makeLabel("for_modified2")
+                val loopvarName = asmgen.asmIdentifierName(stmt.loopVar!!)
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $modifiedLabel+1
+                    sty  $modifiedLabel+2
+                    lda  #<$iterableName+1
+                    ldy  #>$iterableName+1
+                    sta  $modifiedLabel2+1
+                    sty  $modifiedLabel2+2
+                    ldy  #0
+$loopLabel          sty  $counterLabel
+$modifiedLabel      lda  ${65535.toHex()},y       ; modified
+                    sta  $loopvarName
+$modifiedLabel2     lda  ${65535.toHex()},y       ; modified
+                    sta  $loopvarName+1""")
+                asmgen.translate(stmt.body)
+                asmgen.out("""
+$continueLabel      ldy  $counterLabel
+                    iny
+                    iny
+                    cpy  #${length and 255}
+                    beq  $endLabel
+                    jmp  $loopLabel
+$counterLabel       .byte  0
+$endLabel""")
+            }
+            DataType.ARRAY_F -> {
+                throw AssemblyError("for loop with floating point variables is not supported")
+            }
+            else -> throw AssemblyError("can't iterate over $iterableDt")
+        }
+        asmgen.loopEndLabels.pop()
+        asmgen.loopContinueLabels.pop()
+    }
+
+    private fun translateForOverConstRange(stmt: ForLoop, iterableDt: DataType, range: IntProgression) {
+        // TODO: optimize loop code when the range is < 256 iterations, don't need a separate counter in such cases
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val continueLabel = asmgen.makeLabel("for_continue")
+        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopContinueLabels.push(continueLabel)
+        when(iterableDt) {
+            DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                val counterLabel = asmgen.makeLabel("for_counter")
+                if(stmt.loopRegister!=null) {
+
+                    // loop register over range
+
+                    if(stmt.loopRegister!= Register.A)
+                        throw AssemblyError("can only use A")
+                    when {
+                        range.step==1 -> {
+                            // step = 1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $loopLabel+1
+                lda  #${range.last-range.first+1 and 255}
+                sta  $counterLabel
+$loopLabel      lda  #0                 ; modified""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                inc  $loopLabel+1
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step==-1 -> {
+                            // step = -1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $loopLabel+1
+                lda  #${range.first-range.last+1 and 255}
+                sta  $counterLabel
+$loopLabel      lda  #0                 ; modified """)
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                dec  $loopLabel+1
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step >= 2 -> {
+                            // step >= 2
+                            asmgen.out("""
+                lda  #${(range.last-range.first) / range.step + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+$loopLabel      pha""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  pla
+                dec  $counterLabel
+                beq  $endLabel
+                clc
+                adc  #${range.step}
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        else -> {
+                            // step <= -2
+                            asmgen.out("""
+                lda  #${(range.first-range.last) / range.step.absoluteValue + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+$loopLabel      pha""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  pla
+                dec  $counterLabel
+                beq  $endLabel
+                sec
+                sbc  #${range.step.absoluteValue}
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                    }
+
+                } else {
+
+                    // loop over byte range via loopvar
+                    val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                    when {
+                        range.step==1 -> {
+                            // step = 1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $varname
+                lda  #${range.last-range.first+1 and 255}
+                sta  $counterLabel
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                inc  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step==-1 -> {
+                            // step = -1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $varname
+                lda  #${range.first-range.last+1 and 255}
+                sta  $counterLabel
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                dec  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step >= 2 -> {
+                            // step >= 2
+                            asmgen.out("""
+                lda  #${(range.last-range.first) / range.step + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+                sta  $varname
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                lda  $varname
+                clc
+                adc  #${range.step}
+                sta  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        else -> {
+                            // step <= -2
+                            asmgen.out("""
+                lda  #${(range.first-range.last) / range.step.absoluteValue + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+                sta  $varname
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                lda  $varname
+                sec
+                sbc  #${range.step.absoluteValue}
+                sta  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                    }
+                }
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                // loop over word range via loopvar
+                val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                when {
+                    range.step == 1 -> {
+                        // word, step = 1
+                        val lastValue = range.last+1
+                        asmgen.out("""
+                lda  #<${range.first}
+                ldy  #>${range.first}
+                sta  $varname
+                sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  inc  $varname
+                bne  +
+                inc  $varname+1
++               lda  $varname
+                cmp  #<$lastValue
+                bne  +
+                lda  $varname+1
+                cmp  #>$lastValue
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel""")
+                    }
+                    range.step == -1 -> {
+                        // word, step = 1
+                        val lastValue = range.last-1
+                        asmgen.out("""
+                lda  #<${range.first}
+                ldy  #>${range.first}
+                sta  $varname
+                sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  lda  $varname
+                bne  +
+                dec  $varname+1
++               dec  $varname
+                lda  $varname
+                cmp  #<$lastValue
+                bne  +
+                lda  $varname+1
+                cmp  #>$lastValue
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel""")
+                    }
+                    range.step >= 2 -> {
+                        // word, step >= 2
+                        TODO("for, word, step>=2")
+                    }
+                    else -> {
+                        // step <= -2
+                        TODO("for, word, step<=-2")
+                    }
+                }
+            }
+            else -> throw AssemblyError("range expression can only be byte or word")
+        }
+        asmgen.loopEndLabels.pop()
+        asmgen.loopContinueLabels.pop()
+    }
+
+}

compiler/src/prog8/compiler/target/c64/codegen/FunctionCallAsmGen.kt

@@ -0,0 +1,235 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.IFunctionCall
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Subroutine
+import prog8.ast.statements.SubroutineParameter
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.toHex
+
+internal class FunctionCallAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateFunctionCall(stmt: IFunctionCall) {
+        // output the code to setup the parameters and perform the actual call
+        // does NOT output the code to deal with the result values!
+        val sub = stmt.target.targetSubroutine(program.namespace) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
+        if(Register.X in sub.asmClobbers)
+            asmgen.out("  stx  c64.SCRATCH_ZPREGX")        // we only save X for now (required! is the eval stack pointer), screw A and Y...
+
+        val subName = asmgen.asmIdentifierName(stmt.target)
+        if(stmt.arglist.isNotEmpty()) {
+            for(arg in sub.parameters.withIndex().zip(stmt.arglist)) {
+                translateFuncArguments(arg.first, arg.second, sub)
+            }
+        }
+        asmgen.out("  jsr  $subName")
+
+        if(Register.X in sub.asmClobbers)
+            asmgen.out("  ldx  c64.SCRATCH_ZPREGX")        // restore X again
+    }
+
+    private fun translateFuncArguments(parameter: IndexedValue<SubroutineParameter>, value: Expression, sub: Subroutine) {
+        val sourceIDt = value.inferType(program)
+        if(!sourceIDt.isKnown)
+            throw AssemblyError("arg type unknown")
+        val sourceDt = sourceIDt.typeOrElse(DataType.STRUCT)
+        if(!argumentTypeCompatible(sourceDt, parameter.value.type))
+            throw AssemblyError("argument type incompatible")
+        if(sub.asmParameterRegisters.isEmpty()) {
+            // pass parameter via a variable
+            val paramVar = parameter.value
+            val scopedParamVar = (sub.scopedname+"."+paramVar.name).split(".")
+            val target = AssignTarget(null, IdentifierReference(scopedParamVar, sub.position), null, null, sub.position)
+            target.linkParents(value.parent)
+            when (value) {
+                is NumericLiteralValue -> {
+                    // optimize when the argument is a constant literal
+                    when(parameter.value.type) {
+                        in ByteDatatypes -> asmgen.assignFromByteConstant(target, value.number.toShort())
+                        in WordDatatypes -> asmgen.assignFromWordConstant(target, value.number.toInt())
+                        DataType.FLOAT -> asmgen.assignFromFloatConstant(target, value.number.toDouble())
+                        in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as arguments?")
+                        else -> throw AssemblyError("weird parameter datatype")
+                    }
+                }
+                is IdentifierReference -> {
+                    // optimize when the argument is a variable
+                    when (parameter.value.type) {
+                        in ByteDatatypes -> asmgen.assignFromByteVariable(target, value)
+                        in WordDatatypes -> asmgen.assignFromWordVariable(target, value)
+                        DataType.FLOAT -> asmgen.assignFromFloatVariable(target, value)
+                        in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as arguments?")
+                        else -> throw AssemblyError("weird parameter datatype")
+                    }
+                }
+                is RegisterExpr -> {
+                    asmgen.assignFromRegister(target, value.register)
+                }
+                is DirectMemoryRead -> {
+                    when(value.addressExpression) {
+                        is NumericLiteralValue -> {
+                            val address = (value.addressExpression as NumericLiteralValue).number.toInt()
+                            asmgen.assignFromMemoryByte(target, address, null)
+                        }
+                        is IdentifierReference -> {
+                            asmgen.assignFromMemoryByte(target, null, value.addressExpression as IdentifierReference)
+                        }
+                        else -> {
+                            asmgen.translateExpression(value.addressExpression)
+                            asmgen.out("  jsr  prog8_lib.read_byte_from_address |  inx")
+                            asmgen.assignFromRegister(target, Register.A)
+                        }
+                    }
+                }
+                else -> {
+                    asmgen.translateExpression(value)
+                    asmgen.assignFromEvalResult(target)
+                }
+            }
+        } else {
+            // pass parameter via a register parameter
+            val paramRegister = sub.asmParameterRegisters[parameter.index]
+            val statusflag = paramRegister.statusflag
+            val register = paramRegister.registerOrPair
+            val stack = paramRegister.stack
+            when {
+                stack -> {
+                    // push arg onto the stack
+                    // note: argument order is reversed (first argument will be deepest on the stack)
+                    asmgen.translateExpression(value)
+                }
+                statusflag!=null -> {
+                    if (statusflag == Statusflag.Pc) {
+                        // this param needs to be set last, right before the jsr
+                        // for now, this is already enforced on the subroutine definition by the Ast Checker
+                        when(value) {
+                            is NumericLiteralValue -> {
+                                val carrySet = value.number.toInt() != 0
+                                asmgen.out(if(carrySet) "  sec" else "  clc")
+                            }
+                            is IdentifierReference -> {
+                                val sourceName = asmgen.asmIdentifierName(value)
+                                asmgen.out("""
+            lda  $sourceName
+            beq  +
+            sec  
+            bcs  ++
++           clc
++
+""")
+                            }
+                            is RegisterExpr -> {
+                                when(value.register) {
+                                    Register.A -> asmgen.out("  cmp  #0")
+                                    Register.X -> asmgen.out("  txa")
+                                    Register.Y -> asmgen.out("  tya")
+                                }
+                                asmgen.out("""
+            beq  +
+            sec
+            bcs  ++
++           clc
++
+""")
+                            }
+                            else -> {
+                                asmgen.translateExpression(value)
+                                asmgen.out("""
+            inx                        
+            lda  ${MachineDefinition.ESTACK_LO_HEX},x
+            beq  +
+            sec  
+            bcs  ++
++           clc
++
+""")
+                            }
+                        }
+                    }
+                    else throw AssemblyError("can only use Carry as status flag parameter")
+                }
+                register!=null && register.name.length==1 -> {
+                    when (value) {
+                        is NumericLiteralValue -> {
+                            val target = AssignTarget(Register.valueOf(register.name), null, null, null, sub.position)
+                            target.linkParents(value.parent)
+                            asmgen.assignFromByteConstant(target, value.number.toShort())
+                        }
+                        is IdentifierReference -> {
+                            val target = AssignTarget(Register.valueOf(register.name), null, null, null, sub.position)
+                            target.linkParents(value.parent)
+                            asmgen.assignFromByteVariable(target, value)
+                        }
+                        else -> {
+                            asmgen.translateExpression(value)
+                            when(register) {
+                                RegisterOrPair.A -> asmgen.out("  inx | lda  ${MachineDefinition.ESTACK_LO_HEX},x")
+                                RegisterOrPair.X -> throw AssemblyError("can't pop into X register - use a variable instead")
+                                RegisterOrPair.Y -> asmgen.out("  inx | ldy  ${MachineDefinition.ESTACK_LO_HEX},x")
+                                else -> throw AssemblyError("cannot assign to register pair")
+                            }
+                        }
+                    }
+                }
+                register!=null && register.name.length==2 -> {
+                    // register pair as a 16-bit value (only possible for subroutine parameters)
+                    when (value) {
+                        is NumericLiteralValue -> {
+                            // optimize when the argument is a constant literal
+                            val hex = value.number.toHex()
+                            when (register) {
+                                RegisterOrPair.AX -> asmgen.out("  lda  #<$hex  |  ldx  #>$hex")
+                                RegisterOrPair.AY -> asmgen.out("  lda  #<$hex  |  ldy  #>$hex")
+                                RegisterOrPair.XY -> asmgen.out("  ldx  #<$hex  |  ldy  #>$hex")
+                                else -> {}
+                            }
+                        }
+                        is AddressOf -> {
+                            // optimize when the argument is an address of something
+                            val sourceName = asmgen.asmIdentifierName(value.identifier)
+                            when (register) {
+                                RegisterOrPair.AX -> asmgen.out("  lda  #<$sourceName  |  ldx  #>$sourceName")
+                                RegisterOrPair.AY -> asmgen.out("  lda  #<$sourceName  |  ldy  #>$sourceName")
+                                RegisterOrPair.XY -> asmgen.out("  ldx  #<$sourceName  |  ldy  #>$sourceName")
+                                else -> {}
+                            }
+                        }
+                        is IdentifierReference -> {
+                            val sourceName = asmgen.asmIdentifierName(value)
+                            when (register) {
+                                RegisterOrPair.AX -> asmgen.out("  lda  $sourceName  |  ldx  $sourceName+1")
+                                RegisterOrPair.AY -> asmgen.out("  lda  $sourceName  |  ldy  $sourceName+1")
+                                RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName  |  ldy  $sourceName+1")
+                                else -> {}
+                            }
+                        }
+                        else -> {
+                            asmgen.translateExpression(value)
+                            if (register == RegisterOrPair.AX || register == RegisterOrPair.XY)
+                                throw AssemblyError("can't use X register here - use a variable")
+                            else if (register == RegisterOrPair.AY)
+                                asmgen.out("  inx |  lda  ${MachineDefinition.ESTACK_LO_HEX},x  |  ldy  ${MachineDefinition.ESTACK_HI_HEX},x")
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private fun argumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
+        if(argType isAssignableTo paramType)
+            return true
+
+        // we have a special rule for some types.
+        // strings are assignable to UWORD, for example, and vice versa
+        if(argType in StringDatatypes && paramType==DataType.UWORD)
+            return true
+        if(argType==DataType.UWORD && paramType in StringDatatypes)
+            return true
+
+        return false
+    }
+}

compiler/src/prog8/compiler/target/c64/codegen/PostIncrDecrAsmGen.kt

@@ -0,0 +1,149 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.RegisterExpr
+import prog8.ast.statements.PostIncrDecr
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.toHex
+
+internal class PostIncrDecrAsmGen(private val program: Program, private val asmgen: AsmGen) {
+    internal fun translate(stmt: PostIncrDecr) {
+        val incr = stmt.operator=="++"
+        val targetIdent = stmt.target.identifier
+        val targetMemory = stmt.target.memoryAddress
+        val targetArrayIdx = stmt.target.arrayindexed
+        val targetRegister = stmt.target.register
+        when {
+            targetRegister!=null -> {
+                when(targetRegister) {
+                    Register.A -> {
+                        if(incr)
+                            asmgen.out("  clc |  adc  #1 ")
+                        else
+                            asmgen.out("  sec |  sbc  #1 ")
+                    }
+                    Register.X -> {
+                        if(incr) asmgen.out("  inx") else asmgen.out("  dex")
+                    }
+                    Register.Y -> {
+                        if(incr) asmgen.out("  iny") else asmgen.out("  dey")
+                    }
+                }
+            }
+            targetIdent!=null -> {
+                val what = asmgen.asmIdentifierName(targetIdent)
+                val dt = stmt.target.inferType(program, stmt).typeOrElse(DataType.STRUCT)
+                when (dt) {
+                    in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what" else "  dec  $what")
+                    in WordDatatypes -> {
+                        if(incr)
+                            asmgen.out(" inc  $what |  bne  + |  inc  $what+1 |+")
+                        else
+                            asmgen.out("""
+        lda  $what
+        bne  +
+        dec  $what+1
++       dec  $what 
+""")
+                    }
+                    DataType.FLOAT -> {
+                        asmgen.out("  lda  #<$what |  ldy  #>$what")
+                        asmgen.out(if(incr) "  jsr  c64flt.inc_var_f" else "  jsr  c64flt.dec_var_f")
+                    }
+                    else -> throw AssemblyError("need numeric type")
+                }
+            }
+            targetMemory!=null -> {
+                val addressExpr = targetMemory.addressExpression
+                when (addressExpr) {
+                    is NumericLiteralValue -> {
+                        val what = addressExpr.number.toHex()
+                        asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
+                    }
+                    is IdentifierReference -> {
+                        val what = asmgen.asmIdentifierName(addressExpr)
+                        asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
+                    }
+                    else -> throw AssemblyError("weird target type $targetMemory")
+                }
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val what = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
+                val elementDt = ArrayElementTypes.getValue(arrayDt)
+                when(index) {
+                    is NumericLiteralValue -> {
+                        val indexValue = index.number.toInt() * elementDt.memorySize()
+                        when(elementDt) {
+                            in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what+$indexValue" else "  dec  $what+$indexValue")
+                            in WordDatatypes -> {
+                                if(incr)
+                                    asmgen.out(" inc  $what+$indexValue |  bne  + |  inc  $what+$indexValue+1 |+")
+                                else
+                                    asmgen.out("""
+        lda  $what+$indexValue
+        bne  +
+        dec  $what+$indexValue+1
++       dec  $what+$indexValue 
+""")
+                            }
+                            DataType.FLOAT -> {
+                                asmgen.out("  lda  #<$what+$indexValue |  ldy  #>$what+$indexValue")
+                                asmgen.out(if(incr) "  jsr  c64flt.inc_var_f" else "  jsr  c64flt.dec_var_f")
+                            }
+                            else -> throw AssemblyError("need numeric type")
+                        }
+                    }
+                    is RegisterExpr -> {
+                        // TODO optimize common cases
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                    }
+                    is IdentifierReference -> {
+                        // TODO optimize common cases
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                    }
+                    else -> {
+                        // TODO optimize common cases
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                    }
+                }
+            }
+            else -> throw AssemblyError("weird target type ${stmt.target}")
+        }
+    }
+
+    private fun incrDecrArrayvalueWithIndexA(incr: Boolean, arrayDt: DataType, arrayVarName: String) {
+        asmgen.out("  stx  ${MachineDefinition.C64Zeropage.SCRATCH_REG_X} |  tax")
+        when(arrayDt) {
+            DataType.STR, DataType.STR_S,
+            DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                asmgen.out(if(incr) "  inc  $arrayVarName,x" else "  dec  $arrayVarName,x")
+            }
+            DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                if(incr)
+                    asmgen.out(" inc  $arrayVarName,x |  bne  + |  inc  $arrayVarName+1,x |+")
+                else
+                    asmgen.out("""
+        lda  $arrayVarName,x
+        bne  +
+        dec  $arrayVarName+1,x
++       dec  $arrayVarName 
+""")
+            }
+            DataType.ARRAY_F -> {
+                asmgen.out("  lda  #<$arrayVarName |  ldy  #>$arrayVarName")
+                asmgen.out(if(incr) "  jsr  c64flt.inc_indexed_var_f" else "  jsr  c64flt.dec_indexed_var_f")
+            }
+            else -> throw AssemblyError("weird array dt")
+        }
+        asmgen.out("  ldx  ${MachineDefinition.C64Zeropage.SCRATCH_REG_X}")
+    }
+
+}

compiler/src/prog8/functions/BuiltinFunctions.kt

@@ -1,21 +1,22 @@
 package prog8.functions
 
-import prog8.ast.*
+import prog8.ast.Program
 import prog8.ast.base.*
-import prog8.ast.expressions.DirectMemoryRead
-import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.LiteralValue
-import prog8.ast.statements.VarDecl
+import prog8.ast.expressions.*
 import prog8.compiler.CompilerException
 import kotlin.math.*
 
 
 class BuiltinFunctionParam(val name: String, val possibleDatatypes: Set<DataType>)
 
+
+typealias ConstExpressionCaller = (args: List<Expression>, position: Position, program: Program) -> NumericLiteralValue
+
+
 class FunctionSignature(val pure: Boolean,      // does it have side effects?
                         val parameters: List<BuiltinFunctionParam>,
                         val returntype: DataType?,
-                        val constExpressionFunc: ((args: List<IExpression>, position: Position, program: Program) -> LiteralValue)? = null)
+                        val constExpressionFunc: ConstExpressionCaller? = null)
 
 
 val BuiltinFunctions = mapOf(
@@ -27,12 +28,13 @@ val BuiltinFunctions = mapOf(
     "lsl"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", IntegerDatatypes)), null),
     "lsr"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", IntegerDatatypes)), null),
         // these few have a return value depending on the argument(s):
-    "max"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArgOutputNumber(a, p, prg) { it.max()!! }},    // type depends on args
-    "min"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArgOutputNumber(a, p, prg) { it.min()!! }},    // type depends on args
-    "sum"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArgOutputNumber(a, p, prg) { it.sum() }},      // type depends on args
+    "max"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, _ -> collectionArgNeverConst(a, p) },    // type depends on args
+    "min"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, _ -> collectionArgNeverConst(a, p) },    // type depends on args
+    "sum"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, _ -> collectionArgNeverConst(a, p) },      // type depends on args
     "abs"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", NumericDatatypes)), null, ::builtinAbs),      // type depends on argument
     "len"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", IterableDatatypes)), null, ::builtinLen),    // type is UBYTE or UWORD depending on actual length
         // normal functions follow:
+    "sgn"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", NumericDatatypes)), DataType.BYTE, ::builtinSgn ),
     "sin"         to FunctionSignature(true, listOf(BuiltinFunctionParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sin) },
     "sin8"        to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.BYTE, ::builtinSin8 ),
     "sin8u"       to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.UBYTE, ::builtinSin8u ),
@@ -51,12 +53,11 @@ val BuiltinFunctions = mapOf(
     "sqrt"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sqrt) },
     "rad"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toRadians) },
     "deg"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toDegrees) },
-    "avg"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.FLOAT, ::builtinAvg),
     "round"       to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::round) },
     "floor"       to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::floor) },
     "ceil"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::ceil) },
-    "any"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArgOutputBoolean(a, p, prg) { it.any { v -> v != 0.0} }},
-    "all"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArgOutputBoolean(a, p, prg) { it.all { v -> v != 0.0} }},
+    "any"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, _ -> collectionArgNeverConst(a, p) },
+    "all"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, _ -> collectionArgNeverConst(a, p) },
     "lsb"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x and 255 }},
     "msb"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x ushr 8 and 255}},
     "mkword"      to FunctionSignature(true, listOf(
@@ -112,26 +113,29 @@ val BuiltinFunctions = mapOf(
 )
 
 
-fun builtinFunctionReturnType(function: String, args: List<IExpression>, program: Program): DataType? {
+fun builtinFunctionReturnType(function: String, args: List<Expression>, program: Program): InferredTypes.InferredType {
 
-    fun datatypeFromIterableArg(arglist: IExpression): DataType {
-        if(arglist is LiteralValue) {
+    fun datatypeFromIterableArg(arglist: Expression): DataType {
+        if(arglist is ArrayLiteralValue) {
             if(arglist.type== DataType.ARRAY_UB || arglist.type== DataType.ARRAY_UW || arglist.type== DataType.ARRAY_F) {
-                val dt = arglist.arrayvalue!!.map {it.inferType(program)}
-                if(dt.any { it!= DataType.UBYTE && it!= DataType.UWORD && it!= DataType.FLOAT}) {
+                val dt = arglist.value.map {it.inferType(program)}
+                if(dt.any { !(it istype DataType.UBYTE) && !(it istype DataType.UWORD) && !(it istype DataType.FLOAT)}) {
                     throw FatalAstException("fuction $function only accepts arraysize of numeric values")
                 }
-                if(dt.any { it== DataType.FLOAT }) return DataType.FLOAT
-                if(dt.any { it== DataType.UWORD }) return DataType.UWORD
+                if(dt.any { it istype DataType.FLOAT }) return DataType.FLOAT
+                if(dt.any { it istype DataType.UWORD }) return DataType.UWORD
                 return DataType.UBYTE
             }
         }
         if(arglist is IdentifierReference) {
-            val dt = arglist.inferType(program)
+            val idt = arglist.inferType(program)
+            if(!idt.isKnown)
+                throw FatalAstException("couldn't determine type of iterable $arglist")
+            val dt = idt.typeOrElse(DataType.STRUCT)
             return when(dt) {
-                in NumericDatatypes -> dt!!
-                in StringDatatypes -> dt!!
-                in ArrayDatatypes -> ArrayElementTypes.getValue(dt!!)
+                in NumericDatatypes -> dt
+                in StringDatatypes -> dt
+                in ArrayDatatypes -> ArrayElementTypes.getValue(dt)
                 else -> throw FatalAstException("function '$function' requires one argument which is an iterable")
             }
         }
@@ -140,229 +144,142 @@ fun builtinFunctionReturnType(function: String, args: List<IExpression>, program
 
     val func = BuiltinFunctions.getValue(function)
     if(func.returntype!=null)
-        return func.returntype
+        return InferredTypes.knownFor(func.returntype)
     // function has return values, but the return type depends on the arguments
 
     return when (function) {
         "abs" -> {
             val dt = args.single().inferType(program)
-            when(dt) {
-                in ByteDatatypes -> DataType.UBYTE
-                in WordDatatypes -> DataType.UWORD
-                DataType.FLOAT -> DataType.FLOAT
-                else -> throw FatalAstException("weird datatype passed to abs $dt")
-            }
+            if(dt.typeOrElse(DataType.STRUCT) in NumericDatatypes)
+                return dt
+            else
+                throw FatalAstException("weird datatype passed to abs $dt")
         }
         "max", "min" -> {
-            val dt = datatypeFromIterableArg(args.single())
-            when(dt) {
-                in NumericDatatypes -> dt
-                in StringDatatypes -> DataType.UBYTE
-                in ArrayDatatypes -> ArrayElementTypes.getValue(dt)
-                else -> null
+            when(val dt = datatypeFromIterableArg(args.single())) {
+                in NumericDatatypes -> InferredTypes.knownFor(dt)
+                in StringDatatypes -> InferredTypes.knownFor(DataType.UBYTE)
+                in ArrayDatatypes -> InferredTypes.knownFor(ArrayElementTypes.getValue(dt))
+                else -> InferredTypes.unknown()
             }
         }
         "sum" -> {
             when(datatypeFromIterableArg(args.single())) {
-                DataType.UBYTE, DataType.UWORD -> DataType.UWORD
-                DataType.BYTE, DataType.WORD -> DataType.WORD
-                DataType.FLOAT -> DataType.FLOAT
-                DataType.ARRAY_UB, DataType.ARRAY_UW -> DataType.UWORD
-                DataType.ARRAY_B, DataType.ARRAY_W -> DataType.WORD
-                DataType.ARRAY_F -> DataType.FLOAT
-                in StringDatatypes -> DataType.UWORD
-                else -> null
+                DataType.UBYTE, DataType.UWORD -> InferredTypes.knownFor(DataType.UWORD)
+                DataType.BYTE, DataType.WORD -> InferredTypes.knownFor(DataType.WORD)
+                DataType.FLOAT -> InferredTypes.knownFor(DataType.FLOAT)
+                DataType.ARRAY_UB, DataType.ARRAY_UW -> InferredTypes.knownFor(DataType.UWORD)
+                DataType.ARRAY_B, DataType.ARRAY_W -> InferredTypes.knownFor(DataType.WORD)
+                DataType.ARRAY_F -> InferredTypes.knownFor(DataType.FLOAT)
+                in StringDatatypes -> InferredTypes.knownFor(DataType.UWORD)
+                else -> InferredTypes.unknown()
             }
         }
         "len" -> {
             // a length can be >255 so in that case, the result is an UWORD instead of an UBYTE
             // but to avoid a lot of code duplication we simply assume UWORD in all cases for now
-            return DataType.UWORD
+            return InferredTypes.knownFor(DataType.UWORD)
         }
-        else -> return null
+        else -> return InferredTypes.unknown()
     }
 }
 
 
-class NotConstArgumentException: AstException("not a const argument to a built-in function")
+class NotConstArgumentException: AstException("not a const argument to a built-in function")        // TODO: ugly, remove throwing exceptions for control flow
 
 
-private fun oneDoubleArg(args: List<IExpression>, position: Position, program: Program, function: (arg: Double)->Number): LiteralValue {
+private fun oneDoubleArg(args: List<Expression>, position: Position, program: Program, function: (arg: Double)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("built-in function requires one floating point argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val float = getFloatArg(constval, args[0].position)
+    val float = constval.number.toDouble()
     return numericLiteral(function(float), args[0].position)
 }
 
-private fun getFloatArg(v: LiteralValue, position: Position): Double {
-    val nv = v.asNumericValue ?: throw SyntaxError("numerical argument required", position)
-    return nv.toDouble()
-}
-
-private fun oneDoubleArgOutputWord(args: List<IExpression>, position: Position, program: Program, function: (arg: Double)->Number): LiteralValue {
+private fun oneDoubleArgOutputWord(args: List<Expression>, position: Position, program: Program, function: (arg: Double)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("built-in function requires one floating point argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val float = getFloatArg(constval, args[0].position)
-    return LiteralValue(DataType.WORD, wordvalue = function(float).toInt(), position = args[0].position)
+    val float = constval.number.toDouble()
+    return NumericLiteralValue(DataType.WORD, function(float).toInt(), args[0].position)
 }
 
-private fun oneIntArgOutputInt(args: List<IExpression>, position: Position, program: Program, function: (arg: Int)->Number): LiteralValue {
+private fun oneIntArgOutputInt(args: List<Expression>, position: Position, program: Program, function: (arg: Int)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("built-in function requires one integer argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    if(constval.type!= DataType.UBYTE && constval.type!= DataType.UWORD)
+    if(constval.type != DataType.UBYTE && constval.type!= DataType.UWORD)
         throw SyntaxError("built-in function requires one integer argument", position)
 
-    val integer = constval.asNumericValue?.toInt()!!
+    val integer = constval.number.toInt()
     return numericLiteral(function(integer).toInt(), args[0].position)
 }
 
-private fun collectionArgOutputNumber(args: List<IExpression>, position: Position,
-                                      program: Program,
-                                      function: (arg: Collection<Double>)->Number): LiteralValue {
+private fun collectionArgNeverConst(args: List<Expression>, position: Position): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("builtin function requires one non-scalar argument", position)
-    val iterable = args[0].constValue(program) ?: throw NotConstArgumentException()
 
-    val result = if(iterable.arrayvalue != null) {
-        val constants = iterable.arrayvalue.map { it.constValue(program)?.asNumericValue }
-        if(null in constants)
-            throw NotConstArgumentException()
-        function(constants.map { it!!.toDouble() }).toDouble()
-    } else {
-        when(iterable.type) {
-            DataType.UBYTE, DataType.UWORD, DataType.FLOAT -> throw SyntaxError("function expects an iterable type", position)
-            else -> {
-                val heapId = iterable.heapId ?: throw FatalAstException("iterable value should be on the heap")
-                val array = program.heap.get(heapId).array ?: throw SyntaxError("function expects an iterable type", position)
-                function(array.map {
-                    if(it.integer!=null)
-                        it.integer.toDouble()
-                    else
-                        throw FatalAstException("cannot perform function over array that contains other values besides constant integers")
-                })
-            }
-        }
-    }
-    return numericLiteral(result, args[0].position)
+    // max/min/sum etc only work on arrays and these are never considered to be const for these functions
+    throw NotConstArgumentException()
 }
 
-private fun collectionArgOutputBoolean(args: List<IExpression>, position: Position,
-                                       program: Program,
-                                       function: (arg: Collection<Double>)->Boolean): LiteralValue {
-    if(args.size!=1)
-        throw SyntaxError("builtin function requires one non-scalar argument", position)
-    val iterable = args[0].constValue(program) ?: throw NotConstArgumentException()
-
-    val result = if(iterable.arrayvalue != null) {
-        val constants = iterable.arrayvalue.map { it.constValue(program)?.asNumericValue }
-        if(null in constants)
-            throw NotConstArgumentException()
-        function(constants.map { it!!.toDouble() })
-    } else {
-        val array = program.heap.get(iterable.heapId!!).array ?: throw SyntaxError("function requires array argument", position)
-        function(array.map {
-            if(it.integer!=null)
-                it.integer.toDouble()
-            else
-                throw FatalAstException("cannot perform function over array that contains other values besides constant integers")
-        })
-    }
-    return LiteralValue.fromBoolean(result, position)
-}
-
-private fun builtinAbs(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinAbs(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     // 1 arg, type = float or int, result type= isSameAs as argument type
     if(args.size!=1)
         throw SyntaxError("abs requires one numeric argument", position)
 
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val number = constval.asNumericValue
-    return when (number) {
-        is Int, is Byte, is Short -> numericLiteral(abs(number.toInt()), args[0].position)
-        is Double -> numericLiteral(abs(number.toDouble()), args[0].position)
+    return when (constval.type) {
+        in IntegerDatatypes -> numericLiteral(abs(constval.number.toInt()), args[0].position)
+        DataType.FLOAT -> numericLiteral(abs(constval.number.toDouble()), args[0].position)
         else -> throw SyntaxError("abs requires one numeric argument", position)
     }
 }
 
-private fun builtinAvg(args: List<IExpression>, position: Position, program: Program): LiteralValue {
-    if(args.size!=1)
-        throw SyntaxError("avg requires array argument", position)
-    val iterable = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val result = if(iterable.arrayvalue!=null) {
-        val constants = iterable.arrayvalue.map { it.constValue(program)?.asNumericValue }
-        if (null in constants)
-            throw NotConstArgumentException()
-        (constants.map { it!!.toDouble() }).average()
-    }
-    else {
-        val heapId = iterable.heapId!!
-        val integerarray = program.heap.get(heapId).array
-        if(integerarray!=null) {
-            if (integerarray.all { it.integer != null }) {
-                integerarray.map { it.integer!! }.average()
-            } else {
-                throw ExpressionError("cannot avg() over array that does not only contain constant numerical values", position)
-            }
-        } else {
-            val doublearray = program.heap.get(heapId).doubleArray
-            doublearray?.average() ?: throw SyntaxError("avg requires array argument", position)
-        }
-    }
-    return numericLiteral(result, args[0].position)
-}
-
-private fun builtinStrlen(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinStrlen(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("strlen requires one argument", position)
     val argument = args[0].constValue(program) ?: throw NotConstArgumentException()
     if(argument.type !in StringDatatypes)
         throw SyntaxError("strlen must have string argument", position)
-    val string = argument.strvalue!!
-    val zeroIdx = string.indexOf('\u0000')
-    return if(zeroIdx>=0)
-        LiteralValue.optimalInteger(zeroIdx, position=position)
-    else
-        LiteralValue.optimalInteger(string.length, position=position)
+
+    throw NotConstArgumentException()       // this function is not considering the string argument a constant
 }
 
-private fun builtinLen(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinLen(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     // note: in some cases the length is > 255 and then we have to return a UWORD type instead of a UBYTE.
     if(args.size!=1)
         throw SyntaxError("len requires one argument", position)
-    var argument = args[0].constValue(program)
-    if(argument==null) {
-        val directMemVar = ((args[0] as? DirectMemoryRead)?.addressExpression as? IdentifierReference)?.targetVarDecl(program.namespace)
-        val arraySize = directMemVar?.arraysize?.size()
-        if(arraySize != null)
-            return LiteralValue.optimalInteger(arraySize, position)
-        if(args[0] !is IdentifierReference)
-            throw SyntaxError("len argument should be an identifier, but is ${args[0]}", position)
-        val target = (args[0] as IdentifierReference).targetStatement(program.namespace)
-        val argValue = (target as? VarDecl)?.value
-        argument = argValue?.constValue(program)
-                ?: throw NotConstArgumentException()
-    }
-    return when(argument.type) {
+    val constArg = args[0].constValue(program)
+    if(constArg!=null)
+        throw SyntaxError("len of weird argument ${args[0]}", position)
+
+    val directMemVar = ((args[0] as? DirectMemoryRead)?.addressExpression as? IdentifierReference)?.targetVarDecl(program.namespace)
+    var arraySize = directMemVar?.arraysize?.size()
+    if(arraySize != null)
+        return NumericLiteralValue.optimalInteger(arraySize, position)
+    if(args[0] !is IdentifierReference)
+        throw SyntaxError("len argument should be an identifier, but is ${args[0]}", position)
+    val target = (args[0] as IdentifierReference).targetVarDecl(program.namespace)!!
+
+    return when(target.datatype) {
         DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
-            val arraySize = argument.arrayvalue?.size ?: program.heap.get(argument.heapId!!).arraysize
+            arraySize = target.arraysize!!.size()!!
             if(arraySize>256)
-                throw CompilerException("array length exceeds byte limit ${argument.position}")
-            LiteralValue.optimalInteger(arraySize, args[0].position)
+                throw CompilerException("array length exceeds byte limit ${target.position}")
+            NumericLiteralValue.optimalInteger(arraySize, args[0].position)
         }
         DataType.ARRAY_F -> {
-            val arraySize = argument.arrayvalue?.size ?: program.heap.get(argument.heapId!!).arraysize
+            arraySize = target.arraysize!!.size()!!
             if(arraySize>256)
-                throw CompilerException("array length exceeds byte limit ${argument.position}")
-            LiteralValue.optimalInteger(arraySize, args[0].position)
+                throw CompilerException("array length exceeds byte limit ${target.position}")
+            NumericLiteralValue.optimalInteger(arraySize, args[0].position)
         }
         in StringDatatypes -> {
-            val str = argument.strvalue!!
-            if(str.length>255)
-                throw CompilerException("string length exceeds byte limit ${argument.position}")
-            LiteralValue.optimalInteger(str.length, args[0].position)
+            val refLv = target.value as StringLiteralValue
+            if(refLv.value.length>255)
+                throw CompilerException("string length exceeds byte limit ${refLv.position}")
+            NumericLiteralValue.optimalInteger(refLv.value.length, args[0].position)
         }
         in NumericDatatypes -> throw SyntaxError("len of weird argument ${args[0]}", position)
         else -> throw CompilerException("weird datatype")
@@ -370,80 +287,87 @@ private fun builtinLen(args: List<IExpression>, position: Position, program: Pro
 }
 
 
-private fun builtinMkword(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinMkword(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 2)
         throw SyntaxError("mkword requires lsb and msb arguments", position)
     val constLsb = args[0].constValue(program) ?: throw NotConstArgumentException()
     val constMsb = args[1].constValue(program) ?: throw NotConstArgumentException()
-    val result = (constMsb.asIntegerValue!! shl 8) or constLsb.asIntegerValue!!
-    return LiteralValue(DataType.UWORD, wordvalue = result, position = position)
+    val result = (constMsb.number.toInt() shl 8) or constLsb.number.toInt()
+    return NumericLiteralValue(DataType.UWORD, result, position)
 }
 
-private fun builtinSin8(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin8(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin8 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.BYTE, bytevalue = (127.0 * sin(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.BYTE, (127.0 * sin(rad)).toShort(), position)
 }
 
