Should it be possible to have property named "__proto__" which is inaccessible in modern implementations? 30 lis 2014 18:53 "Allen Wirfs-Brock" <[email protected]> napisał(a):
> > On Nov 29, 2014, at 3:38 PM, Nicholas C. Zakas wrote: > > In Rev 28, B.3.1 it states: > > - > > It is a Syntax Error if PropertyNameList of PropertyDefinitionList contains > any duplicate entries for"__proto__" and at least two of those entries > were obtained from productions of the formPropertyDefinition : > PropertyName : AssignmentExpression . > > I noted that the duplicate name restriction was eliminated back in July[1] > and was just wondering if __proto__ is indeed a special case? > > Thanks. > > [1] > https://github.com/rwaldron/tc39-notes/blob/46d2396e02fd73121b5985d5a0fafbcdbf9c9072/es6/2014-07/jul-29.md#41-review-latest-draft > > > Yes, `__proto__ : <expr>` in an object literal is a special form with > different semantics than the other *PropertyDefinition* forms. The > relaxation of the duplicate entry was explicitly not applied to it. > > It's worth noting that: > __proto__: <expr> > and > ["__proto__"] : <expr> > do not mean the same thing. > > The first form does a [[SetPrototypeOf]] and is the form that the above > early error applies to. > The second form does a [[DefineProperty]] and does not place any > restrictions of duplicates. > > Allen > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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