struct literals

compiler/src/prog8/ast/Interfaces.kt

@@ -6,6 +6,10 @@ import prog8.ast.processing.IAstModifyingVisitor
 import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
 
+
+// TODO sealed classes instead??
+
+
 interface Node {
     val position: Position
     var parent: Node             // will be linked correctly later (late init)

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

@@ -443,6 +443,10 @@ private fun prog8Parser.ExpressionContext.toAst() : IExpression {
                     // the ConstantFolder takes care of that and converts the type if needed.
                     ReferenceLiteralValue(DataType.ARRAY_UB, array = 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")
             }
         }
@@ -518,6 +522,9 @@ private fun prog8Parser.BooleanliteralContext.toAst() = when(text) {
 private fun prog8Parser.ArrayliteralContext.toAst() : Array<IExpression> =
         expression().map { it.toAst() }.toTypedArray()
 
+private fun prog8Parser.StructliteralContext.toAst() : Array<IExpression> =
+        expression().map { it.toAst() }.toTypedArray()
+
 
 private fun prog8Parser.If_stmtContext.toAst(): IfStatement {
     val condition = expression().toAst()

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

@@ -420,6 +420,26 @@ class NumericLiteralValue(val type: DataType,    // only numerical types allowed
     }
 }
 
+class StructLiteralValue(var values: List<IExpression>,
+                         override val position: Position): IExpression {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent=parent
+        values.forEach { it.linkParents(this) }
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue?  = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = values.any { it.referencesIdentifiers(*name) }
+    override fun inferType(program: Program) = DataType.STRUCT
+
+    override fun toString(): String {
+        return "struct{ ${values.joinToString(", ")} }"
+    }
+}
+
 class ReferenceLiteralValue(val type: DataType,     // only reference types allowed here
                             val str: String? = null,
                             val array: Array<IExpression>? = null,
@@ -428,9 +448,7 @@ class ReferenceLiteralValue(val type: DataType,     // only reference types allo
                             override val position: Position) : IExpression {
     override lateinit var parent: Node
 
-    override fun referencesIdentifiers(vararg name: String): Boolean {
-        return array?.any { it.referencesIdentifiers(*name) } ?: false
-    }
+    override fun referencesIdentifiers(vararg name: String) = array?.any { it.referencesIdentifiers(*name) } ?: false
 
     val isString = type in StringDatatypes
     val isArray = type in ArrayDatatypes
@@ -443,8 +461,6 @@ class ReferenceLiteralValue(val type: DataType,     // only reference types allo
                 if(str==null && heapId==null) throw FatalAstException("literal value missing strvalue/heapId")
             in ArrayDatatypes ->
                 if(array==null && heapId==null) throw FatalAstException("literal value missing arrayvalue/heapId")
-//            DataType.STRUCT ->
-//                if(struct==null && heapId==null) throw FatalAstException("literal value missing structvalue/heapId")
             else -> throw FatalAstException("invalid type $type")
         }
         if(array==null && str==null && heapId==null)

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

@@ -526,6 +526,29 @@ internal class AstChecker(private val program: Program,
                     is NumericLiteralValue -> {
                         checkValueTypeAndRange(decl.datatype, decl.value as NumericLiteralValue)
                     }
+                    is StructLiteralValue -> {
+                        if(decl.datatype==DataType.STRUCT) {
+                            val struct = decl.struct!!
+                            val structLv = decl.value as StructLiteralValue
+                            if(struct.numberOfElements != structLv.values.size) {
+                                checkResult.add(ExpressionError("struct value has incorrect number of elements", structLv.position))
+                                return
+                            }
+                            for(value in structLv.values.zip(struct.statements)) {
+                                val memberdecl = value.second as VarDecl
+                                val constValue = value.first.constValue(program)
+                                if(constValue==null) {
+                                    checkResult.add(ExpressionError("struct literal value for field '${memberdecl.name}' should consist of compile-time constants", value.first.position))
+                                    return
+                                }
+                                val memberDt = memberdecl.datatype
+                                if(!checkValueTypeAndRange(memberDt, constValue)) {
+                                    checkResult.add(ExpressionError("struct member value's type is not compatible with member field '${memberdecl.name}'", value.first.position))
+                                    return
+                                }
+                            }
+                        }
+                    }
                     else -> {
                         err("var/const declaration needs a compile-time constant initializer value, or range, instead found: ${decl.value!!.javaClass.simpleName}")
                         super.visit(decl)
@@ -1245,21 +1268,12 @@ internal class AstChecker(private val program: Program,
             DataType.STR -> sourceDatatype== DataType.STR
             DataType.STR_S -> sourceDatatype== DataType.STR_S
             DataType.STRUCT -> {
-                // for now we've decided you cannot assign struct by-value.
-                // but you can however assign an array to it of the correct size
-                if(sourceDatatype in ArrayDatatypes) {
-                    val identifier = sourceValue as IdentifierReference
-                    val sourceArraySize = identifier.targetVarDecl(program.namespace)!!.arraysize?.size()
+                if(sourceDatatype==DataType.STRUCT) {
+                    val structLv = sourceValue as StructLiteralValue
+                    val numValues = structLv.values.size
                     val targetstruct = target.identifier!!.targetVarDecl(program.namespace)!!.struct!!
-                    return targetstruct.numberOfElements == sourceArraySize
+                    return targetstruct.numberOfElements == numValues
                 }
-//                if(sourceDatatype==DataType.STRUCT) {
-//                    val sourcename = (sourceValue as IdentifierReference).nameInSource
-//                    val vd1 = program.namespace.lookup(sourcename, target) as? VarDecl
-//                    val targetname = target.identifier!!.nameInSource
-//                    val vd2 = program.namespace.lookup(targetname, target) as? VarDecl
-//                    return vd1?.struct == vd2?.struct
-//                }
                 false
             }
             else -> checkResult.add(SyntaxError("cannot assign new value to variable of type $targetDatatype", position))

