bool http_parser::parse_http_version(header::version &version)
{
    // HTTP-Version   = "HTTP" "/" 1*DIGIT "." 1*DIGIT
    save();

    if (parse_static_string("HTTP/")
            && parse_decimal_number_unsigned(version.major)
            && parse_static_string(".")
            && parse_decimal_number_unsigned(version.minor))
        return commit();

    return restore();
}

bool http_parser::parse_decimal_number_unsigned(uint &number)
{
    save();

    next_char();
    if (!is_digit_nonzero())
        return restore();

    number = 0;
    do {
        number *= 10;
        number += current_seek_next() - '0';
    } while (is_digit());

    return commit();
}

bool http_parser::parse_comment(std::string &comment)
{
  // comment        = "(" *( ctext | quoted-pair | comment ) ")"
  save();

  current_seek_next();
  if (current() != '(')
    return restore();

  std::string text;
  while (parse_ctext(text) || parse_quoted_pair(text) || parse_comment(text))
    comment += text;

  if (current() != '(')
    return restore();

  return commit();
}