On Mar 17, 2012, at 2:03 AM, Russell Leggett wrote: > Given the recent go at finding alternative syntax for the <| operator, I > thought about it and decided to split the functionality between creating > "instances" using alternative prototypes, and the other side of the fence > making reusable extended objects easier to make. > > Its a little long so I threw it in a gist: https://gist.github.com/2056771
I've already replied WRT : vs <| in another message so this is about the rest of the ideas in your gist. Some of this feels like it is circulating back to things we already discussed, for example at http://www.mail-archive.com/[email protected]/msg10365.html I also wanted to point out that there is another way to express object instantiation with arbitrary [[Prototype]]. It is the new <object> operator as described in https://mail.mozilla.org/pipermail/es-discuss/2011-September/016736.html Essentially, let proto = { ... }; //some literally defined object let instance = proto <| { }; //instance is new object with no own properties who [[Prototype]] is proto could be expressed as let instance = new proto; //instance is new object with no own properties who [[Prototype]] is proto The only difference is that |new proto| would also apply an initialization function (proto's constructor property) on the new instance. Other than that, the only real difference I see is that the "magic" you are applying regarding functions is different from that defined for <| but it is still treated as a special case. You magic is that if the LHS is a function you always use the value of its prototype property (BTW, what if it doesn't have one) as the [[Prototype]] value. so if you say: (functtion f1() {}) : function f2() {} the [[Prototype]] of f2 will be f1.prototype and f2 will not inherit at all from Function.prototype. This doesn't seem right. If you just think about <| (or :) as an instantiation operator you still have to take into account what it means to have "function (,,,) {,,,}" on the RHS. The issue is that such a function express is actually instantiating two objects and they both need to get their [[Prototype]] values set to something reasonable. I think that my <| definition supplies a more reasonable (fewer new user surprises) then your : definition. Allen
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