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Re: Futures

From: Kevin Smith <zenparsing@gmail.com>
Date: Fri, 26 Apr 2013 16:11:49 -0400
Message-ID: <CA+mDt2zZWQ9Gwvk7NWt0vgT8+hLby82p600dTfwLQW+xzHGEZw@mail.gmail.com>
To: Domenic Denicola <domenic@domenicdenicola.com>
Cc: Juan Ignacio Dopazo <dopazo.juan@gmail.com>, "public-script-coord@w3.org" <public-script-coord@w3.org>, EcmaScript <es-discuss@mozilla.org>
> > The difference would only surface when testing that case.
>
> Not quite. You can still have thenables that call `onFulfilled` with
> another thenable, to any depth. You can also insert a real promise at the
> end of any-length thenable chain.


I understand now.  Essentially, in the test you create an ad-hoc "promise"
whose value is a promise, by virtue of it calling its `then` callback with
another promise.

So A+ 1.1 does present an opinion on `then` semantics for
promises-of-promises.

FWIW, I think the DOMFuture behavior is more intuitive in this particular
edge case.  I also think that promises-for-promises are an edge case best
avoided at all costs.

{ Kevin }
Received on Friday, 26 April 2013 20:12:16 UTC

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