Thing parse(string* text) {
  if (text.accept "(") {
    Thing[] things;
    while (!text.accept ")")
      things ~= parse text;
    return new List things;
  }
  if (gotNum(text, &float f)) {
    return new Number f;
  }
  if (text.accept("\"")) {
    auto str = slice(text, "\"");
    return new String str;
  }
  if (text.accept("'")) {
    return new Escape (parse text);
  }
  auto t2 = *text #.strip();
  char[auto~] token;
  while (t2.length && t2[0] != " " && t2[0] != ")" && t2[0] != "(" && t2[0] != "\r" && t2[0] != "\n") {
    token ~= t2[0];
    t2 = t2[1..$];
  }
  if (!token.length)
    error "Don't know what to do at $t2";
  *text = t2;
  return new Token token[];
}