On Fri, Apr 19, 2013 at 6:37 PM, Ron Buckton <rbuck...@chronicles.org> wrote: >> -----Original Message----- >> From: Tab Atkins Jr. [mailto:jackalm...@gmail.com] >> Sent: Friday, April 19, 2013 5:18 PM >> To: Kevin Gadd >> Cc: Ron Buckton; es-discuss >> Subject: Re: Futures (was: Request for JSON-LD API review) >> >> On Fri, Apr 19, 2013 at 4:02 PM, Kevin Gadd <kevin.g...@gmail.com> wrote: >> >> One simple possibility would be to just expose accept/resolve/reject on the >> returned Future itself. Calling any of these cancels the Future (if the >> Future >> has a notion of cancellation), and forces it to adopt the passed state as >> appropriate. The constructor would take two callbacks, one for normal >> operation (called immediately) and one to handle cancellation (called when >> needed). This has the nice benefit that a consumer can provide a default >> value for other consumers to use, and it doesn't require any new codeflow >> channels. > > I'd be more interested in having a creatable FutureResolver with a .future > accessor property for those cases. Given the current API, its possible (but > not pretty) to do something like:
That doesn't help our main use-cases, which is allowing you to get a cancelable future out of *platform* APIs, where the platform constructs the future for you. >> It would be so nice if JS had multiple return values, so we could let >> cancellable future-returning APIs just return a naked resolver as their >> second >> value, and only clueful call sites would need to care about it. ^_^ >> Instead, >> we'll probably need to have API variants that instead return something like a >> Deferred, or that return a pair of a future and a resolver. > > That sounds like what I just mentioned in > https://gist.github.com/rbuckton/5424214. It's inverted, actually, but it works out similarly. That might be the way to go - it lets you keep a single calling function, but still optionally send in cancellation notices. ~TJ _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
