I mixed up ... sorry, let me recap: 1. `Object.getOwnPropertyNames(O)` list of `properties` and `Object.getOwnPropertySymbols(O)` list of `Symbols` can be both used, per each item of each list, with `Object.getOwnPropertyDescriptor(O, propertyOrSymbol)` 2. `Object.getOwnPropertyDescriptor(O, propertyOrSymbol)` accepts, as second argument, only as a `property` name or a `Symbol`, otherwise it throws [as specified here]( https://people.mozilla.org/~jorendorff/es6-draft.html#sec-topropertykey) 3. accordingly, the most meaningful collection as `Object` of descriptors the proposed plural `Object.getOwnPropertyDescriptors(O)` should return is a collection that includes descriptors for both `properties` and `Symbols`
I hope this makes sense. Thanks again Rick for, at least, trying and helping out with this. Cheers On Tue, Mar 4, 2014 at 9:48 AM, Andrea Giammarchi < [email protected]> wrote: > yes, because `Object.getOwnPropertyDescriptor(O, k)` accepts both > `propertyName` and `Symbol` as second argument. The plural, and to be > consistent with the shallowCopy example, should return a list of both. > > This is also because all descriptors returned by > `Object.getOwnPropertySymbols` can be used same way > `Object.getOwnPropertyNames` ... so, unless `Object.defineProperty(O, k, > d)` does not accept `k` as `Symbol` (basically breaking this proposal via > `Object.create`) I don't see why the plural version should not return > descriptors for both kind of properties. > > My 2 cents > > > On Tue, Mar 4, 2014 at 9:38 AM, Rick Waldron <[email protected]>wrote: > >> Question: should the returned array include property descriptors for >> properties whose key is a symbol? >> >> Rick >> >> >> >> On Tue, Mar 4, 2014 at 12:34 PM, Rick Waldron <[email protected]>wrote: >> >>> >>> >>> >>> On Tue, Mar 4, 2014 at 12:30 PM, Andrea Giammarchi < >>> [email protected]> wrote: >>> >>>> Apparently this triggered an @rwaldron which seems to be >>>> super-effective >>>> >>>> In agenda for April's meeting. >>>> >>> >>> Yep: https://github.com/tc39/agendas/blob/master/2014/04.md >>> >>> Going to try, but it's so late in the game that I really can't promise >>> anything--I think it's simple enough that we can get away with it. I will >>> write up a proposed normative spec (likely based on Andrea's work) before I >>> present, I've found that's a pretty powerful way to make a case for late >>> additions ;) >>> >>> >>> Rick >>> >>> >>>> >>>> Thanks >>>> >>>> Sent from my Windows Phone >>>> ------------------------------ >>>> From: C. Scott Ananian <[email protected]> >>>> Sent: 3/4/2014 6:16 >>>> To: Andrea Giammarchi <[email protected]> >>>> Cc: [email protected] list <[email protected]> >>>> Subject: Re: Object.getOwnPropertyDescriptors(O) ? // plural >>>> >>>> Have you filed a bugzilla ticket for this? That seems the best way to >>>> ensure it will get discussed at the next TC39 meeting and resolved one way >>>> or the other. >>>> --scott >>>> On Mar 3, 2014 8:44 PM, "Andrea Giammarchi" < >>>> [email protected]> wrote: >>>> >>>>> up ? >>>>> >>>>> >>>>> On Sun, Mar 2, 2014 at 5:43 PM, Andrea Giammarchi < >>>>> [email protected]> wrote: >>>>> >>>>>> Brandon I take your answer as +1, thanks. >>>>>> >>>>>> I've also "gisted" a possible/basic polyfill here: >>>>>> https://gist.github.com/WebReflection/9317065 >>>>>> >>>>>> Cheers >>>>>> >>>>>> >>>>>> On Sun, Mar 2, 2014 at 5:16 PM, Andrea Giammarchi < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> actually, since `Object.getOwnPropertyDescriptor` accepts `Symbols` >>>>>>> too as second argument, the equivalent with current ES6 would be even >>>>>>> more >>>>>>> prolix than that >>>>>>> >>>>>>> ```javascript >>>>>>> >>>>>>> var shallowCopy = Object.create( >>>>>>> Object.getPrototypeOf(originalObject), >>>>>>> Object.getOwnPropertyNames(originalObject).concat( >>>>>>> Object.getOwnPropertySymbols(originalObject) >>>>>>> ).reduce(function (descriptors, name) { >>>>>>> descriptors[name] = Object.getOwnPropertyDescriptor( >>>>>>> originalObject, name >>>>>>> ); >>>>>>> return descriptors; >>>>>>> }, {}) >>>>>>> ); >>>>>>> >>>>>>> ``` >>>>>>> >>>>>>> assuming Symbols will be definable through descriptors ... all this >>>>>>> VS >>>>>>> >>>>>>> ```javascript >>>>>>> var shallowCopy = Object.create( >>>>>>> Object.getPrototypeOf(originalObject), >>>>>>> Object.getOwnPropertyDescriptors(originalObject) >>>>>>> ); >>>>>>> ``` >>>>>>> >>>>>>> which I believe is a win. >>>>>>> >>>>>>> Thanks >>>>>>> >>>>>>> >>>>>>> On Sun, Mar 2, 2014 at 5:01 PM, Andrea Giammarchi < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>>> I wonder if by any chance this could sneak into ES6 ... we have >>>>>>>> only singular version here: >>>>>>>> >>>>>>>> https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.getownpropertydescriptor >>>>>>>> >>>>>>>> **rationale** >>>>>>>> The easiest way to create a shallow copy of a generic object could >>>>>>>> be: >>>>>>>> >>>>>>>> ```javascript >>>>>>>> var shallowCopy = Object.create( >>>>>>>> Object.getPrototypeOf(originalObject), >>>>>>>> Object.getOwnPropertyDescriptors(originalObject) >>>>>>>> ); >>>>>>>> ``` >>>>>>>> >>>>>>>> Today what we have to do this instead: >>>>>>>> >>>>>>>> ```javascript >>>>>>>> var shallowCopy = Object.create( >>>>>>>> Object.getPrototypeOf(originalObject), >>>>>>>> Object.getOwnPropertyNames(originalObject).reduce( >>>>>>>> function (descriptors, name) { >>>>>>>> descriptors[name] = Object.getOwnPropertyDescriptor( >>>>>>>> originalObject, name >>>>>>>> ); >>>>>>>> return descriptors; >>>>>>>> }, {}) >>>>>>>> ); >>>>>>>> ``` >>>>>>>> >>>>>>>> I see latter pattern as sort of unnecessary overhead that could be >>>>>>>> also much faster in core and polyfilled in the meanwhile. >>>>>>>> >>>>>>>> Thoughts ? >>>>>>>> >>>>>>>> Cheers >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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 >>>> >>>> >>> >> >
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