Add simple evaluation

src/memory.c

@@ -48,6 +48,15 @@ struct nl_object *nl_error_create(const char *error)
     return obj;
 }
 
+
+struct nl_object *nl_builtin_create(nl_builtin builtin)
+{
+    struct nl_object* obj = nl_object_alloc();
+    obj->type = NL_TYPE_BUILTIN;
+    obj->builtin = builtin;
+    return obj;
+}
+
 static struct nl_object* nl_object_alloc() {
     return malloc(sizeof(struct nl_object));
 }
@@ -77,6 +86,7 @@ void nl_object_delete(struct nl_object *obj) {
             obj->error = NULL;
             break;
         case NL_TYPE_INT:
+        case NL_TYPE_BUILTIN:
         case NL_TYPE_COUNT:
             break;
     }