improved expr_inspect

}

std::string expr_inspect(const Expr* expr) {

  if (!expr) {

    return "()";

  }

  std::stringstream s;

  for (; expr; expr = expr_next(expr)) {

    switch (expr->type) {

      case ExprType::VALUE:

      case ExprType::VALUE_LITERAL:

      return expr->value;

        s << expr->value;

        break;

      case ExprType::LIST:

      expr = expr_get_list(expr);

        s << "(";

        s << expr_inspect(expr_get_list(expr));

        s << ")";

        break;

    }

  std::stringstream str;

  str << "(";

  while (expr) {

    str << expr_inspect(expr);

    expr = expr_next(expr);

    if (expr) {

      str << " ";

    if (expr_next(expr)) {

      s << " ";

    }

  }

  str << ")";

  return str.str();

  return s.str();

}

} // namespace fviz