[About async in ecmascript] Is it possible to implement Thread.sleep() ?

[Lanius-collaris]

I saw a example on mdn.

function resolveAfter2Seconds() {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve('resolved')
    }, 2000)
  })
}
async function asyncCall() {
  console.log('calling');
  const result = await resolveAfter2Seconds()
  console.log(result)
  // expected output: "resolved"
}
asyncCall()

babel try it out output:

"use strict"
function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }
​function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }
function resolveAfter2Seconds() {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve('resolved')
    }, 2000)
  })
}
function asyncCall() {
  return _asyncCall.apply(this, arguments)
}
function _asyncCall() {
  _asyncCall = _asyncToGenerator(function* () {
    console.log('calling')
    const result = yield resolveAfter2Seconds()
    console.log(result); // expected output: "resolved"
  })
  return _asyncCall.apply(this, arguments)
}
asyncCall()

[BobHanson]

Sorry for not spotting this. It is not possible to implement Thread.sleep.

[BobHanson]

But in every case we have seen there are simple alternatives. See the javajs.async.SwingJSUtil$StateMachine class and many examples. There is a discussion of how to use equivalents to java.lang.Thread in doc/Differences.txt as well.

These methods have been used many times in multiple projects.