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

@@ -225,4 +225,9 @@ interface IAstModifyingVisitor {
         structDecl.statements = structDecl.statements.map{ it.accept(this) }.toMutableList()
         return structDecl
     }
+
+    fun visit(structLv: StructLiteralValue): IExpression {
+        structLv.values = structLv.values.map { it.accept(this) }
+        return structLv
+    }
 }

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

@@ -173,4 +173,8 @@ interface IAstVisitor {
     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/StatementReorderer.kt

@@ -9,47 +9,41 @@ import prog8.ast.statements.*
 import prog8.functions.BuiltinFunctions
 
 
-fun flattenStructAssignment(structAssignment: Assignment, program: Program): List<Assignment> {
+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!!
-    val sourceVar = (structAssignment.value as IdentifierReference).targetVarDecl(program.namespace)!!
-    if(!sourceVar.isArray && sourceVar.struct==null)
-        throw FatalAstException("can only assign arrays or structs to structs")
-    if(sourceVar.isArray) {
-        val sourceArray = (sourceVar.value as ReferenceLiteralValue).array!!
-        return struct.statements.zip(sourceArray).map { member ->
-            val decl = member.first as VarDecl
-            val mangled = mangledStructMemberName(identifierName, decl.name)
-            val idref = IdentifierReference(listOf(mangled), structAssignment.position)
-            val assign = Assignment(AssignTarget(null, idref, null, null, structAssignment.position),
-                    null, member.second, member.second.position)
-            assign.linkParents(structAssignment)
-            assign
+    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
+            }
         }
-    }
-    else {
-        // 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")
     }
 }
 
@@ -215,52 +209,59 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
     }
 
     override fun visit(assignment: Assignment): IStatement {
+        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 valuetype = assignment.value.inferType(program)
-        val targettype = assignment.target.inferType(program, assignment)
+        val valuetype = assg.value.inferType(program)
+        val targettype = assg.target.inferType(program, assg)
         if(targettype!=null && valuetype!=null) {
             if(valuetype!=targettype) {
                 if (valuetype isAssignableTo targettype) {
-                    assignment.value = TypecastExpression(assignment.value, targettype, true, assignment.value.position)
-                    assignment.value.linkParents(assignment)
+                    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
             }
         }
 
-        // struct assignments will be flattened
+        // struct assignments will be flattened (if it's not a struct literal)
         if(valuetype==DataType.STRUCT && targettype==DataType.STRUCT) {
-            val assignments = flattenStructAssignment(assignment, program)
+            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'
             if(assignments.isEmpty()) {
                 // something went wrong (probably incompatible struct types)
                 // we'll get an error later from the AstChecker
-                return assignment
+                return assg
             } else {
-                val scope = AnonymousScope(assignments.toMutableList(), assignment.position)
-                scope.linkParents(assignment.parent)
+                val scope = AnonymousScope(assignments.toMutableList(), assg.position)
+                scope.linkParents(assg.parent)
                 return scope
             }
         }
 
