gistfile1.js

function* asyncIterator() {
  let value, done;
  while ({value, done} = (yield null), !done) {
    console.log("got", value);
  }
  console.log("done");
}

it = asyncIterator();
it.next();

let i = 0;
(function loop() {
  if (i > 10)
    return it.next({ done: true });

  it.next({ value: i++, done: false });
  setTimeout(loop, 500);
}());