ES6 generators: transforming callbacks to iterators

Question

I\'m experimenting with ES6 generators with the help of babel, and I have trouble understand how (or if!) I can effectively use callback based async function to output an it

Answer 1

Is there a way to get the intended behaviour using standard and current features

Yes, use promises and generators. Many promise libraries, and some standalone ones, feature the use of generator "coroutines".

But notice that you cannot mix iteration with asynchrony, you can use generators for either only. Your example seems to confuse them a bit - it looks like you expect that for ( {url, data} of downloadUrls(urls) ) { loop to work synchronously, which cannot work.

do I have to wait for async/await?

No, you don't have to wait, Babel already supports them!