-private fun builtinSin8u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin8u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin8u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UBYTE, bytevalue = (128.0 + 127.5 * sin(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toShort(), position)
 }
 
-private fun builtinCos8(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos8(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos8 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.BYTE, bytevalue = (127.0 * cos(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.BYTE, (127.0 * cos(rad)).toShort(), position)
 }
 
-private fun builtinCos8u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos8u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos8u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UBYTE, bytevalue = (128.0 + 127.5 * cos(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toShort(), position)
 }
 
-private fun builtinSin16(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin16(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin16 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.WORD, wordvalue = (32767.0 * sin(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.WORD, (32767.0 * sin(rad)).toInt(), position)
 }
 
-private fun builtinSin16u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin16u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin16u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UWORD, wordvalue = (32768.0 + 32767.5 * sin(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UWORD, (32768.0 + 32767.5 * sin(rad)).toInt(), position)
 }
 
-private fun builtinCos16(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos16(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos16 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.WORD, wordvalue = (32767.0 * cos(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.WORD, (32767.0 * cos(rad)).toInt(), position)
 }
 
-private fun builtinCos16u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos16u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos16u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UWORD, wordvalue = (32768.0 + 32767.5 * cos(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UWORD, (32768.0 + 32767.5 * cos(rad)).toInt(), position)
 }
 
-private fun numericLiteral(value: Number, position: Position): LiteralValue {
+private fun builtinSgn(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
+    if (args.size != 1)
+        throw SyntaxError("sgn requires one argument", position)
+    val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
+    return NumericLiteralValue(DataType.BYTE, constval.number.toDouble().sign.toShort(), position)
+}
+
+private fun numericLiteral(value: Number, position: Position): NumericLiteralValue {
     val floatNum=value.toDouble()
     val tweakedValue: Number =
             if(floatNum== floor(floatNum) && (floatNum>=-32768 && floatNum<=65535))
@@ -452,11 +376,11 @@ private fun numericLiteral(value: Number, position: Position): LiteralValue {
                 floatNum
 
     return when(tweakedValue) {
-        is Int -> LiteralValue.optimalNumeric(value.toInt(), position)
-        is Short -> LiteralValue.optimalNumeric(value.toInt(), position)
-        is Byte -> LiteralValue(DataType.UBYTE, bytevalue = value.toShort(), position = position)
-        is Double -> LiteralValue(DataType.FLOAT, floatvalue = value.toDouble(), position = position)
-        is Float -> LiteralValue(DataType.FLOAT, floatvalue = value.toDouble(), position = position)
+        is Int -> NumericLiteralValue.optimalNumeric(value.toInt(), position)
+        is Short -> NumericLiteralValue.optimalNumeric(value.toInt(), position)
+        is Byte -> NumericLiteralValue(DataType.UBYTE, value.toShort(), position)
+        is Double -> NumericLiteralValue(DataType.FLOAT, value.toDouble(), position)
+        is Float -> NumericLiteralValue(DataType.FLOAT, value.toDouble(), position)
         else -> throw FatalAstException("invalid number type ${value::class}")
     }
 }

compiler/src/prog8/optimizer/CallGraph.kt

@@ -1,6 +1,10 @@
 package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.DataType
 import prog8.ast.base.ParentSentinel
 import prog8.ast.base.VarDeclType
 import prog8.ast.base.initvarsSubName
@@ -17,7 +21,8 @@ class CallGraph(private val program: Program): IAstVisitor {
     val modulesImportedBy = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
     val subroutinesCalling = mutableMapOf<INameScope, List<Subroutine>>().withDefault { mutableListOf() }
     val subroutinesCalledBy = mutableMapOf<Subroutine, List<Node>>().withDefault { mutableListOf() }
-    val usedSymbols = mutableSetOf<IStatement>()
+    // TODO  add dataflow graph: what statements use what variables
+    val usedSymbols = mutableSetOf<Statement>()
 
     init {
         visit(program)
@@ -92,11 +97,11 @@ class CallGraph(private val program: Program): IAstVisitor {
         super.visit(identifier)
     }
 
-    private fun addNodeAndParentScopes(stmt: IStatement) {
+    private fun addNodeAndParentScopes(stmt: Statement) {
         usedSymbols.add(stmt)
         var node: Node=stmt
         do {
-            if(node is INameScope && node is IStatement) {
+            if(node is INameScope && node is Statement) {
                 usedSymbols.add(node)
             }
             node=node.parent
@@ -104,7 +109,13 @@ class CallGraph(private val program: Program): IAstVisitor {
     }
 
     override fun visit(subroutine: Subroutine) {
-        if((subroutine.name=="start" && subroutine.definingScope().name=="main")
+        val alwaysKeepSubroutines = setOf(
+                Pair("main", "start"),
+                Pair("irq", "irq"),
+                Pair("prog8_lib", "init_system")
+        )
+
+        if(Pair(subroutine.definingScope().name, subroutine.name) in alwaysKeepSubroutines
                 || subroutine.name== initvarsSubName || subroutine.definingModule().isLibraryModule) {
             // make sure the entrypoint is mentioned in the used symbols
             addNodeAndParentScopes(subroutine)
@@ -113,10 +124,14 @@ class CallGraph(private val program: Program): IAstVisitor {
     }
 
     override fun visit(decl: VarDecl) {
-        if(decl.autoGenerated || (decl.definingModule().isLibraryModule && decl.type!=VarDeclType.VAR)) {
+        if(decl.autogeneratedDontRemove || (decl.definingModule().isLibraryModule && decl.type!=VarDeclType.VAR)) {
             // make sure autogenerated vardecls are in the used symbols
             addNodeAndParentScopes(decl)
         }
+
+        if(decl.datatype==DataType.STRUCT)
+            addNodeAndParentScopes(decl)
+
         super.visit(decl)
     }
 
@@ -153,6 +168,11 @@ class CallGraph(private val program: Program): IAstVisitor {
         super.visit(jump)
     }
 
+    override fun visit(structDecl: StructDecl) {
+        usedSymbols.add(structDecl)
+        usedSymbols.addAll(structDecl.statements)
+    }
+
     override fun visit(inlineAssembly: InlineAssembly) {
         // parse inline asm for subroutine calls (jmp, jsr)
         val scope = inlineAssembly.definingScope()
@@ -160,7 +180,7 @@ class CallGraph(private val program: Program): IAstVisitor {
         super.visit(inlineAssembly)
     }
 
-    private fun scanAssemblyCode(asm: String, context: IStatement, scope: INameScope) {
+    private fun scanAssemblyCode(asm: String, context: Statement, scope: INameScope) {
         val asmJumpRx = Regex("""[\-+a-zA-Z0-9_ \t]+(jmp|jsr)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
         val asmRefRx = Regex("""[\-+a-zA-Z0-9_ \t]+(...)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
         asm.lines().forEach { line ->
@@ -186,10 +206,12 @@ class CallGraph(private val program: Program): IAstVisitor {
                 if (matches2 != null) {
                     val target= matches2.groups[2]?.value
                     if (target != null && (target[0].isLetter() || target[0] == '_')) {
-                        val node = program.namespace.lookup(listOf(target.substringBefore('.')), context)
-                        if (node is Subroutine) {
-                            subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node)
-                            subroutinesCalledBy[node] = subroutinesCalledBy.getValue(node).plus(context)
+                        if(target.contains('.')) {
+                            val node = program.namespace.lookup(listOf(target.substringBefore('.')), context)
+                            if (node is Subroutine) {
+                                subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node)
+                                subroutinesCalledBy[node] = subroutinesCalledBy.getValue(node).plus(context)
+                            }
                         }
                     }
                 }

compiler/src/prog8/optimizer/ConstExprEvaluator.kt

@@ -1,17 +1,14 @@
 package prog8.optimizer
 
-import prog8.ast.*
-import prog8.ast.base.DataType
-import prog8.ast.base.ExpressionError
-import prog8.ast.base.FatalAstException
-import prog8.ast.base.Position
-import prog8.ast.expressions.LiteralValue
+import prog8.ast.base.*
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.NumericLiteralValue
 import kotlin.math.pow
 
 
 class ConstExprEvaluator {
 
-    fun evaluate(left: LiteralValue, operator: String, right: LiteralValue): IExpression {
+    fun evaluate(left: NumericLiteralValue, operator: String, right: NumericLiteralValue): Expression {
         return when(operator) {
             "+" -> plus(left, right)
             "-" -> minus(left, right)
@@ -25,200 +22,188 @@ class ConstExprEvaluator {
             "and" -> logicaland(left, right)
             "or" -> logicalor(left, right)
             "xor" -> logicalxor(left, right)
-            "<" -> LiteralValue.fromBoolean(left < right, left.position)
-            ">" -> LiteralValue.fromBoolean(left > right, left.position)
-            "<=" -> LiteralValue.fromBoolean(left <= right, left.position)
-            ">=" -> LiteralValue.fromBoolean(left >= right, left.position)
-            "==" -> LiteralValue.fromBoolean(left == right, left.position)
-            "!=" -> LiteralValue.fromBoolean(left != right, left.position)
+            "<" -> NumericLiteralValue.fromBoolean(left < right, left.position)
+            ">" -> NumericLiteralValue.fromBoolean(left > right, left.position)
+            "<=" -> NumericLiteralValue.fromBoolean(left <= right, left.position)
+            ">=" -> NumericLiteralValue.fromBoolean(left >= right, left.position)
+            "==" -> NumericLiteralValue.fromBoolean(left == right, left.position)
+            "!=" -> NumericLiteralValue.fromBoolean(left != right, left.position)
             "<<" -> shiftedleft(left, right)
             ">>" -> shiftedright(left, right)
             else -> throw FatalAstException("const evaluation for invalid operator $operator")
         }
     }
 
-    private fun shiftedright(left: LiteralValue, amount: LiteralValue): IExpression {
-        if(left.asIntegerValue==null || amount.asIntegerValue==null)
+    private fun shiftedright(left: NumericLiteralValue, amount: NumericLiteralValue): Expression {
+        if(left.type !in IntegerDatatypes || amount.type !in IntegerDatatypes)
             throw ExpressionError("cannot compute $left >> $amount", left.position)
         val result =
                 if(left.type== DataType.UBYTE || left.type== DataType.UWORD)
-                    left.asIntegerValue.ushr(amount.asIntegerValue)
+                    left.number.toInt().ushr(amount.number.toInt())
                 else
-                    left.asIntegerValue.shr(amount.asIntegerValue)
-        return LiteralValue.fromNumber(result, left.type, left.position)
+                    left.number.toInt().shr(amount.number.toInt())
+        return NumericLiteralValue(left.type, result, left.position)
     }
 
-    private fun shiftedleft(left: LiteralValue, amount: LiteralValue): IExpression {
-        if(left.asIntegerValue==null || amount.asIntegerValue==null)
+    private fun shiftedleft(left: NumericLiteralValue, amount: NumericLiteralValue): Expression {
+        if(left.type !in IntegerDatatypes || amount.type !in IntegerDatatypes)
             throw ExpressionError("cannot compute $left << $amount", left.position)
-        val result = left.asIntegerValue.shl(amount.asIntegerValue)
-        return LiteralValue.fromNumber(result, left.type, left.position)
+        val result = left.number.toInt().shl(amount.number.toInt())
+        return NumericLiteralValue(left.type, result, left.position)
     }
 
-    private fun logicalxor(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun logicalxor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot compute $left locical-bitxor $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean((left.asIntegerValue != 0) xor (right.asIntegerValue != 0), left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean((left.asIntegerValue != 0) xor (right.floatvalue != 0.0), left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.fromBoolean((left.number.toInt() != 0) xor (right.number.toInt() != 0), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue.fromBoolean((left.number.toInt() != 0) xor (right.number.toDouble() != 0.0), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean((left.floatvalue != 0.0) xor (right.asIntegerValue != 0), left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean((left.floatvalue != 0.0) xor (right.floatvalue != 0.0), left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.fromBoolean((left.number.toDouble() != 0.0) xor (right.number.toInt() != 0), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue.fromBoolean((left.number.toDouble() != 0.0) xor (right.number.toDouble() != 0.0), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
         }
     }
 
-    private fun logicalor(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun logicalor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot compute $left locical-or $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 || right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 || right.floatvalue != 0.0, left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 || right.number.toInt() != 0, left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 || right.number.toDouble() != 0.0, left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 || right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 || right.floatvalue != 0.0, left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 || right.number.toInt() != 0, left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 || right.number.toDouble() != 0.0, left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
         }
     }
 
-    private fun logicaland(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun logicaland(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot compute $left locical-and $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 && right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 && right.floatvalue != 0.0, left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 && right.number.toInt() != 0, left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 && right.number.toDouble() != 0.0, left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 && right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 && right.floatvalue != 0.0, left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 && right.number.toInt() != 0, left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 && right.number.toDouble() != 0.0, left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
         }
     }
 
-    private fun bitwisexor(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun bitwisexor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         if(left.type== DataType.UBYTE) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UBYTE, bytevalue = (left.bytevalue!!.toInt() xor (right.asIntegerValue and 255)).toShort(), position = left.position)
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() xor (right.number.toInt() and 255)).toShort(), left.position)
             }
         } else if(left.type== DataType.UWORD) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UWORD, wordvalue = left.wordvalue!! xor right.asIntegerValue, position = left.position)
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() xor right.number.toInt(), left.position)
             }
         }
         throw ExpressionError("cannot calculate $left ^ $right", left.position)
     }
 
-    private fun bitwiseor(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun bitwiseor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         if(left.type== DataType.UBYTE) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UBYTE, bytevalue = (left.bytevalue!!.toInt() or (right.asIntegerValue and 255)).toShort(), position = left.position)
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() or (right.number.toInt() and 255)).toShort(), left.position)
             }
         } else if(left.type== DataType.UWORD) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UWORD, wordvalue = left.wordvalue!! or right.asIntegerValue, position = left.position)
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() or right.number.toInt(), left.position)
             }
         }
         throw ExpressionError("cannot calculate $left | $right", left.position)
     }
 
-    private fun bitwiseand(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun bitwiseand(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         if(left.type== DataType.UBYTE) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UBYTE, bytevalue = (left.bytevalue!!.toInt() or (right.asIntegerValue and 255)).toShort(), position = left.position)
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() or (right.number.toInt() and 255)).toShort(), left.position)
             }
         } else if(left.type== DataType.UWORD) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UWORD, wordvalue = left.wordvalue!! or right.asIntegerValue, position = left.position)
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() or right.number.toInt(), left.position)
             }
         }
         throw ExpressionError("cannot calculate $left & $right", left.position)
     }
 
-    private fun power(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun power(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot calculate $left ** $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue.toDouble().pow(right.asIntegerValue), left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue.toDouble().pow(right.floatvalue), position = left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt().toDouble().pow(right.number.toInt()), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt().toDouble().pow(right.number.toDouble()), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue.pow(right.asIntegerValue), position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue.pow(right.floatvalue), position = left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble().pow(right.number.toInt()), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble().pow(right.number.toDouble()), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
         }
     }
 
-    private fun plus(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun plus(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot add $left and $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue + right.asIntegerValue, left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue + right.floatvalue, position = left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() + right.number.toInt(), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() + right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue + right.asIntegerValue, position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue + right.floatvalue, position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.isString -> when {
-                right.isString -> {
-                    val newStr = left.strvalue!! + right.strvalue!!
-                    if(newStr.length > 255) throw ExpressionError("string too long", left.position)
-                    LiteralValue(DataType.STR, strvalue = newStr, position = left.position)
-                }
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() + right.number.toInt(), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() + right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
         }
     }
 
-    private fun minus(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun minus(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot subtract $left and $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue - right.asIntegerValue, left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue - right.floatvalue, position = left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() - right.number.toInt(), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() - right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue - right.asIntegerValue, position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue - right.floatvalue, position = left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() - right.number.toInt(), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() - right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
         }
     }
 
-    private fun multiply(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun multiply(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot multiply ${left.type} and ${right.type}"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue * right.asIntegerValue, left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue * right.floatvalue, position = left.position)
-                right.isString -> {
-                    if(right.strvalue!!.length * left.asIntegerValue > 255) throw ExpressionError("string too long", left.position)
-                    LiteralValue(DataType.STR, strvalue = right.strvalue.repeat(left.asIntegerValue), position = left.position)
-                }
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() * right.number.toInt(), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() * right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue * right.asIntegerValue, position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue * right.floatvalue, position = left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() * right.number.toInt(), left.position)
+                right.type == DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() * right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
             else -> throw ExpressionError(error, left.position)
@@ -228,29 +213,29 @@ class ConstExprEvaluator {
     private fun divideByZeroError(pos: Position): Unit =
             throw ExpressionError("division by zero", pos)
 
-    private fun divide(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun divide(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot divide $left by $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    val result: Int = left.asIntegerValue / right.asIntegerValue
-                    LiteralValue.optimalNumeric(result, left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    val result: Int = left.number.toInt() / right.number.toInt()
+                    NumericLiteralValue.optimalNumeric(result, left.position)
                 }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue / right.floatvalue, position = left.position)
+                right.type == DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toInt() / right.number.toDouble(), left.position)
                 }
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue / right.asIntegerValue, position = left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() / right.number.toInt(), left.position)
                 }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue / right.floatvalue, position = left.position)
+                right.type == DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() / right.number.toDouble(), left.position)
                 }
                 else -> throw ExpressionError(error, left.position)
             }
@@ -258,28 +243,28 @@ class ConstExprEvaluator {
         }
     }
 
-    private fun remainder(left: LiteralValue, right: LiteralValue): LiteralValue {
+    private fun remainder(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         val error = "cannot compute remainder of $left by $right"
         return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    LiteralValue.optimalNumeric(left.asIntegerValue.toDouble() % right.asIntegerValue.toDouble(), left.position)
+            left.type in IntegerDatatypes -> when {
+                right.type in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    NumericLiteralValue.optimalNumeric(left.number.toInt().toDouble() % right.number.toInt().toDouble(), left.position)
                 }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue % right.floatvalue, position = left.position)
+                right.type == DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toInt() % right.number.toDouble(), left.position)
                 }
                 else -> throw ExpressionError(error, left.position)
             }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue % right.asIntegerValue, position = left.position)
+            left.type == DataType.FLOAT -> when {
+                right.type in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() % right.number.toInt(), left.position)
                 }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue % right.floatvalue, position = left.position)
+                right.type == DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() % right.number.toDouble(), left.position)
                 }
                 else -> throw ExpressionError(error, left.position)
             }

compiler/src/prog8/optimizer/ConstantFolding.kt

@@ -1,21 +1,22 @@
 package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.IFunctionCall
+import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.fixupArrayDatatype
 import prog8.ast.statements.*
-import prog8.compiler.HeapValues
-import prog8.compiler.IntegerOrAddressOf
-import prog8.compiler.target.c64.FLOAT_MAX_NEGATIVE
-import prog8.compiler.target.c64.FLOAT_MAX_POSITIVE
+import prog8.compiler.target.c64.MachineDefinition.FLOAT_MAX_NEGATIVE
+import prog8.compiler.target.c64.MachineDefinition.FLOAT_MAX_POSITIVE
+import prog8.compiler.target.c64.codegen.AssemblyError
+import prog8.functions.BuiltinFunctions
 import kotlin.math.floor
 
 
 class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
     var optimizationsDone: Int = 0
     var errors : MutableList<AstException> = mutableListOf()
-
     private val reportedErrorMessages = mutableSetOf<String>()
 
     fun addError(x: AstException) {
@@ -26,30 +27,25 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
         }
     }
 
-    override fun visit(decl: VarDecl): IStatement {
+    override fun visit(decl: VarDecl): Statement {
         // the initializer value can't refer to the variable itself (recursive definition)
-        if(decl.value?.referencesIdentifier(decl.name) == true || decl.arraysize?.index?.referencesIdentifier(decl.name) == true) {
+        // TODO: use call tree for this?
+        if(decl.value?.referencesIdentifiers(decl.name) == true || decl.arraysize?.index?.referencesIdentifiers(decl.name) == true) {
             errors.add(ExpressionError("recursive var declaration", decl.position))
             return decl
         }
 
         if(decl.type==VarDeclType.CONST || decl.type==VarDeclType.VAR) {
-            val litval = decl.value as? LiteralValue
-            if(litval!=null && litval.isArray && litval.heapId!=null)
-                fixupArrayTypeOnHeap(decl, litval)
-
             if(decl.isArray){
-                // for arrays that have no size specifier (or a non-constant one) attempt to deduce the size
                 if(decl.arraysize==null) {
-                    val arrayval = (decl.value as? LiteralValue)?.arrayvalue
-                    if(arrayval!=null) {
-                        decl.arraysize = ArrayIndex(LiteralValue.optimalInteger(arrayval.size, decl.position), decl.position)
-                        optimizationsDone++
-                    }
+                    // for arrays that have no size specifier (or a non-constant one) attempt to deduce the size
+                    val arrayval = (decl.value as ArrayLiteralValue).value
+                    decl.arraysize = ArrayIndex(NumericLiteralValue.optimalInteger(arrayval.size, decl.position), decl.position)
+                    optimizationsDone++
                 }
                 else if(decl.arraysize?.size()==null) {
                     val size = decl.arraysize!!.index.accept(this)
-                    if(size is LiteralValue) {
+                    if(size is NumericLiteralValue) {
                         decl.arraysize = ArrayIndex(size, decl.position)
                         optimizationsDone++
                     }
@@ -59,87 +55,100 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
             when(decl.datatype) {
                 DataType.FLOAT -> {
                     // vardecl: for scalar float vars, promote constant integer initialization values to floats
-                    if (litval != null && litval.type in IntegerDatatypes) {
-                        val newValue = LiteralValue(DataType.FLOAT, floatvalue = litval.asNumericValue!!.toDouble(), position = litval.position)
+                    val litval = decl.value as? NumericLiteralValue
+                    if (litval!=null && litval.type in IntegerDatatypes) {
+                        val newValue = NumericLiteralValue(DataType.FLOAT, litval.number.toDouble(), litval.position)
                         decl.value = newValue
                         optimizationsDone++
-                        return decl
+                        return super.visit(decl)
                     }
                 }
+                in StringDatatypes -> {
+                    // nothing to do for strings
+                }
+                DataType.STRUCT -> {
+                    // struct defintions don't have anything else in them
+                }
                 DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                    val numericLv = decl.value as? NumericLiteralValue
                     val rangeExpr = decl.value as? RangeExpr
                     if(rangeExpr!=null) {
-                        // convert the initializer range expression to an actual array (will be put on heap later)
+                        // convert the initializer range expression to an actual array
                         val declArraySize = decl.arraysize?.size()
                         if(declArraySize!=null && declArraySize!=rangeExpr.size())
                             errors.add(ExpressionError("range expression size doesn't match declared array size", decl.value?.position!!))
                         val constRange = rangeExpr.toConstantIntegerRange()
                         if(constRange!=null) {
-                            val eltType = rangeExpr.inferType(program)!!
+                            val eltType = rangeExpr.inferType(program).typeOrElse(DataType.UBYTE)
                             if(eltType in ByteDatatypes) {
-                                decl.value = LiteralValue(decl.datatype,
-                                        arrayvalue = constRange.map { LiteralValue(eltType, bytevalue = it.toShort(), position = decl.value!!.position) }
-                                                .toTypedArray(), position = decl.value!!.position)
+                                decl.value = ArrayLiteralValue(decl.datatype,
+                                        constRange.map { NumericLiteralValue(eltType, it.toShort(), decl.value!!.position) }.toTypedArray(),
+                                        position = decl.value!!.position)
                             } else {
-                                decl.value = LiteralValue(decl.datatype,
-                                        arrayvalue = constRange.map { LiteralValue(eltType, wordvalue = it, position = decl.value!!.position) }
-                                                .toTypedArray(), position = decl.value!!.position)
+                                decl.value = ArrayLiteralValue(decl.datatype,
+                                        constRange.map { NumericLiteralValue(eltType, it, decl.value!!.position) }.toTypedArray(),
+                                        position = decl.value!!.position)
                             }
                             decl.value!!.linkParents(decl)
                             optimizationsDone++
-                            return decl
+                            return super.visit(decl)
                         }
                     }
-                    if(litval?.type== DataType.FLOAT)
-                        errors.add(ExpressionError("arraysize requires only integers here", litval.position))
+                    if(numericLv!=null && numericLv.type== DataType.FLOAT)
+                        errors.add(ExpressionError("arraysize requires only integers here", numericLv.position))
                     val size = decl.arraysize?.size() ?: return decl
-                    if ((litval==null || !litval.isArray) && rangeExpr==null) {
+                    if (rangeExpr==null && numericLv!=null) {
                         // arraysize initializer is empty or a single int, and we know the size; create the arraysize.
-                        val fillvalue = if (litval == null) 0 else litval.asIntegerValue ?: 0
+                        val fillvalue = numericLv.number.toInt()
                         when(decl.datatype){
                             DataType.ARRAY_UB -> {
                                 if(fillvalue !in 0..255)
-                                    errors.add(ExpressionError("ubyte value overflow", litval?.position
-                                            ?: decl.position))
+                                    errors.add(ExpressionError("ubyte value overflow", numericLv.position))
                             }
                             DataType.ARRAY_B -> {
                                 if(fillvalue !in -128..127)
-                                    errors.add(ExpressionError("byte value overflow", litval?.position
-                                            ?: decl.position))
+                                    errors.add(ExpressionError("byte value overflow", numericLv.position))
                             }
                             DataType.ARRAY_UW -> {
                                 if(fillvalue !in 0..65535)
-                                    errors.add(ExpressionError("uword value overflow", litval?.position
-                                            ?: decl.position))
+                                    errors.add(ExpressionError("uword value overflow", numericLv.position))
                             }
                             DataType.ARRAY_W -> {
                                 if(fillvalue !in -32768..32767)
-                                    errors.add(ExpressionError("word value overflow", litval?.position
-                                            ?: decl.position))
+                                    errors.add(ExpressionError("word value overflow", numericLv.position))
                             }
                             else -> {}
                         }
-                        val heapId = program.heap.addIntegerArray(decl.datatype, Array(size) { IntegerOrAddressOf(fillvalue, null) })
-                        decl.value = LiteralValue(decl.datatype, initHeapId = heapId, position = litval?.position
-                                ?: decl.position)
+                        // create the array itself, filled with the fillvalue.
+                        val array = Array(size) {fillvalue}.map { NumericLiteralValue.optimalInteger(it, numericLv.position) as Expression}.toTypedArray()
+                        val refValue = ArrayLiteralValue(decl.datatype, array, position = numericLv.position)
+                        refValue.addToHeap(program.heap)
+                        decl.value = refValue
+                        refValue.parent=decl
                         optimizationsDone++
-                        return decl
+                        return super.visit(decl)
                     }
                 }
                 DataType.ARRAY_F  -> {
                     val size = decl.arraysize?.size() ?: return decl
-                    if (litval==null || !litval.isArray) {
-                        // arraysize initializer is empty or a single int, and we know the size; create the arraysize.
-                        val fillvalue = if (litval == null) 0.0 else litval.asNumericValue?.toDouble() ?: 0.0
-                        if(fillvalue< FLOAT_MAX_NEGATIVE || fillvalue> FLOAT_MAX_POSITIVE)
-                            errors.add(ExpressionError("float value overflow", litval?.position
-                                    ?: decl.position))
+                    val litval = decl.value as? NumericLiteralValue
+                    if(litval==null) {
+                        // there's no initialization value, but the size is known, so we're ok.
+                        return super.visit(decl)
+                    } else {
+                        // arraysize initializer is a single int, and we know the size.
+                        val fillvalue = litval.number.toDouble()
+                        if (fillvalue < FLOAT_MAX_NEGATIVE || fillvalue > FLOAT_MAX_POSITIVE)
+                            errors.add(ExpressionError("float value overflow", litval.position))
                         else {
-                            val heapId = program.heap.addDoublesArray(DoubleArray(size) { fillvalue })
-                            decl.value = LiteralValue(DataType.ARRAY_F, initHeapId = heapId, position = litval?.position
-                                    ?: decl.position)
+                            // create the array itself, filled with the fillvalue.
+                            val array = Array(size) {fillvalue}.map { NumericLiteralValue(DataType.FLOAT, it, litval.position) as Expression}.toTypedArray()
+                            val refValue = ArrayLiteralValue(DataType.ARRAY_F, array, position = litval.position)
+                            refValue.addToHeap(program.heap)
+                            decl.value = refValue
+                            refValue.parent=decl
                             optimizationsDone++
-                            return decl
+                            return super.visit(decl)
                         }
                     }
                 }
@@ -152,52 +161,28 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
         return super.visit(decl)
     }
 
-    private fun fixupArrayTypeOnHeap(decl: VarDecl, litval: LiteralValue) {
-        // fix the type of the array value that's on the heap, to match the vardecl.
-        // notice that checking the bounds of the actual values is not done here, but in the AstChecker later.
-
-        if(decl.datatype==litval.type)
-            return   // already correct datatype
-        val heapId = litval.heapId ?: throw FatalAstException("expected array to be on heap $litval")
-        val array = program.heap.get(heapId)
-        when(decl.datatype) {
-            DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
-                if(array.array!=null) {
-                    program.heap.update(heapId, HeapValues.HeapValue(decl.datatype, null, array.array, null))
-                    decl.value = LiteralValue(decl.datatype, initHeapId = heapId, position = litval.position)
-                }
-            }
-            DataType.ARRAY_F -> {
-                if(array.array!=null) {
-                    // convert a non-float array to floats
-                    val doubleArray = array.array.map { it.integer!!.toDouble() }.toDoubleArray()
-                    program.heap.update(heapId, HeapValues.HeapValue(DataType.ARRAY_F, null, null, doubleArray))
-                    decl.value = LiteralValue(decl.datatype, initHeapId = heapId, position = litval.position)
-                }
-            }
-            else -> throw FatalAstException("invalid array vardecl type ${decl.datatype}")
-        }
-    }
-
     /**
      * replace identifiers that refer to const value, with the value itself (if it's a simple type)
      */
-    override fun visit(identifier: IdentifierReference): IExpression {
+    override fun visit(identifier: IdentifierReference): Expression {
         return try {
             val cval = identifier.constValue(program) ?: return identifier
-            return if(cval.isNumeric) {
-                val copy = LiteralValue(cval.type, cval.bytevalue, cval.wordvalue, cval.floatvalue, null, cval.arrayvalue, position = identifier.position)
-                copy.parent = identifier.parent
-                copy
-            } else
-                identifier
+            return when {
+                cval.type in NumericDatatypes -> {
+                    val copy = NumericLiteralValue(cval.type, cval.number, identifier.position)
+                    copy.parent = identifier.parent
+                    copy
+                }
+                cval.type in PassByReferenceDatatypes -> throw AssemblyError("pass-by-reference type should not be considered a constant")
+                else -> identifier
+            }
         } catch (ax: AstException) {
             addError(ax)
             identifier
         }
     }
 
-    override fun visit(functionCall: FunctionCall): IExpression {
+    override fun visit(functionCall: FunctionCall): Expression {
         return try {
             super.visit(functionCall)
             typeCastConstArguments(functionCall)
@@ -208,13 +193,30 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
         }
     }
 
-    override fun visit(functionCallStatement: FunctionCallStatement): IStatement {
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
         super.visit(functionCallStatement)
         typeCastConstArguments(functionCallStatement)
         return functionCallStatement
     }
 
     private fun typeCastConstArguments(functionCall: IFunctionCall) {
+        if(functionCall.target.nameInSource.size==1) {
+            val builtinFunction = BuiltinFunctions[functionCall.target.nameInSource.single()]
+            if(builtinFunction!=null) {
+                // match the arguments of a builtin function signature.
+                for(arg in functionCall.arglist.withIndex().zip(builtinFunction.parameters)) {
+                    val possibleDts = arg.second.possibleDatatypes
+                    val argConst = arg.first.value.constValue(program)
+                    if(argConst!=null && argConst.type !in possibleDts) {
+                        val convertedValue = argConst.cast(possibleDts.first())
+                        functionCall.arglist[arg.first.index] = convertedValue
+                        optimizationsDone++
+                    }
+                }
+                return
+            }
+        }
+        // match the arguments of a subroutine.
         val subroutine = functionCall.target.targetSubroutine(program.namespace)
         if(subroutine!=null) {
             // if types differ, try to typecast constant arguments to the function call to the desired data type of the parameter
@@ -223,16 +225,14 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
                 val argConst = arg.first.value.constValue(program)
                 if(argConst!=null && argConst.type!=expectedDt) {
                     val convertedValue = argConst.cast(expectedDt)
-                    if(convertedValue!=null) {
-                        functionCall.arglist[arg.first.index] = convertedValue
-                        optimizationsDone++
-                    }
+                    functionCall.arglist[arg.first.index] = convertedValue
+                    optimizationsDone++
                 }
             }
         }
     }
 
-    override fun visit(memread: DirectMemoryRead): IExpression {
+    override fun visit(memread: DirectMemoryRead): Expression {
         // @( &thing )  -->  thing
         val addrOf = memread.addressExpression as? AddressOf
         if(addrOf!=null)
@@ -245,48 +245,43 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
      * Compile-time constant sub expressions will be evaluated on the spot.
      * For instance, the expression for "- 4.5" will be optimized into the float literal -4.5
      */
-    override fun visit(expr: PrefixExpression): IExpression {
+    override fun visit(expr: PrefixExpression): Expression {
         return try {
-            super.visit(expr)
+            val prefixExpr=super.visit(expr)
+            if(prefixExpr !is PrefixExpression)
+                return prefixExpr
 
-            val subexpr = expr.expression
-            if (subexpr is LiteralValue) {
+            val subexpr = prefixExpr.expression
+            if (subexpr is NumericLiteralValue) {
                 // accept prefixed literal values (such as -3, not true)
                 return when {
-                    expr.operator == "+" -> subexpr
-                    expr.operator == "-" -> when {
-                        subexpr.asIntegerValue!= null -> {
+                    prefixExpr.operator == "+" -> subexpr
+                    prefixExpr.operator == "-" -> when {
+                        subexpr.type in IntegerDatatypes -> {
                             optimizationsDone++
-                            LiteralValue.optimalNumeric(-subexpr.asIntegerValue, subexpr.position)
+                            NumericLiteralValue.optimalNumeric(-subexpr.number.toInt(), subexpr.position)
                         }
-                        subexpr.floatvalue != null -> {
+                        subexpr.type == DataType.FLOAT -> {
                             optimizationsDone++
-                            LiteralValue(DataType.FLOAT, floatvalue = -subexpr.floatvalue, position = subexpr.position)
+                            NumericLiteralValue(DataType.FLOAT, -subexpr.number.toDouble(), subexpr.position)
                         }
                         else -> throw ExpressionError("can only take negative of int or float", subexpr.position)
                     }
-                    expr.operator == "~" -> when {
-                        subexpr.asIntegerValue != null -> {
+                    prefixExpr.operator == "~" -> when {
+                        subexpr.type in IntegerDatatypes -> {
                             optimizationsDone++
-                            LiteralValue.optimalNumeric(subexpr.asIntegerValue.inv(), subexpr.position)
+                            NumericLiteralValue.optimalNumeric(subexpr.number.toInt().inv(), subexpr.position)
                         }
                         else -> throw ExpressionError("can only take bitwise inversion of int", subexpr.position)
                     }
-                    expr.operator == "not" -> when {
-                        subexpr.asIntegerValue != null -> {
-                            optimizationsDone++
-                            LiteralValue.fromBoolean(subexpr.asIntegerValue == 0, subexpr.position)
-                        }
-                        subexpr.floatvalue != null -> {
-                            optimizationsDone++
-                            LiteralValue.fromBoolean(subexpr.floatvalue == 0.0, subexpr.position)
-                        }
-                        else -> throw ExpressionError("can not take logical not of $subexpr", subexpr.position)
+                    prefixExpr.operator == "not" -> {
+                        optimizationsDone++
+                        NumericLiteralValue.fromBoolean(subexpr.number.toDouble() == 0.0, subexpr.position)
                     }
-                    else -> throw ExpressionError(expr.operator, subexpr.position)
+                    else -> throw ExpressionError(prefixExpr.operator, subexpr.position)
                 }
             }
-            return expr
+            return prefixExpr
         } catch (ax: AstException) {
             addError(ax)
             expr
@@ -310,9 +305,14 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
      *        (X / c1) * c2  ->  X / (c2/c1)
      *        (X + c1) - c2  ->  X + (c1-c2)
      */
-    override fun visit(expr: BinaryExpression): IExpression {
+    override fun visit(expr: BinaryExpression): Expression {
         return try {
             super.visit(expr)
+
+            if(expr.left is StringLiteralValue || expr.left is ArrayLiteralValue
+                    || expr.right is StringLiteralValue || expr.right is ArrayLiteralValue)
+                throw FatalAstException("binexpr with reference litval instead of numeric")
+
             val leftconst = expr.left.constValue(program)
             val rightconst = expr.right.constValue(program)
 
@@ -333,12 +333,13 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
             }
 
             // const fold when both operands are a const
-            val evaluator = ConstExprEvaluator()
             return when {
                 leftconst != null && rightconst != null -> {
                     optimizationsDone++
+                    val evaluator = ConstExprEvaluator()
                     evaluator.evaluate(leftconst, expr.operator, rightconst)
                 }
+
                 else -> expr
             }
         } catch (ax: AstException) {
@@ -352,9 +353,9 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
                                        leftIsConst: Boolean,
                                        rightIsConst: Boolean,
                                        subleftIsConst: Boolean,
-                                       subrightIsConst: Boolean): IExpression
+                                       subrightIsConst: Boolean): Expression
     {
-        // @todo this implements only a small set of possible reorderings for now
+        // todo: this implements only a small set of possible reorderings at this time
         if(expr.operator==subExpr.operator) {
             // both operators are the isSameAs.
             // If + or *,  we can simply swap the const of expr and Var in subexpr.
@@ -539,29 +540,31 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
         }
     }
 
-    override fun visit(forLoop: ForLoop): IStatement {
+    override fun visit(forLoop: ForLoop): Statement {
 
-        fun adjustRangeDt(rangeFrom: LiteralValue, targetDt: DataType, rangeTo: LiteralValue, stepLiteral: LiteralValue?, range: RangeExpr): RangeExpr {
-            val newFrom = rangeFrom.cast(targetDt)
-            val newTo = rangeTo.cast(targetDt)
-            if (newFrom != null && newTo != null) {
-                val newStep: IExpression =
-                        if (stepLiteral != null) (stepLiteral.cast(targetDt) ?: stepLiteral) else range.step
-                return RangeExpr(newFrom, newTo, newStep, range.position)
+        fun adjustRangeDt(rangeFrom: NumericLiteralValue, targetDt: DataType, rangeTo: NumericLiteralValue, stepLiteral: NumericLiteralValue?, range: RangeExpr): RangeExpr {
+            val newFrom: NumericLiteralValue
+            val newTo: NumericLiteralValue
+            try {
+                newFrom = rangeFrom.cast(targetDt)
+                newTo = rangeTo.cast(targetDt)
+            } catch (x: ExpressionError) {
+                return range
             }
-            return range
+            val newStep: Expression = stepLiteral?.cast(targetDt) ?: range.step
+            return RangeExpr(newFrom, newTo, newStep, range.position)
         }
 
