traverseState<B, S> method

State<S, IList<B>> traverseState<B, S>(State<S, B> f(A a))

Implementation

State<S, IList<B>> traverseState<B, S>(State<S, B> f(A a)) {
  State<S, IList<B>> result = new State((s) => tuple2(nil(), s));
  var current = this;
  while(current._isCons()) {
    final gb = f(current._unsafeHead());
    result = result.flatMap((a) => gb.map((h) => new Cons(h, a)));
    current = current._unsafeTail();
  }
  return result.map((l) => l.reverse());
}