Any reason why __proto__ is not a well known symbol?

Coroutines coroutines at
Tue Feb 16 05:14:18 UTC 2016

On Mon, Feb 15, 2016 at 8:51 PM, Tab Atkins Jr. <jackalmage at> wrote:

> It was specified before symbols existed, and all implementations do it
> as a string property.  If we were reinventing it today it would either
> be a symbol or something in the MOP, but are hands are tied by legacy.
>> Being that it was not formally spec'd it shouldn't have broke backwards
>> compatibility either.
> Backwards compat has nothing to do with specs, and everything to do
> with existing implementations.  Multiple implementations agreed on
> __proto__, so our choice was either to leave it unstandardized or spec
> what the browsers did.

Is there a migration to make it a Symbol in ES7?  (ignorant question?)

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