         // adjust the datatype of a range expression in for loops to the loop variable.
         val resultStmt = super.visit(forLoop) as ForLoop
         val iterableRange = resultStmt.iterable as? RangeExpr ?: return resultStmt
-        val rangeFrom = iterableRange.from as? LiteralValue
-        val rangeTo = iterableRange.to as? LiteralValue
+        val rangeFrom = iterableRange.from as? NumericLiteralValue
+        val rangeTo = iterableRange.to as? NumericLiteralValue
         if(rangeFrom==null || rangeTo==null) return resultStmt
 
         val loopvar = resultStmt.loopVar?.targetVarDecl(program.namespace)
         if(loopvar!=null) {
-            val stepLiteral = iterableRange.step as? LiteralValue
+            val stepLiteral = iterableRange.step as? NumericLiteralValue
             when(loopvar.datatype) {
                 DataType.UBYTE -> {
                     if(rangeFrom.type!= DataType.UBYTE) {
@@ -593,123 +596,78 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
         return resultStmt
     }
 
-    override fun visit(literalValue: LiteralValue): LiteralValue {
-        val litval = super.visit(literalValue)
-        if(litval.isString) {
-            // intern the string; move it into the heap
-            if(litval.strvalue!!.length !in 1..255)
-                addError(ExpressionError("string literal length must be between 1 and 255", litval.position))
-            else {
-                litval.addToHeap(program.heap)  // TODO: we don't know the actual string type yet, STR != STR_S etc...
+    override fun visit(arrayLiteral: ArrayLiteralValue): Expression {
+        val array = super.visit(arrayLiteral)
+        if(array is ArrayLiteralValue) {
+            val vardecl = array.parent as? VarDecl
+            if (vardecl!=null) {
+                return fixupArrayDatatype(array, vardecl, program.heap)
             }
-        } else if(litval.arrayvalue!=null) {
-            // first, adjust the array datatype
-            val litval2 = adjustArrayValDatatype(litval)
-            litval2.addToHeap(program.heap)
-            return litval2
         }
-        return litval
+        return array
     }
 
-    private fun adjustArrayValDatatype(litval: LiteralValue): LiteralValue {
-        val array = litval.arrayvalue!!
-        val typesInArray = array.mapNotNull { it.inferType(program) }.toSet()
-        val arrayDt =
-                when {
-                    array.any { it is AddressOf } -> DataType.ARRAY_UW
-                    DataType.FLOAT in typesInArray -> DataType.ARRAY_F
-                    DataType.WORD in typesInArray -> DataType.ARRAY_W
-                    else -> {
-                        val allElementsAreConstantOrAddressOf = array.fold(true) { c, expr-> c and (expr is LiteralValue || expr is AddressOf)}
-                        if(!allElementsAreConstantOrAddressOf) {
-                            addError(ExpressionError("array literal can only consist of constant primitive numerical values or memory pointers", litval.position))
-                            return litval
-                        } else {
-                            val integerArray = array.map { it.constValue(program)!!.asIntegerValue!! }
-                            val maxValue = integerArray.max()!!
-                            val minValue = integerArray.min()!!
-                            if (minValue >= 0) {
-                                // unsigned
-                                if (maxValue <= 255)
-                                    DataType.ARRAY_UB
-                                else
-                                    DataType.ARRAY_UW
-                            } else {
-                                // signed
-                                if (maxValue <= 127)
-                                    DataType.ARRAY_B
-                                else
-                                    DataType.ARRAY_W
-                            }
-                        }
-                    }
-                }
-
-        if(arrayDt!=litval.type) {
-            return LiteralValue(arrayDt, arrayvalue = litval.arrayvalue, position = litval.position)
-        }
-        return litval
-    }
-
-    override fun visit(assignment: Assignment): IStatement {
+    override fun visit(assignment: Assignment): Statement {
         super.visit(assignment)
-        val lv = assignment.value as? LiteralValue
+        val lv = assignment.value as? NumericLiteralValue
         if(lv!=null) {
             // see if we can promote/convert a literal value to the required datatype
-            when(assignment.singleTarget?.inferType(program, assignment)) {
+            val idt = assignment.target.inferType(program, assignment)
+            if(!idt.isKnown)
+                return assignment
+            when(idt.typeOrElse(DataType.STRUCT)) {
                 DataType.UWORD -> {
                     // we can convert to UWORD: any UBYTE, BYTE/WORD that are >=0, FLOAT that's an integer 0..65535,
                     if(lv.type== DataType.UBYTE)
-                        assignment.value = LiteralValue(DataType.UWORD, wordvalue = lv.asIntegerValue, position = lv.position)
-                    else if(lv.type== DataType.BYTE && lv.bytevalue!!>=0)
-                        assignment.value = LiteralValue(DataType.UWORD, wordvalue = lv.asIntegerValue, position = lv.position)
-                    else if(lv.type== DataType.WORD && lv.wordvalue!!>=0)
-                        assignment.value = LiteralValue(DataType.UWORD, wordvalue = lv.asIntegerValue, position = lv.position)
+                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.BYTE && lv.number.toInt()>=0)
+                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.WORD && lv.number.toInt()>=0)
+                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
                     else if(lv.type== DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d>=0 && d<=65535)
-                            assignment.value = LiteralValue(DataType.UWORD, wordvalue = floor(d).toInt(), position = lv.position)
+                            assignment.value = NumericLiteralValue(DataType.UWORD, floor(d).toInt(), lv.position)
                     }
                 }
                 DataType.UBYTE -> {
                     // we can convert to UBYTE: UWORD <=255, BYTE >=0, FLOAT that's an integer 0..255,
-                    if(lv.type== DataType.UWORD && lv.wordvalue!! <= 255)
-                        assignment.value = LiteralValue(DataType.UBYTE, lv.wordvalue.toShort(), position = lv.position)
-                    else if(lv.type== DataType.BYTE && lv.bytevalue!! >=0)
-                        assignment.value = LiteralValue(DataType.UBYTE, lv.bytevalue.toShort(), position = lv.position)
+                    if(lv.type== DataType.UWORD && lv.number.toInt() <= 255)
+                        assignment.value = NumericLiteralValue(DataType.UBYTE, lv.number.toShort(), lv.position)
+                    else if(lv.type== DataType.BYTE && lv.number.toInt() >=0)
+                        assignment.value = NumericLiteralValue(DataType.UBYTE, lv.number.toShort(), lv.position)
                     else if(lv.type== DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d >=0 && d<=255)
-                            assignment.value = LiteralValue(DataType.UBYTE, floor(d).toShort(), position = lv.position)
+                            assignment.value = NumericLiteralValue(DataType.UBYTE, floor(d).toShort(), lv.position)
                     }
                 }
                 DataType.BYTE -> {
                     // we can convert to BYTE: UWORD/UBYTE <= 127, FLOAT that's an integer 0..127
-                    if(lv.type== DataType.UWORD && lv.wordvalue!! <= 127)
-                        assignment.value = LiteralValue(DataType.BYTE, lv.wordvalue.toShort(), position = lv.position)
-                    else if(lv.type== DataType.UBYTE && lv.bytevalue!! <= 127)
-                        assignment.value = LiteralValue(DataType.BYTE, lv.bytevalue, position = lv.position)
+                    if(lv.type== DataType.UWORD && lv.number.toInt() <= 127)
+                        assignment.value = NumericLiteralValue(DataType.BYTE, lv.number.toShort(), lv.position)
+                    else if(lv.type== DataType.UBYTE && lv.number.toInt() <= 127)
+                        assignment.value = NumericLiteralValue(DataType.BYTE, lv.number.toShort(), lv.position)
                     else if(lv.type== DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d>=0 && d<=127)
-                            assignment.value = LiteralValue(DataType.BYTE, floor(d).toShort(), position = lv.position)
+                            assignment.value = NumericLiteralValue(DataType.BYTE, floor(d).toShort(), lv.position)
                     }
                 }
                 DataType.WORD -> {
                     // we can convert to WORD: any UBYTE/BYTE, UWORD <= 32767, FLOAT that's an integer -32768..32767,
                     if(lv.type== DataType.UBYTE || lv.type== DataType.BYTE)
-                        assignment.value = LiteralValue(DataType.WORD, wordvalue = lv.bytevalue!!.toInt(), position = lv.position)
-                    else if(lv.type== DataType.UWORD && lv.wordvalue!! <= 32767)
-                        assignment.value = LiteralValue(DataType.WORD, wordvalue = lv.wordvalue, position = lv.position)
+                        assignment.value = NumericLiteralValue(DataType.WORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.UWORD && lv.number.toInt() <= 32767)
+                        assignment.value = NumericLiteralValue(DataType.WORD, lv.number.toInt(), lv.position)
                     else if(lv.type== DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d>=-32768 && d<=32767)
-                            assignment.value = LiteralValue(DataType.BYTE, floor(d).toShort(), position = lv.position)
+                            assignment.value = NumericLiteralValue(DataType.BYTE, floor(d).toShort(), lv.position)
                     }
                 }
                 DataType.FLOAT -> {
-                    if(lv.isNumeric)
-                        assignment.value = LiteralValue(DataType.FLOAT, floatvalue = lv.asNumericValue?.toDouble(), position = lv.position)
+                    assignment.value = NumericLiteralValue(DataType.FLOAT, lv.number.toDouble(), lv.position)
                 }
                 else -> {}
             }

compiler/src/prog8/optimizer/Extensions.kt

@@ -1,8 +1,7 @@
 package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.Program
 import prog8.ast.base.AstException
-import prog8.ast.statements.NopStatement
 import prog8.parser.ParsingFailedError
 
 
@@ -28,17 +27,9 @@ internal fun Program.constantFold() {
 }
 
 
-internal fun Program.optimizeStatements(optimizeInlining: Boolean): Int {
-    val optimizer = StatementOptimizer(this, optimizeInlining)
+internal fun Program.optimizeStatements(): Int {
+    val optimizer = StatementOptimizer(this)
     optimizer.visit(this)
-    for(scope in optimizer.scopesToFlatten.reversed()) {
-        val namescope = scope.parent as INameScope
-        val idx = namescope.statements.indexOf(scope as IStatement)
-        if(idx>=0) {
-            namescope.statements[idx] = NopStatement(scope.position)
-            namescope.statements.addAll(idx, scope.statements)
-        }
-    }
     modules.forEach { it.linkParents(this.namespace) }   // re-link in final configuration
 
     return optimizer.optimizationsDone

compiler/src/prog8/optimizer/SimplifyExpressions.kt

@@ -1,15 +1,14 @@
 package prog8.optimizer
 
-import prog8.ast.*
-import prog8.ast.base.AstException
-import prog8.ast.base.DataType
-import prog8.ast.base.IntegerDatatypes
-import prog8.ast.base.NumericDatatypes
+import prog8.ast.Program
+import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.processing.IAstModifyingVisitor
 import prog8.ast.statements.Assignment
+import prog8.ast.statements.Statement
 import kotlin.math.abs
 import kotlin.math.log2
+import kotlin.math.pow
 
 /*
     todo advanced expression optimization: common (sub) expression elimination (turn common expressions into single subroutine call + introduce variable to hold it)
@@ -21,13 +20,13 @@ import kotlin.math.log2
 internal class SimplifyExpressions(private val program: Program) : IAstModifyingVisitor {
     var optimizationsDone: Int = 0
 
-    override fun visit(assignment: Assignment): IStatement {
+    override fun visit(assignment: Assignment): Statement {
         if (assignment.aug_op != null)
             throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
         return super.visit(assignment)
     }
 
-    override fun visit(memread: DirectMemoryRead): IExpression {
+    override fun visit(memread: DirectMemoryRead): Expression {
         // @( &thing )  -->  thing
         val addrOf = memread.addressExpression as? AddressOf
         if(addrOf!=null)
@@ -35,28 +34,53 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return super.visit(memread)
     }
 
-    override fun visit(typecast: TypecastExpression): IExpression {
-        // remove redundant typecasts
+    override fun visit(typecast: TypecastExpression): Expression {
         var tc = typecast
+
+        // try to statically convert a literal value into one of the desired type
+        val literal = tc.expression as? NumericLiteralValue
+        if(literal!=null) {
+            val newLiteral = literal.cast(tc.type)
+            if(newLiteral!==literal) {
+                optimizationsDone++
+                return newLiteral
+            }
+        }
+
+        // remove redundant typecasts
         while(true) {
             val expr = tc.expression
             if(expr !is TypecastExpression || expr.type!=tc.type) {
                 val assignment = typecast.parent as? Assignment
                 if(assignment!=null) {
-                    val targetDt = assignment.singleTarget?.inferType(program, assignment)
+                    val targetDt = assignment.target.inferType(program, assignment)
                     if(tc.expression.inferType(program)==targetDt) {
                         optimizationsDone++
                         return tc.expression
                     }
                 }
+
+                val subTc = tc.expression as? TypecastExpression
+                if(subTc!=null) {
+                    // if the previous typecast was casting to a 'bigger' type, just ignore that one
+                    // if the previous typecast was casting to a similar type, ignore that one
+                    if(subTc.type largerThan tc.type || subTc.type equalsSize tc.type) {
+                        subTc.type = tc.type
+                        subTc.parent = tc.parent
+                        optimizationsDone++
+                        return subTc
+                    }
+                }
+
                 return super.visit(tc)
             }
+
             optimizationsDone++
             tc = expr
         }
     }
 
-    override fun visit(expr: PrefixExpression): IExpression {
+    override fun visit(expr: PrefixExpression): Expression {
         if (expr.operator == "+") {
             // +X --> X
             optimizationsDone++
@@ -103,16 +127,21 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return super.visit(expr)
     }
 
-    override fun visit(expr: BinaryExpression): IExpression {
+    override fun visit(expr: BinaryExpression): Expression {
         super.visit(expr)
         val leftVal = expr.left.constValue(program)
         val rightVal = expr.right.constValue(program)
-        val constTrue = LiteralValue.fromBoolean(true, expr.position)
-        val constFalse = LiteralValue.fromBoolean(false, expr.position)
+        val constTrue = NumericLiteralValue.fromBoolean(true, expr.position)
+        val constFalse = NumericLiteralValue.fromBoolean(false, expr.position)
 
-        val leftDt = expr.left.inferType(program)
-        val rightDt = expr.right.inferType(program)
-        if (leftDt != null && rightDt != null && leftDt != rightDt) {
+        val leftIDt = expr.left.inferType(program)
+        val rightIDt = expr.right.inferType(program)
+        if(!leftIDt.isKnown || !rightIDt.isKnown)
+            throw FatalAstException("can't determine datatype of both expression operands $expr")
+
+        val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
+        val rightDt = rightIDt.typeOrElse(DataType.STRUCT)
+        if (leftDt != rightDt) {
             // try to convert a datatype into the other (where ddd
             if (adjustDatatypes(expr, leftVal, leftDt, rightVal, rightDt)) {
                 optimizationsDone++
@@ -149,10 +178,10 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
 
         // X + (-value)  -->  X - value
         if (expr.operator == "+" && rightVal != null) {
-            val rv = rightVal.asNumericValue?.toDouble()
-            if (rv != null && rv < 0.0) {
+            val rv = rightVal.number.toDouble()
+            if (rv < 0.0) {
                 expr.operator = "-"
-                expr.right = LiteralValue.fromNumber(-rv, rightVal.type, rightVal.position)
+                expr.right = NumericLiteralValue(rightVal.type, -rv, rightVal.position)
                 optimizationsDone++
                 return expr
             }
@@ -160,10 +189,10 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
 
         // (-value) + X  -->  X - value
         if (expr.operator == "+" && leftVal != null) {
-            val lv = leftVal.asNumericValue?.toDouble()
-            if (lv != null && lv < 0.0) {
+            val lv = leftVal.number.toDouble()
+            if (lv < 0.0) {
                 expr.operator = "-"
-                expr.right = LiteralValue.fromNumber(-lv, leftVal.type, leftVal.position)
+                expr.right = NumericLiteralValue(leftVal.type, -lv, leftVal.position)
                 optimizationsDone++
                 return expr
             }
@@ -179,10 +208,10 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
 
         // X - (-value)  -->  X + value
         if (expr.operator == "-" && rightVal != null) {
-            val rv = rightVal.asNumericValue?.toDouble()
-            if (rv != null && rv < 0.0) {
+            val rv = rightVal.number.toDouble()
+            if (rv < 0.0) {
                 expr.operator = "+"
-                expr.right = LiteralValue.fromNumber(-rv, rightVal.type, rightVal.position)
+                expr.right = NumericLiteralValue(rightVal.type, -rv, rightVal.position)
                 optimizationsDone++
                 return expr
             }
@@ -200,7 +229,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                     val x = expr.right
                     val y = determineY(x, leftBinExpr)
                     if(y!=null) {
-                        val yPlus1 = BinaryExpression(y, "+", LiteralValue.fromNumber(1, leftDt!!, y.position), y.position)
+                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue(leftDt, 1, y.position), y.position)
                         return BinaryExpression(x, "*", yPlus1, x.position)
                     }
                 } else {
@@ -209,7 +238,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                     val x = expr.right
                     val y = determineY(x, leftBinExpr)
                     if(y!=null) {
-                        val yMinus1 = BinaryExpression(y, "-", LiteralValue.fromNumber(1, leftDt!!, y.position), y.position)
+                        val yMinus1 = BinaryExpression(y, "-", NumericLiteralValue(leftDt, 1, y.position), y.position)
                         return BinaryExpression(x, "*", yMinus1, x.position)
                     }
                 }
@@ -221,7 +250,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                     val x = expr.left
                     val y = determineY(x, rightBinExpr)
                     if(y!=null) {
-                        val yPlus1 = BinaryExpression(y, "+", LiteralValue.optimalInteger(1, y.position), y.position)
+                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue.optimalInteger(1, y.position), y.position)
                         return BinaryExpression(x, "*", yPlus1, x.position)
                     }
                 } else {
@@ -230,7 +259,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                     val x = expr.left
                     val y = determineY(x, rightBinExpr)
                     if(y!=null) {
-                        val oneMinusY = BinaryExpression(LiteralValue.optimalInteger(1, y.position), "-", y, y.position)
+                        val oneMinusY = BinaryExpression(NumericLiteralValue.optimalInteger(1, y.position), "-", y, y.position)
                         return BinaryExpression(x, "*", oneMinusY, x.position)
                     }
                 }
@@ -312,11 +341,13 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
             "-" -> return optimizeSub(expr, leftVal, rightVal)
             "**" -> return optimizePower(expr, leftVal, rightVal)
             "%" -> return optimizeRemainder(expr, leftVal, rightVal)
+            ">>" -> return optimizeShiftRight(expr, rightVal)
+            "<<" -> return optimizeShiftLeft(expr, rightVal)
         }
         return expr
     }
 
-    private fun determineY(x: IExpression, subBinExpr: BinaryExpression): IExpression? {
+    private fun determineY(x: Expression, subBinExpr: BinaryExpression): Expression? {
         return when {
             subBinExpr.left isSameAs x -> subBinExpr.right
             subBinExpr.right isSameAs x -> subBinExpr.left
@@ -325,58 +356,58 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
     }
 
     private fun adjustDatatypes(expr: BinaryExpression,
-                                leftConstVal: LiteralValue?, leftDt: DataType,
-                                rightConstVal: LiteralValue?, rightDt: DataType): Boolean {
+                                leftConstVal: NumericLiteralValue?, leftDt: DataType,
+                                rightConstVal: NumericLiteralValue?, rightDt: DataType): Boolean {
 
-        fun adjust(value: LiteralValue, targetDt: DataType): Pair<Boolean, LiteralValue>{
+        fun adjust(value: NumericLiteralValue, targetDt: DataType): Pair<Boolean, NumericLiteralValue>{
             if(value.type==targetDt)
                 return Pair(false, value)
             when(value.type) {
                 DataType.UBYTE -> {
                     if (targetDt == DataType.BYTE) {
-                        if(value.bytevalue!! < 127)
-                            return Pair(true, LiteralValue(targetDt, value.bytevalue, position = value.position))
+                        if(value.number.toInt() < 127)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.UWORD || targetDt == DataType.WORD)
-                        return Pair(true, LiteralValue(targetDt, wordvalue = value.bytevalue!!.toInt(), position = value.position))
+                        return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                 }
                 DataType.BYTE -> {
                     if (targetDt == DataType.UBYTE) {
-                        if(value.bytevalue!! >= 0)
-                            return Pair(true, LiteralValue(targetDt, value.bytevalue, position = value.position))
+                        if(value.number.toInt() >= 0)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                     }
                     else if (targetDt == DataType.UWORD) {
-                        if(value.bytevalue!! >= 0)
-                            return Pair(true, LiteralValue(targetDt, wordvalue = value.bytevalue.toInt(), position = value.position))
+                        if(value.number.toInt() >= 0)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                     }
-                    else if (targetDt == DataType.WORD) return Pair(true, LiteralValue(targetDt, wordvalue = value.bytevalue!!.toInt(), position = value.position))
+                    else if (targetDt == DataType.WORD) return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                 }
                 DataType.UWORD -> {
                     if (targetDt == DataType.UBYTE) {
-                        if(value.wordvalue!! <= 255)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position = value.position))
+                        if(value.number.toInt() <= 255)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.BYTE) {
-                        if(value.wordvalue!! <= 127)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position = value.position))
+                        if(value.number.toInt() <= 127)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.WORD) {
-                        if(value.wordvalue!! <= 32767)
-                            return Pair(true, LiteralValue(targetDt, wordvalue = value.wordvalue, position = value.position))
+                        if(value.number.toInt() <= 32767)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                     }
                 }
                 DataType.WORD -> {
                     if (targetDt == DataType.UBYTE) {
-                        if(value.wordvalue!! in 0..255)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position = value.position))
+                        if(value.number.toInt() in 0..255)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.BYTE) {
-                        if(value.wordvalue!! in -128..127)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position = value.position))
+                        if(value.number.toInt() in -128..127)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.UWORD) {
-                        if(value.wordvalue!! >= 0)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position = value.position))
+                        if(value.number.toInt() >= 0)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                 }
                 else -> {}
@@ -385,7 +416,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         }
 
         if(leftConstVal==null && rightConstVal!=null) {
-            if(leftDt biggerThan rightDt) {
+            if(leftDt largerThan rightDt) {
                 val (adjusted, newValue) = adjust(rightConstVal, leftDt)
                 if (adjusted) {
                     expr.right = newValue
@@ -395,7 +426,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
             }
             return false
         } else if(leftConstVal!=null && rightConstVal==null) {
-            if(rightDt biggerThan leftDt) {
+            if(rightDt largerThan leftDt) {
                 val (adjusted, newValue) = adjust(leftConstVal, rightDt)
                 if (adjusted) {
                     expr.left = newValue
@@ -409,9 +440,9 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         }
     }
 
-    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: LiteralValue?, val rightVal: LiteralValue?)
+    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: NumericLiteralValue?, val rightVal: NumericLiteralValue?)
 
-    private fun reorderAssociative(expr: BinaryExpression, leftVal: LiteralValue?): ReorderedAssociativeBinaryExpr {
+    private fun reorderAssociative(expr: BinaryExpression, leftVal: NumericLiteralValue?): ReorderedAssociativeBinaryExpr {
         if(expr.operator in associativeOperators && leftVal!=null) {
             // swap left and right so that right is always the constant
             val tmp = expr.left
@@ -423,15 +454,15 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return ReorderedAssociativeBinaryExpr(expr, leftVal, expr.right.constValue(program))
     }
 
-    private fun optimizeAdd(pexpr: BinaryExpression, pleftVal: LiteralValue?, prightVal: LiteralValue?): IExpression {
+    private fun optimizeAdd(pexpr: BinaryExpression, pleftVal: NumericLiteralValue?, prightVal: NumericLiteralValue?): Expression {
         if(pleftVal==null && prightVal==null)
             return pexpr
 
         val (expr, _, rightVal) = reorderAssociative(pexpr, pleftVal)
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            when(rightConst.asNumericValue?.toDouble()) {
+            val rightConst: NumericLiteralValue = rightVal
+            when(rightConst.number.toDouble()) {
                 0.0 -> {
                     // left
                     optimizationsDone++
@@ -444,14 +475,14 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return expr
     }
 
-    private fun optimizeSub(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private fun optimizeSub(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            when(rightConst.asNumericValue?.toDouble()) {
+            val rightConst: NumericLiteralValue = rightVal
+            when(rightConst.number.toDouble()) {
                 0.0 -> {
                     // left
                     optimizationsDone++
@@ -461,7 +492,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         }
         if(leftVal!=null) {
             // left value is a constant, see if we can optimize
-            when(leftVal.asNumericValue?.toDouble()) {
+            when(leftVal.number.toDouble()) {
                 0.0 -> {
                     // -right
                     optimizationsDone++
@@ -473,38 +504,38 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return expr
     }
 
-    private fun optimizePower(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private fun optimizePower(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            when(rightConst.asNumericValue?.toDouble()) {
+            val rightConst: NumericLiteralValue = rightVal
+            when(rightConst.number.toDouble()) {
                 -3.0 -> {
                     // -1/(left*left*left)
                     optimizationsDone++
-                    return BinaryExpression(LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position), "/",
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
                             BinaryExpression(expr.left, "*", BinaryExpression(expr.left, "*", expr.left, expr.position), expr.position),
                             expr.position)
                 }
                 -2.0 -> {
                     // -1/(left*left)
                     optimizationsDone++
-                    return BinaryExpression(LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position), "/",
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
                             BinaryExpression(expr.left, "*", expr.left, expr.position),
                             expr.position)
                 }
                 -1.0 -> {
                     // -1/left
                     optimizationsDone++
-                    return BinaryExpression(LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position), "/",
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
                             expr.left, expr.position)
                 }
                 0.0 -> {
                     // 1
                     optimizationsDone++
-                    return LiteralValue.fromNumber(1, rightConst.type, expr.position)
+                    return NumericLiteralValue(rightConst.type, 1, expr.position)
                 }
                 0.5 -> {
                     // sqrt(left)
@@ -530,21 +561,21 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         }
         if(leftVal!=null) {
             // left value is a constant, see if we can optimize
-            when(leftVal.asNumericValue?.toDouble()) {
+            when(leftVal.number.toDouble()) {
                 -1.0 -> {
                     // -1
                     optimizationsDone++
-                    return LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position)
+                    return NumericLiteralValue(DataType.FLOAT, -1.0, expr.position)
                 }
                 0.0 -> {
                     // 0
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, leftVal.type, expr.position)
+                    return NumericLiteralValue(leftVal.type, 0, expr.position)
                 }
                 1.0 -> {
                     //1
                     optimizationsDone++
-                    return LiteralValue.fromNumber(1, leftVal.type, expr.position)
+                    return NumericLiteralValue(leftVal.type, 1, expr.position)
                 }
 
             }
@@ -553,22 +584,22 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return expr
     }
 
-    private fun optimizeRemainder(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private fun optimizeRemainder(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         // simplify assignments  A = B <operator> C
 
-        val cv = rightVal?.asIntegerValue?.toDouble()
+        val cv = rightVal?.number?.toInt()?.toDouble()
         when(expr.operator) {
             "%" -> {
                 if (cv == 1.0) {
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, expr.inferType(program)!!, expr.position)
+                    return NumericLiteralValue(expr.inferType(program).typeOrElse(DataType.STRUCT), 0, expr.position)
                 } else if (cv == 2.0) {
                     optimizationsDone++
                     expr.operator = "&"
-                    expr.right = LiteralValue.optimalInteger(1, expr.position)
+                    expr.right = NumericLiteralValue.optimalInteger(1, expr.position)
                     return expr
                 }
             }
@@ -577,17 +608,24 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
 
     }
 
-    private fun optimizeDivision(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private val powersOfTwo = (1 .. 16).map { (2.0).pow(it) }
+    private val negativePowersOfTwo = powersOfTwo.map { -it }
+
+    private fun optimizeDivision(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
-        // cannot shuffle assiciativity with division!
+        // TODO fix bug in this routine!
 
+        // cannot shuffle assiciativity with division!
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            val cv = rightConst.asNumericValue?.toDouble()
-            val leftDt = expr.left.inferType(program)
+            val rightConst: NumericLiteralValue = rightVal
+            val cv = rightConst.number.toDouble()
+            val leftIDt = expr.left.inferType(program)
+            if(!leftIDt.isKnown)
+                return expr
+            val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
             when(cv) {
                 -1.0 -> {
                     //  '/' -> -left
@@ -603,45 +641,45 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                         return expr.left
                     }
                 }
-                2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0, 512.0, 1024.0, 2048.0, 4096.0, 8192.0, 16384.0, 32768.0, 65536.0 -> {
+                in powersOfTwo -> {
                     if(leftDt in IntegerDatatypes) {
                         // divided by a power of two => shift right
                         optimizationsDone++
                         val numshifts = log2(cv).toInt()
-                        return BinaryExpression(expr.left, ">>", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(expr.left, ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
-                -2.0, -4.0, -8.0, -16.0, -32.0, -64.0, -128.0, -256.0, -512.0, -1024.0, -2048.0, -4096.0, -8192.0, -16384.0, -32768.0, -65536.0 -> {
+                in negativePowersOfTwo -> {
                     if(leftDt in IntegerDatatypes) {
                         // divided by a negative power of two => negate, then shift right
                         optimizationsDone++
                         val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), ">>", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
             }
 
             if (leftDt == DataType.UBYTE) {
-                if(abs(rightConst.asNumericValue!!.toDouble()) >= 256.0) {
+                if(abs(rightConst.number.toDouble()) >= 256.0) {
                     optimizationsDone++
-                    return LiteralValue(DataType.UBYTE, 0, position = expr.position)
+                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
                 }
             }
             else if (leftDt == DataType.UWORD) {
-                if(abs(rightConst.asNumericValue!!.toDouble()) >= 65536.0) {
+                if(abs(rightConst.number.toDouble()) >= 65536.0) {
                     optimizationsDone++
-                    return LiteralValue(DataType.UBYTE, 0, position = expr.position)
+                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
                 }
             }
         }
 
         if(leftVal!=null) {
             // left value is a constant, see if we can optimize
-            when(leftVal.asNumericValue?.toDouble()) {
+            when(leftVal.number.toDouble()) {
                 0.0 -> {
                     // 0
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, leftVal.type, expr.position)
+                    return NumericLiteralValue(leftVal.type, 0, expr.position)
                 }
             }
         }
@@ -649,16 +687,16 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
         return expr
     }
 
-    private fun optimizeMultiplication(pexpr: BinaryExpression, pleftVal: LiteralValue?, prightVal: LiteralValue?): IExpression {
+    private fun optimizeMultiplication(pexpr: BinaryExpression, pleftVal: NumericLiteralValue?, prightVal: NumericLiteralValue?): Expression {
         if(pleftVal==null && prightVal==null)
             return pexpr
 
         val (expr, _, rightVal) = reorderAssociative(pexpr, pleftVal)
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val leftValue: IExpression = expr.left
-            val rightConst: LiteralValue = rightVal
-            when(val cv = rightConst.asNumericValue?.toDouble()) {
+            val leftValue: Expression = expr.left
+            val rightConst: NumericLiteralValue = rightVal
+            when(val cv = rightConst.number.toDouble()) {
                 -1.0 -> {
                     // -left
                     optimizationsDone++
@@ -667,7 +705,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                 0.0 -> {
                     // 0
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, rightConst.type, expr.position)
+                    return NumericLiteralValue(rightConst.type, 0, expr.position)
                 }
                 1.0 -> {
                     // left
@@ -675,19 +713,19 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
                     return expr.left
                 }
                 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0, 512.0, 1024.0, 2048.0, 4096.0, 8192.0, 16384.0, 32768.0, 65536.0 -> {
-                    if(leftValue.inferType(program) in IntegerDatatypes) {
+                    if(leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
                         // times a power of two => shift left
                         optimizationsDone++
                         val numshifts = log2(cv).toInt()
-                        return BinaryExpression(expr.left, "<<", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(expr.left, "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
                 -2.0, -4.0, -8.0, -16.0, -32.0, -64.0, -128.0, -256.0, -512.0, -1024.0, -2048.0, -4096.0, -8192.0, -16384.0, -32768.0, -65536.0 -> {
-                    if(leftValue.inferType(program) in IntegerDatatypes) {
+                    if(leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
                         // times a negative power of two => negate, then shift left
                         optimizationsDone++
                         val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), "<<", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
             }
@@ -696,4 +734,97 @@ internal class SimplifyExpressions(private val program: Program) : IAstModifying
 
         return expr
     }
+
+    private fun optimizeShiftLeft(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression {
+        if(amountLv==null)
+            return expr
+
+        val amount=amountLv.number.toInt()
+        if(amount==0) {
+            optimizationsDone++
+            return expr.left
+        }
+        val targetDt = expr.left.inferType(program).typeOrElse(DataType.STRUCT)
+        when(targetDt) {
+            DataType.UBYTE, DataType.BYTE -> {
+                if(amount>=8) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+            }
+            DataType.UWORD, DataType.WORD -> {
+                if(amount>=16) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+                else if(amount>=8) {
+                    optimizationsDone++
+                    val lsb=TypecastExpression(expr.left, DataType.UBYTE, true, expr.position)
+                    if(amount==8) {
+                        return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(NumericLiteralValue.optimalInteger(0, expr.position), lsb), expr.position)
+                    }
+                    val shifted = BinaryExpression(lsb, "<<", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
+                    return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(NumericLiteralValue.optimalInteger(0, expr.position), shifted), expr.position)
+                }
+            }
+            else -> {}
+        }
+        return expr
+    }
+
+    private fun optimizeShiftRight(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression {
+        if(amountLv==null)
+            return expr
+
+        val amount=amountLv.number.toInt()
+        if(amount==0) {
+            optimizationsDone++
+            return expr.left
+        }
+        val targetDt = expr.left.inferType(program).typeOrElse(DataType.STRUCT)
+        when(targetDt) {
+            DataType.UBYTE -> {
+                if(amount>=8) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+            }
+            DataType.BYTE -> {
+                if(amount>8) {
+                    expr.right = NumericLiteralValue.optimalInteger(8, expr.right.position)
+                    return expr
+                }
+            }
+            DataType.UWORD -> {
+                if(amount>=16) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+                else if(amount>=8) {
+                    optimizationsDone++
+                    val msb=FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position)
+                    if(amount==8)
+                        return msb
+                    return BinaryExpression(msb, ">>", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
+                }
+            }
+            DataType.WORD -> {
+                if(amount>16) {
+                    expr.right = NumericLiteralValue.optimalInteger(16, expr.right.position)
+                    return expr
+                } else if(amount>=8) {
+                    optimizationsDone++
+                    val msbAsByte = TypecastExpression(
+                            FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position),
+                            DataType.BYTE,
+                            true, expr.position)
+                    if(amount==8)
+                        return msbAsByte
+                    return BinaryExpression(msbAsByte, ">>", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
+                }
+            }
+            else -> {}
+        }
+        return expr
+    }
 }

compiler/src/prog8/optimizer/StatementOptimizer.kt

@@ -1,104 +1,36 @@
 package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
 import prog8.compiler.target.c64.Petscii
+import prog8.compiler.target.c64.codegen.AssemblyError
 import prog8.functions.BuiltinFunctions
 import kotlin.math.floor
 
 
 /*
-    todo: subroutines with 1 or 2 byte args or 1 word arg can be converted to asm sub calling convention (args in registers)
-    todo analyse for unreachable code and remove that (f.i. code after goto or return that has no label so can never be jumped to) + print warning about this
+    TODO: analyse for unreachable code and remove that (f.i. code after goto or return that has no label so can never be jumped to) + print warning about this
+    TODO: proper inlining of small subroutines (correctly renaming/relocating all variables in them and refs to those as well, or restrict to subs without variables?)
 */
 
-internal class StatementOptimizer(private val program: Program, private val optimizeInlining: Boolean) : IAstModifyingVisitor {
+
+internal class StatementOptimizer(private val program: Program) : IAstModifyingVisitor {
     var optimizationsDone: Int = 0
         private set
-    var scopesToFlatten = mutableListOf<INameScope>()
-    val nopStatements = mutableListOf<NopStatement>()
 
     private val pureBuiltinFunctions = BuiltinFunctions.filter { it.value.pure }
     private val callgraph = CallGraph(program)
 
-    companion object {
-        private var generatedLabelSequenceNumber = 0
-    }
-
     override fun visit(program: Program) {
         removeUnusedCode(callgraph)
-        if(optimizeInlining) {
-            inlineSubroutines(callgraph)
-        }
         super.visit(program)
-
-        // at the end, remove the encountered NOP statements
-        this.nopStatements.forEach { it.definingScope().remove(it) }
-    }
-
-    private fun inlineSubroutines(callgraph: CallGraph) {
-        val entrypoint = program.entrypoint()
-        program.modules.forEach {
-            callgraph.forAllSubroutines(it) { sub ->
-                if(sub!==entrypoint && !sub.isAsmSubroutine) {
-                    if (sub.statements.size <= 3 && !sub.expensiveToInline) {
-                        sub.calledBy.toList().forEach { caller -> inlineSubroutine(sub, caller) }
-                    } else if (sub.calledBy.size==1 && sub.statements.size < 50) {
-                        inlineSubroutine(sub, sub.calledBy[0])
-                    } else if(sub.calledBy.size<=3 && sub.statements.size < 10 && !sub.expensiveToInline) {
-                        sub.calledBy.toList().forEach { caller -> inlineSubroutine(sub, caller) }
-                    }
-                }
-            }
-        }
-    }
-
-    private fun inlineSubroutine(sub: Subroutine, caller: Node) {
-        // if the sub is called multiple times from the isSameAs scope, we can't inline (would result in duplicate definitions)
-        // (unless we add a sequence number to all vars/labels and references to them in the inlined code, but I skip that for now)
-        val scope = caller.definingScope()
-        if(sub.calledBy.count { it.definingScope()===scope } > 1)
-            return
-        if(caller !is IFunctionCall || caller !is IStatement || sub.statements.any { it is Subroutine })
-            return
-
-        if(sub.parameters.isEmpty() && sub.returntypes.isEmpty()) {
-            // sub without params and without return value can be easily inlined
-            val parent = caller.parent as INameScope
-            val inlined = AnonymousScope(sub.statements.toMutableList(), caller.position)
-            parent.statements[parent.statements.indexOf(caller)] = inlined
-            // replace return statements in the inlined sub by a jump to the end of it
-            var haveNewEndLabel = false
-            var endLabelUsed = false
-            var endlabel = inlined.statements.last() as? Label
-            if(endlabel==null) {
-                endlabel = makeLabel("_prog8_auto_sub_end", inlined.statements.last().position)
-                endlabel.parent = inlined
-                haveNewEndLabel = true
-            }
-            val returns = inlined.statements.withIndex().filter { iv -> iv.value is Return }.map { iv -> Pair(iv.index, iv.value as Return)}
-            for(returnIdx in returns) {
-                assert(returnIdx.second.values.isEmpty())
-                val jump = Jump(null, IdentifierReference(listOf(endlabel.name), returnIdx.second.position), null, returnIdx.second.position)
-                inlined.statements[returnIdx.first] = jump
-                endLabelUsed = true
-            }
-            if(endLabelUsed && haveNewEndLabel)
-                inlined.statements.add(endlabel)
-            inlined.linkParents(caller.parent)
-            sub.calledBy.remove(caller)     // if there are no callers left, the sub will be removed automatically later
-            optimizationsDone++
-        } else {
-            // TODO inline subroutine that has params or returnvalues or both
-        }
-    }
-
-    private fun makeLabel(name: String, position: Position): Label {
-        generatedLabelSequenceNumber++
-        return Label("${name}_$generatedLabelSequenceNumber", position)
     }
 
     private fun removeUnusedCode(callgraph: CallGraph) {
@@ -140,32 +72,32 @@ internal class StatementOptimizer(private val program: Program, private val opti
         }
     }
 
