Object.getOwnPropertyDescriptors(O) ? // plural
andrea.giammarchi at gmail.com
Thu Mar 6 14:34:52 PST 2014
Thanks Andrew, I wonder if I should update the proposed spec somehow, but I
thought as it is combines both Names and Symbols as abstract.
Please let me know and I'll update.
On Thu, Mar 6, 2014 at 1:21 PM, André Bargull <andre.bargull at udo.edu> wrote:
> I would rephrase into this:
> if you need a getOwnPropertyNames trap, you might need for consistency a
> getOwnPropertySymbols independently from getOwnPropertyDescriptors since
> these methods are already available.
> While it shares the same name with Object.getOwnPropertyNames(), this
> getOwnPropertyNames trap is supposed to return string and symbol keyed
> properties, see http://esdiscuss.org/topic/ownpropertykeys .
> I also would like to add a couple of links to support the fact
> is needed, and has been asked for, since quite a while: this was 11th of
> November 2011 ... I didn't know it, and now that I do I wonder why this has
> been post-poned for so long and never discussed again.
> Or even earlier,
> http://wiki.ecmascript.org/doku.php?id=strawman:extended_object_api from
> Best Regards
> On Thu, Mar 6, 2014 at 11:24 AM, C. Scott Ananian <ecmascript at cscott.net <https://mail.mozilla.org/listinfo/es-discuss>>wrote:
> >* If you use a getOwnPropertyNames trap, then you also need a
> >* getOwnPropertySymbols trap to implement getOwnPropertyDescriptors.
> *>* --scott
> >* On Thu, Mar 6, 2014 at 2:16 AM, Tom Van Cutsem <tomvc.be at gmail.com <https://mail.mozilla.org/listinfo/es-discuss>> wrote:
> *>* > 2014-03-05 20:11 GMT+01:00 C. Scott Ananian <ecmascript at cscott.net <https://mail.mozilla.org/listinfo/es-discuss>>:
> *>* >>
> *>* >> On Wed, Mar 5, 2014 at 1:39 PM, Tom Van Cutsem <tomvc.be at gmail.com <https://mail.mozilla.org/listinfo/es-discuss>>
> >* wrote:
> *>* >> > Object.getOwnPropertyDescriptors(proxy) would trigger the
> *>* >> > getOwnPropertyNames trap, followed by calls to the
> *>* >> > getOwnPropertyDescriptor
> *>* >> > trap for each individual property.
> *>* >>
> *>* >> [[OwnPropertyKeys]], `ownKeys` trap.
> *>* >
> *>* >
> *>* > Yes, according to the current draft spec. I have a pending discussion
> *>* with
> *>* > Allen that we actually need to reintroduce a [[GetOwnPropertyNames]]
> *>* > internal method / getOwnPropertyNames trap, as the `ownKeys` trap
> *>* doesn't do
> *>* > any invariant checking, which is needed for a reliable Object.isFrozen
> *>* test.
> *>* >
> *>* > Regards,
> *>* > Tom
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