Function ParseCCName

extern/re2/re2/parse.cc:1820–1852

Parses a character class name like [:alnum:]. Sets *s to span the remainder of the string. Adds the ranges corresponding to the class to ranges.

// Sets *s to span the remainder of the string.
// Adds the ranges corresponding to the class to ranges.
static ParseStatus ParseCCName(StringPiece* s, Regexp::ParseFlags parse_flags,
                               CharClassBuilder *cc,
                               RegexpStatus* status) {
  // Check begins with [:
  const char* p = s->data();
  const char* ep = s->data() + s->size();
  if (ep - p < 2 || p[0] != '[' || p[1] != ':')
    return kParseNothing;

  // Look for closing :].
  const char* q;
  for (q = p+2; q <= ep-2 && (*q != ':' || *(q+1) != ']'); q++)
    ;

  // If no closing :], then ignore.
  if (q > ep-2)
    return kParseNothing;

  // Got it.  Check that it's valid.
  q += 2;
  StringPiece name(p, static_cast<size_t>(q - p));

  const UGroup *g = LookupPosixGroup(name);
  if (g == NULL) {
    status->set_code(kRegexpBadCharRange);
    status->set_error_arg(name);
    return kParseError;
  }

  s->remove_prefix(name.size());
  AddUGroup(cc, g, g->sign, parse_flags);
  return kParseOk;
}

// Parses a character inside a character class.
// There are fewer special characters here than in the rest of the regexp.