-    override fun visit(block: Block): IStatement {
+    override fun visit(block: Block): Statement {
         if("force_output" !in block.options()) {
             if (block.containsNoCodeNorVars()) {
                 optimizationsDone++
                 printWarning("removing empty block '${block.name}'", block.position)
-                return NopStatement(block.position)
+                return NopStatement.insteadOf(block)
             }
 
             if (block !in callgraph.usedSymbols) {
                 optimizationsDone++
                 printWarning("removing unused block '${block.name}'", block.position)
-                return NopStatement(block.position)  // remove unused block
+                return NopStatement.insteadOf(block)  // remove unused block
             }
         }
 
         return super.visit(block)
     }
 
-    override fun visit(subroutine: Subroutine): IStatement {
+    override fun visit(subroutine: Subroutine): Statement {
         super.visit(subroutine)
         val forceOutput = "force_output" in subroutine.definingBlock().options()
         if(subroutine.asmAddress==null && !forceOutput) {
             if(subroutine.containsNoCodeNorVars()) {
                 printWarning("removing empty subroutine '${subroutine.name}'", subroutine.position)
                 optimizationsDone++
-                return NopStatement(subroutine.position)
+                return NopStatement.insteadOf(subroutine)
             }
         }
 
@@ -174,54 +106,42 @@ internal class StatementOptimizer(private val program: Program, private val opti
             linesToRemove.reversed().forEach{subroutine.statements.removeAt(it)}
         }
 
-        if(subroutine.canBeAsmSubroutine) {
-            optimizationsDone++
-            return subroutine.intoAsmSubroutine()   // TODO this doesn't work yet due to parameter vardecl issue
-
-            // TODO fix parameter passing so this also works:
-//            asmsub aa(byte arg @ Y) -> clobbers() -> () {
-//                byte local = arg            ; @todo fix 'undefined symbol arg' by some sort of alias name for the parameter
-//                A=44
-//            }
-
-        }
-
         if(subroutine !in callgraph.usedSymbols && !forceOutput) {
             printWarning("removing unused subroutine '${subroutine.name}'", subroutine.position)
             optimizationsDone++
-            return NopStatement(subroutine.position)        // remove unused subroutine
+            return NopStatement.insteadOf(subroutine)
         }
 
         return subroutine
     }
 
-    override fun visit(decl: VarDecl): IStatement {
+    override fun visit(decl: VarDecl): Statement {
         val forceOutput = "force_output" in decl.definingBlock().options()
         if(decl !in callgraph.usedSymbols && !forceOutput) {
-            if(decl.type!=VarDeclType.CONST)
-                printWarning("removing unused variable '${decl.name}'", decl.position)
+            if(decl.type == VarDeclType.VAR)
+                printWarning("removing unused variable ${decl.type} '${decl.name}'", decl.position)
             optimizationsDone++
-            return NopStatement(decl.position)        // remove unused variable
+            return NopStatement.insteadOf(decl)
         }
 
         return super.visit(decl)
     }
 
-    private fun deduplicateAssignments(statements: List<IStatement>): MutableList<Int> {
+    private fun deduplicateAssignments(statements: List<Statement>): MutableList<Int> {
         // removes 'duplicate' assignments that assign the isSameAs target
         val linesToRemove = mutableListOf<Int>()
         var previousAssignmentLine: Int? = null
         for (i in 0 until statements.size) {
             val stmt = statements[i] as? Assignment
-            if (stmt != null && stmt.value is LiteralValue) {
+            if (stmt != null && stmt.value is NumericLiteralValue) {
                 if (previousAssignmentLine == null) {
                     previousAssignmentLine = i
                     continue
                 } else {
                     val prev = statements[previousAssignmentLine] as Assignment
-                    if (prev.targets.size == 1 && stmt.targets.size == 1 && prev.targets[0].isSameAs(stmt.targets[0], program)) {
+                    if (prev.target.isSameAs(stmt.target, program)) {
                         // get rid of the previous assignment, if the target is not MEMORY
-                        if (prev.targets[0].isNotMemory(program.namespace))
+                        if (prev.target.isNotMemory(program.namespace))
                             linesToRemove.add(previousAssignmentLine)
                     }
                     previousAssignmentLine = i
@@ -232,21 +152,19 @@ internal class StatementOptimizer(private val program: Program, private val opti
         return linesToRemove
     }
 
-    override fun visit(functionCallStatement: FunctionCallStatement): IStatement {
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
         if(functionCallStatement.target.nameInSource.size==1 && functionCallStatement.target.nameInSource[0] in BuiltinFunctions) {
             val functionName = functionCallStatement.target.nameInSource[0]
             if (functionName in pureBuiltinFunctions) {
                 printWarning("statement has no effect (function return value is discarded)", functionCallStatement.position)
                 optimizationsDone++
-                return NopStatement(functionCallStatement.position)
+                return NopStatement.insteadOf(functionCallStatement)
             }
         }
 
         if(functionCallStatement.target.nameInSource==listOf("c64scr", "print") ||
                 functionCallStatement.target.nameInSource==listOf("c64scr", "print_p")) {
             // printing a literal string of just 2 or 1 characters is replaced by directly outputting those characters
-            if(functionCallStatement.arglist.single() is LiteralValue)
-                throw AstException("string argument should be on heap already")
             val stringVar = functionCallStatement.arglist.single() as? IdentifierReference
             if(stringVar!=null) {
                 val heapId = stringVar.heapId(program.namespace)
@@ -254,7 +172,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
                 if(string.length==1) {
                     val petscii = Petscii.encodePetscii(string, true)[0]
                     functionCallStatement.arglist.clear()
-                    functionCallStatement.arglist.add(LiteralValue.optimalInteger(petscii, functionCallStatement.position))
+                    functionCallStatement.arglist.add(NumericLiteralValue.optimalInteger(petscii.toInt(), functionCallStatement.position))
                     functionCallStatement.target = IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position)
                     optimizationsDone++
                     return functionCallStatement
@@ -262,9 +180,9 @@ internal class StatementOptimizer(private val program: Program, private val opti
                     val petscii = Petscii.encodePetscii(string, true)
                     val scope = AnonymousScope(mutableListOf(), functionCallStatement.position)
                     scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
-                            mutableListOf(LiteralValue.optimalInteger(petscii[0], functionCallStatement.position)), functionCallStatement.position))
+                            mutableListOf(NumericLiteralValue.optimalInteger(petscii[0].toInt(), functionCallStatement.position)), functionCallStatement.position))
                     scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
-                            mutableListOf(LiteralValue.optimalInteger(petscii[1], functionCallStatement.position)), functionCallStatement.position))
+                            mutableListOf(NumericLiteralValue.optimalInteger(petscii[1].toInt(), functionCallStatement.position)), functionCallStatement.position))
                     optimizationsDone++
                     return scope
                 }
@@ -283,14 +201,14 @@ internal class StatementOptimizer(private val program: Program, private val opti
             }
             if(first is ReturnFromIrq || first is Return) {
                 optimizationsDone++
-                return NopStatement(functionCallStatement.position)
+                return NopStatement.insteadOf(functionCallStatement)
             }
         }
 
         return super.visit(functionCallStatement)
     }
 
-    override fun visit(functionCall: FunctionCall): IExpression {
+    override fun visit(functionCall: FunctionCall): Expression {
         // if it calls a subroutine,
         // and the first instruction in the subroutine is a jump, call that jump target instead
         // if the first instruction in the subroutine is a return statement with constant value, replace with the constant value
@@ -301,8 +219,8 @@ internal class StatementOptimizer(private val program: Program, private val opti
                 optimizationsDone++
                 return FunctionCall(first.identifier, functionCall.arglist, functionCall.position)
             }
-            if(first is Return && first.values.size==1) {
-                val constval = first.values[0].constValue(program)
+            if(first is Return && first.value!=null) {
+                val constval = first.value?.constValue(program)
                 if(constval!=null)
                     return constval
             }
@@ -310,12 +228,12 @@ internal class StatementOptimizer(private val program: Program, private val opti
         return super.visit(functionCall)
     }
 
-    override fun visit(ifStatement: IfStatement): IStatement {
+    override fun visit(ifStatement: IfStatement): Statement {
         super.visit(ifStatement)
 
         if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsNoCodeNorVars()) {
             optimizationsDone++
-            return NopStatement(ifStatement.position)
+            return NopStatement.insteadOf(ifStatement)
         }
 
         if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsCodeOrVars()) {
@@ -344,18 +262,18 @@ internal class StatementOptimizer(private val program: Program, private val opti
         return ifStatement
     }
 
-    override fun visit(forLoop: ForLoop): IStatement {
+    override fun visit(forLoop: ForLoop): Statement {
         super.visit(forLoop)
         if(forLoop.body.containsNoCodeNorVars()) {
             // remove empty for loop
             optimizationsDone++
-            return NopStatement(forLoop.position)
+            return NopStatement.insteadOf(forLoop)
         } else if(forLoop.body.statements.size==1) {
             val loopvar = forLoop.body.statements[0] as? VarDecl
             if(loopvar!=null && loopvar.name==forLoop.loopVar?.nameInSource?.singleOrNull()) {
                 // remove empty for loop
                 optimizationsDone++
-                return NopStatement(forLoop.position)
+                return NopStatement.insteadOf(forLoop)
             }
         }
 
@@ -365,7 +283,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
             if(range.size()==1) {
                 // for loop over a (constant) range of just a single value-- optimize the loop away
                 // loopvar/reg = range value , follow by block
-                val assignment = Assignment(listOf(AssignTarget(forLoop.loopRegister, forLoop.loopVar, null, null, forLoop.position)), null, range.from, forLoop.position)
+                val assignment = Assignment(AssignTarget(forLoop.loopRegister, forLoop.loopVar, null, null, forLoop.position), null, range.from, forLoop.position)
                 forLoop.body.statements.add(0, assignment)
                 optimizationsDone++
                 return forLoop.body
@@ -374,7 +292,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
         return forLoop
     }
 
-    override fun visit(whileLoop: WhileLoop): IStatement {
+    override fun visit(whileLoop: WhileLoop): Statement {
         super.visit(whileLoop)
         val constvalue = whileLoop.condition.constValue(program)
         if(constvalue!=null) {
@@ -383,10 +301,10 @@ internal class StatementOptimizer(private val program: Program, private val opti
                 printWarning("condition is always true", whileLoop.position)
                 if(hasContinueOrBreak(whileLoop.body))
                     return whileLoop
-                val label = Label("__back", whileLoop.condition.position)
+                val label = Label("_prog8_back", whileLoop.condition.position)
                 whileLoop.body.statements.add(0, label)
                 whileLoop.body.statements.add(Jump(null,
-                        IdentifierReference(listOf("__back"), whileLoop.condition.position),
+                        IdentifierReference(listOf("_prog8_back"), whileLoop.condition.position),
                         null, whileLoop.condition.position))
                 optimizationsDone++
                 return whileLoop.body
@@ -394,13 +312,13 @@ internal class StatementOptimizer(private val program: Program, private val opti
                 // always false -> ditch whole statement
                 printWarning("condition is always false", whileLoop.position)
                 optimizationsDone++
-                NopStatement(whileLoop.position)
+                NopStatement.insteadOf(whileLoop)
             }
         }
         return whileLoop
     }
 
-    override fun visit(repeatLoop: RepeatLoop): IStatement {
+    override fun visit(repeatLoop: RepeatLoop): Statement {
         super.visit(repeatLoop)
         val constvalue = repeatLoop.untilCondition.constValue(program)
         if(constvalue!=null) {
@@ -430,12 +348,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
         return repeatLoop
     }
 
-    override fun visit(nopStatement: NopStatement): IStatement {
-        this.nopStatements.add(nopStatement)
-        return nopStatement
-    }
-
-    override fun visit(whenStatement: WhenStatement): IStatement {
+    override fun visit(whenStatement: WhenStatement): Statement {
         val choices = whenStatement.choices.toList()
         for(choice in choices) {
             if(choice.statements.containsNoCodeNorVars())
@@ -450,12 +363,12 @@ internal class StatementOptimizer(private val program: Program, private val opti
         {
             var count=0
 
-            override fun visit(breakStmt: Break): IStatement {
+            override fun visit(breakStmt: Break): Statement {
                 count++
                 return super.visit(breakStmt)
             }
 
-            override fun visit(contStmt: Continue): IStatement {
+            override fun visit(contStmt: Continue): Statement {
                 count++
                 return super.visit(contStmt)
             }
@@ -469,7 +382,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
         return s.count > 0
     }
 
-    override fun visit(jump: Jump): IStatement {
+    override fun visit(jump: Jump): Statement {
         val subroutine = jump.identifier?.targetSubroutine(program.namespace)
         if(subroutine!=null) {
             // if the first instruction in the subroutine is another jump, shortcut this one
@@ -486,136 +399,137 @@ internal class StatementOptimizer(private val program: Program, private val opti
         if(label!=null) {
             if(scope.statements.indexOf(label) == scope.statements.indexOf(jump)+1) {
                 optimizationsDone++
-                return NopStatement(jump.position)
+                return NopStatement.insteadOf(jump)
             }
         }
 
         return jump
     }
 
-    override fun visit(assignment: Assignment): IStatement {
+    override fun visit(assignment: Assignment): Statement {
         if(assignment.aug_op!=null)
             throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
 
-        if(assignment.targets.size==1) {
-            val target=assignment.targets[0]
-            if(target isSameAs assignment.value) {
+        if(assignment.target isSameAs assignment.value) {
+            if(assignment.target.isNotMemory(program.namespace)) {
                 optimizationsDone++
-                return NopStatement(assignment.position)
+                return NopStatement.insteadOf(assignment)
             }
-            val targetDt = target.inferType(program, assignment)
-            val bexpr=assignment.value as? BinaryExpression
-            if(bexpr!=null) {
-                val cv = bexpr.right.constValue(program)?.asNumericValue?.toDouble()
-                if(cv==null) {
-                    if(bexpr.operator=="+" && targetDt!= DataType.FLOAT) {
-                        if (bexpr.left isSameAs bexpr.right && target isSameAs bexpr.left) {
-                            bexpr.operator = "*"
-                            bexpr.right = LiteralValue.optimalInteger(2, assignment.value.position)
-                            optimizationsDone++
-                            return assignment
-                        }
+        }
+        val targetIDt = assignment.target.inferType(program, assignment)
+        if(!targetIDt.isKnown)
+            throw AssemblyError("can't infer type of assignment target")
+        val targetDt = targetIDt.typeOrElse(DataType.STRUCT)
+        val bexpr=assignment.value as? BinaryExpression
+        if(bexpr!=null) {
+            val cv = bexpr.right.constValue(program)?.number?.toDouble()
+            if (cv == null) {
+                if (bexpr.operator == "+" && targetDt != DataType.FLOAT) {
+                    if (bexpr.left isSameAs bexpr.right && assignment.target isSameAs bexpr.left) {
+                        bexpr.operator = "*"
+                        bexpr.right = NumericLiteralValue.optimalInteger(2, assignment.value.position)
+                        optimizationsDone++
+                        return assignment
                     }
-                } else {
-                    if (target isSameAs bexpr.left) {
-                        // remove assignments that have no effect  X=X , X+=0, X-=0, X*=1, X/=1, X//=1, A |= 0, A ^= 0, A<<=0, etc etc
-                        // A = A <operator> B
-                        val vardeclDt = (target.identifier?.targetVarDecl(program.namespace))?.type
+                }
+            } else {
+                if (assignment.target isSameAs bexpr.left) {
+                    // remove assignments that have no effect  X=X , X+=0, X-=0, X*=1, X/=1, X//=1, A |= 0, A ^= 0, A<<=0, etc etc
+                    // A = A <operator> B
+                    val vardeclDt = (assignment.target.identifier?.targetVarDecl(program.namespace))?.type
 
-                        when (bexpr.operator) {
-                            "+" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
-                                    if((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt!=VarDeclType.MEMORY && cv in 1.0..8.0)) {
-                                        // replace by several INCs (a bit less when dealing with memory targets)
-                                        val decs = AnonymousScope(mutableListOf(), assignment.position)
-                                        repeat(cv.toInt()) {
-                                            decs.statements.add(PostIncrDecr(target, "++", assignment.position))
-                                        }
-                                        return decs
+                    when (bexpr.operator) {
+                        "+" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
+                                if ((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt != VarDeclType.MEMORY && cv in 1.0..8.0)) {
+                                    // replace by several INCs (a bit less when dealing with memory targets)
+                                    val decs = AnonymousScope(mutableListOf(), assignment.position)
+                                    repeat(cv.toInt()) {
+                                        decs.statements.add(PostIncrDecr(assignment.target, "++", assignment.position))
                                     }
+                                    return decs
                                 }
                             }
-                            "-" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
-                                    if((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt!=VarDeclType.MEMORY && cv in 1.0..8.0)) {
-                                        // replace by several DECs (a bit less when dealing with memory targets)
-                                        val decs = AnonymousScope(mutableListOf(), assignment.position)
-                                        repeat(cv.toInt()) {
-                                            decs.statements.add(PostIncrDecr(target, "--", assignment.position))
-                                        }
-                                        return decs
+                        }
+                        "-" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
+                                if ((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt != VarDeclType.MEMORY && cv in 1.0..8.0)) {
+                                    // replace by several DECs (a bit less when dealing with memory targets)
+                                    val decs = AnonymousScope(mutableListOf(), assignment.position)
+                                    repeat(cv.toInt()) {
+                                        decs.statements.add(PostIncrDecr(assignment.target, "--", assignment.position))
                                     }
+                                    return decs
                                 }
                             }
-                            "*" -> if (cv == 1.0) {
+                        }
+                        "*" -> if (cv == 1.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "/" -> if (cv == 1.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "**" -> if (cv == 1.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "|" -> if (cv == 0.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "^" -> if (cv == 0.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "<<" -> {
+                            if (cv == 0.0) {
                                 optimizationsDone++
-                                return NopStatement(assignment.position)
+                                return NopStatement.insteadOf(assignment)
                             }
-                            "/" -> if (cv == 1.0) {
+                            if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
+                                    ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
+                                assignment.value = NumericLiteralValue.optimalInteger(0, assignment.value.position)
+                                assignment.value.linkParents(assignment)
                                 optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "**" -> if (cv == 1.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "|" -> if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "^" -> if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "<<" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                }
-                                if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
-                                        ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
-                                    assignment.value = LiteralValue.optimalInteger(0, assignment.value.position)
-                                    assignment.value.linkParents(assignment)
-                                    optimizationsDone++
-                                } else {
-                                    // replace by in-place lsl(...) call
-                                    val scope = AnonymousScope(mutableListOf(), assignment.position)
-                                    var numshifts = cv.toInt()
-                                    while (numshifts > 0) {
-                                        scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsl"), assignment.position), mutableListOf(bexpr.left), assignment.position))
-                                        numshifts--
-                                    }
-                                    optimizationsDone++
-                                    return scope
+                            } else {
+                                // replace by in-place lsl(...) call
+                                val scope = AnonymousScope(mutableListOf(), assignment.position)
+                                var numshifts = cv.toInt()
+                                while (numshifts > 0) {
+                                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsl"), assignment.position), mutableListOf(bexpr.left), assignment.position))
+                                    numshifts--
                                 }
+                                optimizationsDone++
+                                return scope
                             }
-                            ">>" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                }
-                                if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
-                                        ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
-                                    assignment.value = LiteralValue.optimalInteger(0, assignment.value.position)
-                                    assignment.value.linkParents(assignment)
-                                    optimizationsDone++
-                                } else {
-                                    // replace by in-place lsr(...) call
-                                    val scope = AnonymousScope(mutableListOf(), assignment.position)
-                                    var numshifts = cv.toInt()
-                                    while (numshifts > 0) {
-                                        scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsr"), assignment.position), mutableListOf(bexpr.left), assignment.position))
-                                        numshifts--
-                                    }
-                                    optimizationsDone++
-                                    return scope
+                        }
+                        ">>" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            }
+                            if ((targetDt == DataType.UWORD && cv > 15.0) || (targetDt == DataType.UBYTE && cv > 7.0)) {
+                                assignment.value = NumericLiteralValue.optimalInteger(0, assignment.value.position)
+                                assignment.value.linkParents(assignment)
+                                optimizationsDone++
+                            } else {
+                                // replace by in-place lsr(...) call
+                                val scope = AnonymousScope(mutableListOf(), assignment.position)
+                                var numshifts = cv.toInt()
+                                while (numshifts > 0) {
+                                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsr"), assignment.position), mutableListOf(bexpr.left), assignment.position))
+                                    numshifts--
                                 }
+                                optimizationsDone++
+                                return scope
                             }
                         }
                     }
@@ -623,28 +537,24 @@ internal class StatementOptimizer(private val program: Program, private val opti
             }
         }
 
+
         return super.visit(assignment)
     }
 
-    override fun visit(scope: AnonymousScope): IStatement {
+    override fun visit(scope: AnonymousScope): Statement {
         val linesToRemove = deduplicateAssignments(scope.statements)
         if(linesToRemove.isNotEmpty()) {
             linesToRemove.reversed().forEach{scope.statements.removeAt(it)}
         }
-
-        if(scope.parent is INameScope) {
-            scopesToFlatten.add(scope)  // get rid of the anonymous scope
-        }
-
         return super.visit(scope)
     }
 
-    override fun visit(label: Label): IStatement {
+    override fun visit(label: Label): Statement {
         // remove duplicate labels
         val stmts = label.definingScope().statements
         val startIdx = stmts.indexOf(label)
         if(startIdx<(stmts.size-1) && stmts[startIdx+1] == label)
-            return NopStatement(label.position)
+            return NopStatement.insteadOf(label)
 
         return super.visit(label)
     }
@@ -652,3 +562,39 @@ internal class StatementOptimizer(private val program: Program, private val opti
 
 
 
+internal class FlattenAnonymousScopesAndRemoveNops: IAstVisitor {
+    private var scopesToFlatten = mutableListOf<INameScope>()
+    private val nopStatements = mutableListOf<NopStatement>()
+
+    override fun visit(program: Program) {
+        super.visit(program)
+        for(scope in scopesToFlatten.reversed()) {
+            val namescope = scope.parent as INameScope
+            val idx = namescope.statements.indexOf(scope as Statement)
+            if(idx>=0) {
+                val nop = NopStatement.insteadOf(namescope.statements[idx])
+                nop.parent = namescope as Node
+                namescope.statements[idx] = nop
+                namescope.statements.addAll(idx, scope.statements)
+                scope.statements.forEach { it.parent = namescope }
+                visit(nop)
+            }
+        }
+
+        this.nopStatements.forEach {
+            it.definingScope().remove(it)
+        }
+    }
+
+    override fun visit(scope: AnonymousScope) {
+        if(scope.parent is INameScope) {
+            scopesToFlatten.add(scope)  // get rid of the anonymous scope
+        }
+
+        return super.visit(scope)
+    }
+
+    override fun visit(nopStatement: NopStatement) {
+        nopStatements.add(nopStatement)
+    }
+}

compiler/src/prog8/parser/ModuleParsing.kt

@@ -1,7 +1,8 @@
 package prog8.parser
 
 import org.antlr.v4.runtime.*
-import prog8.ast.*
+import prog8.ast.Module
+import prog8.ast.Program
 import prog8.ast.antlr.toAst
 import prog8.ast.base.Position
 import prog8.ast.base.SyntaxError

compiler/src/prog8/vm/RuntimeValue.kt

@@ -1,19 +1,23 @@
 package prog8.vm
 
 import prog8.ast.base.*
-import prog8.ast.expressions.LiteralValue
+import prog8.ast.expressions.ArrayLiteralValue
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.StringLiteralValue
 import prog8.compiler.HeapValues
 import prog8.compiler.target.c64.Petscii
+import java.util.*
 import kotlin.math.abs
 import kotlin.math.pow
 
 
 /**
- * Rather than a literal value (LiteralValue) that occurs in the parsed source code,
+ * Rather than a literal value (NumericLiteralValue) that occurs in the parsed source code,
  * this runtime value can be used to *execute* the parsed Ast (or another intermediary form)
  * It contains a value of a variable during run time of the program and provides arithmetic operations on the value.
  */
-open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=null, val array: Array<Number>?=null, val heapId: Int?=null) {
+open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=null,
+                        val array: Array<Number>?=null, val heapId: Int?=null) {
 
     val byteval: Short?
     val wordval: Int?
@@ -21,16 +25,14 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
     val asBoolean: Boolean
 
     companion object {
-        fun from(literalValue: LiteralValue, heap: HeapValues): RuntimeValue {
-            return when(literalValue.type) {
-                in NumericDatatypes -> RuntimeValue(literalValue.type, num = literalValue.asNumericValue!!)
-                in StringDatatypes -> from(literalValue.heapId!!, heap)
-                in ArrayDatatypes -> from(literalValue.heapId!!, heap)
-                else -> TODO("type")
-            }
+        fun fromLv(literalValue: NumericLiteralValue): RuntimeValue {
+            return RuntimeValue(literalValue.type, num = literalValue.number)
         }
 
-        fun from(heapId: Int, heap: HeapValues): RuntimeValue {
+        fun fromLv(string: StringLiteralValue, heap: HeapValues): RuntimeValue = fromHeapId(string.heapId!!, heap)
+        fun fromLv(array: ArrayLiteralValue, heap: HeapValues): RuntimeValue = fromHeapId(array.heapId!!, heap)
+
+        fun fromHeapId(heapId: Int, heap: HeapValues): RuntimeValue {
             val value = heap.get(heapId)
             return when {
                 value.type in StringDatatypes ->
@@ -40,11 +42,18 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
                         RuntimeValue(value.type, array = value.doubleArray!!.toList().toTypedArray(), heapId = heapId)
                     } else {
                         val array = value.array!!
-                        if (array.any { it.addressOf != null })
-                            TODO("addressof values")
-                        RuntimeValue(value.type, array = array.map { it.integer!! }.toTypedArray(), heapId = heapId)
+                        val resultArray = mutableListOf<Number>()
+                        for(elt in array.withIndex()){
+                            if(elt.value.integer!=null)
+                                resultArray.add(elt.value.integer!!)
+                            else {
+                                TODO("ADDRESSOF ${elt.value}")
+                            }
+                        }
+                        RuntimeValue(value.type, array = resultArray.toTypedArray(), heapId = heapId)
+                        //RuntimeValue(value.type, array = array.map { it.integer!! }.toTypedArray(), heapId = heapId)
                     }
-                else -> TODO("weird type on heap")
+                else -> throw IllegalArgumentException("weird value type on heap $value")
             }
         }
 
@@ -53,27 +62,37 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
     init {
         when(type) {
             DataType.UBYTE -> {
-                byteval = (num!!.toInt() and 255).toShort()
+                val inum = num!!.toInt()
+                if(inum !in 0 .. 255)
+                    throw IllegalArgumentException("invalid value for ubyte: $inum")
+                byteval = inum.toShort()
                 wordval = null
                 floatval = null
                 asBoolean = byteval != 0.toShort()
             }
             DataType.BYTE -> {
-                val v = num!!.toInt() and 255
-                byteval = (if(v<128) v else v-256).toShort()
+                val inum = num!!.toInt()
+                if(inum !in -128 .. 127)
+                    throw IllegalArgumentException("invalid value for byte: $inum")
+                byteval = inum.toShort()
                 wordval = null
                 floatval = null
                 asBoolean = byteval != 0.toShort()
             }
             DataType.UWORD -> {
-                wordval = num!!.toInt() and 65535
+                val inum = num!!.toInt()
+                if(inum !in 0 .. 65535)
+                    throw IllegalArgumentException("invalid value for uword: $inum")
+                wordval = inum
                 byteval = null
                 floatval = null
                 asBoolean = wordval != 0
             }
             DataType.WORD -> {
-                val v = num!!.toInt() and 65535
-                wordval = if(v<32768) v else v - 65536
+                val inum = num!!.toInt()
+                if(inum !in -32768 .. 32767)
+                    throw IllegalArgumentException("invalid value for word: $inum")
+                wordval = inum
                 byteval = null
                 floatval = null
                 asBoolean = wordval != 0
@@ -85,8 +104,6 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
                 asBoolean = floatval != 0.0
             }
             else -> {
-                if(heapId==null)
-                    throw IllegalArgumentException("for non-numeric types, a heapId should be given")
                 byteval = null
                 wordval = null
                 floatval = null
@@ -95,19 +112,6 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
         }
     }
 
-    fun asLiteralValue(): LiteralValue {
-        return when(type) {
-            in ByteDatatypes -> LiteralValue(type, byteval, position = Position("", 0, 0, 0))
-            in WordDatatypes -> LiteralValue(type, wordvalue = wordval, position = Position("", 0, 0, 0))
-            DataType.FLOAT -> LiteralValue(type, floatvalue = floatval, position = Position("", 0, 0, 0))
-            in StringDatatypes -> LiteralValue(type, strvalue = str, position = Position("", 0, 0, 0))
-            in ArrayDatatypes -> LiteralValue(type,
-                    arrayvalue = array?.map { LiteralValue.optimalNumeric(it, Position("", 0, 0, 0)) }?.toTypedArray(),
-                    position = Position("", 0, 0, 0))
-            else -> TODO("strange type")
-        }
-    }
-
     override fun toString(): String {
         return when(type) {
             DataType.UBYTE -> "ub:%02x".format(byteval)
@@ -147,12 +151,7 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
         }
     }
 
-    override fun hashCode(): Int {
-        val bh = byteval?.hashCode() ?: 0x10001234
-        val wh = wordval?.hashCode() ?: 0x01002345
-        val fh = floatval?.hashCode() ?: 0x00103456
-        return bh xor wh xor fh xor heapId.hashCode() xor type.hashCode()
-    }
+    override fun hashCode(): Int = Objects.hash(byteval, wordval, floatval, type)
 
     override fun equals(other: Any?): Boolean {
         if(other==null || other !is RuntimeValue)
@@ -179,20 +178,44 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
                     if(leftDt== DataType.UBYTE)
                         RuntimeValue(DataType.UBYTE, (number xor 255) + 1)
                     else
-                        RuntimeValue(DataType.UBYTE, (number xor 65535) + 1)
+                        RuntimeValue(DataType.UWORD, (number xor 65535) + 1)
+                }
+                DataType.BYTE -> {
+                    val v=result.toInt() and 255
+                    if(v<128)
+                        RuntimeValue(DataType.BYTE, v)
+                    else
+                        RuntimeValue(DataType.BYTE, v-256)
+                }
+                DataType.WORD -> {
+                    val v=result.toInt() and 65535
+                    if(v<32768)
+                        RuntimeValue(DataType.WORD, v)
+                    else
+                        RuntimeValue(DataType.WORD, v-65536)
                 }
-                DataType.BYTE -> RuntimeValue(DataType.BYTE, result.toInt())
-                DataType.WORD -> RuntimeValue(DataType.WORD, result.toInt())
                 DataType.FLOAT -> RuntimeValue(DataType.FLOAT, result)
                 else -> throw ArithmeticException("$op on non-numeric type")
             }
         }
 
         return when(leftDt) {
-            DataType.UBYTE -> RuntimeValue(DataType.UBYTE, result.toInt())
-            DataType.BYTE -> RuntimeValue(DataType.BYTE, result.toInt())
-            DataType.UWORD -> RuntimeValue(DataType.UWORD, result.toInt())
-            DataType.WORD -> RuntimeValue(DataType.WORD, result.toInt())
+            DataType.UBYTE -> RuntimeValue(DataType.UBYTE, result.toInt() and 255)
+            DataType.BYTE -> {
+                val v = result.toInt() and 255
+                if(v<128)
+                    RuntimeValue(DataType.BYTE, v)
+                else
+                    RuntimeValue(DataType.BYTE, v-256)
+            }
+            DataType.UWORD -> RuntimeValue(DataType.UWORD, result.toInt() and 65535)
+            DataType.WORD -> {
+                val v = result.toInt() and 65535
+                if(v<32768)
+                    RuntimeValue(DataType.WORD, v)
+                else
+                    RuntimeValue(DataType.WORD, v-65536)
+            }
             DataType.FLOAT -> RuntimeValue(DataType.FLOAT, result)
             else -> throw ArithmeticException("$op on non-numeric type")
         }
@@ -268,10 +291,22 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
     fun shl(): RuntimeValue {
         val v = integerValue()
         return when (type) {
-            DataType.UBYTE,
-            DataType.BYTE,
-            DataType.UWORD,
-            DataType.WORD -> RuntimeValue(type, v shl 1)
+            DataType.UBYTE -> RuntimeValue(type, (v shl 1) and 255)
+            DataType.UWORD -> RuntimeValue(type, (v shl 1) and 65535)
+            DataType.BYTE -> {
+                val value = v shl 1
+                if(value<128)
+                    RuntimeValue(type, value)
+                else
+                    RuntimeValue(type, value-256)
+            }
+            DataType.WORD -> {
+                val value = v shl 1
+                if(value<32768)
+                    RuntimeValue(type, value)
+                else
+                    RuntimeValue(type, value-65536)
+            }
             else -> throw ArithmeticException("invalid type for shl: $type")
         }
     }
@@ -409,16 +444,32 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
 
     fun inv(): RuntimeValue {
         return when(type) {
-            in ByteDatatypes -> RuntimeValue(type, byteval!!.toInt().inv())
-            in WordDatatypes -> RuntimeValue(type, wordval!!.inv())
+            DataType.UBYTE -> RuntimeValue(type, byteval!!.toInt().inv() and 255)
+            DataType.UWORD -> RuntimeValue(type, wordval!!.inv() and 65535)
+            DataType.BYTE -> RuntimeValue(type, byteval!!.toInt().inv())
+            DataType.WORD -> RuntimeValue(type, wordval!!.inv())
             else -> throw ArithmeticException("inv can only work on byte/word")
         }
     }
 
     fun inc(): RuntimeValue {
         return when(type) {
-            in ByteDatatypes -> RuntimeValue(type, byteval!! + 1)
-            in WordDatatypes -> RuntimeValue(type, wordval!! + 1)
+            DataType.UBYTE -> RuntimeValue(type, (byteval!! + 1) and 255)
+            DataType.UWORD -> RuntimeValue(type, (wordval!! + 1) and 65535)
+            DataType.BYTE -> {
+                val newval = byteval!! + 1
+                if(newval == 128)
+                    RuntimeValue(type, -128)
+                else
+                    RuntimeValue(type, newval)
+            }
+            DataType.WORD -> {
+                val newval = wordval!! + 1
+                if(newval == 32768)
+                    RuntimeValue(type, -32768)
+                else
+                    RuntimeValue(type, newval)
+            }
             DataType.FLOAT -> RuntimeValue(DataType.FLOAT, floatval!! + 1)
             else -> throw ArithmeticException("inc can only work on numeric types")
         }
@@ -426,8 +477,22 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
 
     fun dec(): RuntimeValue {
         return when(type) {
-            in ByteDatatypes -> RuntimeValue(type, byteval!! - 1)
-            in WordDatatypes -> RuntimeValue(type, wordval!! - 1)
+            DataType.UBYTE -> RuntimeValue(type, (byteval!! - 1) and 255)
+            DataType.UWORD -> RuntimeValue(type, (wordval!! - 1) and 65535)
+            DataType.BYTE -> {
+                val newval = byteval!! - 1
+                if(newval == -129)
+                    RuntimeValue(type, 127)
+                else
+                    RuntimeValue(type, newval)
+            }
+            DataType.WORD -> {
+                val newval = wordval!! - 1
+                if(newval == -32769)
+                    RuntimeValue(type, 32767)
+                else
+                    RuntimeValue(type, newval)
+            }
             DataType.FLOAT -> RuntimeValue(DataType.FLOAT, floatval!! - 1)
             else -> throw ArithmeticException("dec can only work on numeric types")
         }
@@ -446,9 +511,21 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
             DataType.UBYTE -> {
                 when (targetType) {
                     DataType.UBYTE -> this
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, byteval)
+                    DataType.BYTE -> {
+                        val nval=byteval!!.toInt()
+                        if(nval<128)
+                            RuntimeValue(DataType.BYTE, nval)
+                        else
+                            RuntimeValue(DataType.BYTE, nval-256)
+                    }
                     DataType.UWORD -> RuntimeValue(DataType.UWORD, numericValue())
-                    DataType.WORD -> RuntimeValue(DataType.WORD, numericValue())
+                    DataType.WORD -> {
+                        val nval = numericValue().toInt()
+                        if(nval<32768)
+                            RuntimeValue(DataType.WORD, nval)
+                        else
+                            RuntimeValue(DataType.WORD, nval-65536)
+                    }
                     DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
                     else -> throw ArithmeticException("invalid type cast from $type to $targetType")
                 }
@@ -456,8 +533,8 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
             DataType.BYTE -> {
                 when (targetType) {
                     DataType.BYTE -> this
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue())
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, integerValue())
+                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue() and 255)
+                    DataType.UWORD -> RuntimeValue(DataType.UWORD, integerValue() and 65535)
                     DataType.WORD -> RuntimeValue(DataType.WORD, integerValue())
                     DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
                     else -> throw ArithmeticException("invalid type cast from $type to $targetType")
@@ -465,18 +542,36 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
             }
             DataType.UWORD -> {
                 when (targetType) {
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, integerValue())
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue())
+                    DataType.BYTE -> {
+                        val v=integerValue()
+                        if(v<128)
+                            RuntimeValue(DataType.BYTE, v)
+                        else
+                            RuntimeValue(DataType.BYTE, v-256)
+                    }
+                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue() and 255)
                     DataType.UWORD -> this
-                    DataType.WORD -> RuntimeValue(DataType.WORD, integerValue())
+                    DataType.WORD -> {
+                        val v=integerValue()
+                        if(v<32768)
+                            RuntimeValue(DataType.WORD, v)
+                        else
+                            RuntimeValue(DataType.WORD, v-65536)
+                    }
                     DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
                     else -> throw ArithmeticException("invalid type cast from $type to $targetType")
                 }
             }
             DataType.WORD -> {
                 when (targetType) {
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, integerValue())
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue())
+                    DataType.BYTE -> {
+                        val v = integerValue() and 255
+                        if(v<128)
+                            RuntimeValue(DataType.BYTE, v)
+                        else
+                            RuntimeValue(DataType.BYTE, v-256)
+                    }
+                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue() and 65535)
                     DataType.UWORD -> RuntimeValue(DataType.UWORD, integerValue())
                     DataType.WORD -> this
                     DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
@@ -523,7 +618,7 @@ open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=
 }
 
