range like python for dart

readme.md

Create by https://gist.github.com/CaiJingLong/a299d15b92edc2d09a8a06cf6dd5a1b0

main.dart

void main() {
  print(range(100, start: 1, step: 7));
}

Iterable<int> range(int end, {int start = 0, int step = 1}) sync* {
  assert(step >= 1);
  int r = start;

  while (r < end) {
    yield r;
    r += step;
  }
}