getPrototypeOf invariant

Brendan Eich brendan at
Thu Oct 4 15:59:34 PDT 2012

David Bruant wrote:
> Le 04/10/2012 22:01, Mark S. Miller a écrit :
>> If the extensible proxy has no access to the original
>> Object.prototype.__proto__, then it cannot modify the [[Prototype]] of
>> its target, and so should not be able to seem to have its own mutable
>> [[Prototype]]
> Ok, so the rationale behind the invariant is:
> You can report a different prototype only if you're able to modify it on
> the target.
> And it makes a lot of sense indeed. Sorry it took me about 3 round-trips
> to understand this :-s

That's the beauty of 'delete Object.prototype.__proto__'! ;-)


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