Thanks Brendan, that make sense but that's more than what I think I'm looking for. What I'm looking for is a way to store a value in a object's property that can only be accessed from a property access stand point by the object itself. My only goal is to make sure that outside code can't break encapsulation for code robustness/quality reason.
Isn't it possible internally to allow a property access only by "this" ? Benoit On Jan 24, 2013, at 10:10 AM, Brendan Eich <[email protected]> wrote: > Benoit Marchant wrote: >> I guess I don't quite understand why it seems contentious to add a "private" >> property to property descriptors which already "reserve" properties like >> "value", "enumerable" or "writable". >> >> "private" is a meta description of a property like "value", "enumerable" or >> "writable. >> >> That feels a more natural extension than adding class to the language. > > As David wrote, this does not work in a dynamic language. > > function generic_get(obj, prop) { > return obj[prop]; > } > > obj = {private foo: 42, get bar() { return this.foo; }}; // or equivalent > class syntax > > // elsewhere > var steal = generic_get(obj, 'foo'); > > How do you enforce that only bar can access foo from obj? A private attribute > on a property with a public string-equated name 'foo' does not help. > > The mistake is treating name privacy as a property attribute. Privacy is not > an attribute of property descriptors, it's a restriction on property names. > It is not a static restriction in any sense, rather a capability. If you keep > the private symbol or weak map confined, privacy is assured. > > /be > _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
