`getOwnPropertyDescriptors` retrieves at once everything that both `
getOwnProperty{Names,Symbol}` plus `getOwnPropertyDescriptor` per each name
or symbol would .. we have few shortcut/utilities in ES, why you see this
so useless? Even Array#forEach can be decomposed in a for loop ... how
about using `getOwnPropertyDescriptors` for debugging too?All I am saying is that I don't see why this should not land ... there's much more to do for ES7 than this, IMO, like ... finalizing specs for `Object.mixin` and **then** eventually talk about dropping this already spec'd one On Tue, Apr 22, 2014 at 12:53 PM, Claude Pache <[email protected]>wrote: > > Le 22 avr. 2014 à 21:05, Andrea Giammarchi <[email protected]> > a écrit : > > > IMO every time you use `getOwnPropertyDescriptor` over a > `getOwnPropertyNames` you are asking for a `getOwnPropertyDescriptors` > implementation, that's the use case. > > And in these cases, again, are the descriptors used for something else > than applying them immediately to another object? (This is a real question, > for personally I barely use `getOwnPropertyNames` for other purpose than > debugging.) > > > > > Twisting your question, do you have any use case for > `getOwnPropertyNames` that won't require later on > `getOwnPropertyDescriptor` ? > > Maybe, but `Object.getOwnPropertyNames` and > `Object.getOwnPropertyDescriptor` (in ES5) are fundamental methods that > cannot be decomposed into other methods, and on which libraries can build > more complex functionalities. (Not sure about the > `getOwnProperty{Names,Symbol}` dichotomy of ES6, but that's another > question.) On the other hand `Object.getOwnPropertyDescriptors` and > `Object.mixin` are complex methods. > > —Claude > > > > > > > On Tue, Apr 22, 2014 at 11:59 AM, Claude Pache <[email protected]> > wrote: > > > > Le 22 avr. 2014 à 19:58, Andrea Giammarchi <[email protected]> > a écrit : > > > > > while I think that > > > Object.create( > > > > > > > > > Object.getPrototypeOf(originalObject), > > > > > > > > > Object.getOwnPropertyDescriptors(originalObject) > > > ) > > > looks semantically better than > > > Object.mixin( > > > > > > > > > Object.create(Object.getPrototypeOf(originalObject)), > > > > > > originalObject > > > > > > ) > > > I also think that Object.mixin could be used for similar cases but I > am not sure if: > > > • is able to mixin also not enumerable and Symbols > > > > When it was still in the ES6 draft, `Object.mixin` *did* copy all own > properties. > > > > > • performs some unrequired magic such rebinding getters and > setters that should not happen or actually does not make sense to me > > > > My feeling is that in most cases where that magic is not required, it is > also not very important. Or there could be an option for enabling/disabling > that functionality, for that would seem better to me than two wildly > different ways for getting almost the same result. > > > > > The reason such long method name has been proposed was for symmetry > with defineProperties and as meaningful plural version that should not > exclude Object.mixin > > > > > > Long story short, when mixin is needed, use mixin, otherwise when all > descriptors are needed, use getOwnPropertyDescriptors? > > > > Do you have cases where getting all descriptors is used for something > else than setting them immediately to another object? My point is that I > don't see the added value of `Object.getOwnPropertyDescriptiors` once you > have a correctly designed `Object.mixin`-like method. > > > > —Claude > > > > > > > > > > In few words I don't see how having both could hurt anyone > > > > > > > > > > > > > > > On Tue, Apr 22, 2014 at 10:27 AM, Claude Pache <[email protected]> > wrote: > > > Hi, > > > > > > There has been request to add `Object.getOwnPropertyDescriptors` > (plural) to the standard. Reviewing use cases presented in thread [1] or in > older thread [2], it seems to me that all of them boil down to copy all own > properties of one object to another, e.g., > > > > > > Object.defineProperties(target, > Object.getOwnPropertyDescriptors(source)) > > > Object.create(proto, Object.getOwnPropertyDescriptors(source)) > > > // etc. > > > > > > However, this is exactly what `Object.mixin` (deferred from ES6) was > designed for: > > > > > > Object.mixin(target, source) > > > Object.mixin(Object.create(proto), source) > > > // etc. > > > > > > Besides being shorter to write, `Object.mixin` has the advantages of > (1) not creating an intermediate object; (2) taking care of some > subtleties, like rebinding `super` for methods, getters and setters if > needed. > > > > > > Therefore, I think that `Object.mixin` is a better function to have > than `Object.getOwnPropertyDescriptors`. > > > > > > —Claude > > > > > > > > > [1] > http://esdiscuss.org/topic/object-getownpropertydescriptors-o-plural > > > [2] http://esdiscuss.org/topic/object-getownpropertydescriptor > > > _______________________________________________ > > > es-discuss mailing list > > > [email protected] > > > https://mail.mozilla.org/listinfo/es-discuss > > > > > > > > >
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