 
-class RuntimeValueRange(type: DataType, val range: IntProgression): RuntimeValue(type, 0) {
+class RuntimeValueRange(type: DataType, val range: IntProgression): RuntimeValue(type, array=range.toList().toTypedArray()) {
     override fun iterator(): Iterator<Number> {
         return range.iterator()
     }

compiler/src/prog8/vm/astvm/AstVm.kt

@@ -1,18 +1,24 @@
 package prog8.vm.astvm
 
-import prog8.ast.*
+import prog8.ast.INameScope
+import prog8.ast.Program
 import prog8.ast.base.*
-import prog8.ast.base.initvarsSubName
+import prog8.ast.expressions.Expression
 import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.LiteralValue
+import prog8.ast.expressions.NumericLiteralValue
 import prog8.ast.statements.*
+import prog8.compiler.IntegerOrAddressOf
+import prog8.compiler.target.c64.MachineDefinition
+import prog8.compiler.target.c64.Petscii
 import prog8.vm.RuntimeValue
 import prog8.vm.RuntimeValueRange
-import prog8.compiler.target.c64.Petscii
 import java.awt.EventQueue
+import java.io.CharConversionException
+import java.util.*
 import kotlin.NoSuchElementException
 import kotlin.concurrent.fixedRateTimer
-import kotlin.math.min
+import kotlin.math.*
+import kotlin.random.Random
 
 
 class VmExecutionException(msg: String?) : Exception(msg)
@@ -28,31 +34,31 @@ class StatusFlags {
     var negative: Boolean = false
     var irqd: Boolean = false
 
-    private fun setFlags(value: LiteralValue?) {
+    private fun setFlags(value: NumericLiteralValue?) {
         if (value != null) {
             when (value.type) {
                 DataType.UBYTE -> {
-                    val v = value.bytevalue!!.toInt()
+                    val v = value.number.toInt()
                     negative = v > 127
                     zero = v == 0
                 }
                 DataType.BYTE -> {
-                    val v = value.bytevalue!!.toInt()
+                    val v = value.number.toInt()
                     negative = v < 0
                     zero = v == 0
                 }
                 DataType.UWORD -> {
-                    val v = value.wordvalue!!
+                    val v = value.number.toInt()
                     negative = v > 32767
                     zero = v == 0
                 }
                 DataType.WORD -> {
-                    val v = value.wordvalue!!
+                    val v = value.number.toInt()
                     negative = v < 0
                     zero = v == 0
                 }
                 DataType.FLOAT -> {
-                    val flt = value.floatvalue!!
+                    val flt = value.number.toDouble()
                     negative = flt < 0.0
                     zero = flt == 0.0
                 }
@@ -94,14 +100,12 @@ class RuntimeVariables {
 
     fun get(scope: INameScope, name: String): RuntimeValue {
         val where = vars.getValue(scope)
-        val value = where[name] ?: throw NoSuchElementException("no such runtime variable: ${scope.name}.$name")
-        return value
+        return where[name] ?: throw NoSuchElementException("no such runtime variable: ${scope.name}.$name")
     }
 
     fun getMemoryAddress(scope: INameScope, name: String): Int {
         val where = memvars.getValue(scope)
-        val address = where[name] ?: throw NoSuchElementException("no such runtime memory-variable: ${scope.name}.$name")
-        return address
+        return where[name] ?: throw NoSuchElementException("no such runtime memory-variable: ${scope.name}.$name")
     }
 
     fun swap(a1: VarDecl, a2: VarDecl) = swap(a1.definingScope(), a1.name, a2.definingScope(), a2.name)
@@ -128,9 +132,18 @@ class AstVm(val program: Program) {
     val bootTime = System.currentTimeMillis()
     var rtcOffset = bootTime
 
+    private val rnd = Random(0)
+    private val statusFlagsSave = Stack<StatusFlags>()
+    private val registerXsave = Stack<RuntimeValue>()
+    private val registerYsave = Stack<RuntimeValue>()
+    private val registerAsave = Stack<RuntimeValue>()
+
+
     init {
-        // observe the jiffyclock
+        // observe the jiffyclock and screen matrix
         mem.observe(0xa0, 0xa1, 0xa2)
+        for(i in 1024..2023)
+            mem.observe(i)
 
         dialog.requestFocusInWindow()
 
@@ -153,12 +166,17 @@ class AstVm(val program: Program) {
     fun memwrite(address: Int, value: Short): Short {
         if(address==0xa0 || address==0xa1 || address==0xa2) {
             // a write to the jiffy clock, update the clock offset for the irq
-            val time_hi = if(address==0xa0) value else mem.getUByte_DMA(0xa0)
-            val time_mid = if(address==0xa1) value else mem.getUByte_DMA(0xa1)
-            val time_lo = if(address==0xa2) value else mem.getUByte_DMA(0xa2)
-            val jiffies = (time_hi.toInt() shl 16) + (time_mid.toInt() shl 8) + time_lo
+            val timeHi = if(address==0xa0) value else mem.getUByte_DMA(0xa0)
+            val timeMid = if(address==0xa1) value else mem.getUByte_DMA(0xa1)
+            val timeLo = if(address==0xa2) value else mem.getUByte_DMA(0xa2)
+            val jiffies = (timeHi.toInt() shl 16) + (timeMid.toInt() shl 8) + timeLo
             rtcOffset = bootTime - (jiffies*1000/60)
         }
+        if(address in 1024..2023) {
+            // write to the screen matrix
+            val scraddr = address-1024
+            dialog.canvas.setChar(scraddr % 40, scraddr / 40, value, 1)
+        }
         return value
     }
 
@@ -213,6 +231,7 @@ class AstVm(val program: Program) {
                     }
                 }
             }
+            dialog.canvas.printText("\n<program ended>", true)
             println("PROGRAM EXITED!")
             dialog.title = "PROGRAM EXITED"
         } catch (tx: VmTerminationException) {
@@ -228,7 +247,11 @@ class AstVm(val program: Program) {
         if(statusflags.irqd)
             return      // interrupt is disabled
 
-        val jiffies = min((timeStamp-rtcOffset)*60/1000, 24*3600*60-1)
+        var jiffies = (timeStamp-rtcOffset)*60/1000
+        if(jiffies>24*3600*60-1) {
+            jiffies = 0
+            rtcOffset = timeStamp
+        }
         // update the C-64 60hz jiffy clock in the ZP addresses:
         mem.setUByte_DMA(0x00a0, (jiffies ushr 16).toShort())
         mem.setUByte_DMA(0x00a1, (jiffies ushr 8 and 255).toShort())
@@ -236,17 +259,19 @@ class AstVm(val program: Program) {
     }
 
     private val runtimeVariables = RuntimeVariables()
-    private val functions = BuiltinFunctions()
-    private val evalCtx = EvalContext(program, mem, statusflags, runtimeVariables, functions, ::executeSubroutine)
+    private val evalCtx = EvalContext(program, mem, statusflags, runtimeVariables, ::performBuiltinFunction, ::executeSubroutine)
 
     class LoopControlBreak : Exception()
     class LoopControlContinue : Exception()
-    class LoopControlReturn(val returnvalues: List<RuntimeValue>) : Exception()
+    class LoopControlReturn(val returnvalue: RuntimeValue?) : Exception()
     class LoopControlJump(val identifier: IdentifierReference?, val address: Int?, val generatedLabel: String?) : Exception()
 
 
-    internal fun executeSubroutine(sub: Subroutine, arguments: List<RuntimeValue>, startlabel: Label?=null): List<RuntimeValue> {
-        assert(!sub.isAsmSubroutine)
+    internal fun executeSubroutine(sub: Subroutine, arguments: List<RuntimeValue>, startAtLabel: Label?=null): RuntimeValue? {
+        if(sub.isAsmSubroutine) {
+            return performSyscall(sub, arguments)
+        }
+
         if (sub.statements.isEmpty())
             throw VmTerminationException("scope contains no statements: $sub")
         if (arguments.size != sub.parameters.size)
@@ -259,10 +284,10 @@ class AstVm(val program: Program) {
         }
 
         val statements = sub.statements.iterator()
-        if(startlabel!=null) {
+        if(startAtLabel!=null) {
             do {
                 val stmt = statements.next()
-            } while(stmt!==startlabel)
+            } while(stmt!==startAtLabel)
         }
 
         try {
@@ -277,7 +302,7 @@ class AstVm(val program: Program) {
                 }
             }
         } catch (r: LoopControlReturn) {
-            return r.returnvalues
+            return r.returnvalue
         }
         throw VmTerminationException("instruction pointer overflow, is a return missing? $sub")
     }
@@ -289,7 +314,7 @@ class AstVm(val program: Program) {
     }
 
 
-    private fun executeStatement(sub: INameScope, stmt: IStatement) {
+    private fun executeStatement(sub: INameScope, stmt: Statement) {
         instructionCounter++
         if (instructionCounter % 200 == 0)
             Thread.sleep(1)
@@ -324,7 +349,7 @@ class AstVm(val program: Program) {
                             executeSwap(stmt)
                         } else {
                             val args = evaluate(stmt.arglist)
-                            functions.performBuiltinFunction(target.name, args, statusflags)
+                            performBuiltinFunction(target.name, args, statusflags)
                         }
                     }
                     else -> {
@@ -332,37 +357,83 @@ class AstVm(val program: Program) {
                     }
                 }
             }
-            is Return -> throw LoopControlReturn(stmt.values.map { evaluate(it, evalCtx) })
+            is Return -> {
+                val value =
+                        if(stmt.value==null)
+                            null
+                        else
+                            evaluate(stmt.value!!, evalCtx)
+                throw LoopControlReturn(value)
+            }
             is Continue -> throw LoopControlContinue()
             is Break -> throw LoopControlBreak()
             is Assignment -> {
                 if (stmt.aug_op != null)
                     throw VmExecutionException("augmented assignment should have been converted into regular one $stmt")
-                val target = stmt.singleTarget
-                if (target != null) {
-                    val value = evaluate(stmt.value, evalCtx)
-                    performAssignment(target, value, stmt, evalCtx)
-                } else TODO("assign multitarget $stmt")
+                val value = evaluate(stmt.value, evalCtx)
+                performAssignment(stmt.target, value, stmt, evalCtx)
             }
             is PostIncrDecr -> {
                 when {
                     stmt.target.identifier != null -> {
                         val ident = stmt.definingScope().lookup(stmt.target.identifier!!.nameInSource, stmt) as VarDecl
                         val identScope = ident.definingScope()
-                        var value = runtimeVariables.get(identScope, ident.name)
+                        when(ident.type){
+                            VarDeclType.VAR -> {
+                                var value = runtimeVariables.get(identScope, ident.name)
+                                value = when {
+                                    stmt.operator == "++" -> value.add(RuntimeValue(value.type, 1))
+                                    stmt.operator == "--" -> value.sub(RuntimeValue(value.type, 1))
+                                    else -> throw VmExecutionException("strange postincdec operator $stmt")
+                                }
+                                runtimeVariables.set(identScope, ident.name, value)
+                            }
+                            VarDeclType.MEMORY -> {
+                                val addr=ident.value!!.constValue(program)!!.number.toInt()
+                                val newval = when {
+                                    stmt.operator == "++" -> mem.getUByte(addr)+1 and 255
+                                    stmt.operator == "--" -> mem.getUByte(addr)-1 and 255
+                                    else -> throw VmExecutionException("strange postincdec operator $stmt")
+                                }
+                                mem.setUByte(addr,newval.toShort())
+                            }
+                            VarDeclType.CONST -> throw VmExecutionException("can't be const")
+                        }
+                    }
+                    stmt.target.memoryAddress != null -> {
+                        val addr = evaluate(stmt.target.memoryAddress!!.addressExpression, evalCtx).integerValue()
+                        val newval = when {
+                            stmt.operator == "++" -> mem.getUByte(addr)+1 and 255
+                            stmt.operator == "--" -> mem.getUByte(addr)-1 and 255
+                            else -> throw VmExecutionException("strange postincdec operator $stmt")
+                        }
+                        mem.setUByte(addr,newval.toShort())
+                    }
+                    stmt.target.arrayindexed != null -> {
+                        val arrayvar = stmt.target.arrayindexed!!.identifier.targetVarDecl(program.namespace)!!
+                        val arrayvalue = runtimeVariables.get(arrayvar.definingScope(), arrayvar.name)
+                        val index = evaluate(stmt.target.arrayindexed!!.arrayspec.index, evalCtx).integerValue()
+                        val elementType = stmt.target.arrayindexed!!.inferType(program)
+                        if(!elementType.isKnown)
+                            throw VmExecutionException("unknown/void elt type")
+                        var value = RuntimeValue(elementType.typeOrElse(DataType.BYTE), arrayvalue.array!![index].toInt())
+                        value = when {
+                            stmt.operator == "++" -> value.inc()
+                            stmt.operator == "--" -> value.dec()
+                            else -> throw VmExecutionException("strange postincdec operator $stmt")
+                        }
+                        arrayvalue.array[index] = value.numericValue()
+                    }
+                    stmt.target.register != null -> {
+                        var value = runtimeVariables.get(program.namespace, stmt.target.register!!.name)
                         value = when {
                             stmt.operator == "++" -> value.add(RuntimeValue(value.type, 1))
                             stmt.operator == "--" -> value.sub(RuntimeValue(value.type, 1))
                             else -> throw VmExecutionException("strange postincdec operator $stmt")
                         }
-                        runtimeVariables.set(identScope, ident.name, value)
-                    }
-                    stmt.target.memoryAddress != null -> {
-                        TODO("postincrdecr memory $stmt")
-                    }
-                    stmt.target.arrayindexed != null -> {
-                        TODO("postincrdecr array $stmt")
+                        runtimeVariables.set(program.namespace, stmt.target.register!!.name, value)
                     }
+                    else -> throw VmExecutionException("empty postincrdecr? $stmt")
                 }
             }
             is Jump -> throw LoopControlJump(stmt.identifier, stmt.address, stmt.generatedLabel)
@@ -370,7 +441,7 @@ class AstVm(val program: Program) {
                 if (sub is Subroutine) {
                     val args = sub.parameters.map { runtimeVariables.get(sub, it.name) }
                     performSyscall(sub, args)
-                    throw LoopControlReturn(emptyList())
+                    throw LoopControlReturn(null)
                 }
                 throw VmExecutionException("can't execute inline assembly in $sub")
             }
@@ -403,8 +474,9 @@ class AstVm(val program: Program) {
                     loopvarDt = DataType.UBYTE
                     loopvar = IdentifierReference(listOf(stmt.loopRegister.name), stmt.position)
                 } else {
-                    loopvarDt = stmt.loopVar!!.inferType(program)!!
-                    loopvar = stmt.loopVar
+                    val dt = stmt.loopVar!!.inferType(program)
+                    loopvarDt = dt.typeOrElse(DataType.UBYTE)
+                    loopvar = stmt.loopVar!!
                 }
                 val iterator = iterable.iterator()
                 for (loopvalue in iterator) {
@@ -445,13 +517,13 @@ class AstVm(val program: Program) {
             is WhenStatement -> {
                 val condition=evaluate(stmt.condition, evalCtx)
                 for(choice in stmt.choices) {
-                    if(choice.value==null) {
+                    if(choice.values==null) {
                         // the 'else' choice
                         executeAnonymousScope(choice.statements)
                         break
                     } else {
-                        val value = choice.value.constValue(evalCtx.program) ?: throw VmExecutionException("can only use const values in when choices ${choice.position}")
-                        val rtval = RuntimeValue.from(value, evalCtx.program.heap)
+                        val value = choice.values!!.single().constValue(evalCtx.program) ?: throw VmExecutionException("can only use const values in when choices ${choice.position}")
+                        val rtval = RuntimeValue.fromLv(value)
                         if(condition==rtval) {
                             executeAnonymousScope(choice.statements)
                             break
@@ -476,11 +548,13 @@ class AstVm(val program: Program) {
         performAssignment(target2, value1, swap, evalCtx)
     }
 
-    fun performAssignment(target: AssignTarget, value: RuntimeValue, contextStmt: IStatement, evalCtx: EvalContext) {
+    fun performAssignment(target: AssignTarget, value: RuntimeValue, contextStmt: Statement, evalCtx: EvalContext) {
+        val targetIdent = target.identifier
+        val targetArrayIndexed = target.arrayindexed
         when {
-            target.identifier != null -> {
-                val decl = contextStmt.definingScope().lookup(target.identifier.nameInSource, contextStmt) as? VarDecl
-                        ?: throw VmExecutionException("can't find assignment target ${target.identifier}")
+            targetIdent != null -> {
+                val decl = contextStmt.definingScope().lookup(targetIdent.nameInSource, contextStmt) as? VarDecl
+                        ?: throw VmExecutionException("can't find assignment target $targetIdent")
                 if (decl.type == VarDeclType.MEMORY) {
                     val address = runtimeVariables.getMemoryAddress(decl.definingScope(), decl.name)
                     when (decl.datatype) {
@@ -491,56 +565,74 @@ class AstVm(val program: Program) {
                         DataType.FLOAT -> mem.setFloat(address, value.floatval!!)
                         DataType.STR -> mem.setString(address, value.str!!)
                         DataType.STR_S -> mem.setScreencodeString(address, value.str!!)
-                        else -> TODO("set memvar $decl")
+                        else -> throw VmExecutionException("weird memaddress type $decl")
                     }
                 } else
                     runtimeVariables.set(decl.definingScope(), decl.name, value)
             }
             target.memoryAddress != null -> {
-                val address = evaluate(target.memoryAddress!!.addressExpression, evalCtx).wordval!!
+                val address = evaluate(target.memoryAddress.addressExpression, evalCtx).wordval!!
                 evalCtx.mem.setUByte(address, value.byteval!!)
             }
-            target.arrayindexed != null -> {
-                val array = evaluate(target.arrayindexed.identifier, evalCtx)
-                val index = evaluate(target.arrayindexed.arrayspec.index, evalCtx)
-                when (array.type) {
-                    DataType.ARRAY_UB -> {
-                        if (value.type != DataType.UBYTE)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+            targetArrayIndexed != null -> {
+                val vardecl = targetArrayIndexed.identifier.targetVarDecl(program.namespace)!!
+                if(vardecl.type==VarDeclType.VAR) {
+                    val array = evaluate(targetArrayIndexed.identifier, evalCtx)
+                    val index = evaluate(targetArrayIndexed.arrayspec.index, evalCtx)
+                    when (array.type) {
+                        DataType.ARRAY_UB -> {
+                            if (value.type != DataType.UBYTE)
+                                throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                        }
+                        DataType.ARRAY_B -> {
+                            if (value.type != DataType.BYTE)
+                                throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                        }
+                        DataType.ARRAY_UW -> {
+                            if (value.type != DataType.UWORD)
+                                throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                        }
+                        DataType.ARRAY_W -> {
+                            if (value.type != DataType.WORD)
+                                throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                        }
+                        DataType.ARRAY_F -> {
+                            if (value.type != DataType.FLOAT)
+                                throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                        }
+                        DataType.STR, DataType.STR_S -> {
+                            if (value.type !in ByteDatatypes)
+                                throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                        }
+                        else -> throw VmExecutionException("strange array type ${array.type}")
                     }
-                    DataType.ARRAY_B -> {
-                        if (value.type != DataType.BYTE)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
+                    if (array.type in ArrayDatatypes)
+                        array.array!![index.integerValue()] = value.numericValue()
+                    else if (array.type in StringDatatypes) {
+                        val indexInt = index.integerValue()
+                        val newchr = Petscii.decodePetscii(listOf(value.numericValue().toShort()), true)
+                        val newstr = array.str!!.replaceRange(indexInt, indexInt + 1, newchr)
+                        val ident = contextStmt.definingScope().lookup(targetArrayIndexed.identifier.nameInSource, contextStmt) as? VarDecl
+                                ?: throw VmExecutionException("can't find assignment target ${target.identifier}")
+                        val identScope = ident.definingScope()
+                        program.heap.update(array.heapId!!, newstr)
+                        runtimeVariables.set(identScope, ident.name, RuntimeValue(array.type, str = newstr, heapId = array.heapId))
                     }
-                    DataType.ARRAY_UW -> {
-                        if (value.type != DataType.UWORD)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.ARRAY_W -> {
-                        if (value.type != DataType.WORD)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.ARRAY_F -> {
-                        if (value.type != DataType.FLOAT)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.STR, DataType.STR_S -> {
-                        if (value.type !in ByteDatatypes)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    else -> throw VmExecutionException("strange array type ${array.type}")
                 }
-                if (array.type in ArrayDatatypes)
-                    array.array!![index.integerValue()] = value.numericValue()
-                else if (array.type in StringDatatypes) {
-                    val indexInt = index.integerValue()
-                    val newchr = Petscii.decodePetscii(listOf(value.numericValue().toShort()), true)
-                    val newstr = array.str!!.replaceRange(indexInt, indexInt + 1, newchr)
-                    val ident = contextStmt.definingScope().lookup(target.arrayindexed.identifier.nameInSource, contextStmt) as? VarDecl
-                            ?: throw VmExecutionException("can't find assignment target ${target.identifier}")
-                    val identScope = ident.definingScope()
-                    program.heap.update(array.heapId!!, newstr)
-                    runtimeVariables.set(identScope, ident.name, RuntimeValue(array.type, str = newstr, heapId = array.heapId))
+                else {
+                    val address = (vardecl.value as NumericLiteralValue).number.toInt()
+                    val index = evaluate(targetArrayIndexed.arrayspec.index, evalCtx).integerValue()
+                    val elementType = targetArrayIndexed.inferType(program)
+                    if(!elementType.isKnown)
+                        throw VmExecutionException("unknown/void array elt type $targetArrayIndexed")
+                    when(elementType.typeOrElse(DataType.UBYTE)) {
+                        DataType.UBYTE -> mem.setUByte(address+index, value.byteval!!)
+                        DataType.BYTE -> mem.setSByte(address+index, value.byteval!!)
+                        DataType.UWORD -> mem.setUWord(address+index*2, value.wordval!!)
+                        DataType.WORD -> mem.setSWord(address+index*2, value.wordval!!)
+                        DataType.FLOAT -> mem.setFloat(address+index* MachineDefinition.Mflpt5.MemorySize, value.floatval!!)
+                        else -> throw VmExecutionException("strange array elt type $elementType")
+                    }
                 }
             }
             target.register != null -> {
@@ -557,56 +649,56 @@ class AstVm(val program: Program) {
         executeAnonymousScope(stmt.body)
     }
 
-    private fun evaluate(args: List<IExpression>) = args.map { evaluate(it, evalCtx) }
+    private fun evaluate(args: List<Expression>) = args.map { evaluate(it, evalCtx) }
 
-    private fun performSyscall(sub: Subroutine, args: List<RuntimeValue>) {
-        assert(sub.isAsmSubroutine)
+    private fun performSyscall(sub: Subroutine, args: List<RuntimeValue>): RuntimeValue? {
+        var result: RuntimeValue? = null
         when (sub.scopedname) {
             "c64scr.print" -> {
                 // if the argument is an UWORD, consider it to be the "address" of the string (=heapId)
                 if (args[0].wordval != null) {
                     val str = program.heap.get(args[0].wordval!!).str!!
-                    dialog.canvas.printText(str, 1, true)
+                    dialog.canvas.printText(str, true)
                 } else
-                    dialog.canvas.printText(args[0].str!!, 1, true)
+                    dialog.canvas.printText(args[0].str!!, true)
             }
             "c64scr.print_ub" -> {
-                dialog.canvas.printText(args[0].byteval!!.toString(), 1, true)
+                dialog.canvas.printText(args[0].byteval!!.toString(), true)
             }
             "c64scr.print_ub0" -> {
-                dialog.canvas.printText("%03d".format(args[0].byteval!!), 1, true)
+                dialog.canvas.printText("%03d".format(args[0].byteval!!), true)
             }
             "c64scr.print_b" -> {
-                dialog.canvas.printText(args[0].byteval!!.toString(), 1, true)
+                dialog.canvas.printText(args[0].byteval!!.toString(), true)
             }
             "c64scr.print_uw" -> {
-                dialog.canvas.printText(args[0].wordval!!.toString(), 1, true)
+                dialog.canvas.printText(args[0].wordval!!.toString(), true)
             }
             "c64scr.print_uw0" -> {
-                dialog.canvas.printText("%05d".format(args[0].wordval!!), 1, true)
+                dialog.canvas.printText("%05d".format(args[0].wordval!!), true)
             }
             "c64scr.print_w" -> {
-                dialog.canvas.printText(args[0].wordval!!.toString(), 1, true)
+                dialog.canvas.printText(args[0].wordval!!.toString(), true)
             }
             "c64scr.print_ubhex" -> {
-                val prefix = if (args[0].asBoolean) "$" else ""
-                val number = args[1].byteval!!
-                dialog.canvas.printText("$prefix${number.toString(16).padStart(2, '0')}", 1, true)
+                val number = args[0].byteval!!
+                val prefix = if (args[1].asBoolean) "$" else ""
+                dialog.canvas.printText("$prefix${number.toString(16).padStart(2, '0')}", true)
             }
             "c64scr.print_uwhex" -> {
-                val prefix = if (args[0].asBoolean) "$" else ""
-                val number = args[1].wordval!!
-                dialog.canvas.printText("$prefix${number.toString(16).padStart(4, '0')}", 1, true)
+                val number = args[0].wordval!!
+                val prefix = if (args[1].asBoolean) "$" else ""
+                dialog.canvas.printText("$prefix${number.toString(16).padStart(4, '0')}", true)
             }
             "c64scr.print_uwbin" -> {
-                val prefix = if (args[0].asBoolean) "%" else ""
-                val number = args[1].wordval!!
-                dialog.canvas.printText("$prefix${number.toString(2).padStart(16, '0')}", 1, true)
+                val number = args[0].wordval!!
+                val prefix = if (args[1].asBoolean) "%" else ""
+                dialog.canvas.printText("$prefix${number.toString(2).padStart(16, '0')}", true)
             }
             "c64scr.print_ubbin" -> {
-                val prefix = if (args[0].asBoolean) "%" else ""
-                val number = args[1].byteval!!
-                dialog.canvas.printText("$prefix${number.toString(2).padStart(8, '0')}", 1, true)
+                val number = args[0].byteval!!
+                val prefix = if (args[1].asBoolean) "%" else ""
+                dialog.canvas.printText("$prefix${number.toString(2).padStart(8, '0')}", true)
             }
             "c64scr.clear_screenchars" -> {
                 dialog.canvas.clearScreen(6)
@@ -620,14 +712,251 @@ class AstVm(val program: Program) {
             "c64scr.plot" -> {
                 dialog.canvas.setCursorPos(args[0].integerValue(), args[1].integerValue())
             }
-            "c64.CHROUT" -> {
-                dialog.canvas.printChar(args[0].byteval!!)
+            "c64scr.input_chars" -> {
+                val input=mutableListOf<Char>()
+                for(i in 0 until 80) {
+                    while(dialog.keyboardBuffer.isEmpty()) {
+                        Thread.sleep(10)
+                    }
+                    val char=dialog.keyboardBuffer.pop()
+                    if(char=='\n')
+                        break
+                    else {
+                        input.add(char)
+                        val printChar = try {
+                            Petscii.encodePetscii("" + char, true).first()
+                        } catch (cv: CharConversionException) {
+                            0x3f.toShort()
+                        }
+                        dialog.canvas.printPetscii(printChar)
+                    }
+                }
+                val inputStr = input.joinToString("")
+                val heapId = args[0].wordval!!
+                val origStr = program.heap.get(heapId).str!!
+                val paddedStr=inputStr.padEnd(origStr.length+1, '\u0000').substring(0, origStr.length)
+                program.heap.update(heapId, paddedStr)
+                result = RuntimeValue(DataType.UBYTE, paddedStr.indexOf('\u0000'))
             }
             "c64flt.print_f" -> {
-                dialog.canvas.printText(args[0].floatval.toString(), 1, true)
+                dialog.canvas.printText(args[0].floatval.toString(), false)
+            }
+            "c64.CHROUT" -> {
+                dialog.canvas.printPetscii(args[0].byteval!!)
+            }
+            "c64.CLEARSCR" -> {
+                dialog.canvas.clearScreen(6)
+            }
+            "c64.CHRIN" -> {
+                while(dialog.keyboardBuffer.isEmpty()) {
+                    Thread.sleep(10)
+                }
+                val char=dialog.keyboardBuffer.pop()
+                result = RuntimeValue(DataType.UBYTE, char.toShort())
+            }
+            "c64utils.str2uword" -> {
+                val heapId = args[0].wordval!!
+                val argString = program.heap.get(heapId).str!!
+                val numericpart = argString.takeWhile { it.isDigit() }
+                result = RuntimeValue(DataType.UWORD, numericpart.toInt() and 65535)
             }
             else -> TODO("syscall  ${sub.scopedname} $sub")
         }
-    }
-}
 
+        return result
+    }
+
+    private fun performBuiltinFunction(name: String, args: List<RuntimeValue>, statusflags: StatusFlags): RuntimeValue? {
+        return when (name) {
+            "rnd" -> RuntimeValue(DataType.UBYTE, rnd.nextInt() and 255)
+            "rndw" -> RuntimeValue(DataType.UWORD, rnd.nextInt() and 65535)
+            "rndf" -> RuntimeValue(DataType.FLOAT, rnd.nextDouble())
+            "lsb" -> RuntimeValue(DataType.UBYTE, args[0].integerValue() and 255)
+            "msb" -> RuntimeValue(DataType.UBYTE, (args[0].integerValue() ushr 8) and 255)
+            "sin" -> RuntimeValue(DataType.FLOAT, sin(args[0].numericValue().toDouble()))
+            "sin8" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.BYTE, (127.0 * sin(rad)).toShort())
+            }
+            "sin8u" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toShort())
+            }
+            "sin16" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.BYTE, (32767.0 * sin(rad)).toShort())
+            }
+            "sin16u" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.UBYTE, (32768.0 + 32767.5 * sin(rad)).toShort())
+            }
+            "cos" -> RuntimeValue(DataType.FLOAT, cos(args[0].numericValue().toDouble()))
+            "cos8" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.BYTE, (127.0 * cos(rad)).toShort())
+            }
+            "cos8u" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toShort())
+            }
+            "cos16" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.BYTE, (32767.0 * cos(rad)).toShort())
+            }
+            "cos16u" -> {
+                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
+                RuntimeValue(DataType.UBYTE, (32768.0 + 32767.5 * cos(rad)).toShort())
+            }
+            "tan" -> RuntimeValue(DataType.FLOAT, tan(args[0].numericValue().toDouble()))
+            "atan" -> RuntimeValue(DataType.FLOAT, atan(args[0].numericValue().toDouble()))
+            "ln" -> RuntimeValue(DataType.FLOAT, ln(args[0].numericValue().toDouble()))
+            "log2" -> RuntimeValue(DataType.FLOAT, log2(args[0].numericValue().toDouble()))
+            "sqrt" -> RuntimeValue(DataType.FLOAT, sqrt(args[0].numericValue().toDouble()))
+            "sqrt16" -> RuntimeValue(DataType.UBYTE, sqrt(args[0].wordval!!.toDouble()).toInt())
+            "rad" -> RuntimeValue(DataType.FLOAT, Math.toRadians(args[0].numericValue().toDouble()))
+            "deg" -> RuntimeValue(DataType.FLOAT, Math.toDegrees(args[0].numericValue().toDouble()))
+            "round" -> RuntimeValue(DataType.FLOAT, round(args[0].numericValue().toDouble()))
+            "floor" -> RuntimeValue(DataType.FLOAT, floor(args[0].numericValue().toDouble()))
+            "ceil" -> RuntimeValue(DataType.FLOAT, ceil(args[0].numericValue().toDouble()))
+            "rol" -> {
+                val (result, newCarry) = args[0].rol(statusflags.carry)
+                statusflags.carry = newCarry
+                return result
+            }
+            "rol2" -> args[0].rol2()
+            "ror" -> {
+                val (result, newCarry) = args[0].ror(statusflags.carry)
+                statusflags.carry = newCarry
+                return result
+            }
+            "ror2" -> args[0].ror2()
+            "lsl" -> args[0].shl()
+            "lsr" -> args[0].shr()
+            "abs" -> {
+                when (args[0].type) {
+                    DataType.UBYTE -> args[0]
+                    DataType.BYTE -> RuntimeValue(DataType.UBYTE, abs(args[0].numericValue().toDouble()))
+                    DataType.UWORD -> args[0]
+                    DataType.WORD -> RuntimeValue(DataType.UWORD, abs(args[0].numericValue().toDouble()))
+                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, abs(args[0].numericValue().toDouble()))
+                    else -> throw VmExecutionException("strange abs type ${args[0]}")
+                }
+            }
+            "max" -> {
+                val numbers = args.single().array!!.map { it.toDouble() }
+                RuntimeValue(ArrayElementTypes.getValue(args[0].type), numbers.max())
+            }
+            "min" -> {
+                val numbers = args.single().array!!.map { it.toDouble() }
+                RuntimeValue(ArrayElementTypes.getValue(args[0].type), numbers.min())
+            }
+            "sum" -> {
+                val sum = args.single().array!!.map { it.toDouble() }.sum()
+                when (args[0].type) {
+                    DataType.ARRAY_UB -> RuntimeValue(DataType.UWORD, sum)
+                    DataType.ARRAY_B -> RuntimeValue(DataType.WORD, sum)
+                    DataType.ARRAY_UW -> RuntimeValue(DataType.UWORD, sum)
+                    DataType.ARRAY_W -> RuntimeValue(DataType.WORD, sum)
+                    DataType.ARRAY_F -> RuntimeValue(DataType.FLOAT, sum)
+                    else -> throw VmExecutionException("weird sum type ${args[0]}")
+                }
+            }
+            "any" -> {
+                val numbers = args.single().array!!.map { it.toDouble() }
+                RuntimeValue(DataType.UBYTE, if (numbers.any { it != 0.0 }) 1 else 0)
+            }
+            "all" -> {
+                val numbers = args.single().array!!.map { it.toDouble() }
+                RuntimeValue(DataType.UBYTE, if (numbers.all { it != 0.0 }) 1 else 0)
+            }
+            "swap" ->
+                throw VmExecutionException("swap() cannot be implemented as a function")
+            "strlen" -> {
+                val zeroIndex = args[0].str!!.indexOf(0.toChar())
+                if (zeroIndex >= 0)
+                    RuntimeValue(DataType.UBYTE, zeroIndex)
+                else
+                    RuntimeValue(DataType.UBYTE, args[0].str!!.length)
+            }
+            "memset" -> {
+                val heapId = args[0].wordval!!
+                val target = program.heap.get(heapId).array ?: throw VmExecutionException("memset target is not an array")
+                val amount = args[1].integerValue()
+                val value = args[2].integerValue()
+                for (i in 0 until amount) {
+                    target[i] = IntegerOrAddressOf(value, null)
+                }
+                null
+            }
+            "memsetw" -> {
+                val heapId = args[0].wordval!!
+                val target = program.heap.get(heapId).array  ?: throw VmExecutionException("memset target is not an array")
+                val amount = args[1].integerValue()
+                val value = args[2].integerValue()
+                for (i in 0 until amount step 2) {
+                    target[i * 2] = IntegerOrAddressOf(value and 255, null)
+                    target[i * 2 + 1] = IntegerOrAddressOf(value ushr 8, null)
+                }
+                null
+            }
+            "memcopy" -> {
+                val sourceHeapId = args[0].wordval!!
+                val destHeapId = args[1].wordval!!
+                val source = program.heap.get(sourceHeapId).array!!
+                val dest = program.heap.get(destHeapId).array!!
+                val amount = args[2].integerValue()
+                for(i in 0 until amount) {
+                    dest[i] = source[i]
+                }
+                null
+            }
+            "mkword" -> {
+                val result = (args[1].integerValue() shl 8) or args[0].integerValue()
+                RuntimeValue(DataType.UWORD, result)
+            }
+            "set_carry" -> {
+                statusflags.carry=true
+                null
+            }
+            "clear_carry" -> {
+                statusflags.carry=false
+                null
+            }
+            "set_irqd" -> {
+                statusflags.irqd=true
+                null
+            }
+            "clear_irqd" -> {
+                statusflags.irqd=false
+                null
+            }
+            "read_flags" -> {
+                val carry = if(statusflags.carry) 1 else 0
+                val zero = if(statusflags.zero) 2 else 0
+                val irqd = if(statusflags.irqd) 4 else 0
+                val negative = if(statusflags.negative) 128 else 0
+                RuntimeValue(DataType.UBYTE, carry or zero or irqd or negative)
+            }
+            "rsave" -> {
+                statusFlagsSave.push(statusflags)
+                registerAsave.push(runtimeVariables.get(program.namespace, Register.A.name))
+                registerXsave.push(runtimeVariables.get(program.namespace, Register.X.name))
+                registerYsave.push(runtimeVariables.get(program.namespace, Register.Y.name))
+                null
+            }
+            "rrestore" -> {
+                val flags = statusFlagsSave.pop()
+                statusflags.carry = flags.carry
+                statusflags.negative = flags.negative
+                statusflags.zero = flags.zero
+                statusflags.irqd = flags.irqd
+                runtimeVariables.set(program.namespace, Register.A.name, registerAsave.pop())
+                runtimeVariables.set(program.namespace, Register.X.name, registerXsave.pop())
+                runtimeVariables.set(program.namespace, Register.Y.name, registerYsave.pop())
+                null
+            }
+            else -> TODO("builtin function $name")
+        }
+    }
+
+}

