const MatchImplementation(
    String this.pattern,
    String this.str,
    int this._start,
    int this._end,
    List<String> this._groups);

int end() => _end;

String group(int index) => _groups[index];

int groupCount() => _groups.length - 1;

List<String> groups(List<int> groups) {
  List<String> out = [];
  for (int i in groups) {
    out.add(group(i));
  }
  return out;
}

String operator [](int index) => group(index);

int start() => _start;