where-not-in.dart

void main() {
  final lst1 = ["t1" , "t2" , "t3" , "t4"];
  final lst2 = ["t2" , "t4" , "t5"];
  final diff = lst1.whereNotIn(lst2).toList();
  print(diff);
}

extension WhereNotInExt<T> on Iterable<T> {
  Iterable<T> whereNotIn(Iterable<T> reject) {
    final rejectSet = reject.toSet();
    return where((el) => !rejectSet.contains(el));
  }
}