Function TopEqual

extern/re2/re2/regexp.cc:347–410

Tests equality of all top-level structure but not subregexps.

// Tests equality of all top-level structure but not subregexps.
static bool TopEqual(Regexp* a, Regexp* b) {
  if (a->op() != b->op())
    return false;

  switch (a->op()) {
    case kRegexpNoMatch:
    case kRegexpEmptyMatch:
    case kRegexpAnyChar:
    case kRegexpAnyByte:
    case kRegexpBeginLine:
    case kRegexpEndLine:
    case kRegexpWordBoundary:
    case kRegexpNoWordBoundary:
    case kRegexpBeginText:
      return true;

    case kRegexpEndText:
      // The parse flags remember whether it's \z or (?-m:$),
      // which matters when testing against PCRE.
      return ((a->parse_flags() ^ b->parse_flags()) & Regexp::WasDollar) == 0;

    case kRegexpLiteral:
      return a->rune() == b->rune() &&
             ((a->parse_flags() ^ b->parse_flags()) & Regexp::FoldCase) == 0;

    case kRegexpLiteralString:
      return a->nrunes() == b->nrunes() &&
             ((a->parse_flags() ^ b->parse_flags()) & Regexp::FoldCase) == 0 &&
             memcmp(a->runes(), b->runes(),
                    a->nrunes() * sizeof a->runes()[0]) == 0;

    case kRegexpAlternate:
    case kRegexpConcat:
      return a->nsub() == b->nsub();

    case kRegexpStar:
    case kRegexpPlus:
    case kRegexpQuest:
      return ((a->parse_flags() ^ b->parse_flags()) & Regexp::NonGreedy) == 0;

    case kRegexpRepeat:
      return ((a->parse_flags() ^ b->parse_flags()) & Regexp::NonGreedy) == 0 &&
             a->min() == b->min() &&
             a->max() == b->max();

    case kRegexpCapture:
      return a->cap() == b->cap() && a->name() == b->name();

    case kRegexpHaveMatch:
      return a->match_id() == b->match_id();

    case kRegexpCharClass: {
      CharClass* acc = a->cc();
      CharClass* bcc = b->cc();
      return acc->size() == bcc->size() &&
             acc->end() - acc->begin() == bcc->end() - bcc->begin() &&
             memcmp(acc->begin(), bcc->begin(),
                    (acc->end() - acc->begin()) * sizeof acc->begin()[0]) == 0;