zip2<T1, T2> function

Iterable<Tuple2<T1, T2>> zip2<T1, T2>(
  1. Iterable<T1> it1,
  2. Iterable<T2> it2
)

Implementation

Iterable<Tuple2<T1, T2>> zip2<T1, T2>(
    Iterable<T1> it1, Iterable<T2> it2) sync* {
  final iter1 = it1.iterator;
  final iter2 = it2.iterator;
  var keep_running = true;
  while (keep_running) {
    final move1 = iter1.moveNext();
    final move2 = iter2.moveNext();
    final all_true = move1 && move2;
    final all_false = !move1 && !move2;
    assert((all_true || all_false), 'iteration length must be equal');
    if (all_true) {
      yield Tuple2<T1, T2>(iter1.current, iter2.current);
    }
    keep_running = all_true;
  }
}