compiler/src/prog8/vm/astvm/BuiltinFunctions.kt

@@ -1,204 +0,0 @@
-package prog8.vm.astvm
-
-import prog8.ast.base.DataType
-import prog8.vm.RuntimeValue
-import java.lang.Math.toDegrees
-import java.lang.Math.toRadians
-import java.util.*
-import kotlin.math.*
-import kotlin.random.Random
-
-
-class BuiltinFunctions {
-
-    private val rnd = Random(0)
-    private val statusFlagsSave = Stack<StatusFlags>()
-
-
-    fun performBuiltinFunction(name: String, args: List<RuntimeValue>, statusflags: StatusFlags): RuntimeValue? {
-        return when (name) {
-            "rnd" -> RuntimeValue(DataType.UBYTE, rnd.nextInt() and 255)
-            "rndw" -> RuntimeValue(DataType.UWORD, rnd.nextInt() and 65535)
-            "rndf" -> RuntimeValue(DataType.FLOAT, rnd.nextDouble())
-            "lsb" -> RuntimeValue(DataType.UBYTE, args[0].integerValue() and 255)
-            "msb" -> RuntimeValue(DataType.UBYTE, (args[0].integerValue() ushr 8) and 255)
-            "sin" -> RuntimeValue(DataType.FLOAT, sin(args[0].numericValue().toDouble()))
-            "sin8" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (127.0 * sin(rad)).toShort())
-            }
-            "sin8u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toShort())
-            }
-            "sin16" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (32767.0 * sin(rad)).toShort())
-            }
-            "sin16u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (32768.0 + 32767.5 * sin(rad)).toShort())
-            }
-            "cos" -> RuntimeValue(DataType.FLOAT, cos(args[0].numericValue().toDouble()))
-            "cos8" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (127.0 * cos(rad)).toShort())
-            }
-            "cos8u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toShort())
-            }
-            "cos16" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (32767.0 * cos(rad)).toShort())
-            }
-            "cos16u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (32768.0 + 32767.5 * cos(rad)).toShort())
-            }
-            "tan" -> RuntimeValue(DataType.FLOAT, tan(args[0].numericValue().toDouble()))
-            "atan" -> RuntimeValue(DataType.FLOAT, atan(args[0].numericValue().toDouble()))
-            "ln" -> RuntimeValue(DataType.FLOAT, ln(args[0].numericValue().toDouble()))
-            "log2" -> RuntimeValue(DataType.FLOAT, log2(args[0].numericValue().toDouble()))
-            "sqrt" -> RuntimeValue(DataType.FLOAT, sqrt(args[0].numericValue().toDouble()))
-            "sqrt16" -> RuntimeValue(DataType.UBYTE, sqrt(args[0].wordval!!.toDouble()).toInt())
-            "rad" -> RuntimeValue(DataType.FLOAT, toRadians(args[0].numericValue().toDouble()))
-            "deg" -> RuntimeValue(DataType.FLOAT, toDegrees(args[0].numericValue().toDouble()))
-            "round" -> RuntimeValue(DataType.FLOAT, round(args[0].numericValue().toDouble()))
-            "floor" -> RuntimeValue(DataType.FLOAT, floor(args[0].numericValue().toDouble()))
-            "ceil" -> RuntimeValue(DataType.FLOAT, ceil(args[0].numericValue().toDouble()))
-            "rol" -> {
-                val (result, newCarry) = args[0].rol(statusflags.carry)
-                statusflags.carry = newCarry
-                return result
-            }
-            "rol2" -> args[0].rol2()
-            "ror" -> {
-                val (result, newCarry) = args[0].ror(statusflags.carry)
-                statusflags.carry = newCarry
-                return result
-            }
-            "ror2" -> args[0].ror2()
-            "lsl" -> args[0].shl()
-            "lsr" -> args[0].shr()
-            "abs" -> {
-                when (args[0].type) {
-                    DataType.UBYTE -> args[0]
-                    DataType.BYTE -> RuntimeValue(DataType.UBYTE, abs(args[0].numericValue().toDouble()))
-                    DataType.UWORD -> args[0]
-                    DataType.WORD -> RuntimeValue(DataType.UWORD, abs(args[0].numericValue().toDouble()))
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, abs(args[0].numericValue().toDouble()))
-                    else -> TODO("strange abs type")
-                }
-            }
-            "max" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(args[0].type, numbers.max())
-            }
-            "min" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(args[0].type, numbers.min())
-            }
-            "avg" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(DataType.FLOAT, numbers.average())
-            }
-            "sum" -> {
-                val sum = args.map { it.numericValue().toDouble() }.sum()
-                when (args[0].type) {
-                    DataType.UBYTE -> RuntimeValue(DataType.UWORD, sum)
-                    DataType.BYTE -> RuntimeValue(DataType.WORD, sum)
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, sum)
-                    DataType.WORD -> RuntimeValue(DataType.WORD, sum)
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, sum)
-                    else -> TODO("weird sum type")
-                }
-            }
-            "any" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(DataType.UBYTE, if (numbers.any { it != 0.0 }) 1 else 0)
-            }
-            "all" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(DataType.UBYTE, if (numbers.all { it != 0.0 }) 1 else 0)
-            }
-            "swap" ->
-                throw VmExecutionException("swap() cannot be implemented as a function")
-            "strlen" -> {
-                val zeroIndex = args[0].str!!.indexOf(0.toChar())
-                if (zeroIndex >= 0)
-                    RuntimeValue(DataType.UBYTE, zeroIndex)
-                else
-                    RuntimeValue(DataType.UBYTE, args[0].str!!.length)
-            }
-            "memset" -> {
-                val target = args[0].array!!
-                val amount = args[1].integerValue()
-                val value = args[2].integerValue()
-                for (i in 0 until amount) {
-                    target[i] = value
-                }
-                null
-            }
-            "memsetw" -> {
-                val target = args[0].array!!
-                val amount = args[1].integerValue()
-                val value = args[2].integerValue()
-                for (i in 0 until amount step 2) {
-                    target[i * 2] = value and 255
-                    target[i * 2 + 1] = value ushr 8
-                }
-                null
-            }
-            "memcopy" -> {
-                val source = args[0].array!!
-                val dest = args[1].array!!
-                val amount = args[2].integerValue()
-                for(i in 0 until amount) {
-                    dest[i] = source[i]
-                }
-                null
-            }
-            "mkword" -> {
-                val result = (args[1].integerValue() shl 8) or args[0].integerValue()
-                RuntimeValue(DataType.UWORD, result)
-            }
-            "set_carry" -> {
-                statusflags.carry=true
-                null
-            }
-            "clear_carry" -> {
-                statusflags.carry=false
-                null
-            }
-            "set_irqd" -> {
-                statusflags.irqd=true
-                null
-            }
-            "clear_irqd" -> {
-                statusflags.irqd=false
-                null
-            }
-            "read_flags" -> {
-                val carry = if(statusflags.carry) 1 else 0
-                val zero = if(statusflags.zero) 2 else 0
-                val irqd = if(statusflags.irqd) 4 else 0
-                val negative = if(statusflags.negative) 128 else 0
-                RuntimeValue(DataType.UBYTE, carry or zero or irqd or negative)
-            }
-            "rsave" -> {
-                statusFlagsSave.push(statusflags)
-                null
-            }
-            "rrestore" -> {
-                val flags = statusFlagsSave.pop()
-                statusflags.carry = flags.carry
-                statusflags.negative = flags.negative
-                statusflags.zero = flags.zero
-                statusflags.irqd = flags.irqd
-                null
-            }
-            else -> TODO("builtin function $name")
-        }
-    }
-}

compiler/src/prog8/vm/astvm/CallStack.kt

@@ -1,18 +0,0 @@
-package prog8.vm.astvm
-
-import prog8.ast.INameScope
-import java.util.*
-
-class CallStack {
-
-    private val stack = Stack<Pair<INameScope, Int>>()
-
-    fun pop(): Pair<INameScope, Int> {
-        return stack.pop()
-    }
-
-    fun push(scope: INameScope, index: Int) {
-        stack.push(Pair(scope, index))
-    }
-
-}

compiler/src/prog8/vm/astvm/Expressions.kt

@@ -1,8 +1,9 @@
 package prog8.vm.astvm
 
-import prog8.ast.*
+import prog8.ast.Program
 import prog8.ast.base.ArrayElementTypes
 import prog8.ast.base.DataType
+import prog8.ast.base.FatalAstException
 import prog8.ast.base.VarDeclType
 import prog8.ast.expressions.*
 import prog8.ast.statements.BuiltinFunctionStatementPlaceholder
@@ -11,21 +12,26 @@ import prog8.ast.statements.Subroutine
 import prog8.ast.statements.VarDecl
 import prog8.vm.RuntimeValue
 import prog8.vm.RuntimeValueRange
-import kotlin.math.abs
+
+
+typealias BuiltinfunctionCaller =  (name: String, args: List<RuntimeValue>, flags: StatusFlags) -> RuntimeValue?
+typealias SubroutineCaller =  (sub: Subroutine, args: List<RuntimeValue>, startAtLabel: Label?) -> RuntimeValue?
+
 
 class EvalContext(val program: Program, val mem: Memory, val statusflags: StatusFlags,
-                  val runtimeVars: RuntimeVariables, val functions: BuiltinFunctions,
-                  val executeSubroutine: (sub: Subroutine, args: List<RuntimeValue>, startlabel: Label?) -> List<RuntimeValue>)
+                  val runtimeVars: RuntimeVariables,
+                  val performBuiltinFunction: BuiltinfunctionCaller,
+                  val executeSubroutine: SubroutineCaller)
 
-fun evaluate(expr: IExpression, ctx: EvalContext): RuntimeValue {
+fun evaluate(expr: Expression, ctx: EvalContext): RuntimeValue {
     val constval = expr.constValue(ctx.program)
     if(constval!=null)
-        return RuntimeValue.from(constval, ctx.program.heap)
+        return RuntimeValue.fromLv(constval)
 
     when(expr) {
-        is LiteralValue -> {
-            return RuntimeValue.from(expr, ctx.program.heap)
-        }
+        is NumericLiteralValue -> return RuntimeValue.fromLv(expr)
+        is StringLiteralValue -> return RuntimeValue.fromLv(expr, ctx.program.heap)
+        is ArrayLiteralValue -> return RuntimeValue.fromLv(expr, ctx.program.heap)
         is PrefixExpression -> {
             return when(expr.operator) {
                 "-" -> evaluate(expr.expression, ctx).neg()
@@ -81,8 +87,14 @@ fun evaluate(expr: IExpression, ctx: EvalContext): RuntimeValue {
         }
         is AddressOf -> {
             // we support: address of heap var -> the heap id
-            val heapId = expr.identifier.heapId(ctx.program.namespace)
-            return RuntimeValue(DataType.UWORD, heapId)
+            return try {
+                val heapId = expr.identifier.heapId(ctx.program.namespace)
+                RuntimeValue(DataType.UWORD, heapId)
+            } catch( f: FatalAstException) {
+                // fallback: use the hash of the name, so we have at least *a* value...
+                val address = expr.identifier.hashCode() and 65535
+                RuntimeValue(DataType.UWORD, address)
+            }
         }
         is DirectMemoryRead -> {
             val address = evaluate(expr.addressExpression, ctx).wordval!!
@@ -93,19 +105,21 @@ fun evaluate(expr: IExpression, ctx: EvalContext): RuntimeValue {
             val scope = expr.definingScope()
             val variable = scope.lookup(expr.nameInSource, expr)
             if(variable is VarDecl) {
-                if(variable.type==VarDeclType.VAR)
-                    return ctx.runtimeVars.get(variable.definingScope(), variable.name)
-                else {
-                    val address = ctx.runtimeVars.getMemoryAddress(variable.definingScope(), variable.name)
-                    return when(variable.datatype) {
-                        DataType.UBYTE -> RuntimeValue(DataType.UBYTE, ctx.mem.getUByte(address))
-                        DataType.BYTE -> RuntimeValue(DataType.BYTE, ctx.mem.getSByte(address))
-                        DataType.UWORD -> RuntimeValue(DataType.UWORD, ctx.mem.getUWord(address))
-                        DataType.WORD -> RuntimeValue(DataType.WORD, ctx.mem.getSWord(address))
-                        DataType.FLOAT -> RuntimeValue(DataType.FLOAT, ctx.mem.getFloat(address))
-                        DataType.STR -> RuntimeValue(DataType.STR, str = ctx.mem.getString(address))
-                        DataType.STR_S -> RuntimeValue(DataType.STR_S, str = ctx.mem.getScreencodeString(address))
-                        else -> throw VmExecutionException("unexpected datatype $variable")
+                when {
+                    variable.type==VarDeclType.VAR -> return ctx.runtimeVars.get(variable.definingScope(), variable.name)
+                    variable.datatype==DataType.STRUCT -> throw VmExecutionException("cannot process structs by-value.  at ${expr.position}")
+                    else -> {
+                        val address = ctx.runtimeVars.getMemoryAddress(variable.definingScope(), variable.name)
+                        return when(variable.datatype) {
+                            DataType.UBYTE -> RuntimeValue(DataType.UBYTE, ctx.mem.getUByte(address))
+                            DataType.BYTE -> RuntimeValue(DataType.BYTE, ctx.mem.getSByte(address))
+                            DataType.UWORD -> RuntimeValue(DataType.UWORD, ctx.mem.getUWord(address))
+                            DataType.WORD -> RuntimeValue(DataType.WORD, ctx.mem.getSWord(address))
+                            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, ctx.mem.getFloat(address))
+                            DataType.STR -> RuntimeValue(DataType.STR, str = ctx.mem.getString(address))
+                            DataType.STR_S -> RuntimeValue(DataType.STR_S, str = ctx.mem.getScreencodeString(address))
+                            else -> throw VmExecutionException("unexpected datatype $variable")
+                        }
                     }
                 }
             } else
@@ -116,13 +130,12 @@ fun evaluate(expr: IExpression, ctx: EvalContext): RuntimeValue {
             val args = expr.arglist.map { evaluate(it, ctx) }
             return when(sub) {
                 is Subroutine -> {
-                    val results = ctx.executeSubroutine(sub, args, null)
-                    if(results.size!=1)
-                        throw VmExecutionException("expected 1 result from functioncall $expr")
-                    results[0]
+                    val result = ctx.executeSubroutine(sub, args, null)
+                            ?: throw VmExecutionException("expected a result from functioncall $expr")
+                    result
                 }
                 is BuiltinFunctionStatementPlaceholder -> {
-                    val result = ctx.functions.performBuiltinFunction(sub.name, args, ctx.statusflags)
+                    val result = ctx.performBuiltinFunction(sub.name, args, ctx.statusflags)
                             ?: throw VmExecutionException("expected 1 result from functioncall $expr")
                     result
                 }
@@ -133,24 +146,22 @@ fun evaluate(expr: IExpression, ctx: EvalContext): RuntimeValue {
         }
         is RangeExpr -> {
             val cRange = expr.toConstantIntegerRange()
-            if(cRange!=null)
-                return RuntimeValueRange(expr.inferType(ctx.program)!!, cRange)
+            if(cRange!=null) {
+                val dt = expr.inferType(ctx.program)
+                if(dt.isKnown)
+                    return RuntimeValueRange(dt.typeOrElse(DataType.UBYTE), cRange)
+                else
+                    throw VmExecutionException("couldn't determine datatype")
+            }
             val fromVal = evaluate(expr.from, ctx).integerValue()
             val toVal = evaluate(expr.to, ctx).integerValue()
             val stepVal = evaluate(expr.step, ctx).integerValue()
-            val range = when {
-                fromVal <= toVal -> when {
-                    stepVal <= 0 -> IntRange.EMPTY
-                    stepVal == 1 -> fromVal..toVal
-                    else -> fromVal..toVal step stepVal
-                }
-                else -> when {
-                    stepVal >= 0 -> IntRange.EMPTY
-                    stepVal == -1 -> fromVal downTo toVal
-                    else -> fromVal downTo toVal step abs(stepVal)
-                }
-            }
-            return RuntimeValueRange(expr.inferType(ctx.program)!!, range)
+            val range = makeRange(fromVal, toVal, stepVal)
+            val dt = expr.inferType(ctx.program)
+            if(dt.isKnown)
+                return RuntimeValueRange(dt.typeOrElse(DataType.UBYTE), range)
+            else
+                throw VmExecutionException("couldn't determine datatype")
         }
         else -> {
             throw VmExecutionException("unimplemented expression node $expr")

compiler/src/prog8/vm/astvm/Memory.kt

@@ -1,6 +1,6 @@
 package prog8.vm.astvm
 
-import prog8.compiler.target.c64.Mflpt5
+import prog8.compiler.target.c64.MachineDefinition
 import prog8.compiler.target.c64.Petscii
 import kotlin.math.abs
 
@@ -80,7 +80,7 @@ class Memory(private val readObserver: (address: Int, value: Short) -> Short,
     }
 
     fun setFloat(address: Int, value: Double) {
-        val mflpt5 = Mflpt5.fromNumber(value)
+        val mflpt5 = MachineDefinition.Mflpt5.fromNumber(value)
         setUByte(address, mflpt5.b0)
         setUByte(address+1, mflpt5.b1)
         setUByte(address+2, mflpt5.b2)
@@ -89,7 +89,7 @@ class Memory(private val readObserver: (address: Int, value: Short) -> Short,
     }
 
     fun getFloat(address: Int): Double {
-        return Mflpt5(getUByte(address), getUByte(address + 1), getUByte(address + 2),
+        return MachineDefinition.Mflpt5(getUByte(address), getUByte(address + 1), getUByte(address + 2),
                 getUByte(address + 3), getUByte(address + 4)).toDouble()
     }
 

compiler/src/prog8/vm/astvm/ScreenDialog.kt

@@ -1,12 +1,12 @@
 package prog8.vm.astvm
 
-import prog8.compiler.target.c64.Charset
-import prog8.compiler.target.c64.Colors
+import prog8.compiler.target.c64.MachineDefinition
 import prog8.compiler.target.c64.Petscii
 import java.awt.*
 import java.awt.event.KeyEvent
 import java.awt.event.KeyListener
 import java.awt.image.BufferedImage
+import java.util.*
 import javax.swing.JFrame
 import javax.swing.JPanel
 import javax.swing.Timer
@@ -18,6 +18,7 @@ class BitmapScreenPanel : KeyListener, JPanel() {
     private val g2d = image.graphics as Graphics2D
     private var cursorX: Int=0
     private var cursorY: Int=0
+    val keyboardBuffer: Deque<Char> = LinkedList()
 
     init {
         val size = Dimension(image.width * SCALING, image.height * SCALING)
@@ -30,14 +31,14 @@ class BitmapScreenPanel : KeyListener, JPanel() {
         addKeyListener(this)
     }
 
-    override fun keyTyped(p0: KeyEvent?) {}
+    override fun keyTyped(p0: KeyEvent) {
+        keyboardBuffer.add(p0.keyChar)
+    }
 
-    override fun keyPressed(p0: KeyEvent?) {
-        println("pressed: $p0.k")
+    override fun keyPressed(p0: KeyEvent) {
     }
 
     override fun keyReleased(p0: KeyEvent?) {
-        println("released: $p0")
     }
 
     override fun paint(graphics: Graphics?) {
@@ -49,61 +50,82 @@ class BitmapScreenPanel : KeyListener, JPanel() {
     }
 
     fun clearScreen(color: Short) {
-        g2d.background = Colors.palette[color % Colors.palette.size]
+        g2d.background = MachineDefinition.colorPalette[color % MachineDefinition.colorPalette.size]
         g2d.clearRect(0, 0, SCREENWIDTH, SCREENHEIGHT)
         cursorX = 0
         cursorY = 0
     }
     fun setPixel(x: Int, y: Int, color: Short) {
-        image.setRGB(x, y, Colors.palette[color % Colors.palette.size].rgb)
+        image.setRGB(x, y, MachineDefinition.colorPalette[color % MachineDefinition.colorPalette.size].rgb)
     }
     fun drawLine(x1: Int, y1: Int, x2: Int, y2: Int, color: Short) {
-        g2d.color = Colors.palette[color % Colors.palette.size]
+        g2d.color = MachineDefinition.colorPalette[color % MachineDefinition.colorPalette.size]
         g2d.drawLine(x1, y1, x2, y2)
     }
-    fun printText(text: String, color: Short, lowercase: Boolean) {
+
+    fun printText(text: String, lowercase: Boolean, inverseVideo: Boolean=false) {
         val t2 = text.substringBefore(0.toChar())
         val lines = t2.split('\n')
         for(line in lines.withIndex()) {
-            printTextSingleLine(line.value, color, lowercase)
+            val petscii = Petscii.encodePetscii(line.value, lowercase)
+            petscii.forEach { printPetscii(it, inverseVideo) }
             if(line.index<lines.size-1) {
-                cursorX=0
-                cursorY++
-            }
-        }
-    }
-    private fun printTextSingleLine(text: String, color: Short, lowercase: Boolean) {
-        for(clearx in cursorX until cursorX+text.length) {
-            g2d.clearRect(8*clearx, 8*y, 8, 8)
-        }
-        for(sc in Petscii.encodeScreencode(text, lowercase)) {
-            setChar(cursorX, cursorY, sc, color)
-            cursorX++
-            if(cursorX>=(SCREENWIDTH /8)) {
-                cursorY++
-                cursorX=0
+                printPetscii(13)    // newline
             }
         }
     }
 
-    fun printChar(char: Short) {
+    fun printPetscii(char: Short, inverseVideo: Boolean=false) {
         if(char==13.toShort() || char==141.toShort()) {
             cursorX=0
             cursorY++
         } else {
-            setChar(cursorX, cursorY, char, 1)
+            setPetscii(cursorX, cursorY, char, 1, inverseVideo)
             cursorX++
             if (cursorX >= (SCREENWIDTH / 8)) {
                 cursorY++
                 cursorX = 0
             }
         }
+        while(cursorY>=(SCREENHEIGHT/8)) {
+            // scroll the screen up because the cursor went past the last line
+            Thread.sleep(10)
+            val screen = image.copy()
+            val graphics = image.graphics as Graphics2D
+            graphics.drawImage(screen, 0, -8, null)
+            val color = graphics.color
+            graphics.color = MachineDefinition.colorPalette[6]
+            graphics.fillRect(0, 24*8, SCREENWIDTH, 25*8)
+            graphics.color=color
+            cursorY--
+        }
     }
 
-    fun setChar(x: Int, y: Int, screenCode: Short, color: Short) {
+    fun writeTextAt(x: Int, y: Int, text: String, color: Short, lowercase: Boolean, inverseVideo: Boolean=false) {
+        val colorIdx = (color % MachineDefinition.colorPalette.size).toShort()
+        var xx=x
+        for(clearx in xx until xx+text.length) {
+            g2d.clearRect(8*clearx, 8*y, 8, 8)
+        }
+        for(sc in Petscii.encodePetscii(text, lowercase)) {
+            if(sc==0.toShort())
+                break
+            setPetscii(xx++, y, sc, colorIdx, inverseVideo)
+        }
+    }
+
+    fun setPetscii(x: Int, y: Int, petscii: Short, color: Short, inverseVideo: Boolean) {
         g2d.clearRect(8*x, 8*y, 8, 8)
-        val colorIdx = (color % Colors.palette.size).toShort()
-        val coloredImage = Charset.getColoredChar(screenCode, colorIdx)
+        val colorIdx = (color % MachineDefinition.colorPalette.size).toShort()
+        val screencode = Petscii.petscii2scr(petscii, inverseVideo)
+        val coloredImage = MachineDefinition.Charset.getColoredChar(screencode, colorIdx)
+        g2d.drawImage(coloredImage, 8*x, 8*y , null)
+    }
+
+    fun setChar(x: Int, y: Int, screencode: Short, color: Short) {
+        g2d.clearRect(8*x, 8*y, 8, 8)
+        val colorIdx = (color % MachineDefinition.colorPalette.size).toShort()
+        val coloredImage = MachineDefinition.Charset.getColoredChar(screencode, colorIdx)
         g2d.drawImage(coloredImage, 8*x, 8*y , null)
     }
 
@@ -116,20 +138,6 @@ class BitmapScreenPanel : KeyListener, JPanel() {
         return Pair(cursorX, cursorY)
     }
 
-    fun writeText(x: Int, y: Int, text: String, color: Short, lowercase: Boolean) {
-        val colorIdx = (color % Colors.palette.size).toShort()
-        var xx=x
-        for(clearx in xx until xx+text.length) {
-            g2d.clearRect(8*clearx, 8*y, 8, 8)
-        }
-        for(sc in Petscii.encodeScreencode(text, lowercase)) {
-            if(sc==0.toShort())
-                break
-            setChar(xx++, y, sc, colorIdx)
-        }
-    }
-
-
     companion object {
         const val SCREENWIDTH = 320
         const val SCREENHEIGHT = 200
@@ -140,29 +148,30 @@ class BitmapScreenPanel : KeyListener, JPanel() {
 
 class ScreenDialog(title: String) : JFrame(title) {
     val canvas = BitmapScreenPanel()
+    val keyboardBuffer = canvas.keyboardBuffer
 
     init {
         val borderWidth = 16
         layout = GridBagLayout()
-        defaultCloseOperation = JFrame.EXIT_ON_CLOSE
+        defaultCloseOperation = EXIT_ON_CLOSE
         isResizable = false
 
         // the borders (top, left, right, bottom)
         val borderTop = JPanel().apply {
             preferredSize = Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH +2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
-            background = Colors.palette[14]
+            background = MachineDefinition.colorPalette[14]
         }
         val borderBottom = JPanel().apply {
             preferredSize =Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH +2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
-            background = Colors.palette[14]
+            background = MachineDefinition.colorPalette[14]
         }
         val borderLeft = JPanel().apply {
             preferredSize =Dimension(BitmapScreenPanel.SCALING * borderWidth, BitmapScreenPanel.SCALING * BitmapScreenPanel.SCREENHEIGHT)
-            background = Colors.palette[14]
+            background = MachineDefinition.colorPalette[14]
         }
         val borderRight = JPanel().apply {
             preferredSize =Dimension(BitmapScreenPanel.SCALING * borderWidth, BitmapScreenPanel.SCALING * BitmapScreenPanel.SCREENHEIGHT)
-            background = Colors.palette[14]
+            background = MachineDefinition.colorPalette[14]
         }
         var c = GridBagConstraints()
         c.gridx=0; c.gridy=1; c.gridwidth=3
@@ -189,3 +198,12 @@ class ScreenDialog(title: String) : JFrame(title) {
         repaintTimer.start()
     }
 }
+
+
+private fun BufferedImage.copy(): BufferedImage {
+    val bcopy = BufferedImage(this.width, this.height, this.type)
+    val g = bcopy.graphics
+    g.drawImage(this, 0, 0, null)
+    g.dispose()
+    return bcopy
+}

compiler/src/prog8/vm/astvm/VariablesCreator.kt

@@ -1,10 +1,18 @@
 package prog8.vm.astvm
 
-import prog8.ast.*
-import prog8.ast.base.*
-import prog8.ast.expressions.LiteralValue
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.Position
+import prog8.ast.base.Register
+import prog8.ast.base.VarDeclType
+import prog8.ast.expressions.ArrayLiteralValue
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.StringLiteralValue
 import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.statements.Statement
+import prog8.ast.statements.StructDecl
 import prog8.ast.statements.VarDecl
+import prog8.ast.statements.ZeropageWish
 import prog8.compiler.HeapValues
 import prog8.vm.RuntimeValue
 
@@ -17,9 +25,12 @@ class VariablesCreator(private val runtimeVariables: RuntimeVariables, private v
         runtimeVariables.define(program.namespace, Register.Y.name, RuntimeValue(DataType.UBYTE, 0))
 
         val globalpos = Position("<<global>>", 0, 0, 0)
-        val vdA = VarDecl(VarDeclType.VAR, DataType.UBYTE, false, null, Register.A.name, LiteralValue.optimalInteger(0, globalpos), isArray = false, autoGenerated = true, position = globalpos)
-        val vdX = VarDecl(VarDeclType.VAR, DataType.UBYTE, false, null, Register.X.name, LiteralValue.optimalInteger(255, globalpos), isArray = false, autoGenerated = true, position = globalpos)
-        val vdY = VarDecl(VarDeclType.VAR, DataType.UBYTE, false, null, Register.Y.name, LiteralValue.optimalInteger(0, globalpos), isArray = false, autoGenerated = true, position = globalpos)
+        val vdA = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.DONTCARE, null, Register.A.name, null,
+                NumericLiteralValue.optimalInteger(0, globalpos), isArray = false, autogeneratedDontRemove = true, position = globalpos)
+        val vdX = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.DONTCARE, null, Register.X.name, null,
+                NumericLiteralValue.optimalInteger(255, globalpos), isArray = false, autogeneratedDontRemove = true, position = globalpos)
+        val vdY = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.DONTCARE, null, Register.Y.name, null,
+                NumericLiteralValue.optimalInteger(0, globalpos), isArray = false, autogeneratedDontRemove = true, position = globalpos)
         vdA.linkParents(program.namespace)
         vdX.linkParents(program.namespace)
         vdY.linkParents(program.namespace)
@@ -30,24 +41,36 @@ class VariablesCreator(private val runtimeVariables: RuntimeVariables, private v
         super.visit(program)
     }
 
-    override fun visit(decl: VarDecl): IStatement {
-        when(decl.type) {
-            // we can assume the value in the vardecl already has been converted into a constant LiteralValue here.
-            VarDeclType.VAR -> {
-                val value = RuntimeValue.from(decl.value as LiteralValue, heap)
-                runtimeVariables.define(decl.definingScope(), decl.name, value)
-            }
-            VarDeclType.MEMORY -> {
-                runtimeVariables.defineMemory(decl.definingScope(), decl.name, (decl.value as LiteralValue).asIntegerValue!!)
-            }
-            VarDeclType.CONST -> {
-                // consts should have been const-folded away
+    override fun visit(decl: VarDecl): Statement {
+        // if the decl is part of a struct, just skip it
+        if(decl.parent !is StructDecl) {
+            when (decl.type) {
+                VarDeclType.VAR -> {
+                    if(decl.datatype!=DataType.STRUCT) {
+                        val numericLv = decl.value as? NumericLiteralValue
+                        val value = if(numericLv!=null) {
+                            RuntimeValue.fromLv(numericLv)
+                        } else {
+                            if(decl.value is StringLiteralValue)
+                                RuntimeValue.fromLv(decl.value as StringLiteralValue, heap)
+                            else
+                                RuntimeValue.fromLv(decl.value as ArrayLiteralValue, heap)
+                        }
+                        runtimeVariables.define(decl.definingScope(), decl.name, value)
+                    }
+                }
+                VarDeclType.MEMORY -> {
+                    runtimeVariables.defineMemory(decl.definingScope(), decl.name, (decl.value as NumericLiteralValue).number.toInt())
+                }
+                VarDeclType.CONST -> {
+                    // consts should have been const-folded away
+                }
             }
         }
         return super.visit(decl)
     }
 
-//    override fun accept(assignment: Assignment): IStatement {
+//    override fun accept(assignment: Assignment): Statement {
 //        if(assignment is VariableInitializationAssignment) {
 //            println("INIT VAR $assignment")
 //        }

compiler/test/LiteralValueTests.kt

@@ -3,24 +3,29 @@ package prog8tests
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
 import prog8.ast.base.DataType
-import prog8.ast.expressions.LiteralValue
 import prog8.ast.base.Position
-import kotlin.test.*
+import prog8.ast.expressions.ArrayLiteralValue
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.StringLiteralValue
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNotEquals
+import kotlin.test.assertTrue
 
 
-private fun sameValueAndType(lv1: LiteralValue, lv2: LiteralValue): Boolean {
+private fun sameValueAndType(lv1: NumericLiteralValue, lv2: NumericLiteralValue): Boolean {
     return lv1.type==lv2.type && lv1==lv2
 }
 
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
-class TestParserLiteralValue {
+class TestParserNumericLiteralValue {
 
     private val dummyPos = Position("test", 0, 0, 0)
 
     @Test
     fun testIdentity() {
-        val v = LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos)
+        val v = NumericLiteralValue(DataType.UWORD, 12345, dummyPos)
         assertEquals(v, v)
         assertFalse(v != v)
         assertTrue(v <= v)
@@ -28,104 +33,109 @@ class TestParserLiteralValue {
         assertFalse(v < v)
         assertFalse(v > v)
 
-        assertTrue(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos)))
+        assertTrue(sameValueAndType(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.UWORD, 12345, dummyPos)))
     }
 
     @Test
     fun testEqualsAndNotEquals() {
-        assertEquals(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UBYTE, 100, position = dummyPos))
-        assertEquals(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 100, position = dummyPos))
-        assertEquals(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos))
-        assertEquals(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos), LiteralValue(DataType.UBYTE, 254, position = dummyPos))
-        assertEquals(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos))
-        assertEquals(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 12345.0, position = dummyPos))
-        assertEquals(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos), LiteralValue(DataType.UBYTE, 100, position = dummyPos))
-        assertEquals(LiteralValue(DataType.FLOAT, floatvalue = 22239.0, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 22239, position = dummyPos))
-        assertEquals(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos))
+        assertEquals(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UBYTE, 100, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UWORD, 100, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.UWORD, 254, dummyPos), NumericLiteralValue(DataType.UBYTE, 254, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.UWORD, 12345, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.FLOAT, 12345.0, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos), NumericLiteralValue(DataType.UBYTE, 100, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.FLOAT, 22239.0, dummyPos), NumericLiteralValue(DataType.UWORD, 22239, dummyPos))
+        assertEquals(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos))
 
-        assertTrue(sameValueAndType(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UBYTE, 100, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 100, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos), LiteralValue(DataType.UBYTE, 254, position = dummyPos)))
-        assertTrue(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 12345.0, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos), LiteralValue(DataType.UBYTE, 100, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.FLOAT, floatvalue = 22239.0, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 22239, position = dummyPos)))
-        assertTrue(sameValueAndType(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos)))
+        assertTrue(sameValueAndType(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UBYTE, 100, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UWORD, 100, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UWORD, 254, dummyPos), NumericLiteralValue(DataType.UBYTE, 254, dummyPos)))
+        assertTrue(sameValueAndType(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.UWORD, 12345, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.FLOAT, 12345.0, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos), NumericLiteralValue(DataType.UBYTE, 100, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.FLOAT, 22239.0, dummyPos), NumericLiteralValue(DataType.UWORD, 22239, dummyPos)))
+        assertTrue(sameValueAndType(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos)))
 
-        assertNotEquals(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UBYTE, 101, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 101, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 101.0, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.UWORD, wordvalue = 245, position = dummyPos), LiteralValue(DataType.UBYTE, 246, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 12346, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 12346.0, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.UBYTE, 9, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 9, position = dummyPos))
-        assertNotEquals(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 9.0, position = dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UBYTE, 101, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UWORD, 101, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.FLOAT, 101.0, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.UWORD, 245, dummyPos), NumericLiteralValue(DataType.UBYTE, 246, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.UWORD, 12346, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.FLOAT, 12346.0, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.UBYTE, 9, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.UWORD, 9, dummyPos))
+        assertNotEquals(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.FLOAT, 9.0, dummyPos))
 
-        assertFalse(sameValueAndType(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UBYTE, 101, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 101, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UBYTE, 100, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 101.0, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 245, position = dummyPos), LiteralValue(DataType.UBYTE, 246, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 12346, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.UWORD, wordvalue = 12345, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 12346.0, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.UBYTE, 9, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.UWORD, wordvalue = 9, position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.FLOAT, floatvalue = 9.99, position = dummyPos), LiteralValue(DataType.FLOAT, floatvalue = 9.0, position = dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UBYTE, 101, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.UWORD, 101, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UBYTE, 100, dummyPos), NumericLiteralValue(DataType.FLOAT, 101.0, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UWORD, 245, dummyPos), NumericLiteralValue(DataType.UBYTE, 246, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.UWORD, 12346, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.UWORD, 12345, dummyPos), NumericLiteralValue(DataType.FLOAT, 12346.0, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.UBYTE, 9, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.UWORD, 9, dummyPos)))
+        assertFalse(sameValueAndType(NumericLiteralValue(DataType.FLOAT, 9.99, dummyPos), NumericLiteralValue(DataType.FLOAT, 9.0, dummyPos)))
 
-        assertTrue(sameValueAndType(LiteralValue(DataType.STR, strvalue = "hello", position = dummyPos), LiteralValue(DataType.STR, strvalue = "hello", position = dummyPos)))
-        assertFalse(sameValueAndType(LiteralValue(DataType.STR, strvalue = "hello", position = dummyPos), LiteralValue(DataType.STR, strvalue = "bye", position = dummyPos)))
 
-        val lvOne = LiteralValue(DataType.UBYTE, 1, position = dummyPos)
-        val lvTwo = LiteralValue(DataType.UBYTE, 2, position = dummyPos)
-        val lvThree = LiteralValue(DataType.UBYTE, 3, position = dummyPos)
-        val lvOneR = LiteralValue(DataType.UBYTE, 1, position = dummyPos)
-        val lvTwoR = LiteralValue(DataType.UBYTE, 2, position = dummyPos)
-        val lvThreeR = LiteralValue(DataType.UBYTE, 3, position = dummyPos)
-        val lvFour= LiteralValue(DataType.UBYTE, 4, position = dummyPos)
-        val lv1 = LiteralValue(DataType.ARRAY_UB, arrayvalue = arrayOf(lvOne, lvTwo, lvThree), position = dummyPos)
-        val lv2 = LiteralValue(DataType.ARRAY_UB, arrayvalue = arrayOf(lvOneR, lvTwoR, lvThreeR), position = dummyPos)
-        val lv3 = LiteralValue(DataType.ARRAY_UB, arrayvalue = arrayOf(lvOneR, lvTwoR, lvFour), position = dummyPos)
+    }
+
+    @Test
+    fun testEqualsRef() {
+        assertTrue(StringLiteralValue(DataType.STR, "hello", position = dummyPos) == StringLiteralValue(DataType.STR, "hello", position = dummyPos))
+        assertFalse(StringLiteralValue(DataType.STR, "hello", position = dummyPos) == StringLiteralValue(DataType.STR, "bye", position = dummyPos))
+
+        val lvOne = NumericLiteralValue(DataType.UBYTE, 1, dummyPos)
+        val lvTwo = NumericLiteralValue(DataType.UBYTE, 2, dummyPos)
+        val lvThree = NumericLiteralValue(DataType.UBYTE, 3, dummyPos)
+        val lvOneR = NumericLiteralValue(DataType.UBYTE, 1, dummyPos)
+        val lvTwoR = NumericLiteralValue(DataType.UBYTE, 2, dummyPos)
+        val lvThreeR = NumericLiteralValue(DataType.UBYTE, 3, dummyPos)
+        val lvFour= NumericLiteralValue(DataType.UBYTE, 4, dummyPos)
+        val lv1 = ArrayLiteralValue(DataType.ARRAY_UB, arrayOf(lvOne, lvTwo, lvThree), position = dummyPos)
+        val lv2 = ArrayLiteralValue(DataType.ARRAY_UB, arrayOf(lvOneR, lvTwoR, lvThreeR), position = dummyPos)
+        val lv3 = ArrayLiteralValue(DataType.ARRAY_UB, arrayOf(lvOneR, lvTwoR, lvFour), position = dummyPos)
         assertEquals(lv1, lv2)
         assertNotEquals(lv1, lv3)
     }
 
     @Test
     fun testGreaterThan(){
-        assertTrue(LiteralValue(DataType.UBYTE, 100, position = dummyPos) > LiteralValue(DataType.UBYTE, 99, position = dummyPos))
-        assertTrue(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) > LiteralValue(DataType.UWORD, wordvalue = 253, position = dummyPos))
-        assertTrue(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) > LiteralValue(DataType.FLOAT, floatvalue = 99.9, position = dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) > NumericLiteralValue(DataType.UBYTE, 99, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UWORD, 254, dummyPos) > NumericLiteralValue(DataType.UWORD, 253, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) > NumericLiteralValue(DataType.FLOAT, 99.9, dummyPos))
 
-        assertTrue(LiteralValue(DataType.UBYTE, 100, position = dummyPos) >= LiteralValue(DataType.UBYTE, 100, position = dummyPos))
-        assertTrue(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) >= LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos))
-        assertTrue(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) >= LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) >= NumericLiteralValue(DataType.UBYTE, 100, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UWORD, 254, dummyPos) >= NumericLiteralValue(DataType.UWORD, 254, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) >= NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos))
 
-        assertFalse(LiteralValue(DataType.UBYTE, 100, position = dummyPos) > LiteralValue(DataType.UBYTE, 100, position = dummyPos))
-        assertFalse(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) > LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos))
-        assertFalse(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) > LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) > NumericLiteralValue(DataType.UBYTE, 100, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UWORD, 254, dummyPos) > NumericLiteralValue(DataType.UWORD, 254, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) > NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos))
 
-        assertFalse(LiteralValue(DataType.UBYTE, 100, position = dummyPos) >= LiteralValue(DataType.UBYTE, 101, position = dummyPos))
-        assertFalse(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) >= LiteralValue(DataType.UWORD, wordvalue = 255, position = dummyPos))
-        assertFalse(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) >= LiteralValue(DataType.FLOAT, floatvalue = 100.1, position = dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) >= NumericLiteralValue(DataType.UBYTE, 101, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UWORD, 254, dummyPos) >= NumericLiteralValue(DataType.UWORD, 255, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) >= NumericLiteralValue(DataType.FLOAT, 100.1, dummyPos))
     }
 