-        if(assignment.aug_op!=null) {
-            // transform augmented assignment into normal assignment so we have one case less to deal with later
+        if(assg.aug_op!=null) {
+            // transform augmented assg into normal assg so we have one case less to deal with later
             val newTarget: IExpression =
                     when {
-                        assignment.target.register != null -> RegisterExpr(assignment.target.register!!, assignment.target.position)
-                        assignment.target.identifier != null -> assignment.target.identifier!!
-                        assignment.target.arrayindexed != null -> assignment.target.arrayindexed!!
-                        assignment.target.memoryAddress != null -> DirectMemoryRead(assignment.target.memoryAddress!!.addressExpression, assignment.value.position)
-                        else -> throw FatalAstException("strange assignment")
+                        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")
                     }
 
-            val expression = BinaryExpression(newTarget, assignment.aug_op.substringBeforeLast('='), assignment.value, assignment.position)
-            expression.linkParents(assignment.parent)
-            val convertedAssignment = Assignment(assignment.target, null, expression, assignment.position)
-            convertedAssignment.linkParents(assignment.parent)
+            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)
         }
 
-        return super.visit(assignment)
+        return assg
     }
 
     override fun visit(functionCallStatement: FunctionCallStatement): IStatement {
@@ -319,28 +320,6 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
         }
     }
 
-    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 sorted = sequence.sortedWith(compareBy({it.value.inferType(program)}, {it.target.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)) {
@@ -397,4 +376,42 @@ internal class StatementReorderer(private val program: Program): IAstModifyingVi
         }
         super.visit(memwrite)
     }
+
+    override fun visit(structLv: StructLiteralValue): IExpression {
+        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 != memberDt)
+                TypecastExpression(it.second, memberDt, true, it.second.position)
+            else
+                it.second
+        }
+    }
 }

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

@@ -225,7 +225,7 @@ class VarDecl(val type: VarDeclType,
             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, structName, 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
@@ -234,7 +234,7 @@ class VarDecl(val type: VarDeclType,
     fun flattenStructMembers(): MutableList<IStatement> {
         val result = struct!!.statements.withIndex().map {
             val member = it.value as VarDecl
-            val initvalue = if(value!=null) (value as ReferenceLiteralValue).array!![it.index] else null
+            val initvalue = if(value!=null) (value as StructLiteralValue).values[it.index] else null
             VarDecl(
                     VarDeclType.VAR,
                     member.datatype,

compiler/src/prog8/compiler/AstToSourceCode.kt

@@ -1,16 +1,13 @@
 package prog8.compiler
 
+import 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.expressions.*
 import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
 
-class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
+class AstToSourceCode(val output: (text: String) -> Unit, val program: Program): IAstVisitor {
     var scopelevel = 0
 
     fun indent(s: String) = "    ".repeat(scopelevel) + s
@@ -261,30 +258,42 @@ class AstToSourceCode(val output: (text: String) -> Unit): IAstVisitor {
             refLiteral.isString -> output("\"${escape(refLiteral.str!!)}\"")
             refLiteral.isArray -> {
                 if(refLiteral.array!=null) {
-                    var counter = 0
-                    output("[")
-                    scopelevel++
-                    for (v in refLiteral.array) {
-                        v.accept(this)
-                        if (v !== refLiteral.array.last())
-                            output(", ")
-                        counter++
-                        if(counter > 16) {
-                            outputln("")
-                            outputi("")
-                            counter=0
-                        }
-                    }
-                    scopelevel--
-                    output("]")
+                    outputListMembers(refLiteral.array.asSequence(), '[', ']')
                 }
             }
         }
     }
 
+    private fun outputListMembers(array: Sequence<IExpression>, 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) {
+        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)
+        if (assignment.aug_op != null)
             output(" ${assignment.aug_op} ")
         else
             output(" = ")
@@ -432,6 +441,11 @@ 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) {
         output("; NOP @ ${nopStatement.position}  $nopStatement")
     }

compiler/src/prog8/compiler/Compiler.kt

@@ -4,7 +4,6 @@ import prog8.ast.*
 import prog8.ast.base.*
 import prog8.ast.base.RegisterOrPair.*
 import prog8.ast.expressions.*
-import prog8.ast.processing.flattenStructAssignment
 import prog8.ast.statements.*
 import prog8.compiler.intermediate.IntermediateProgram
 import prog8.compiler.intermediate.Opcode
@@ -593,6 +592,7 @@ internal class Compiler(private val program: Program) {
             is TypecastExpression -> translate(expr)
             is DirectMemoryRead -> translate(expr)
             is AddressOf -> translate(expr)
+            is StructLiteralValue -> throw CompilerException("a struct Lv should have been flattened as assignments")
             else -> {
                 val lv = expr.constValue(program) ?: throw CompilerException("constant expression required, not $expr")
                 when(lv.type) {
@@ -1404,6 +1404,26 @@ internal class Compiler(private val program: Program) {
 
