fixed

Author: ProgrammerKR

compile.bat

@@ -1,5 +1,5 @@
 @echo off
-clang -o proxpl.exe -Iinclude -Isrc -D_CRT_SECURE_NO_WARNINGS -DPROX_STATIC ^
+clang -o proxpl.exe -Iinclude -Isrc -D_CRT_SECURE_NO_WARNINGS -DPROX_STATIC -DDEBUG_SUBSTR -DDEBUG_PROPERTY_ACCESS ^
  src/main.c ^
  src/compiler/lexer/scanner.c ^
  src/compiler/parser/ast.c ^

src/runtime/vm.c

@@ -398,10 +398,29 @@ static InterpretResult run(VM* vm) {
       Value target = peek(vm, 0);
       ObjString* name = READ_STRING();
 
+      #ifdef DEBUG_PROPERTY_ACCESS
+      printf("[DEBUG_PROP] OP_GET_PROPERTY: property=%s\n", name->chars);
+      printf("[DEBUG_PROP] target: IS_INST=%d IS_MOD=%d\n", 
+             IS_INSTANCE(target), IS_MODULE(target));
+      #endif
+
       if (IS_INSTANCE(target)) {
           struct ObjInstance* instance = AS_INSTANCE(target);
           Value value;
           if (tableGet(&instance->fields, name, &value)) {
+              #ifdef DEBUG_PROPERTY_ACCESS
+              printf("[DEBUG_PROP] Found field '%s': IS_OBJ=%d IS_STRING=%d\n", 
+                     name->chars, IS_OBJ(value), IS_STRING(value));
+              if (IS_OBJ(value)) {
+                  Obj* obj = AS_OBJ(value);
+                  printf("[DEBUG_PROP] Field obj: type=%d ptr=%p\n", obj->type, (void*)obj);
+                  if (IS_STRING(value)) {
+                      ObjString* str = AS_STRING(value);
+                      printf("[DEBUG_PROP] Field string: len=%d ptr=%p hash=%u\n",
+                             str->length, (void*)str, str->hash);
+                  }
+              }
+              #endif
               pop(vm); // Instance
               push(vm, value);
               DISPATCH();

src/stdlib/stdlib_core.c

@@ -73,20 +73,54 @@ static Value native_pop(int argCount, Value* args) {
 }
 
 static Value native_substr(int argCount, Value* args) {
+    // DEBUG: Track substr calls
+    #ifdef DEBUG_SUBSTR
+    printf("[DEBUG_SUBSTR] Called with %d args\n", argCount);
+    if (argCount >= 1) {
+        printf("[DEBUG_SUBSTR] arg[0]: IS_OBJ=%d IS_STRING=%d\n", 
+               IS_OBJ(args[0]), IS_STRING(args[0]));
+        if (IS_OBJ(args[0])) {
+            Obj* obj = AS_OBJ(args[0]);
+            printf("[DEBUG_SUBSTR] arg[0] obj type=%d ptr=%p\n", obj->type, (void*)obj);
+            if (IS_STRING(args[0])) {
+                ObjString* str = AS_STRING(args[0]);
+                printf("[DEBUG_SUBSTR] arg[0] string: len=%d ptr=%p hash=%u\n", 
+                       str->length, (void*)str, str->hash);
+            }
+        }
+    }
+    #endif
+    
     if (argCount < 3) return NIL_VAL;
-    if (!IS_STRING(args[0]) || !IS_NUMBER(args[1]) || !IS_NUMBER(args[2])) return NIL_VAL;
+    if (!IS_STRING(args[0]) || !IS_NUMBER(args[1]) || !IS_NUMBER(args[2])) {
+        #ifdef DEBUG_SUBSTR
+        printf("[DEBUG_SUBSTR] Type check failed: IS_STRING=%d IS_NUM[1]=%d IS_NUM[2]=%d\n",
+               IS_STRING(args[0]), IS_NUMBER(args[1]), IS_NUMBER(args[2]));
+        #endif
+        return NIL_VAL;
+    }
 
     ObjString* source = AS_STRING(args[0]);
     int start = (int)AS_NUMBER(args[1]);
     int length = (int)AS_NUMBER(args[2]);
 
+    #ifdef DEBUG_SUBSTR
+    printf("[DEBUG_SUBSTR] source string: len=%d start=%d length=%d\n", 
+           source->length, start, length);
+    #endif
+    
     if (start < 0 || start >= source->length) {
         return OBJ_VAL(copyString("", 0));
     }
     if (length < 0) length = 0;
     if (start + length > source->length) length = source->length - start;
 
-    return OBJ_VAL(copyString(source->chars + start, length));
+    ObjString* result = copyString(source->chars + start, length);
+    #ifdef DEBUG_SUBSTR
+    printf("[DEBUG_SUBSTR] result string: len=%d ptr=%p\n", result->length, (void*)result);
+    #endif
+    
+    return OBJ_VAL(result);
 }
 
 /*