fix multi-var decl in nested scopes

compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt

@@ -1,9 +1,12 @@
 package prog8.compiler.astprocessing
 
-import prog8.ast.*
+import prog8.ast.IFunctionCall
+import prog8.ast.Node
+import prog8.ast.Program
 import prog8.ast.base.FatalAstException
 import prog8.ast.base.SyntaxError
 import prog8.ast.expressions.*
+import prog8.ast.findParentNode
 import prog8.ast.statements.*
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
@@ -113,11 +116,26 @@ class AstPreprocessor(val program: Program,
                     movements.add(IAstModification.InsertFirst(decl, parentscope))
                     replacements.add(IAstModification.Remove(decl, scope))
                 } else {
+                    val declToInsert: VarDecl
                     if(decl.names.size>1) {
                         // we need to handle multi-decl here too, the desugarer maybe has not processed it here yet...
-                        TODO("handle multi-decl movement")
+                        if(decl.value!=null) {
+                            decl.names.forEach { name ->
+                                val target = AssignTarget(IdentifierReference(listOf(name), decl.position), null, null, decl.position)
+                                val assign = Assignment(target.copy(), decl.value!!.copy(), AssignmentOrigin.VARINIT, decl.position)
+                                replacements.add(IAstModification.InsertAfter(decl, assign, scope))
+                            }
+                            replacements.add(IAstModification.Remove(decl, scope))
+                            decl.value = null
+                            decl.allowInitializeWithZero = false
+                            declToInsert = decl
+                        } else {
+                            // just move it to the defining scope
+                            replacements.add(IAstModification.Remove(decl, scope))
+                            declToInsert = decl
+                        }
                     } else {
-                        val declToInsert: VarDecl
+                        // handle declaration of a single variable
                         if(decl.value!=null && decl.datatype in NumericDatatypes) {
                             val target = AssignTarget(IdentifierReference(listOf(decl.name), decl.position), null, null, decl.position)
                             val assign = Assignment(target, decl.value!!, AssignmentOrigin.VARINIT, decl.position)
@@ -129,8 +147,8 @@ class AstPreprocessor(val program: Program,
                             replacements.add(IAstModification.Remove(decl, scope))
                             declToInsert = decl
                         }
-                        movements.add(IAstModification.InsertFirst(declToInsert, parentscope))
                     }
+                    movements.add(IAstModification.InsertFirst(declToInsert, parentscope))
                 }
             }
             return movements + replacements
@@ -152,20 +170,6 @@ class AstPreprocessor(val program: Program,
     }
 
     override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
-        if(decl.names.size>1) {
-            // note: the desugaring of a multi-variable vardecl has to be done here
-            // and not in CodeDesugarer, that one is too late (identifiers can't be found otherwise)
-            if(decl.datatype !in NumericDatatypes)
-                errors.err("can only multi declare numeric variables", decl.position)
-            return if(errors.noErrors()) {
-                // desugar into individual vardecl per name.
-                decl.desugarMultiDecl().map {
-                    IAstModification.InsertAfter(decl, it, parent as IStatementContainer)
-                } + IAstModification.Remove(decl, parent as IStatementContainer)
-            } else
-                noModifications
-        }
-
         val nextAssignment = decl.nextSibling() as? Assignment
         if(nextAssignment!=null && nextAssignment.origin!=AssignmentOrigin.VARINIT) {
             // check if it's a proper initializer assignment for the variable

compiler/src/prog8/compiler/astprocessing/LiteralsToAutoVars.kt

@@ -1,6 +1,7 @@
 package prog8.compiler.astprocessing
 
 import prog8.ast.IFunctionCall
+import prog8.ast.IStatementContainer
 import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.expressions.ArrayLiteral
@@ -12,10 +13,7 @@ import prog8.ast.statements.VarDecl
 import prog8.ast.statements.WhenChoice
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
-import prog8.code.core.DataType
-import prog8.code.core.ICompilationTarget
-import prog8.code.core.IErrorReporter
-import prog8.code.core.SplitWordArrayTypes
+import prog8.code.core.*
 
 
 internal class LiteralsToAutoVars(private val program: Program,
@@ -73,4 +71,20 @@ internal class LiteralsToAutoVars(private val program: Program,
         }
         return noModifications
     }
+
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        if(decl.names.size>1) {
+            // note: the desugaring of a multi-variable vardecl has to be done here
+            // and not in CodeDesugarer, that one is too late (identifiers can't be found otherwise)
+            if(decl.datatype !in NumericDatatypes)
+                errors.err("can only multi declare numeric variables", decl.position)
+            if(errors.noErrors()) {
+                // desugar into individual vardecl per name.
+                return decl.desugarMultiDecl().map {
+                    IAstModification.InsertAfter(decl, it, parent as IStatementContainer)
+                } + IAstModification.Remove(decl, parent as IStatementContainer)
+            }
+        }
+        return noModifications
+    }
 }

compilerAst/src/prog8/ast/AstToSourceTextConverter.kt

@@ -131,7 +131,10 @@ class AstToSourceTextConverter(val output: (text: String) -> Unit, val program:
             output(" @zp")
         if(decl.sharedWithAsm)
             output(" @shared")
-        output(" ${decl.name} ")
+        if(decl.names.size>1)
+            output(decl.names.joinToString(prefix=" "))
+        else
+            output(" ${decl.name} ")
         if(decl.value!=null) {
             output("= ")
             decl.value?.accept(this)

docs/source/todo.rst

@@ -2,8 +2,6 @@
 TODO
 ====
 
-- fix multi-decl in for loops, see AstPreprocessor TODO("handle multi-decl movement")
-
 - [on branch: shortcircuit] investigate McCarthy evaluation again? this may also reduce code size perhaps for things like if a>4 or a<2 ....
 
 ...
@@ -80,6 +78,7 @@ What if we were to re-introduce Structs in prog8? Some thoughts:
 Other language/syntax features to think about
 ---------------------------------------------
 
+- underscores in numeric literals for grouping
 - chained comparisons   `10<x<20` ,   `x==y==z`   (desugars to  `10<x and x<20`,   `x==y and y==z`) BUT this changes the semantics of what it is right now ! (x==(y==z) 0> x==true)
 - postincrdecr as expression, preincrdecr expression   (`y = x++`,   `y = ++x`)    .... is this even possible, expression with side effects like this?
 - negative array index to refer to an element from the end of the array.  Python `[-1]` or Raku syntax `[\*-1]`  , `[\*/2]` .... \*=size of the array

examples/test.p8

@@ -5,17 +5,21 @@ main {
     const ubyte VAL = 11
     sub start() {
         uword w
-        ubyte @zp x,y,z = 99
 
-        txt.print_ub(x)
-        txt.spc()
-        txt.print_ub(y)
-        txt.spc()
-        txt.print_ub(z)
-        txt.spc()
-        txt.print_uw(w)
-        txt.nl()
-        if x==y==z
+        for w in 0 to 20 {
+            ubyte x,y,z=13
+
+            txt.print_ub(x)
+            txt.spc()
+            txt.print_ub(y)
+            txt.spc()
+            txt.print_ub(z)
+            txt.spc()
+            txt.print_uw(w)
+            txt.nl()
             x++
+            y++
+            z++
+        }
     }
 }