AFAIK, this wont work because what clearTimeout() is actually expecting is the id returned by setTimeout(). El 12/8/2015 16:00, "Nick Krempel" <[email protected]> escribió:
> On 12 August 2015 at 02:56, Isiah Meadows <[email protected]> wrote: > >> ```js >> >> let p = new Promise((resolve, reject) => >> setTimeout((x => () => x(x))(handler => { >> onNotNeeded(() => clearTimeout(handler)); >> >> // `return` is to take advantage of TCO >> return doSomethingAsync(err => { >> if (err != null) return reject(err) >> else return resolve(); >> }); >> })); >> ``` >> > This doesn't work as the function passed to clearTimeout does not === the > function passed to setTimeout. > > In fact, they're not even behaviorally equal as the function passed to > setTimeout is expecting no parameters and the function passed to > clearTimeout is expecting one parameter - i.e. this is not even correct in > lambda calculus. > > A lambda-calculus-correct version could be: > > ``` > setTimeout((x=>(y=>()=>x(y(y)))(y=>()=>x(y(y))))(handler => {...})); > ``` > > But this would still suffer from the object identity problem mentioned > above. A final JS-correct version could be: > > ``` > setTimeout((x => {const y = () => x(y); return y;})(handler => {...})); > ``` > > Nick > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
