I agree that the spec should clearly state that a non-extensible object has a finite collection of own properties. Regarding infinite extensible objects, the only problem I see off the top of my head is: What would Object.getOwnPropertyNames return?
On Tue, Sep 6, 2011 at 8:00 AM, David Bruant <[email protected]> wrote: > Hi, > > There is a current expectation of objects being a /finite/ collection of > properties, but I don't see this information written anywhere. ES5.1 - 4.3.3 > says: > "An object is a collection of properties..." > "Collection" is nowhere defined in the spec. The Wikipedia page does not > state clearly anything about collection finiteness. > > I have re-read very carefully the ES5.1 invariants regarding non-extensible > objects and they do not prevent (host) objects with an infinite set of > properties. More precisely, calls to [[GetOwnProperty]] on non-extensible > objects are not forbidden to describe as existent, properties which have not > been observed as non-existent (which leaves (infinite) room since within in > a finite time, only a finite set of properties can be observed as > non-existent). > > The current design of the fix trap explicitely asks for an regular object > (which has a finite set of properties). The same applies to the current > design of non-extensible proxies which has an internal set of properties > (finite in current Tom's implementation). > > Should the spec clearly state something about object property finiteness? > (I have some crazy ideas with the fix trap returning RegExps, there is > still time to stop me :-p ) > PLEASE STOP ;) > > David > ______________________________**_________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/**listinfo/es-discuss<https://mail.mozilla.org/listinfo/es-discuss> > -- Cheers, --MarkM
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
