impl scopes more or less properly

main.c

@@ -37,11 +37,15 @@ int main(int argc, char **argv) {
     }
 #endif
 
+    Scopes scopes = {0};
+    build_scopes(&scopes);
+
     Node *result = parse(&tokens);
     if (result == NULL)
         return 1;
 
-    result = eval(result);
+    result = eval(result, &scopes);
+    printf("= ");
     node_print(*result);
     printf("\n");