Are Promises and Microtasks introduced into ES6?

Alex Russell slightlyoff at
Thu Oct 3 07:43:45 PDT 2013

On 3 Oct 2013 08:23, "Yusuke SUZUKI" <yusukesuzuki at> wrote:
> Hi,
> I'm very interested in implementing Promises and integrating it to
ECMAScript engine (e.g. V8, SpiderMonkey, JSC)
> Last night, I saw the meeting notes of Sep TC39 meetings carefully and I
was very surprised that it is said that Promises will be introduced into
> It refers the microtasks and the event loop. But I can't find details of
the event loop consensus. Is there any consensus about event loop
abstraction in ES6?

Only that a suitable hook is needed that embedders can implement. Luckily
that's simple WRT existing semantics (we are oblivious to future turns at
the language level) and doesn't demand that we import the event loop itself
into the language. The only requirement is that promises are async WRT the
calling code. Delivery at the end of the current turn is allowed.
Object.observe will require that we define an order, but until then, hand
waving is sufficient.

> Thanks,
> Yusuke Suzuki
> _______________________________________________
> es-discuss mailing list
> es-discuss at
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