Method PushRegexp

extern/re2/re2/parse.cc:237–267

Pushes the given regular expression onto the stack. Could check for too much memory used here.

// Pushes the given regular expression onto the stack.
// Could check for too much memory used here.
bool Regexp::ParseState::PushRegexp(Regexp* re) {
  MaybeConcatString(-1, NoParseFlags);

  // Special case: a character class of one character is just
  // a literal.  This is a common idiom for escaping
  // single characters (e.g., [.] instead of \.), and some
  // analysis does better with fewer character classes.
  // Similarly, [Aa] can be rewritten as a literal A with ASCII case folding.
  if (re->op_ == kRegexpCharClass && re->ccb_ != NULL) {
    re->ccb_->RemoveAbove(rune_max_);
    if (re->ccb_->size() == 1) {
      Rune r = re->ccb_->begin()->lo;
      re->Decref();
      re = new Regexp(kRegexpLiteral, flags_);
      re->rune_ = r;
    } else if (re->ccb_->size() == 2) {
      Rune r = re->ccb_->begin()->lo;
      if ('A' <= r && r <= 'Z' && re->ccb_->Contains(r + 'a' - 'A')) {
        re->Decref();
        re = new Regexp(kRegexpLiteral, flags_ | FoldCase);
        re->rune_ = r + 'a' - 'A';
      }
    }
  }

  if (!IsMarker(re->op()))
    re->simple_ = re->ComputeSimple();
  re->down_ = stacktop_;
  stacktop_ = re;
  return true;
}

// Searches the case folding tables and returns the CaseFold* that contains r.
// If there isn't one, returns the CaseFold* with smallest f->lo bigger than r.