Method DoRightParen

extern/re2/re2/parse.cc:676–712

Processes a right parenthesis in the input.

// Processes a right parenthesis in the input.
bool Regexp::ParseState::DoRightParen() {
  // Finish the current concatenation and alternation.
  DoAlternation();

  // The stack should be: LeftParen regexp
  // Remove the LeftParen, leaving the regexp,
  // parenthesized.
  Regexp* r1;
  Regexp* r2;
  if ((r1 = stacktop_) == NULL ||
      (r2 = r1->down_) == NULL ||
      r2->op() != kLeftParen) {
    status_->set_code(kRegexpUnexpectedParen);
    status_->set_error_arg(whole_regexp_);
    return false;
  }

  // Pop off r1, r2.  Will Decref or reuse below.
  stacktop_ = r2->down_;

  // Restore flags from when paren opened.
  Regexp* re = r2;
  flags_ = re->parse_flags();

  // Rewrite LeftParen as capture if needed.
  if (re->cap_ > 0) {
    re->op_ = kRegexpCapture;
    // re->cap_ is already set
    re->AllocSub(1);
    re->sub()[0] = FinishRegexp(r1);
    re->simple_ = re->ComputeSimple();
  } else {
    re->Decref();
    re = r1;
  }
  return PushRegexp(re);
}

// Processes the end of input, returning the final regexp.
Regexp* Regexp::ParseState::DoFinish() {