     private fun translate(stmt: Assignment) {
         prog.line(stmt.position)
+        if(stmt.value is StructLiteralValue) {
+            // flatten into individual struct member assignments
+            val identifier = stmt.target.identifier!!
+            val identifierName = identifier.nameInSource.single()
+            val targetVar = identifier.targetVarDecl(program.namespace)!!
+            val struct = targetVar.struct!!
+            val sourcevalues = (stmt.value as StructLiteralValue).values
+            val assignments = struct.statements.zip(sourcevalues).map { member ->
+                val decl = member.first as VarDecl
+                val mangled = mangledStructMemberName(identifierName, decl.name)
+                val idref = IdentifierReference(listOf(mangled), stmt.position)
+                val assign = Assignment(AssignTarget(null, idref, null, null, stmt.position),
+                        null, member.second, member.second.position)
+                assign.linkParents(stmt)
+                assign
+            }
+            assignments.forEach { translate(it) }
+            return
+        }
+
         translate(stmt.value)
 
         val valueDt = stmt.value.inferType(program)
@@ -1448,11 +1468,6 @@ internal class Compiler(private val program: Program) {
                         else -> throw CompilerException("incompatible data types valueDt=$valueDt  targetDt=$targetDt  at $stmt")
                     }
                 }
-                DataType.STRUCT -> {
-                    // Assume the value is an array. Flatten the struct assignment into memberwise assignments.
-                    flattenStructAssignment(stmt, program).forEach { translate(it) }
-                    return
-                }
                 in StringDatatypes -> throw CompilerException("incompatible data types valueDt=$valueDt  targetDt=$targetDt  at $stmt")
                 in ArrayDatatypes -> throw CompilerException("incompatible data types valueDt=$valueDt  targetDt=$targetDt  at $stmt")
                 else -> throw CompilerException("weird/unknown targetdt")

compiler/src/prog8/compiler/Main.kt

@@ -17,7 +17,6 @@ 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
@@ -146,7 +145,7 @@ fun compileProgram(filepath: Path,
 
 fun printAst(programAst: Program) {
     println()
-    val printer = AstToSourceCode(::print)
+    val printer = AstToSourceCode(::print, programAst)
     printer.visit(programAst)
     println()
 }

compiler/src/prog8/functions/BuiltinFunctions.kt

@@ -261,7 +261,7 @@ private fun builtinLen(args: List<IExpression>, position: Position, program: Pro
         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).targetStatement(program.namespace) as VarDecl
+    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 -> {

examples/test.p8

@@ -12,11 +12,18 @@
     }
 
     sub start() {
-        Color rgb1
+        Color rgb1 = {1,2,3.44}
         Color rgb2
 
+        rgb2 = {22233, 33, 1.1}     ; @todo implicit type conversion
         c64scr.print_b(rgb1.green)
+        c64.CHROUT('\n')
         c64scr.print_b(rgb2.green)
+        c64.CHROUT('\n')
+
+        rgb1=rgb2
+        c64scr.print_b(rgb1.green)
+        c64.CHROUT('\n')
     }
 
 }

parser/antlr/prog8.g4

@@ -214,7 +214,9 @@ wordsuffix : '.w' ;
 
 booleanliteral :  'true' | 'false' ;
 
-arrayliteral :  '[' EOL? expression (',' EOL? expression)* EOL? ']' ;       // you can split the array list over several lines
+arrayliteral :  '[' EOL? expression (',' EOL? expression)* EOL? ']' ;       // you can split the values over several lines
+
+structliteral :  '{' EOL? expression (',' EOL? expression)* EOL? '}' ;       // you can split the values over several lines
 
 stringliteral :  STRING ;
 
@@ -222,6 +224,7 @@ charliteral : SINGLECHAR ;
 
 floatliteral :  FLOAT_NUMBER ;
 
+
 literalvalue :
 	integerliteral
 	| booleanliteral
@@ -229,6 +232,7 @@ literalvalue :
 	| stringliteral
 	| charliteral
 	| floatliteral
+	| structliteral
 	;
 
 inlineasm :  '%asm' INLINEASMBLOCK;