     @Test
     fun testLessThan() {
-        assertTrue(LiteralValue(DataType.UBYTE, 100, position = dummyPos) < LiteralValue(DataType.UBYTE, 101, position = dummyPos))
-        assertTrue(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) < LiteralValue(DataType.UWORD, wordvalue = 255, position = dummyPos))
-        assertTrue(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) < LiteralValue(DataType.FLOAT, floatvalue = 100.1, position = dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) < NumericLiteralValue(DataType.UBYTE, 101, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UWORD, 254, dummyPos) < NumericLiteralValue(DataType.UWORD, 255, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) < NumericLiteralValue(DataType.FLOAT, 100.1, dummyPos))
 
-        assertTrue(LiteralValue(DataType.UBYTE, 100, position = dummyPos) <= LiteralValue(DataType.UBYTE, 100, position = dummyPos))
-        assertTrue(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) <= LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos))
-        assertTrue(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) <= LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) <= NumericLiteralValue(DataType.UBYTE, 100, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.UWORD, 254, dummyPos) <= NumericLiteralValue(DataType.UWORD, 254, dummyPos))
+        assertTrue(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) <= NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos))
 
-        assertFalse(LiteralValue(DataType.UBYTE, 100, position = dummyPos) < LiteralValue(DataType.UBYTE, 100, position = dummyPos))
-        assertFalse(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) < LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos))
-        assertFalse(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) < LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) < NumericLiteralValue(DataType.UBYTE, 100, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UWORD, 254, dummyPos) < NumericLiteralValue(DataType.UWORD, 254, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) < NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos))
 
-        assertFalse(LiteralValue(DataType.UBYTE, 100, position = dummyPos) <= LiteralValue(DataType.UBYTE, 99, position = dummyPos))
-        assertFalse(LiteralValue(DataType.UWORD, wordvalue = 254, position = dummyPos) <= LiteralValue(DataType.UWORD, wordvalue = 253, position = dummyPos))
-        assertFalse(LiteralValue(DataType.FLOAT, floatvalue = 100.0, position = dummyPos) <= LiteralValue(DataType.FLOAT, floatvalue = 99.9, position = dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UBYTE, 100, dummyPos) <= NumericLiteralValue(DataType.UBYTE, 99, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.UWORD, 254, dummyPos) <= NumericLiteralValue(DataType.UWORD, 253, dummyPos))
+        assertFalse(NumericLiteralValue(DataType.FLOAT, 100.0, dummyPos) <= NumericLiteralValue(DataType.FLOAT, 99.9, dummyPos))
     }
 
 }

compiler/test/RuntimeValueTests.kt

@@ -17,39 +17,27 @@ class TestRuntimeValue {
 
     @Test
     fun testValueRanges() {
-        assertEquals(100, RuntimeValue(DataType.UBYTE, 100).integerValue())
-        assertEquals(100, RuntimeValue(DataType.BYTE, 100).integerValue())
-        assertEquals(10000, RuntimeValue(DataType.UWORD, 10000).integerValue())
-        assertEquals(10000, RuntimeValue(DataType.WORD, 10000).integerValue())
-        assertEquals(100.11, RuntimeValue(DataType.FLOAT, 100.11).numericValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 0).integerValue())
+        assertEquals(255, RuntimeValue(DataType.UBYTE, 255).integerValue())
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.UBYTE, -1)}
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.UBYTE, 256)}
 
-        assertEquals(200, RuntimeValue(DataType.UBYTE, 200).integerValue())
-        assertEquals(-56, RuntimeValue(DataType.BYTE, 200).integerValue())
-        assertEquals(50000, RuntimeValue(DataType.UWORD, 50000).integerValue())
-        assertEquals(-15536, RuntimeValue(DataType.WORD, 50000).integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, 0).integerValue())
+        assertEquals(-128, RuntimeValue(DataType.BYTE, -128).integerValue())
+        assertEquals(127, RuntimeValue(DataType.BYTE, 127).integerValue())
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.BYTE, -129)}
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.BYTE, 128)}
 
-        assertEquals(44, RuntimeValue(DataType.UBYTE, 300).integerValue())
-        assertEquals(44, RuntimeValue(DataType.BYTE, 300).integerValue())
-        assertEquals(144, RuntimeValue(DataType.UBYTE, 400).integerValue())
-        assertEquals(-112, RuntimeValue(DataType.BYTE, 400).integerValue())
-        assertEquals(34463, RuntimeValue(DataType.UWORD, 99999).integerValue())
-        assertEquals(-31073, RuntimeValue(DataType.WORD, 99999).integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 0).integerValue())
+        assertEquals(65535, RuntimeValue(DataType.UWORD, 65535).integerValue())
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.UWORD, -1)}
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.UWORD, 65536)}
 
-        assertEquals(156, RuntimeValue(DataType.UBYTE, -100).integerValue())
-        assertEquals(-100, RuntimeValue(DataType.BYTE, -100).integerValue())
-        assertEquals(55536, RuntimeValue(DataType.UWORD, -10000).integerValue())
-        assertEquals(-10000, RuntimeValue(DataType.WORD, -10000).integerValue())
-        assertEquals(-100.11, RuntimeValue(DataType.FLOAT, -100.11).numericValue())
-
-        assertEquals(56, RuntimeValue(DataType.UBYTE, -200).integerValue())
-        assertEquals(56, RuntimeValue(DataType.BYTE, -200).integerValue())
-        assertEquals(45536, RuntimeValue(DataType.UWORD, -20000).integerValue())
-        assertEquals(-20000, RuntimeValue(DataType.WORD, -20000).integerValue())
-
-        assertEquals(212, RuntimeValue(DataType.UBYTE, -300).integerValue())
-        assertEquals(-44, RuntimeValue(DataType.BYTE, -300).integerValue())
-        assertEquals(42184, RuntimeValue(DataType.UWORD, -88888).integerValue())
-        assertEquals(-23352, RuntimeValue(DataType.WORD, -88888).integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, 0).integerValue())
+        assertEquals(-32768, RuntimeValue(DataType.WORD, -32768).integerValue())
+        assertEquals(32767, RuntimeValue(DataType.WORD, 32767).integerValue())
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.WORD, -32769)}
+        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.WORD, 32768)}
     }
 
     @Test
@@ -60,10 +48,6 @@ class TestRuntimeValue {
         assertFalse(RuntimeValue(DataType.WORD, 0).asBoolean)
         assertFalse(RuntimeValue(DataType.UWORD, 0).asBoolean)
         assertFalse(RuntimeValue(DataType.FLOAT, 0.0).asBoolean)
-        assertFalse(RuntimeValue(DataType.BYTE, 256).asBoolean)
-        assertFalse(RuntimeValue(DataType.UBYTE, 256).asBoolean)
-        assertFalse(RuntimeValue(DataType.WORD, 65536).asBoolean)
-        assertFalse(RuntimeValue(DataType.UWORD, 65536).asBoolean)
 
         assertTrue(RuntimeValue(DataType.BYTE, 42).asBoolean)
         assertTrue(RuntimeValue(DataType.UBYTE, 42).asBoolean)
@@ -71,9 +55,7 @@ class TestRuntimeValue {
         assertTrue(RuntimeValue(DataType.UWORD, 42).asBoolean)
         assertTrue(RuntimeValue(DataType.FLOAT, 42.0).asBoolean)
         assertTrue(RuntimeValue(DataType.BYTE, -42).asBoolean)
-        assertTrue(RuntimeValue(DataType.UBYTE, -42).asBoolean)
         assertTrue(RuntimeValue(DataType.WORD, -42).asBoolean)
-        assertTrue(RuntimeValue(DataType.UWORD, -42).asBoolean)
         assertTrue(RuntimeValue(DataType.FLOAT, -42.0).asBoolean)
     }
 
@@ -134,18 +116,6 @@ class TestRuntimeValue {
         assertFalse(sameValueAndType(RuntimeValue(DataType.FLOAT, 9.99), RuntimeValue(DataType.FLOAT, 9.0)))
     }
 
-    @Test
-    fun testRequireHeap()
-    {
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.STR, num = 999) }
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.STR_S, num = 999) }
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.ARRAY_F, num = 999) }
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.ARRAY_W, num = 999) }
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.ARRAY_UW, num = 999) }
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.ARRAY_B, num = 999) }
-        assertFailsWith<IllegalArgumentException> { RuntimeValue(DataType.ARRAY_UB, num = 999) }
-    }
-
     @Test
     fun testEqualityHeapTypes()
     {
@@ -245,4 +215,155 @@ class TestRuntimeValue {
         }
         val result = RuntimeValue(DataType.FLOAT, 233.333).add(RuntimeValue(DataType.FLOAT, 1.234))
     }
+
+    @Test
+    fun arithmetictestUbyte() {
+        assertEquals(255, RuntimeValue(DataType.UBYTE, 200).add(RuntimeValue(DataType.UBYTE, 55)).integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 200).add(RuntimeValue(DataType.UBYTE, 56)).integerValue())
+        assertEquals(1, RuntimeValue(DataType.UBYTE, 200).add(RuntimeValue(DataType.UBYTE, 57)).integerValue())
+
+        assertEquals(1, RuntimeValue(DataType.UBYTE, 2).sub(RuntimeValue(DataType.UBYTE, 1)).integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 2).sub(RuntimeValue(DataType.UBYTE, 2)).integerValue())
+        assertEquals(255, RuntimeValue(DataType.UBYTE, 2).sub(RuntimeValue(DataType.UBYTE, 3)).integerValue())
+
+        assertEquals(255, RuntimeValue(DataType.UBYTE, 254).inc().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 255).inc().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 1).dec().integerValue())
+        assertEquals(255, RuntimeValue(DataType.UBYTE, 0).dec().integerValue())
+
+        assertEquals(255, RuntimeValue(DataType.UBYTE, 0).inv().integerValue())
+        assertEquals(0b00110011, RuntimeValue(DataType.UBYTE, 0b11001100).inv().integerValue())
+//        assertEquals(0, RuntimeValue(DataType.UBYTE, 0).neg().integerValue())
+//        assertEquals(0, RuntimeValue(DataType.UBYTE, 0).neg().integerValue())
+        assertEquals(1, RuntimeValue(DataType.UBYTE, 0).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 1).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 111).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UBYTE, 255).not().integerValue())
+
+        assertEquals(200, RuntimeValue(DataType.UBYTE, 20).mul(RuntimeValue(DataType.UBYTE, 10)).integerValue())
+        assertEquals(144, RuntimeValue(DataType.UBYTE, 20).mul(RuntimeValue(DataType.UBYTE, 20)).integerValue())
+
+        assertEquals(25, RuntimeValue(DataType.UBYTE, 5).pow(RuntimeValue(DataType.UBYTE, 2)).integerValue())
+        assertEquals(125, RuntimeValue(DataType.UBYTE, 5).pow(RuntimeValue(DataType.UBYTE, 3)).integerValue())
+        assertEquals(113, RuntimeValue(DataType.UBYTE, 5).pow(RuntimeValue(DataType.UBYTE, 4)).integerValue())
+
+        assertEquals(100, RuntimeValue(DataType.UBYTE, 50).shl().integerValue())
+        assertEquals(200, RuntimeValue(DataType.UBYTE, 100).shl().integerValue())
+        assertEquals(144, RuntimeValue(DataType.UBYTE, 200).shl().integerValue())
+    }
+
+    @Test
+    fun arithmetictestUWord() {
+        assertEquals(65535, RuntimeValue(DataType.UWORD, 60000).add(RuntimeValue(DataType.UWORD, 5535)).integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 60000).add(RuntimeValue(DataType.UWORD, 5536)).integerValue())
+        assertEquals(1, RuntimeValue(DataType.UWORD, 60000).add(RuntimeValue(DataType.UWORD, 5537)).integerValue())
+
+        assertEquals(1, RuntimeValue(DataType.UWORD, 2).sub(RuntimeValue(DataType.UWORD, 1)).integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 2).sub(RuntimeValue(DataType.UWORD, 2)).integerValue())
+        assertEquals(65535, RuntimeValue(DataType.UWORD, 2).sub(RuntimeValue(DataType.UWORD, 3)).integerValue())
+
+        assertEquals(65535, RuntimeValue(DataType.UWORD, 65534).inc().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 65535).inc().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 1).dec().integerValue())
+        assertEquals(65535, RuntimeValue(DataType.UWORD, 0).dec().integerValue())
+
+        assertEquals(65535, RuntimeValue(DataType.UWORD, 0).inv().integerValue())
+        assertEquals(0b0011001101010101, RuntimeValue(DataType.UWORD, 0b1100110010101010).inv().integerValue())
+//        assertEquals(0, RuntimeValue(DataType.UWORD, 0).neg().integerValue())
+//        assertEquals(0, RuntimeValue(DataType.UWORD, 0).neg().integerValue())
+        assertEquals(1, RuntimeValue(DataType.UWORD, 0).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 1).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 11111).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.UWORD, 65535).not().integerValue())
+
+        assertEquals(2000, RuntimeValue(DataType.UWORD, 200).mul(RuntimeValue(DataType.UWORD, 10)).integerValue())
+        assertEquals(40000, RuntimeValue(DataType.UWORD, 200).mul(RuntimeValue(DataType.UWORD, 200)).integerValue())
+        assertEquals(14464, RuntimeValue(DataType.UWORD, 200).mul(RuntimeValue(DataType.UWORD, 400)).integerValue())
+
+        assertEquals(15625, RuntimeValue(DataType.UWORD, 5).pow(RuntimeValue(DataType.UWORD, 6)).integerValue())
+        assertEquals(12589, RuntimeValue(DataType.UWORD, 5).pow(RuntimeValue(DataType.UWORD, 7)).integerValue())
+
+        assertEquals(10000, RuntimeValue(DataType.UWORD, 5000).shl().integerValue())
+        assertEquals(60000, RuntimeValue(DataType.UWORD, 30000).shl().integerValue())
+        assertEquals(14464, RuntimeValue(DataType.UWORD, 40000).shl().integerValue())
+    }
+
+    @Test
+    fun arithmetictestByte() {
+        assertEquals(127, RuntimeValue(DataType.BYTE, 100).add(RuntimeValue(DataType.BYTE, 27)).integerValue())
+        assertEquals(-128, RuntimeValue(DataType.BYTE, 100).add(RuntimeValue(DataType.BYTE, 28)).integerValue())
+        assertEquals(-127, RuntimeValue(DataType.BYTE, 100).add(RuntimeValue(DataType.BYTE, 29)).integerValue())
+
+        assertEquals(1, RuntimeValue(DataType.BYTE, 2).sub(RuntimeValue(DataType.BYTE, 1)).integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, 2).sub(RuntimeValue(DataType.BYTE, 2)).integerValue())
+        assertEquals(-1, RuntimeValue(DataType.BYTE, 2).sub(RuntimeValue(DataType.BYTE, 3)).integerValue())
+        assertEquals(-128, RuntimeValue(DataType.BYTE, -100).sub(RuntimeValue(DataType.BYTE, 28)).integerValue())
+        assertEquals(127, RuntimeValue(DataType.BYTE, -100).sub(RuntimeValue(DataType.BYTE, 29)).integerValue())
+
+        assertEquals(127, RuntimeValue(DataType.BYTE, 126).inc().integerValue())
+        assertEquals(-128, RuntimeValue(DataType.BYTE, 127).inc().integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, 1).dec().integerValue())
+        assertEquals(-1, RuntimeValue(DataType.BYTE, 0).dec().integerValue())
+        assertEquals(-128, RuntimeValue(DataType.BYTE, -127).dec().integerValue())
+        assertEquals(127, RuntimeValue(DataType.BYTE, -128).dec().integerValue())
+
+        assertEquals(-1, RuntimeValue(DataType.BYTE, 0).inv().integerValue())
+        assertEquals(-103, RuntimeValue(DataType.BYTE, 0b01100110).inv().integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, 0).neg().integerValue())
+        assertEquals(-2, RuntimeValue(DataType.BYTE, 2).neg().integerValue())
+        assertEquals(1, RuntimeValue(DataType.BYTE, 0).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, 1).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, 111).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.BYTE, -33).not().integerValue())
+
+        assertEquals(100, RuntimeValue(DataType.BYTE, 10).mul(RuntimeValue(DataType.BYTE, 10)).integerValue())
+        assertEquals(-56, RuntimeValue(DataType.BYTE, 20).mul(RuntimeValue(DataType.BYTE, 10)).integerValue())
+
+        assertEquals(25, RuntimeValue(DataType.BYTE, 5).pow(RuntimeValue(DataType.BYTE, 2)).integerValue())
+        assertEquals(125, RuntimeValue(DataType.BYTE, 5).pow(RuntimeValue(DataType.BYTE, 3)).integerValue())
+        assertEquals(113, RuntimeValue(DataType.BYTE, 5).pow(RuntimeValue(DataType.BYTE, 4)).integerValue())
+
+        assertEquals(100, RuntimeValue(DataType.BYTE, 50).shl().integerValue())
+        assertEquals(-56, RuntimeValue(DataType.BYTE, 100).shl().integerValue())
+        assertEquals(-2, RuntimeValue(DataType.BYTE, -1).shl().integerValue())
+    }
+
+    @Test
+    fun arithmetictestWorrd() {
+        assertEquals(32767, RuntimeValue(DataType.WORD, 32700).add(RuntimeValue(DataType.WORD, 67)).integerValue())
+        assertEquals(-32768, RuntimeValue(DataType.WORD, 32700).add(RuntimeValue(DataType.WORD, 68)).integerValue())
+        assertEquals(-32767, RuntimeValue(DataType.WORD, 32700).add(RuntimeValue(DataType.WORD, 69)).integerValue())
+
+        assertEquals(1, RuntimeValue(DataType.WORD, 2).sub(RuntimeValue(DataType.WORD, 1)).integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, 2).sub(RuntimeValue(DataType.WORD, 2)).integerValue())
+        assertEquals(-1, RuntimeValue(DataType.WORD, 2).sub(RuntimeValue(DataType.WORD, 3)).integerValue())
+        assertEquals(-32768, RuntimeValue(DataType.WORD, -32700).sub(RuntimeValue(DataType.WORD, 68)).integerValue())
+        assertEquals(32767, RuntimeValue(DataType.WORD, -32700).sub(RuntimeValue(DataType.WORD, 69)).integerValue())
+
+        assertEquals(32767, RuntimeValue(DataType.WORD, 32766).inc().integerValue())
+        assertEquals(-32768, RuntimeValue(DataType.WORD, 32767).inc().integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, 1).dec().integerValue())
+        assertEquals(-1, RuntimeValue(DataType.WORD, 0).dec().integerValue())
+        assertEquals(-32768, RuntimeValue(DataType.WORD, -32767).dec().integerValue())
+        assertEquals(32767, RuntimeValue(DataType.WORD, -32768).dec().integerValue())
+
+        assertEquals(-1, RuntimeValue(DataType.WORD, 0).inv().integerValue())
+        assertEquals(-103, RuntimeValue(DataType.WORD, 0b01100110).inv().integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, 0).neg().integerValue())
+        assertEquals(-2, RuntimeValue(DataType.WORD, 2).neg().integerValue())
+        assertEquals(1, RuntimeValue(DataType.WORD, 0).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, 1).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, 111).not().integerValue())
+        assertEquals(0, RuntimeValue(DataType.WORD, -33).not().integerValue())
+
+        assertEquals(10000, RuntimeValue(DataType.WORD, 100).mul(RuntimeValue(DataType.WORD, 100)).integerValue())
+        assertEquals(-25536, RuntimeValue(DataType.WORD, 200).mul(RuntimeValue(DataType.WORD, 200)).integerValue())
+
+        assertEquals(15625, RuntimeValue(DataType.WORD, 5).pow(RuntimeValue(DataType.WORD, 6)).integerValue())
+        assertEquals(-6487, RuntimeValue(DataType.WORD, 9).pow(RuntimeValue(DataType.WORD, 5)).integerValue())
+
+        assertEquals(18000, RuntimeValue(DataType.WORD, 9000).shl().integerValue())
+        assertEquals(-25536, RuntimeValue(DataType.WORD, 20000).shl().integerValue())
+        assertEquals(-2, RuntimeValue(DataType.WORD, -1).shl().integerValue())
+    }
 }

compiler/test/UnitTests.kt

@@ -7,10 +7,15 @@ import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
 import prog8.ast.base.DataType
 import prog8.ast.base.Position
-import prog8.ast.expressions.LiteralValue
-import prog8.vm.RuntimeValue
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.StringLiteralValue
 import prog8.compiler.*
-import prog8.compiler.target.c64.*
+import prog8.compiler.target.c64.MachineDefinition.C64Zeropage
+import prog8.compiler.target.c64.MachineDefinition.FLOAT_MAX_NEGATIVE
+import prog8.compiler.target.c64.MachineDefinition.FLOAT_MAX_POSITIVE
+import prog8.compiler.target.c64.MachineDefinition.Mflpt5
+import prog8.compiler.target.c64.Petscii
+import prog8.vm.RuntimeValue
 import java.io.CharConversionException
 import kotlin.test.*
 
@@ -140,8 +145,12 @@ class TestZeropage {
         assertFailsWith<CompilerException> {
             zp.allocate("", DataType.FLOAT, null)
         }
-        val zp2 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.FLOATSAFE, emptyList(), true))
-        zp2.allocate("", DataType.FLOAT, null)
+        val zp2 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.DONTUSE, emptyList(), true))
+        assertFailsWith<CompilerException> {
+            zp2.allocate("", DataType.FLOAT, null)
+        }
+        val zp3 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.FLOATSAFE, emptyList(), true))
+        zp3.allocate("", DataType.FLOAT, null)
     }
 
     @Test
@@ -160,14 +169,24 @@ class TestZeropage {
         }
     }
 
+    @Test
+    fun testZpDontuse() {
+        val zp = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.DONTUSE, emptyList(), false))
+        println(zp.free)
+        assertEquals(0, zp.available())
+        assertFailsWith<CompilerException> {
+            zp.allocate("", DataType.BYTE, null)
+        }
+    }
+
     @Test
     fun testFreeSpaces() {
         val zp1 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.BASICSAFE, emptyList(), true))
-        assertEquals(20, zp1.available())
+        assertEquals(16, zp1.available())
         val zp2 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.FLOATSAFE, emptyList(), false))
-        assertEquals(95, zp2.available())
+        assertEquals(91, zp2.available())
         val zp3 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.KERNALSAFE, emptyList(), false))
-        assertEquals(129, zp3.available())
+        assertEquals(125, zp3.available())
         val zp4 = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.FULL, emptyList(), false))
         assertEquals(238, zp4.available())
     }
@@ -197,11 +216,10 @@ class TestZeropage {
     @Test
     fun testBasicsafeAllocation() {
         val zp = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.BASICSAFE, emptyList(), true))
-        assertEquals(20, zp.available())
+        assertEquals(16, zp.available())
 
-        zp.allocate("", DataType.FLOAT, null)
         assertFailsWith<ZeropageDepletedError> {
-            // in regular zp there aren't 5 sequential bytes free after we take the first sequence
+            // in regular zp there aren't 5 sequential bytes free
             zp.allocate("", DataType.FLOAT, null)
         }
 
@@ -251,16 +269,16 @@ class TestZeropage {
     @Test
     fun testEfficientAllocation() {
         val zp = C64Zeropage(CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.BASICSAFE, emptyList(),  true))
-        assertEquals(20, zp.available())
-        assertEquals(0x04, zp.allocate("", DataType.FLOAT, null))
-        assertEquals(0x09, zp.allocate("", DataType.UBYTE, null))
-        assertEquals(0x0d, zp.allocate("", DataType.UWORD, null))
+        assertEquals(16, zp.available())
+        assertEquals(0x04, zp.allocate("", DataType.WORD, null))
+        assertEquals(0x06, zp.allocate("", DataType.UBYTE, null))
+        assertEquals(0x0a, zp.allocate("", DataType.UBYTE, null))
         assertEquals(0x94, zp.allocate("", DataType.UWORD, null))
         assertEquals(0xa7, zp.allocate("", DataType.UWORD, null))
         assertEquals(0xa9, zp.allocate("", DataType.UWORD, null))
         assertEquals(0xb5, zp.allocate("", DataType.UWORD, null))
         assertEquals(0xf7, zp.allocate("", DataType.UWORD, null))
-        assertEquals(0x0a, zp.allocate("", DataType.UBYTE, null))
+        assertEquals(0x0e, zp.allocate("", DataType.UBYTE, null))
         assertEquals(0xf9, zp.allocate("", DataType.UBYTE, null))
         assertEquals(0, zp.available())
     }
@@ -336,8 +354,8 @@ class TestPetscii {
 
     @Test
     fun testLiteralValueComparisons() {
-        val ten = LiteralValue(DataType.UWORD, wordvalue = 10, position = Position("", 0, 0, 0))
-        val nine = LiteralValue(DataType.UBYTE, bytevalue = 9, position = Position("", 0, 0, 0))
+        val ten = NumericLiteralValue(DataType.UWORD, 10, Position("", 0, 0, 0))
+        val nine = NumericLiteralValue(DataType.UBYTE, 9, Position("", 0, 0, 0))
         assertEquals(ten, ten)
         assertNotEquals(ten, nine)
         assertFalse(ten != ten)
@@ -353,17 +371,11 @@ class TestPetscii {
         assertTrue(ten <= ten)
         assertFalse(ten < ten)
 
-        val abc = LiteralValue(DataType.STR, strvalue = "abc", position = Position("", 0, 0, 0))
-        val abd = LiteralValue(DataType.STR, strvalue = "abd", position = Position("", 0, 0, 0))
+        val abc = StringLiteralValue(DataType.STR, "abc", position = Position("", 0, 0, 0))
+        val abd = StringLiteralValue(DataType.STR, "abd", position = Position("", 0, 0, 0))
         assertEquals(abc, abc)
         assertTrue(abc!=abd)
         assertFalse(abc!=abc)
-        assertTrue(abc < abd)
-        assertTrue(abc <= abd)
-        assertFalse(abd <= abc)
-        assertTrue(abd >= abc)
-        assertTrue(abd > abc)
-        assertFalse(abc > abd)
     }
 
     @Test

docs/docs.iml

@@ -2,7 +2,9 @@
 <module type="PYTHON_MODULE" version="4">
   <component name="NewModuleRootManager" inherit-compiler-output="true">
     <exclude-output />
-    <content url="file://$MODULE_DIR$" />
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/build" />
+    </content>
     <orderEntry type="jdk" jdkName="Python 3.7 (py3)" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>

docs/source/building.rst

@@ -2,6 +2,8 @@
 Writing and building a program
 ==============================
 
+.. _building_compiler:
+
 First, getting a working compiler
 ---------------------------------
 
@@ -11,20 +13,38 @@ Then you can choose a few ways to get a compiler:
 
 **Download a precompiled version from github:**
 
-#. download a recent "prog8compiler.jar" from `the releases on Github <https://github.com/irmen/prog8/releases>`_
-#. run the compiler with "java -jar prog8compiler.jar" to see how you can use it.
+#. download a recent "fat-jar" (called something like "prog8compiler-all.jar") from `the releases on Github <https://github.com/irmen/prog8/releases>`_
+#. run the compiler with "java -jar prog8compiler-all.jar" to see how you can use it.
 
-**Using the shell scripts:**
+**using the Gradle build system to make it yourself:**
 
-#. run the "create_compiler_jar.sh" shell script and have a little patience while everything is built
-#. it will output "prog8compiler.jar" file which contains everything.
-#. run the compiler with "java -jar prog8compiler.jar" to see how you can use it.
+The Gradle build system is used to build the compiler.
+The most interesting gradle commands to run are probably:
 
-**using the Gradle build system directly:**
+    ``./gradlew check``
+        Builds the compiler code and runs all available checks and unit-tests.
+    ``./gradlew installDist``
+        Builds the compiler and installs it with scripts to run it, in the directory
+        ``./compiler/build/install/p8compile``
+    ``./gradlew installShadowDist``
+        Creates a 'fat-jar' that contains the compiler and all dependencies, in a single
+        executable .jar file, and includes few start scripts to run it.
+        The output can be found in ``.compiler/build/install/compiler-shadow/``
+    ``./gradlew shadowDistZip``
+        Creates a zipfile with the above in it, for easy distribution.
+        This file can be found in ``./compiler/build/distributions/``
 
-#. run the command "./gradlew installDist" and have a little patience while everything is built
-#. it will create the commands and required libraries in the "./compiler/build/install/p8compile/" directory
-#. run the compiler with the "./compiler/build/install/p8compile/bin/p8compile" command to see how you can use it.
+For normal use, the ``installDist`` target should suffice and ater succesful completion
+of that build task, you can start the compiler with:
+
+    ``./compiler/build/install/p8compile/bin/p8compile <options> <sourcefile>``
+
+(You should probably make an alias...)
+
+.. note::
+    Development and testing is done on Linux, but the compiler should run on most
+    operating systems. If you do have trouble building or running
+    the compiler on another operating system, please let me know!
 
 
 
@@ -54,14 +74,10 @@ The compiler will link everything together into one output program at the end.
 If you start the compiler without arguments, it will print a short usage text.
 For normal use the compiler is invoked with the command:
 
-    ``$ java -jar prog8compiler.jar sourcefile.p8``   if you're using the packaged release version, or
+    ``$ java -jar prog8compiler.jar sourcefile.p8``
 
-    ``$ ./p8compile.sh sourcefile.p8``   if you're running an unpackaged development version.
-
-If you tell it to save the intermediate code for the prog8 virtual machine, you can
-actually run this code with the command:
-
-    ``$ ./p8vm.sh sourcefile.vm.txt``
+    Other options are also available, see the introduction page about how
+    to build and run the compiler.
 
 
 By default, assembly code is generated and written to ``sourcefile.asm``.
@@ -71,6 +87,13 @@ If you use the option to let the compiler auto-start a C-64 emulator, it will do
 a successful compilation. This will load your program and the symbol and breakpoint lists
 (for the machine code monitor) into the emulator.
 
+Continuous compilation mode
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Almost instant compilation times (less than a second) can be achieved when using the continuous compilation mode.
+Start the compiler with the ``-watch`` argument to enable this.
+It will compile your program and then instead of exiting, it waits for any changes in the module source files.
+As soon as a change happens, the program gets compiled again.
+
 
 Module source code files
 ------------------------
@@ -85,6 +108,13 @@ They are embedded into the packaged release version of the compiler so you don't
 where they are, but their names are still reserved.
 
 
+User defined library files
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+You can create library files yourself too that can be shared among programs.
+You can tell the compiler where it should look for these files, by setting the java command line property ``prog8.libdir``
+or by setting the ``PROG8_LIBDIR`` environment variable to the correct directory.
+
+
 .. _debugging:
 
 Debugging (with Vice)
@@ -131,3 +161,24 @@ or::
 
     $ ./p8compile.sh -emu examples/rasterbars.p8
 
+
+
+Virtual Machine
+---------------
+
+You may have noticed the ``-avm`` and ``-vm`` command line options for the compiler:
+
+-avm
+    Launches the "AST virtual machine" that directly executes the parsed program.
+    No compilation steps will be performed.
+    Allows for very fast testing and debugging before actually compiling programs
+    to machine code.
+    It simulates a bare minimum of features from the target platform, so most stuff
+    that calls ROM routines or writes into hardware registers won't work. But basic
+    system routines are emulated.
+
+-vm   <vm bytecode file>
+    Launches the "intermediate code VM"
+    it interprets the intermediate code that the compiler can write when using the ``-writevm``
+    option. This is the code that will be fed to the assembly code generator,
+    so you'll skip that last step.

docs/source/index.rst

@@ -37,15 +37,15 @@ This software is licensed under the GNU GPL 3.0, see https://www.gnu.org/license
     :alt: Fully playable tetris clone
 
 
-Code example
-------------
+Code examples
+-------------
 
 This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
 
     %import c64utils
     %zeropage basicsafe
 
-    ~ main {
+    main {
 
         ubyte[256] sieve
         ubyte candidate_prime = 2
@@ -89,13 +89,47 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
     }
 
 
-when compiled an ran on a C-64 you'll get:
+when compiled an ran on a C-64 you get this:
 
 .. image:: _static/primes_example.png
     :align: center
     :alt: result when run on C-64
 
 
+The following programs shows a use of the high level ``struct`` type::
+
+    %import c64utils
+    %zeropage basicsafe
+
+    main {
+
+        struct Color {
+            ubyte red
+            ubyte green
+            ubyte blue
+        }
+
+        sub start() {
+
+            Color purple = {255, 0, 255}
+            Color other
+            other = purple
+            other.red /= 2
+            other.green = 10 + other.green / 2
+            other.blue = 99
+
+            c64scr.print_ub(other.red)
+            c64.CHROUT(',')
+            c64scr.print_ub(other.green)
+            c64.CHROUT(',')
+            c64scr.print_ub(other.blue)
+            c64.CHROUT('\n')
+        }
+    }
+
+when compiled and ran, it prints  ``127,10,99`` on the screen.
+
+
 Design principles and features
 ------------------------------
 
@@ -106,7 +140,8 @@ Design principles and features
 - 'One statement per line' code style, resulting in clear readable programs.
 - Modular programming and scoping via modules, code blocks, and subroutines.
 - Provide high level programming constructs but stay close to the metal;
-  still able to directly use memory addresses, CPU registers and ROM subroutines
+  still able to directly use memory addresses, CPU registers and ROM subroutines,
+  and inline assembly to have full control when every cycle or byte matters
 - Arbitrary number of subroutine parameters (constrained only by available memory)
 - Complex nested expressions are possible
 - Values are typed. Types supported include signed and unsigned bytes and words, arrays, strings and floats.
@@ -116,13 +151,14 @@ Design principles and features
   the compiled program in an emulator and provide debugging information to the emulator.
 - The compiler outputs a regular 6502 assembly source code file, but doesn't assemble this itself.
   The (separate) '64tass' cross-assembler tool is used for that.
-- Goto is usually considered harmful, but not here: arbitrary control flow jumps and branches are possible,
+- Arbitrary control flow jumps and branches are possible,
   and will usually translate directly into the appropriate single 6502 jump/branch instruction.
 - There are no complicated built-in error handling or overflow checks, you'll have to take care
   of this yourself if required. This keeps the language and code simple and efficient.
 - The compiler tries to optimize the program and generated code, but hand-tuning of the
   performance or space-critical parts will likely still be required. This is supported by
   the ability to easily write embedded assembly code directly in the program source code.
+- There are many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``memset``, ``memcopy``
 
 
 .. _requirements:
@@ -143,37 +179,14 @@ Finally: a **C-64 emulator** (or a real C-64 ofcourse) to run the programs on. T
 of the `Vice emulator <http://vice-emu.sourceforge.net/>`_.
 
 .. important::
-    **Building the compiler itself:**
+    **Building the compiler itself:** (*Only needed if you have not downloaded a pre-built 'fat-jar'*)
 
     (re)building the compiler itself requires a recent Kotlin SDK.
     The compiler is developed using the `IntelliJ IDEA <https://www.jetbrains.com/idea/>`_
     IDE from Jetbrains, with the Kotlin plugin (free community edition of this IDE is available).
     But a bare Kotlin SDK installation should work just as well.
 
-    A shell script (``create_compiler_jar.sh``) is provided to build and package the compiler from the command line.
-    If you have the 'fat-jar' you can run it with ``java -jar prog8compiler.jar``.
-    You can also use the Gradle build system to build the compiler (it will take care of
-    downloading all required libraries for you) by typing ``gradle build`` for instance.
-    The output of this gradle build will appear in the "./compiler/build/install/p8compile/" directory.
-    The most interesting gradle commands to run are probably:
-
-        ``./gradlew check``
-            Builds the compiler code and runs all available checks and unit-tests.
-        ``./gradlew installShadowDist``
-            Creates a 'fat-jar' that contains the compiler and all dependencies,
-            and a few start scripts to run it.
-            The output can be found in ``.compiler/build/install/compiler-shadow/``
-            and you can launch the compiler with the script
-            ``./compiler/build/install/compiler-shadow/bin/p8compile``.
-        ``./gradlew shadowDistZip``
-            Creates a zipfile with the above in it, for easy distribution.
-            This file can be found in ``./compiler/build/distributions/``
-
-
-.. note::
-    Development and testing is done on Linux, but the compiler should run on most
-    operating systems. If you do have trouble building or running
-    the compiler on another operating system, please let me know!
+    Instructions on how to obtain a working compiler are in :ref:`building_compiler`.
 
 
 .. toctree::

docs/source/programming.rst

@@ -93,7 +93,7 @@ Blocks, Scopes, and accessing Symbols
 **Blocks** are the top level separate pieces of code and data of your program. They are combined
 into a single output program.  No code or data can occur outside a block. Here's an example::
 
-	~ main $c000 {
+	main $c000 {
 		; this is code inside the block...
 	}
 
@@ -127,12 +127,20 @@ The address must be >= ``$0200`` (because ``$00``--``$ff`` is the ZP and ``$100`
 to them by their 'short' name directly.  If the symbol is not found in the same scope,
 the enclosing scope is searched for it, and so on, until the symbol is found.
 
-Scopes are created using several statements:
+Scopes are created using either of these two statements:
 
 - blocks  (top-level named scope)
-- subroutines   (nested named scopes)
-- for, while, repeat loops   (anonymous scope)
-- if statements and branching conditionals    (anonymous scope)
+- subroutines   (nested named scope)
+
+.. note::
+    In contrast to many other programming languages, a new scope is *not* created inside
+    for, while and repeat statements, nor for the if statement and branching conditionals.
+    This is a bit restrictive because you have to think harder about what variables you
+    want to use inside a subroutine. But it is done precisely for this reason; memory in the
+    target system is very limited and it would be a waste to allocate a lot of variables.
+
+    Right now the prog8 compiler is not advanced enough to be able to 'share' or 'overlap'
+    variables intelligently by itself. So for now, it's something the programmer has to think about.
 
 
 Program Start and Entry Point
@@ -151,7 +159,7 @@ taking no parameters and having no return value.
 
 As any subroutine, it has to end with a ``return`` statement (or a ``goto`` call)::
 
-	~ main {
+	main {
 	    sub start ()  {
 	        ; program entrypoint code here
 	        return
@@ -237,6 +245,7 @@ Arrays
 ^^^^^^
 Array types are also supported. They can be made of bytes, words or floats::
 
+    byte[10]  array                   ; array of 10 bytes, initially set to 0
     byte[]  array = [1, 2, 3, 4]      ; initialize the array, size taken from value
     byte[99] array = 255              ; initialize array with 99 times 255 [255, 255, 255, 255, ...]
     byte[] array = 100 to 199         ; initialize array with [100, 101, ..., 198, 199]
@@ -266,6 +275,13 @@ Strings in your source code files will be encoded (translated from ASCII/UTF-8)
 PETSCII is the default choice. If you need screencodes (also called 'poke' codes) instead,
 you have to use the ``str_s`` variants of the string type identifier.
 
+You can concatenate two string literals using '+' (not very useful though) or repeat
+a string literal a given number of times using '*'::
+
+    str string1 = "first part" + "second part"
+    str string2 = "hello!" * 10
+
+
 .. caution::
     It's probably best that you don't change strings after they're created.
     This is because if your program exits and is restarted (without loading it again),
@@ -273,6 +289,39 @@ you have to use the ``str_s`` variants of the string type identifier.
     The same is true for arrays by the way.
 
