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Re: Promise<void> or Promise<undefined>?, was Re: RfC: pre-LC version of Screen Orientation; deadline August 18

From: Jonas Sicking <jonas@sicking.cc>
Date: Thu, 14 Aug 2014 16:30:33 -0700
Message-ID: <CA+c2ei9UFTJO+w6xO526Gd5K-3JwncpBVAP07fm1z2JALg11LQ@mail.gmail.com>
To: Marcos Caceres <marcos@marcosc.com>
Cc: Domenic Denicola <domenic@domenicdenicola.com>, public-script-coord <public-script-coord@w3.org>, Dominique Hazael-Massieux <dom@w3.org>, Mounir Lamouri <mounir@lamouri.fr>
On Thu, Aug 14, 2014 at 1:36 PM, Marcos Caceres <marcos@marcosc.com> wrote:
> interface ScreenOrientation {
>     Promise<undefined> lock (OrientationLockType orientation);
> }

It doesn't make sense to put a *value* between the <>. You should put
a *type* there. I.e. it doesn't make sense to do

Promise<1> returnOne();

The thing you do is

Promise<integer> returnOne();

'void' is the type for 'nothing', so that's what should be used for
functions that only return undefined. Whether they return that
synchronously or asynchronously.

/ Jonas
Received on Thursday, 14 August 2014 23:31:31 UTC

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