fix compiler crash when using strings in if-expression. Remove harmless info message.

codeGenCpu6502/src/prog8/codegen/cpu6502/IfExpressionAsmGen.kt

@@ -9,7 +9,7 @@ import prog8.codegen.cpu6502.assignment.TargetStorageKind
 internal class IfExpressionAsmGen(private val asmgen: AsmGen6502Internal, private val assignmentAsmGen: AssignmentAsmGen, private val errors: IErrorReporter) {
 
     internal fun assignIfExpression(target: AsmAssignTarget, expr: PtIfExpression) {
-        require(target.datatype==expr.type)
+        require(target.datatype==expr.type || target.datatype.isUnsignedWord && expr.type.isString)
         val falseLabel = asmgen.makeLabel("ifexpr_false")
         val endLabel = asmgen.makeLabel("ifexpr_end")
         evalIfExpressionConditonAndBranchWhenFalse(expr.condition, falseLabel)
@@ -22,7 +22,7 @@ internal class IfExpressionAsmGen(private val asmgen: AsmGen6502Internal, privat
                 asmgen.out(endLabel)
                 assignmentAsmGen.assignRegisterByte(target, CpuRegister.A, false, false)
             }
-            expr.type.isWord -> {
+            expr.type.isWord || expr.type.isString -> {
                 asmgen.assignExpressionToRegister(expr.truevalue, RegisterOrPair.AY, false)
                 asmgen.jmp(endLabel)
                 asmgen.out(falseLabel)

compiler/res/prog8lib/cx16/sprites.p8

@@ -1,7 +1,9 @@
 ; Simple routines to control sprites.
+
 ; They're not written for high performance, but for simplicity.
-; That's why they control 1 sprite at a time. The exception is pos_batch().
-; which is quite efficient to update sprite positions of multiple sprites in one go.
+; That's why they control 1 sprite at a time. \
+; The exceptions are pos_batch() and pos_batch_split(); these are quite efficient
+; to update sprite positions of multiple sprites in one call.
 
 ; note: sprites z-order will be in front of all layers.
 ; note: collision mask is not supported here yet.

compiler/src/prog8/compiler/astprocessing/NotExpressionAndIfComparisonExprChanger.kt

@@ -191,7 +191,6 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
         val prefix = ifExpr.condition as? PrefixExpression
         if(prefix?.operator=="not") {
             // if not x  a else b ->  if x  b else a
-            errors.info("invert condition and swap values", ifExpr.condition.position)
             ifExpr.condition = prefix.expression
             ifExpr.condition.parent = ifExpr
             val falsevalue = ifExpr.falsevalue

compiler/test/codegeneration/TestVariousCodeGen.kt

@@ -603,4 +603,18 @@ main {
         ir shouldContain "bit.b ${'$'}ff0a"     // r4
         ir shouldContain "bit.b ${'$'}ff0c"     // r5
     }
+
+    test("strings in if expression") {
+        val src="""
+main {
+    sub start() {
+       str foo = "foo"
+       str bar = "bar"
+       bool flag = true
+       uword @shared foobar = if flag foo else bar
+    }
+}"""
+        compileText(C64Target(), false, src, writeAssembly = true) shouldNotBe null
+        compileText(VMTarget(), false, src, writeAssembly = true) shouldNotBe null
+    }
 })

examples/test.p8

@@ -1,10 +1,12 @@
+%import textio
 %option no_sysinit
 %zeropage basicsafe
 
 main {
     sub start() {
-        cx16.r0L = cx16.r1L
-        cx16.r1=9999
-        cx16.r2=9999
+       str foo = "foo"
+       str bar = "bar"
+       bool flag = true
+       uword @shared foobar = if flag foo else bar
     }
 }