Using map() on an iterator

Question

Say we have a Map: let m = new Map();, using m.values() returns a map iterator.

But I can\'t use forEach() or map() o

Answer 1

Other answers here are... Weird. They seem to be re-implementing parts of the iteration protocol. You can just do this:

function* mapIter(iterable, callback) {
  for (let x of iterable) {
    yield callback(x);
  }
}

and if you want a concrete result just use the spread operator ....

[...iterMap([1, 2, 3], x => x**2)]