  void Inspect::operator()(Assignment_Ptr assn)
  {
    append_token(assn->variable(), assn);
    append_colon_separator();
    assn->value()->perform(this);
    if (assn->is_default()) {
      append_optional_space();
      append_string("!default");
    }
    append_delimiter();
  }
  void Inspect::operator()(Assignment_Ptr assn)
  {
    append_token(assn->variable(), assn);
    append_colon_separator();
    assn->value()->perform(this);
    if (assn->is_default()) {
      append_optional_space();
      append_string("!default");
    }
    append_delimiter();
  }