Python-like range function in Dart

range.dart

Iterable<int> range(int start, [int stop, int increment]) sync* {
  if (increment == null) {
    increment = 1;
  }
  
  if (stop == null) {
    stop = start;
    start = 0;
  }

  for (int i = start; start < stop ? i < stop : i > stop; i += increment) {
    yield i;
  }
}