attempt to fix forloop range datatype issues

compiler/src/prog8/compiler/astprocessing/AstChecker.kt

@@ -222,8 +222,8 @@ internal class AstChecker(private val program: Program,
                     }
                     DataType.WORD -> {
                         if(iterableDt!= DataType.BYTE && iterableDt!= DataType.WORD &&
-                                iterableDt != DataType.ARRAY_B && iterableDt!= DataType.ARRAY_W &&
-                                iterableDt != DataType.ARRAY_W_SPLIT)
+                                iterableDt != DataType.ARRAY_B && iterableDt != DataType.ARRAY_UB &&
+                                iterableDt != DataType.ARRAY_W && iterableDt != DataType.ARRAY_W_SPLIT)
                             errors.err("word loop variable can only loop over bytes or words", forLoop.position)
                     }
                     DataType.FLOAT -> {
@@ -242,7 +242,7 @@ internal class AstChecker(private val program: Program,
                         val to = range.to as? NumericLiteral
                         if(from != null)
                             checkValueTypeAndRange(loopvar.datatype, from)
-                        else if(range.from.inferType(program) isnot loopvar.datatype)
+                        else if(range.from.inferType(program).isNotAssignableTo(loopvar.datatype))
                             errors.err("range start value is incompatible with loop variable type", range.position)
                         if(to != null)
                             checkValueTypeAndRange(loopvar.datatype, to)

compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt

@@ -341,6 +341,7 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
         }
         return noModifications
     }
+
     override fun after(range: RangeExpression, parent: Node): Iterable<IAstModification> {
         val fromDt = range.from.inferType(program).getOr(DataType.UNDEFINED)
         val toDt = range.to.inferType(program).getOr(DataType.UNDEFINED)
@@ -365,6 +366,14 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
         parent: Node
     ): List<IAstModification> {
 
+        if(varDt!=DataType.UNDEFINED) {
+            if(fromDt==varDt && toDt==varDt) {
+                return noModifications
+            } else if(fromDt==toDt && fromDt.isAssignableTo(varDt)) {
+                return noModifications
+            }
+        }
+
         if(fromConst!=null) {
             val smaller = NumericLiteral.optimalInteger(fromConst.number.toInt(), fromConst.position)
             if(fromDt.largerThan(smaller.type)) {

compiler/test/ast/TestAstChecks.kt

@@ -237,4 +237,56 @@ main {
         errors.errors.size shouldBe 1
         errors.errors[0] shouldContain "name conflict"
     }
+
+    test("various range datatype checks allow differences in type") {
+        val src="""
+main {
+    sub func() -> ubyte {
+        cx16.r0++
+        return cx16.r0L
+    }
+
+    sub start() {
+        bool[256] @shared cells
+        word starw
+        byte bb
+        uword uw
+        ubyte ub
+
+        starw = (240-64 as word) + func()
+
+        for starw in 50 downto 10  {
+            cx16.r0++
+        }
+        for starw in cx16.r0L downto 10  {
+            cx16.r0++
+        }
+
+        for ub in 0 to len(cells)-1 {
+            cx16.r0++
+        }
+        for ub in cx16.r0L to len(cells)-1 {
+            cx16.r0++
+        }
+        for bb in 50 downto 10  {
+            cx16.r0++
+        }
+        for bb in cx16.r0sL downto 10  {
+            cx16.r0++
+        }
+
+        for starw in 500 downto 10  {
+            cx16.r0++
+        }
+        for uw in 50 downto 10 {
+            cx16.r0++
+        }
+        for uw in 500 downto 10 {
+            cx16.r0++
+        }
+    }
+}"""
+        compileText(C64Target(), false, src, writeAssembly = false) shouldNotBe null
+        compileText(C64Target(), true, src, writeAssembly = false) shouldNotBe null
+    }
 })

docs/source/todo.rst

@@ -1,8 +1,6 @@
 TODO
 ====
 
-word starw;   for starw in 50 downto 0        -> compiler error word loop variable can only loop over bytes or words  FIX in adjustRangeDts() most likely
-
 Regenerate skeleton doc files.
 
 Improve register load order in subroutine call args assignments:

examples/test.p8

@@ -1,19 +1,25 @@
-%import textio
 %zeropage basicsafe
 %option no_sysinit
 
 main {
+    sub func() -> ubyte {
+        cx16.r0++
+        return cx16.r0L
+    }
+
     sub start() {
-        bool[256] cells
+        bool[256] @shared cells
         word starw
         byte bb
         uword uw
         ubyte ub
 
-        for starw in 50 downto 10  {        ; TODO fix compiler error + add unit test for this
+        starw = (240-64 as word) + func()
+
+        for starw in 50 downto 10  {
             cx16.r0++
         }
-        for starw in cx16.r0L downto 10  {        ; TODO fix compiler error + add unit test for this
+        for starw in cx16.r0L downto 10  {
             cx16.r0++
         }
 
@@ -30,16 +36,15 @@ main {
             cx16.r0++
         }
 
-
-;        for starw in 500 downto 10  {
-;            cx16.r0++
-;        }
-;        for uw in 50 downto 10 {
-;            cx16.r0++
-;        }
-;        for uw in 500 downto 10 {
-;            cx16.r0++
-;        }
+        for starw in 500 downto 10  {
+            cx16.r0++
+        }
+        for uw in 50 downto 10 {
+            cx16.r0++
+        }
+        for uw in 500 downto 10 {
+            cx16.r0++
+        }
     }
 }