On Apr 26, 2013 8:33 PM, "Tab Atkins Jr." <[email protected]> wrote: > > On Fri, Apr 26, 2013 at 11:25 AM, Kevin Smith <[email protected]> wrote: > > Actually, I may have gotten it terribly wrong (apologies). In my prototype > > implementation, the following: > > > > Future.accept(Future.resolve(1)).then(value => { > > > > console.log(value !== 1); > > return Future.accept(Future.resolve(1)); > > > > }).then(value => { > > > > console.log(value === 1); > > }); > > > > logs > > > > - true > > - true > > > > Is that what it should be doing, according to the DOM spec? Anne, Alex? > > No, it should be "true", then "false". > > Future.resolve(1) returns a Future<1>. > > Future.accept(Future.resolve(1)) returns Future<Future<1>>.
This would all be easier to discuss if you weren't writing using invented methods. > If you call .then() on a Future<Future<1>>, the callback receives a > Future<1> as its argument. > > If you return a Future<Future<1>> from the callback, the chained > future adopts its state, which means that the chained future is now > also a Future<Future<1>>. > > So, calling .then() on the chained future will give you the same > result - the callback receives a Future<1> as its argument. > > (Using a mixture of Future.accept and Future.resolve in the way that > you have makes things more confusing than necessary. When called on a > plain value, the two functions are identical. They only act > differently when you call them on a future.) > > ~TJ > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss
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