> (a === b) >= (new Symbol(a) === new Symbol(b)) Not sure I follow... so, I either I don't agree or I don't understand :). I'm having to dig deep to remember my math vocab here, but I think it may be most correct to say that the Symbol constructor, when passed an argument, should be injective [1]. That is,
1. let *F* = *new Symbol* 2. if <http://en.wikipedia.org/wiki/Material_conditional> *a* = *b*, then *F *(*a**)* = *F(b)* 3. if *a* != *b*, then *F(a) *!= *F(b)* > In any case, I'd also say that weak maps are good enough for your use case. In some (most?) cases, but not all. There's already a consensus that the garbage collection semantics of WeakMaps aren't always appropriate [2]. By parameterizing the Symbol constructor, developers can create custom map/set types without the overhead of a "Symbol Factory" (as previously suggested by Allen). I believe this would be a useful building block for interesting and innovative custom types. [1]: https://en.wikipedia.org/wiki/Injective_function#Definition [2]: http://wiki.ecmascript.org/doku.php?id=harmony:simple_maps_and_sets On Mon, Jul 15, 2013 at 5:52 AM, Andreas Rossberg <[email protected]>wrote: > On 12 July 2013 22:29, Jeremy Martin <[email protected]> wrote: > > My expectation would be that... > > > > (a === b) === (new Symbol(a) === new Symbol(b)) > > Nit: you probably either mean > > (a === b) >= (new Symbol(a) === new Symbol(b)) > > or > > (Object.is(a, b)) === (new Symbol(a) === new Symbol(b)) > > In any case, I'd also say that weak maps are good enough for your use case. > > /Andreas > -- Jeremy Martin 661.312.3853 http://devsmash.com @jmar777
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