On Jun 21, 2011, at 8:24 AM, Axel Rauschmayer wrote: > As a loose analog to the prototype-chain-traversing getPropertyDescriptor(), > I would still like to have something that allows one to easily *change* > properties higher up the prototype chain (e.g. to use a prototype to share > state).
Such mutation from a delegating object, because it affects all other objects that delegate to the shared prototype, is usually a bug! Shared mutables are a bitch, even ignoring threads. I think it would be better to require the mutation to have a direct reference to the prototype. Yes, it could be discovered via Object.getPrototypeOf -- assuming no proxies. We cannot assume no proxies, and a Proxy is responsible for delegating to possibly hidden objects other than the |proto| passed to Proxy.create. Even without proxies, or assuming they behave like native objects, mutation from one of N delegating objects is an anti-pattern. /be > > Maybe it would be enough to just have Object.getDefiningObject(obj, propName): > http://www.mail-archive.com/es-discuss@mozilla.org/msg06652.html > > But I can also imagine syntactic sugar: > obj.foo := "abc" > desugars to > Object.getDefiningObject(obj, "foo").foo = "abc" > > -- > Dr. Axel Rauschmayer > > a...@rauschma.de > twitter.com/rauschma > > home: rauschma.de > blog: 2ality.com > > > > _______________________________________________ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
