do..until condition can now refer to variables defined in the loop's inner scope.

compiler/src/prog8/ast/AstToplevel.kt

@@ -137,7 +137,15 @@ interface INameScope {
             }
             return null
         } else {
-            // unqualified name, find the scope the localContext is in, look in that first
+            // unqualified name
+            // special case: the do....until statement can also look INSIDE the anonymous scope
+            if(localContext.parent.parent is UntilLoop) {
+                val symbolFromInnerScope = (localContext.parent.parent as UntilLoop).body.getLabelOrVariable(scopedName[0])
+                if(symbolFromInnerScope!=null)
+                    return symbolFromInnerScope
+            }
+
+            // find the scope the localContext is in, look in that first
             var statementScope = localContext
             while(statementScope !is ParentSentinel) {
                 val localScope = statementScope.definingScope()
@@ -312,6 +320,16 @@ class GlobalNamespace(val modules: List<Module>): Node, INameScope {
                 }
             }
         }
+
+        // special case: the do....until statement can also look INSIDE the anonymous scope
+        if(localContext.parent.parent is UntilLoop) {
+            val symbolFromInnerScope = (localContext.parent.parent as UntilLoop).body.lookup(scopedName, localContext)
+            if(symbolFromInnerScope!=null)
+                return symbolFromInnerScope
+        }
+        val p1 = localContext.parent
+        val p2 = localContext.parent.parent
+
         // lookup something from the module.
         return when (val stmt = localContext.definingModule().lookup(scopedName, localContext)) {
             is Label, is VarDecl, is Block, is Subroutine, is StructDecl -> stmt

docs/source/todo.rst

@@ -4,7 +4,6 @@ TODO
 
 - get rid of all other TODO's in the code ;-)
 - line-circle-gfx examples are now a few hundred bytes larger than before (~4.0/4.1 version i think?). Why is that, can it be fixed?
-- until condition should be able to refer to variables defined IN the do-until block itself.
 - add support? example? for processing arguments to a sys call : sys 999, 1, 2, "aaa"
 - make it possible for array literals to not only contain compile time constants
 - further optimize assignment codegeneration
@@ -20,6 +19,7 @@ More optimizations
 
 Add more compiler optimizations to the existing ones.
 
+- better assembly for comparison expressions most notably == and != (these use eval stack all the time)
 - more targeted optimizations for assigment asm code, such as the following:
 - subroutine calling convention? like: 1 byte arg -> pass in A, 2 bytes -> pass in A+Y, return value likewise.
 - can such parameter passing to subroutines be optimized to avoid copying?

examples/test.p8

@@ -8,8 +8,10 @@ main $0900{
 
     sub start()  {
 
+        ubyte x= 1
         do {
-            ubyte v = 1
+            ubyte v = x
+            x++
         } until v==0
 
         ; @($c000) *= 99        ; TODO implement