 
+Structs
+^^^^^^^
+
+A struct is a group of one or more other variables.
+This allows you to reuse the definition and manipulate it as a whole.
+Individual variables in the struct are accessed as you would expect, just
+use a scoped name to refer to them: ``structvariable.membername``.
+
+Structs are a bit limited in Prog8: you can only use numerical variables
+as member of a struct, so strings and arrays and other structs can not be part of a struct.
+Also, it is not possible to use a struct itself inside an array.
+Structs are mainly syntactic sugar for repeated groups of vardecls
+and assignments that belong together. However,
+*they are layed out in sequence in memory as the members are defined*
+which may be usefulif you want to pass pointers around.
+
+To create a variable of a struct type you need to define the struct itself,
+and then create a variable with it::
+
+    struct Color {
+        ubyte red
+        ubyte green
+        ubyte blue
+    }
+
+    Color rgb = {255,122,0}     ; note the curly braces here instead of brackets
+    Color another               ; the init value is optional, like arrays
+
+    another = rgb           ; assign all of the values of rgb to another
+    another.blue = 255      ; set a single member
+
+
+
 Special types: const and memory-mapped
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -321,10 +370,17 @@ Initial values across multiple runs of the program
 When declaring values with an initial value, this value will be set into the variable each time
 the program reaches the declaration again. This can be in loops, multiple subroutine calls,
 or even multiple invocations of the entire program.  If you omit an initial value, it will
-be set to zero only for the first run of the program. A second run will utilize the last value
+be set to zero *but only for the first run of the program*. A second run will utilize the last value
 where it left off (but your code will be a bit smaller because no initialization instructions
 are generated)
 
+This only works for simple types, *and not for string variables and arrays*.
+It is assumed these are left unchanged by the program; they are not re-initialized on
+a second run.
+If you do modify them in-place, you should take care yourself that they work as
+expected when the program is restarted.
+(This is an optimization choice to avoid having to store two copies of every string and array)
+
 .. caution::
    variables that get allocated in zero-page will *not* have a zero starting value when you omit
    the variable's initialization. They'll be whatever the last value in that zero page
@@ -334,12 +390,6 @@ are generated)
     this behavior may change in a future version so that subsequent runs always
     use the same initial values
 
-This only works for simple types, *and not for string variables and arrays*.
-It is assumed these are left unchanged by the program.
-If you do modify them in-place, you should take care yourself that they work as
-expected when the program is restarted.
-(This is an optimization choice to avoid having to store two copies of every string and array)
-
 
 Loops
 -----
@@ -358,7 +408,9 @@ You can also create loops by using the ``goto`` statement, but this should usual
     The value of the loop variable or register after executing the loop *is undefined*. Don't use it immediately
     after the loop without first assigning a new value to it!
     (this is an optimization issue to avoid having to deal with mostly useless post-loop logic to adjust the loop variable's value)
-    Loop variables that are declared inline are scoped in the loop body so they're not accessible at all after the loop finishes.
+    Loop variables that are declared inline are not different to them being
+    defined in a separate var declaration in the subroutine, it's just a readability convenience.
+    (this may change in the future if the compiler gets more advanced with additional sub-scopes)
 
 
 Conditional Execution
@@ -416,15 +468,26 @@ So ``if_cc goto target`` will directly translate into the single CPU instruction
     Maybe in the future this will be a separate nested scope, but for now, that is
     only possible when defining a subroutine.
 
-when statement (jumptable)
-^^^^^^^^^^^^^^^^^^^^^^^^^^
+when statement ('jump table')
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-.. attention::
-    TODO: docs for this this must still be written.
-    TODO: the code generator for this is not yet working.
+Instead of writing a bunch of sequential if-elseif statements, it is more readable to
+use a ``when`` statement. (It will also result in greatly improved assembly code generation)
+Use a ``when`` statement if you have a set of fixed choices that each should result in a certain
+action. It is possible to combine several choices to result in the same action::
 
-    Use a ``when`` statement if you have a set of choices that each should result in a certain
-    action. It's more readable (and results in faster code) than using a lot of if / else statements.
+    when value {
+        4 -> c64scr.print("four")
+        5 -> c64scr.print("five")
+        10,20,30 -> {
+            c64scr.print("ten or twenty or thirty")
+        }
+        else -> c64scr.print("don't know")
+    }
+
+The when-*value* can be any expression but the choice values have to evaluate to
+compile-time constant integers (bytes or words). They also have to be the same
+datatype as the when-value, otherwise no efficient comparison can be done.
 
 
 Assignments
@@ -644,9 +707,6 @@ max(x)
 min(x)
 	Minimum of the values in the array value x
 
-avg(x)
-	Average of the values in the array value x
-
 sum(x)
 	Sum of the values in the array value x
 
@@ -667,6 +727,9 @@ lsb(x)
 msb(x)
     Get the most significant byte of the word x.
 
+sgn(x)
+    Get the sign of the value. Result is -1, 0 or 1 (negative, zero, positive).
+
 mkword(lsb, msb)
     Efficiently create a word value from two bytes (the lsb and the msb). Avoids multiplication and shifting.
 

docs/source/syntaxreference.rst

@@ -74,6 +74,7 @@ Directives
       As with ``kernalsafe``, it is not possible to cleanly exit the program, other than to reset the machine.
       This option makes programs smaller and faster because even more variables can
       be stored in the ZP (which allows for more efficient assembly code).
+    - style ``dontuse`` -- don't use *any* location in the zeropage.
 
     Also read :ref:`zeropage`.
 
@@ -173,7 +174,7 @@ Code blocks
 A named block of actual program code. Itefines a *scope* (also known as 'namespace') and
 can contain Prog8 *code*, *directives*, *variable declarations* and *subroutines*::
 
-    ~ <blockname> [<address>] {
+    <blockname> [<address>] {
         <directives>
         <variables>
         <statements>
@@ -185,7 +186,7 @@ The <address> is optional. If specified it must be a valid memory address such a
 It's used to tell the compiler to put the block at a certain position in memory.
 Also read :ref:`blocks`.  Here is an example of a code block, to be loaded at ``$c000``::
 
-	~ main $c000 {
+	main $c000 {
 		; this is code inside the block...
 	}
 
@@ -215,7 +216,7 @@ Variable declarations
 ^^^^^^^^^^^^^^^^^^^^^
 
 Variables should be declared with their exact type and size so the compiler can allocate storage
-for them. You must give them an initial value as well. That value can be a simple literal value,
+for them. You can give them an initial value as well. That value can be a simple literal value,
 or an expression. You can add a ``@zp`` zeropage-tag, to tell the compiler to prioritize it
 when selecting variables to be put into zeropage.
 The syntax is::
@@ -231,10 +232,11 @@ Various examples::
     str         name    = "my name is Irmen"
     uword       address = &counter
     byte[]      values  = [11, 22, 33, 44, 55]
+    byte[5]     values                  ; array of 5 bytes, initially set to zero
     byte[5]     values  = 255           ; initialize with five 255 bytes
 
     word  @zp   zpword = 9999           ; prioritize this when selecting vars for zeropage storage
-
+    Color       rgb    = {1,255,0}      ; a struct variable with initial values
 
 
 Data types
@@ -358,6 +360,26 @@ Syntax is familiar with brackets:  ``arrayvar[x]`` ::
     string[4]       ; the fifth character (=byte) in the string
 
 
+Struct
+^^^^^^
+
+A *struct* has to be defined to specify what its member variables are.
+There are one or more members::
+
+    struct  <structname> {
+        <vardecl>
+        [ <vardecl> ...]
+    }
+
+You can only use numerical variables as member of a struct, so strings and arrays
+and other structs can not be part of a struct. Vice versa, a struct can not occur in an array.
+
+After defining a struct you can use the name of the struct as a data type to declare variables with.
+
+Struct variables can be assigned a struct literal value (also in their declaration as initial value)::
+
+    Color rgb = {255, 100, 0}          ; curly braces instead of brackets
+
 
 Operators
 ---------
@@ -366,7 +388,7 @@ arithmetic: ``+``  ``-``  ``*``  ``/``  ``**``  ``%``
     ``+``, ``-``, ``*``, ``/`` are the familiar arithmetic operations.
     ``/`` is division (will result in integer division when using on integer operands, and a floating point division when at least one of the operands is a float)
     ``**`` is the power operator: ``3 ** 5`` is equal to 3*3*3*3*3 and is 243. (it only works on floating point variables)
-    ``%`` is the remainder operator: ``25 % 7`` is 4.  Be careful: without a space, %10 will be parsed as the binary number 2
+    ``%`` is the remainder operator: ``25 % 7`` is 4.  Be careful: without a space, %10 will be parsed as the binary number 2.
     Remainder is only supported on integer operands (not floats).
 
 bitwise arithmetic: ``&``  ``|``  ``^``  ``~``  ``<<``  ``>>``
@@ -444,11 +466,12 @@ Normal subroutines can only return zero or one return values.
 However, the special ``asmsub`` routines (implemented in assembly code or referencing
 a routine in kernel ROM) can return more than one return values, for instance a status
 in the carry bit and a number in A, or a 16-bit value in A/Y registers.
-Only for these kind of subroutines it is possible to write a multi value assignment to
-store the resulting values::
-
-        var1, var2, var3 = asmsubroutine()
-
+It is not possible to process the results of a call to these kind of routines
+directly from the language, because only single value assignments are possible.
+You can still call the subroutine and not store the results.
+But if you want to do something with the values it returns, you'll have to write
+a small block of custom inline assembly that does the call and stores the values
+appropriately. Don't forget to save/restore the registers if required.
 
 
 Subroutine definitions
@@ -610,28 +633,28 @@ The XX corresponds to one of the eigth branching instructions so the possibiliti
 ``if_cs``, ``if_cc``, ``if_eq``, ``if_ne``, ``if_pl``, ``if_mi``, ``if_vs`` and ``if_vc``.
 It can also be one of the four aliases that are easier to read: ``if_z``, ``if_nz``, ``if_pos`` and ``if_neg``.
 
-when statement (jumptable)
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-.. attention::
-   TODO: docs for this this must still be written.
-   TODO: the code generator for this is not yet working.
+when statement ('jump table')
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The structure of a when statement is like this::
 
-    The condition value can only be an integer datatype.
-    The choice values must be constant integer values.
+    when <expression> {
+        <value(s)> -> <statement(s)>
+        <value(s)> -> <statement(s)>
+        ...
+        [ else -> <statement(s)> ]
+    }
 
-    code example::
+The when-*value* can be any expression but the choice values have to evaluate to
+compile-time constant integers (bytes or words).
+The else part is optional.
+Choices can result in a single statement or a block of  multiple statements in which
+case you have to use { } to enclose them::
 
-       when 4+A+Y {
-            10 -> {
-                c64scr.print("ten")
-            }
-            5 -> c64scr.print("five")
-            30 -> c64scr.print("thirty")
-            99 -> c64scr.print("nn")
-            55 -> {
-                ; will be optimized away
-            }
-            else -> {
-                c64scr.print("!??!\n")
-            }
+    when value {
+        4 -> c64scr.print("four")
+        5 -> c64scr.print("five")
+        10,20,30 -> {
+            c64scr.print("ten or twenty or thirty")
         }
+        else -> c64scr.print("don't know")
+    }

docs/source/targetsystem.rst

@@ -168,7 +168,7 @@ These routines are::
 If you activate an IRQ handler with one of these, it expects the handler to be defined
 as a subroutine ``irq`` in the module ``irq`` so like this::
 
-    ~ irq {
+    irq {
         sub irq() {
             ; ... irq handling here ...
         }

docs/source/todo.rst

@@ -19,22 +19,15 @@ these should call optimized pieces of assembly code, so they run as fast as poss
 
 For now, we have the ``memcopy``, ``memset`` and ``strlen`` builtin functions.
 
-
-
 More optimizations
 ^^^^^^^^^^^^^^^^^^
 
 Add more compiler optimizations to the existing ones.
 
 - on the language AST level
-- on the StackVM intermediate code level
 - on the final assembly source level
 - can the parameter passing to subroutines be optimized to avoid copying?
-
-- subroutines with 1 or 2 byte args (or 1 word arg) should be converted to asm calling convention with the args in A/Y register
-  this requires rethinking the way parameters are represented, simply injecting vardecls to
-  declare local variables for them is not always correct anymore
-
+- working subroutine inlining (taking care of vars and identifier refs to them)
 
 Also some library routines and code patterns could perhaps be optimized further
 
@@ -48,30 +41,16 @@ It could then even be moved into the zeropage to greatly reduce code size and sl
 
 Or just move the LSB portion into a slab of the zeropage.
 
-Allocate a fixed word in ZP that is the TOS so we can operate on TOS directly
+Allocate a fixed word in ZP that is the TOS so we can always operate on TOS directly
 without having to to index into the stack?
 
 
-structs?
-^^^^^^^^
-
-A user defined struct type would be nice to group a bunch
-of values together (and use it multiple times). Something like::
-
-    struct Point {
-        ubyte   color
-        word[] vec = [0,0,0]
-    }
-
-    Point p1
-    Point p2
-    Point p3
-
-    p1.color = 3
-    p1.vec[2] = 2
-
-
 Misc
 ^^^^
 
-- are there any other missing instructions in the code generator?
+Add sort() function that can sort an array (ascending and descending)
+
+
+Several ideas were discussed on my reddit post
+https://www.reddit.com/r/programming/comments/alhj59/creating_a_programming_language_and_cross/
+

examples/arithmetic/aggregates.p8

@@ -0,0 +1,110 @@
+%import c64lib
+%import c64utils
+%import c64flt
+%zeropage dontuse
+
+main {
+
+    sub start() {
+        ubyte[]  ubarr = [100, 0, 99, 199, 22]
+        byte[]  barr = [-100, 0, 99, -122, 22]
+        uword[] uwarr = [1000, 0, 222, 4444, 999]
+        word[]  warr = [-1000, 0, 999, -4444, 222]
+        float[]  farr = [-1000.1, 0, 999.9, -4444.4, 222.2]
+        str name = "irmen"
+        ubyte ub
+        byte bb
+        word ww
+        uword uw
+        float ff
+
+        ; LEN/STRLEN
+        ubyte length = len(name)
+        if length!=5 c64scr.print("error len1\n")
+        length = len(uwarr)
+        if length!=5 c64scr.print("error len2\n")
+        length=strlen(name)
+        if length!=5 c64scr.print("error strlen1\n")
+        name[3] = 0
+        length=strlen(name)
+        if length!=3 c64scr.print("error strlen2\n")
+
+        ; MAX
+        ub = max(ubarr)
+        if ub!=199 c64scr.print("error max1\n")
+        bb = max(barr)
+        if bb!=99 c64scr.print("error max2\n")
+        uw = max(uwarr)
+        if uw!=4444 c64scr.print("error max3\n")
+        ww = max(warr)
+        if ww!=999 c64scr.print("error max4\n")
+        ff = max(farr)
+        if ff!=999.9 c64scr.print("error max5\n")
+
+        ; MIN
+        ub = min(ubarr)
+        if ub!=0 c64scr.print("error min1\n")
+        bb = min(barr)
+        if bb!=-122 c64scr.print("error min2\n")
+        uw = min(uwarr)
+        if uw!=0 c64scr.print("error min3\n")
+        ww = min(warr)
+        if ww!=-4444 c64scr.print("error min4\n")
+        ff = min(farr)
+        if ff!=-4444.4 c64scr.print("error min5\n")
+
+        ; SUM
+        uw = sum(ubarr)
+        if uw!=420 c64scr.print("error sum1\n")
+        ww = sum(barr)
+        if ww!=-101 c64scr.print("error sum2\n")
+        uw = sum(uwarr)
+        if uw!=6665 c64scr.print("error sum3\n")
+        ww = sum(warr)
+        if ww!=-4223 c64scr.print("error sum4\n")
+        ff = sum(farr)
+        if ff!=-4222.4 c64scr.print("error sum5\n")
+
+        ; ANY
+        ub = any(ubarr)
+        if ub==0 c64scr.print("error any1\n")
+        ub = any(barr)
+        if ub==0 c64scr.print("error any2\n")
+        ub = any(uwarr)
+        if ub==0 c64scr.print("error any3\n")
+        ub = any(warr)
+        if ub==0 c64scr.print("error any4\n")
+        ub = any(farr)
+        if ub==0 c64scr.print("error any5\n")
+
+        ; ALL
+        ub = all(ubarr)
+        if ub==1 c64scr.print("error all1\n")
+        ub = all(barr)
+        if ub==1 c64scr.print("error all2\n")
+        ub = all(uwarr)
+        if ub==1 c64scr.print("error all3\n")
+        ub = all(warr)
+        if ub==1 c64scr.print("error all4\n")
+        ub = all(farr)
+        if ub==1 c64scr.print("error all5\n")
+        ubarr[1]=$40
+        barr[1]=$40
+        uwarr[1]=$4000
+        warr[1]=$4000
+        farr[1]=1.1
+        ub = all(ubarr)
+        if ub==0 c64scr.print("error all6\n")
+        ub = all(barr)
+        if ub==0 c64scr.print("error all7\n")
+        ub = all(uwarr)
+        if ub==0 c64scr.print("error all8\n")
+        ub = all(warr)
+        if ub==0 c64scr.print("error all9\n")
+        ub = all(farr)
+        if ub==0 c64scr.print("error all10\n")
+
+
+        c64scr.print("\nyou should see no errors above.")
+    }
+}

examples/arithmetic/bitshift.p8

@@ -0,0 +1,77 @@
+%import c64utils
+%zeropage basicsafe
+
+; TODO implement asm generation for all operation in here
+
+main {
+
+    byte bb
+    ubyte ub
+    word ww
+    uword uw
+    &ubyte  membyte=9999
+    &uword  memword=9999
+    ubyte[10] barray
+
+    sub start() {
+        lsr(A)
+        lsl(A)
+        ror(A)
+        rol(A)
+        ror2(A)
+        rol2(A)
+        lsr(membyte)
+        lsl(membyte)
+        ror(membyte)
+        rol(membyte)
+        ror2(membyte)
+        rol2(membyte)
+        lsr(memword)
+        lsl(memword)
+        ror(memword)
+        rol(memword)
+        ror2(memword)
+        rol2(memword)
+        lsl(@(9999))
+        lsr(@(9999))
+        ror(@(9999))
+        rol(@(9999))
+        ror2(@(9999))
+        rol2(@(9999))
+        lsr(barray[1])
+        lsl(barray[1])
+        ror(barray[1])
+        rol(barray[1])
+        ror2(barray[1])
+        rol2(barray[1])
+
+
+        bb /= 2
+        bb >>= 1
+        bb *= 4
+        bb <<= 2
+
+        ub /= 2
+        ub >>= 1
+        ub *= 4
+        ub <<= 2
+        rol(ub)
+        ror(ub)
+        rol2(ub)
+        ror2(ub)
+
+        ww /= 2
+        ww >>= 1
+        ww *= 4
+        ww <<= 2
+
+        uw /= 2
+        uw >>= 1
+        uw *= 4
+        uw <<= 2
+        rol(uw)
+        ror(uw)
+        rol2(uw)
+        ror2(uw)
+    }
+}

examples/arithmetic/div.p8

@@ -0,0 +1,105 @@
+%import c64lib
+%import c64utils
+%import c64flt
+%zeropage basicsafe
+
+main {
+
+    sub start() {
+        div_ubyte(0, 1, 0)
+        div_ubyte(100, 6, 16)
+        div_ubyte(255, 2, 127)
+
+        div_byte(0, 1, 0)
+        div_byte(100, -6, -16)
+        div_byte(127, -2, -63)
+
+        div_uword(0,1,0)
+        div_uword(40000,500,80)
+        div_uword(43211,2,21605)
+
+        div_word(0,1,0)
+        div_word(-20000,500,-40)
+        div_word(-2222,2,-1111)
+
+        div_float(0,1,0)
+        div_float(999.9,111.0,9.008108108108107)
+
+    }
+
+    sub div_ubyte(ubyte a1, ubyte a2, ubyte c) {
+        ubyte r = a1/a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("ubyte ")
+        c64scr.print_ub(a1)
+        c64scr.print(" / ")
+        c64scr.print_ub(a2)
+        c64scr.print(" = ")
+        c64scr.print_ub(r)
+        c64.CHROUT('\n')
+    }
+
+    sub div_byte(byte a1, byte a2, byte c) {
+        byte r = a1/a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("byte ")
+        c64scr.print_b(a1)
+        c64scr.print(" / ")
+        c64scr.print_b(a2)
+        c64scr.print(" = ")
+        c64scr.print_b(r)
+        c64.CHROUT('\n')
+    }
+
+    sub div_uword(uword a1, uword  a2, uword c) {
+        uword  r = a1/a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("uword ")
+        c64scr.print_uw(a1)
+        c64scr.print(" / ")
+        c64scr.print_uw(a2)
+        c64scr.print(" = ")
+        c64scr.print_uw(r)
+        c64.CHROUT('\n')
+    }
+
+    sub div_word(word a1, word a2, word c) {
+        word r = a1/a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("word ")
+        c64scr.print_w(a1)
+        c64scr.print(" / ")
+        c64scr.print_w(a2)
+        c64scr.print(" = ")
+        c64scr.print_w(r)
+        c64.CHROUT('\n')
+    }
+
+    sub div_float(float  a1, float a2, float  c) {
+        float r = a1/a2
+        if abs(r-c)<0.00001
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+
+        c64scr.print("float ")
+        c64flt.print_f(a1)
+        c64scr.print(" / ")
+        c64flt.print_f(a2)
+        c64scr.print(" = ")
+        c64flt.print_f(r)
+        c64.CHROUT('\n')
+    }
+}

examples/arithmetic/minus.p8

@@ -0,0 +1,113 @@
+%import c64lib
+%import c64utils
+%import c64flt
+%zeropage basicsafe
+
+main {
+
+    sub start() {
+        minus_ubyte(0, 0, 0)
+        minus_ubyte(200, 0, 200)
+        minus_ubyte(200, 100, 100)
+        minus_ubyte(100, 200, 156)
+
+        minus_byte(0, 0, 0)
+        minus_byte(100, 100, 0)
+        minus_byte(50, -50, 100)
+        minus_byte(0, -30, 30)
+        minus_byte(-30, 0, -30)
+
+        minus_uword(0,0,0)
+        minus_uword(50000,0, 50000)
+        minus_uword(50000,20000,30000)
+        minus_uword(20000,50000,35536)
+
+        minus_word(0,0,0)
+        minus_word(1000,1000,0)
+        minus_word(-1000,1000,-2000)
+        minus_word(1000,500,500)
+        minus_word(0,-3333,3333)
+        minus_word(-3333,0,-3333)
+
+        minus_float(0,0,0)
+        minus_float(2.5,1.5,1.0)
+        minus_float(-1.5,3.5,-5.0)
+
+    }
+
+    sub minus_ubyte(ubyte a1, ubyte a2, ubyte c) {
+        ubyte r = a1-a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("ubyte ")
+        c64scr.print_ub(a1)
+        c64scr.print(" - ")
+        c64scr.print_ub(a2)
+        c64scr.print(" = ")
+        c64scr.print_ub(r)
+        c64.CHROUT('\n')
+    }
+
+    sub minus_byte(byte a1, byte a2, byte c) {
+        byte r = a1-a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("byte ")
+        c64scr.print_b(a1)
+        c64scr.print(" - ")
+        c64scr.print_b(a2)
+        c64scr.print(" = ")
+        c64scr.print_b(r)
+        c64.CHROUT('\n')
+    }
+
+    sub minus_uword(uword a1, uword  a2, uword c) {
+        uword  r = a1-a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("uword ")
+        c64scr.print_uw(a1)
+        c64scr.print(" - ")
+        c64scr.print_uw(a2)
+        c64scr.print(" = ")
+        c64scr.print_uw(r)
+        c64.CHROUT('\n')
+    }
+
+    sub minus_word(word a1, word a2, word c) {
+        word r = a1-a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("word ")
+        c64scr.print_w(a1)
+        c64scr.print(" - ")
+        c64scr.print_w(a2)
+        c64scr.print(" = ")
+        c64scr.print_w(r)
+        c64.CHROUT('\n')
+    }
+
+    sub minus_float(float  a1, float a2, float  c) {
+        float r = a1-a2
+        if abs(r-c)<0.00001
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+
+        c64scr.print("float ")
+        c64flt.print_f(a1)
+        c64scr.print(" - ")
+        c64flt.print_f(a2)
+        c64scr.print(" = ")
+        c64flt.print_f(r)
+        c64.CHROUT('\n')
+    }
+}

examples/arithmetic/mult.p8

@@ -0,0 +1,107 @@
+%import c64lib
+%import c64utils
+%import c64flt
+%zeropage basicsafe
+
+main {
+
+    sub start() {
+        mul_ubyte(0, 0, 0)
+        mul_ubyte(20, 1, 20)
+        mul_ubyte(20, 10, 200)
+
+        mul_byte(0, 0, 0)
+        mul_byte(10, 10, 100)
+        mul_byte(5, -5, -25)
+        mul_byte(0, -30, 0)
+
+        mul_uword(0,0,0)
+        mul_uword(50000,1, 50000)
+        mul_uword(500,100,50000)
+
+        mul_word(0,0,0)
+        mul_word(-10,1000,-10000)
+        mul_word(1,-3333,-3333)
+
+        mul_float(0,0,0)
+        mul_float(2.5,10,25)
+        mul_float(-1.5,10,-15)
+
+    }
+
+    sub mul_ubyte(ubyte a1, ubyte a2, ubyte c) {
+        ubyte r = a1*a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("ubyte ")
+        c64scr.print_ub(a1)
+        c64scr.print(" * ")
+        c64scr.print_ub(a2)
+        c64scr.print(" = ")
+        c64scr.print_ub(r)
+        c64.CHROUT('\n')
+    }
+
+    sub mul_byte(byte a1, byte a2, byte c) {
+        byte r = a1*a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("byte ")
+        c64scr.print_b(a1)
+        c64scr.print(" * ")
+        c64scr.print_b(a2)
+        c64scr.print(" = ")
+        c64scr.print_b(r)
+        c64.CHROUT('\n')
+    }
+
+    sub mul_uword(uword a1, uword  a2, uword c) {
+        uword  r = a1*a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("uword ")
+        c64scr.print_uw(a1)
+        c64scr.print(" * ")
+        c64scr.print_uw(a2)
+        c64scr.print(" = ")
+        c64scr.print_uw(r)
+        c64.CHROUT('\n')
+    }
+
+    sub mul_word(word a1, word a2, word c) {
+        word r = a1*a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("word ")
+        c64scr.print_w(a1)
+        c64scr.print(" * ")
+        c64scr.print_w(a2)
+        c64scr.print(" = ")
+        c64scr.print_w(r)
+        c64.CHROUT('\n')
+    }
+
+    sub mul_float(float  a1, float a2, float  c) {
+        float r = a1*a2
+        if abs(r-c)<0.00001
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+
+        c64scr.print("float ")
+        c64flt.print_f(a1)
+        c64scr.print(" * ")
+        c64flt.print_f(a2)
+        c64scr.print(" = ")
+        c64flt.print_f(r)
+        c64.CHROUT('\n')
+    }
+}

examples/arithmetic/plus.p8

@@ -0,0 +1,111 @@
+%import c64lib
+%import c64utils
+%import c64flt
+%zeropage basicsafe
+
+main {
+
+    sub start() {
+        plus_ubyte(0, 0, 0)
+        plus_ubyte(0, 200, 200)
+        plus_ubyte(100, 200, 44)
+
+        plus_byte(0, 0, 0)
+        plus_byte(-100, 100, 0)
+        plus_byte(-50, 100, 50)
+        plus_byte(0, -30, -30)
+        plus_byte(-30, 0, -30)
+
+        plus_uword(0,0,0)
+        plus_uword(0,50000,50000)
+        plus_uword(50000,20000,4464)
+
+        plus_word(0,0,0)
+        plus_word(-1000,1000,0)
+        plus_word(-500,1000,500)
+        plus_word(0,-3333,-3333)
+        plus_word(-3333,0,-3333)
+
+        plus_float(0,0,0)
+        plus_float(1.5,2.5,4.0)
+        plus_float(-1.5,3.5,2.0)
+        plus_float(-1.1,3.3,2.2)
+
+    }
+
+    sub plus_ubyte(ubyte a1, ubyte a2, ubyte c) {
+        ubyte r = a1+a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("ubyte ")
+        c64scr.print_ub(a1)
+        c64scr.print(" + ")
+        c64scr.print_ub(a2)
+        c64scr.print(" = ")
+        c64scr.print_ub(r)
+        c64.CHROUT('\n')
+    }
+
+    sub plus_byte(byte a1, byte a2, byte c) {
+        byte r = a1+a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("byte ")
+        c64scr.print_b(a1)
+        c64scr.print(" + ")
+        c64scr.print_b(a2)
+        c64scr.print(" = ")
+        c64scr.print_b(r)
+        c64.CHROUT('\n')
+    }
+
+    sub plus_uword(uword a1, uword  a2, uword c) {
+        uword  r = a1+a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("uword ")
+        c64scr.print_uw(a1)
+        c64scr.print(" + ")
+        c64scr.print_uw(a2)
+        c64scr.print(" = ")
+        c64scr.print_uw(r)
+        c64.CHROUT('\n')
+    }
+
+    sub plus_word(word a1, word a2, word c) {
+        word r = a1+a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("word ")
+        c64scr.print_w(a1)
+        c64scr.print(" + ")
+        c64scr.print_w(a2)
+        c64scr.print(" = ")
+        c64scr.print_w(r)
+        c64.CHROUT('\n')
+    }
+
+    sub plus_float(float  a1, float a2, float  c) {
+        float r = a1+a2
+        if abs(r-c)<0.00001
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+
+        c64scr.print("float ")
+        c64flt.print_f(a1)
+        c64scr.print(" + ")
+        c64flt.print_f(a2)
+        c64scr.print(" = ")
+        c64flt.print_f(r)
+        c64.CHROUT('\n')
+    }
+}

examples/arithmetic/postincrdecr.p8

@@ -0,0 +1,142 @@
+%import c64utils
+%import c64flt
+%option enable_floats
+%zeropage basicsafe
+
+main {
+
+
+    sub start()  {
+
+        c64scr.plot(0,24)
+
+        ubyte ub=200
+        byte bb=-100
+        uword uw = 2000
+        word ww = -1000
+        float fl = 999.99
+        ubyte[3] ubarr = 200
+        byte[3] barr = -100
+        uword[3] uwarr = 2000
+        word[3] warr = -1000
+        float[3] flarr = 999.99
+
+        c64scr.print("++\n")
+        ub++
+        bb++
+        uw++
+        ww++
+        fl++
+        ubarr[1]++
+        barr[1]++
+        uwarr[1]++
+        warr[1]++
+        flarr[1] ++
+
+        check_ub(ub, 201)
+        Y=100
+        Y++
+        check_ub(Y, 101)
+        check_fl(fl, 1000.99)
+        check_b(bb, -99)
+        check_uw(uw, 2001)
+        check_w(ww, -999)
+        check_ub(ubarr[0], 200)
+        check_fl(flarr[0], 999.99)
+        check_b(barr[0], -100)
+        check_uw(uwarr[0], 2000)
+        check_w(warr[0], -1000)
+        check_ub(ubarr[1], 201)
+        check_fl(flarr[1], 1000.99)
+        check_b(barr[1], -99)
+        check_uw(uwarr[1], 2001)
+        check_w(warr[1], -999)
+
+        c64scr.print("--\n")
+        ub--
+        bb--
+        uw--
+        ww--
+        fl--
+        ubarr[1]--
+        barr[1]--
+        uwarr[1]--
+        warr[1]--
+        flarr[1] --
+        check_ub(ub, 200)
+        Y=100
+        Y--
+        check_ub(Y, 99)
+        check_fl(fl, 999.99)
+        check_b(bb, -100)
+        check_uw(uw, 2000)
+        check_w(ww, -1000)
+        check_ub(ubarr[1], 200)
+        check_fl(flarr[1], 999.99)
+        check_b(barr[1], -100)
+        check_uw(uwarr[1], 2000)
+        check_w(warr[1], -1000)
+
+        @($0400+400-1) = X
+    }
+
+    sub check_ub(ubyte value, ubyte expected) {
+        if value==expected
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print(" ubyte ")
+        c64scr.print_ub(value)
+        c64.CHROUT(',')
+        c64scr.print_ub(expected)
+        c64.CHROUT('\n')
+    }
+
+    sub check_b(byte value, byte expected) {
+        if value==expected
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print(" byte ")
+        c64scr.print_b(value)
+        c64.CHROUT(',')
+        c64scr.print_b(expected)
+        c64.CHROUT('\n')
+    }
+
+    sub check_uw(uword value, uword expected) {
+        if value==expected
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print(" uword ")
+        c64scr.print_uw(value)
+        c64.CHROUT(',')
+        c64scr.print_uw(expected)
+        c64.CHROUT('\n')
+    }
+
+    sub check_w(word value, word expected) {
+        if value==expected
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print(" word ")
+        c64scr.print_w(value)
+        c64.CHROUT(',')
+        c64scr.print_w(expected)
+        c64.CHROUT('\n')
+    }
+
+    sub check_fl(float value, float expected) {
+        if value==expected
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print(" float ")
+        c64flt.print_f(value)
+        c64.CHROUT(',')
+        c64flt.print_f(expected)
+        c64.CHROUT('\n')
+    }
+}

examples/arithmetic/remainder.p8

@@ -0,0 +1,49 @@
+%import c64lib
+%import c64utils
+%import c64flt
+%zeropage basicsafe
+
+main {
+
+    sub start() {
+        remainder_ubyte(0, 1, 0)
+        remainder_ubyte(100, 6, 4)
+        remainder_ubyte(255, 2, 1)
+        remainder_ubyte(255, 20, 15)
+
+        remainder_uword(0,1,0)
+        remainder_uword(40000,511,142)
+        remainder_uword(40000,500,0)
+        remainder_uword(43211,12,11)
+    }
+
+    sub remainder_ubyte(ubyte a1, ubyte a2, ubyte c) {
+        ubyte r = a1%a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("ubyte ")
+        c64scr.print_ub(a1)
+        c64scr.print(" % ")
+        c64scr.print_ub(a2)
+        c64scr.print(" = ")
+        c64scr.print_ub(r)
+        c64.CHROUT('\n')
+    }
+
+    sub remainder_uword(uword a1, uword  a2, uword c) {
+        uword  r = a1%a2
+        if r==c
+            c64scr.print(" ok  ")
+        else
+            c64scr.print("err! ")
+        c64scr.print("uword ")
+        c64scr.print_uw(a1)
+        c64scr.print(" % ")
+        c64scr.print_uw(a2)
+        c64scr.print(" = ")
+        c64scr.print_uw(r)
+        c64.CHROUT('\n')
+    }
+}

examples/bdmusic-irq.p8

@@ -0,0 +1,74 @@
+%zeropage basicsafe
+%import c64lib
+
+main {
+
+    sub start() {
+        c64scr.print("playing the music from boulderdash,\nmade in 1984 by peter liepa.\n\n")
+        c64utils.set_rasterirq(60)     ; enable raster irq
+    }
+}
+
+irq {
+    const ubyte waveform = %0001       ; triangle
+    ubyte note_index = 0
+    ubyte delay = 0
+
+    sub irq() {
+        c64.EXTCOL++
+        delay++
+        if delay >= 8 {
+            delay = 0
+            c64.AD1 = %00011010
+            c64.SR1 = %00000000
+            c64.AD2 = %00011010
+            c64.SR2 = %00000000
+            c64.MVOL = 15
+
+            uword note = notes[note_index]
+            note_index++
+            ubyte note1 = lsb(note)
+            ubyte note2 = msb(note)
+            c64.FREQ1 = music_freq_table[note1]    ; set lo+hi freq of voice 1
+            c64.FREQ2 = music_freq_table[note2]    ; set lo+hi freq of voice 2
+
+            ; retrigger voice 1 and 2 ADSR
+            c64.CR1 = waveform <<4 | 0
+            c64.CR2 = waveform <<4 | 0
+            c64.CR1 = waveform <<4 | 1
+            c64.CR2 = waveform <<4 | 1
+        }
+
+        c64.EXTCOL--
+    }
+
+    ; details about the boulderdash music can be found here:
+    ; https://www.elmerproductions.com/sp/peterb/sounds.html#Theme%20tune
+
+    uword[] notes = [
+        $1622, $1d26, $2229, $252e, $1424, $1f27, $2029, $2730,
+        $122a, $122c, $1e2e, $1231, $202c, $3337, $212d, $3135,
+        $1622, $162e, $161d, $1624, $1420, $1430, $1424, $1420,
+        $1622, $162e, $161d, $1624, $1e2a, $1e3a, $1e2e, $1e2a,
+        $142c, $142c, $141b, $1422, $1c28, $1c38, $1c2c, $1c28,
+        $111d, $292d, $111f, $292e, $0f27, $0f27, $1633, $1627,
+        $162e, $162e, $162e, $162e, $222e, $222e, $162e, $162e,
+        $142e, $142e, $142e, $142e, $202e, $202e, $142e, $142e,
+        $162e, $322e, $162e, $332e, $222e, $322e, $162e, $332e,
+        $142e, $322e, $142e, $332e, $202c, $302c, $142c, $312c,
+        $162e, $163a, $162e, $3538, $222e, $2237, $162e, $3135,
+        $142c, $1438, $142c, $1438, $202c, $2033, $142c, $1438,
+        $162e, $322e, $162e, $332e, $222e, $322e, $162e, $332e,
+        $142e, $322e, $142e, $332e, $202c, $302c, $142c, $312c,
+        $2e32, $292e, $2629, $2226, $2c30, $272c, $2427, $1420,
+        $3532, $322e, $2e29, $2926, $2730, $242c, $2027, $1420
+    ]
+
+    uword[] music_freq_table = [
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        732, 778, 826, 876, 928, 978, 1042, 1100, 1170, 1238, 1312, 1390, 1464, 1556,
+        1652, 1752, 1856, 1956, 2084, 2200, 2340, 2476, 2624, 2780, 2928, 3112, 3304,
+        3504, 3712, 3912, 4168, 4400, 4680, 4952, 5248, 5560, 5856, 6224, 6608, 7008,
+        7424, 7824, 8336, 8800, 9360, 9904, 10496, 11120, 11712
+    ]
+}

examples/bdmusic.p8

@@ -1,6 +1,6 @@
 %import c64lib
 
-~ main {
+main {
 
 sub start() {
 
@@ -18,10 +18,10 @@ sub start() {
 
     while(true) {
         for uword note in notes {
-            ubyte n1 = lsb(note)
-            ubyte n2 = msb(note)
-            c64.FREQ1 = music_freq_table[n1]    ; set lo+hi freq of voice 1
-            c64.FREQ2 = music_freq_table[n2]    ; set lo+hi freq of voice 2
+            ubyte note1 = lsb(note)
+            ubyte note2 = msb(note)
+            c64.FREQ1 = music_freq_table[note1]    ; set lo+hi freq of voice 1
+            c64.FREQ2 = music_freq_table[note2]    ; set lo+hi freq of voice 2
 
             ; retrigger voice 1 and 2 ADSR
             c64.CR1 = waveform <<4 | 0
@@ -29,7 +29,7 @@ sub start() {
             c64.CR1 = waveform <<4 | 1
             c64.CR2 = waveform <<4 | 1
 
-            print_notes(n1, n2)
+            print_notes(note1, note2)
             delay()
         }
     }