-1

How would you implement async/await functionality if you had to? - We’re talking about normal JS syntax (ES6) that does something like async/await, of course, not adding it to the syntax)

Tony Soprano
  • 63
  • 8
  • What? using *async function(){ await someotherasync();}* ... – Jonas Wilms May 11 '17 at 17:19
  • Please be more specific – MeestorHok May 11 '17 at 17:19
  • You're question is not really clear. Are you looking for Promise functionality? – Peter LaBanca May 11 '17 at 17:22
  • I use generator functions that yield promises. Something like [bluebird's `Promise.coroutine`](http://bluebirdjs.com/docs/api/promise.coroutine.html) can then be used to wrap those functions into a single `Promise`-returning function. You end up with something syntactically almost identical to `async`/`await`. My code still uses this approach since `async` is not (quite) standardized yet. – Stephen Cleary May 11 '17 at 20:04

1 Answers1

1

async/await are syntactic sugar on top of ES6 Promises. For example, a program that uses async/await like this

async function asyncExample () {
  const foo = await doStuff();
  return foo + 1;
}

is equivalent to the following program in ES6

function promiseExample () {
  return doStuff().then(foo => foo + 1);
}

Functions marked async just return a Promise that resolves to the return value of the function.

Ari Lotter
  • 605
  • 8
  • 23