Symbols, Protocols, Frames, and Versioning

Mark S. Miller erights at
Fri Oct 5 08:23:14 PDT 2012

On Fri, Oct 5, 2012 at 7:11 AM, Sam Tobin-Hochstadt <samth at>wrote:

> Note also that `Symbol.for` has some really weird behavior. For
> example, what does this evaluate to?
>     Symbol.for("x") instanceof Symbol
> That depends if someone has previously evaluated `Symbol.for("x")` in
> a different frame.

If this is true, then it is obviously a fatal problem with the whole
proposal, independent of all other issues. Do symbols have a [[Prototype]]
whose value is a Symbol.prototype?

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