Method Search

extern/re2/re2/nfa.cc:448–629

}

bool NFA::Search(const StringPiece& text, const StringPiece& const_context,
            bool anchored, bool longest,
            StringPiece* submatch, int nsubmatch) {
  if (start_ == 0)
    return false;

  StringPiece context = const_context;
  if (context.data() == NULL)
    context = text;

  // Sanity check: make sure that text lies within context.
  if (text.begin() < context.begin() || text.end() > context.end()) {
    LOG(DFATAL) << "context does not contain text";
    return false;
  }

  if (prog_->anchor_start() && context.begin() != text.begin())
    return false;
  if (prog_->anchor_end() && context.end() != text.end())
    return false;
  anchored |= prog_->anchor_start();
  if (prog_->anchor_end()) {
    longest = true;
    endmatch_ = true;
  }

  if (nsubmatch < 0) {
    LOG(DFATAL) << "Bad args: nsubmatch=" << nsubmatch;
    return false;
  }

  // Save search parameters.
  ncapture_ = 2*nsubmatch;
  longest_ = longest;

  if (nsubmatch == 0) {
    // We need to maintain match[0], both to distinguish the
    // longest match (if longest is true) and also to tell
    // whether we've seen any matches at all.
    ncapture_ = 2;
  }

  match_ = new const char*[ncapture_];
  memset(match_, 0, ncapture_*sizeof match_[0]);
  matched_ = false;

  // For debugging prints.
  btext_ = context.data();
  // For convenience.
  etext_ = text.data() + text.size();

  if (ExtraDebug)
    fprintf(stderr, "NFA::Search %s (context: %s) anchored=%d longest=%d\n",
            std::string(text).c_str(), std::string(context).c_str(), anchored, longest);

  // Set up search.
  Threadq* runq = &q0_;
  Threadq* nextq = &q1_;