Working OOP.

src/parser.c

@@ -534,7 +534,63 @@ long expression() {
     if (pc >= MAX_TOK) return 0;
     if (tokens[pc].type == Id) {
         if (pc + 1 >= MAX_TOK) return 0;
-        if (tokens[pc+1].type == '[') {
+        if (tokens[pc+1].type == '.') {
+            int save_pc = pc;
+            int temp_pc = pc + 1;
+            if (temp_pc < MAX_TOK && tokens[temp_pc].type == '.') {
+                temp_pc++;
+                if (temp_pc < MAX_TOK && tokens[temp_pc].type == Id) {
+                    temp_pc++;
+                    if (temp_pc < MAX_TOK && tokens[temp_pc].type == '=') {
+                        int idx = find_local(tokens[pc].text, tokens[pc].val);
+                        if (idx == -1) error("Unknown object variable");
+                        if (idx < 0 || idx >= loc_cnt) return 0;
+                        long obj_ptr = memory[locals[idx].addr];
+                        if (obj_ptr == 0) {
+                            error("Null pointer dereference in assignment");
+                            return 0;
+                        }
+                        Object *obj = (Object*)obj_ptr;
+                        if (obj < objects || obj >= objects + MAX_OBJECTS) {
+                            error("Invalid object pointer in assignment");
+                            return 0;
+                        }
+                        pc++;
+                        match('.');
+                        if (pc >= MAX_TOK || tokens[pc].type != Id) {
+                            error("Expected field name after '.'");
+                            return 0;
+                        }
+                        Token *field_name = &tokens[pc];
+                        pc++;
+                        match('=');
+
+                        int class_idx = obj->class_idx;
+                        if (class_idx < 0 || class_idx >= class_count) {
+                            error("Invalid class index");
+                            return 0;
+                        }
+
+                        extern int find_class_field(int class_idx, char *name, int len);
+                        int field_idx = find_class_field(class_idx, field_name->text, field_name->val);
+                        if (field_idx < 0) {
+                            error("Unknown field");
+                            return 0;
+                        }
+
+                        int offset = classes[class_idx].fields[field_idx].offset;
+                        if (offset < 0 || offset >= classes[class_idx].size) {
+                            error("Invalid field offset");
+                            return 0;
+                        }
+
+                        long val = expression();
+                        obj->field_data[offset] = val;
+                        return val;
+                    }
+                }
+            }
+        } else if (tokens[pc+1].type == '[') {
             int idx = find_local(tokens[pc].text, tokens[pc].val);
             if (idx == -1) error("Assign to unknown var");
             if (idx < 0 || idx >= loc_cnt) return 0;