Detecting the "type" of a DOM object

Brendan Eich brendan at
Mon Jun 25 01:28:18 PDT 2012

David Bruant wrote:
> Le 24/06/2012 14:51, Brendan Eich a écrit :
>> David Bruant wrote:
>>> Instead of adding a new [[instanceofHint]] internal property, maybe the
>>> [[NativeBrand]] could be reused.
>> +1 on that, which suggests [[NativeBrandMatch]] instead of
>> [[InstanceofMatch]].
>> Your proposal is more general but I think we should extend HasInstance
>> only very concretely, with what's needed for WebIDL, and probably for
>> any such system that reflects nominal types.
> What form would it take?
> The constraints of enabling implementations of WebIDL in pure ES6
> (which, on the ES side is bound to the goal of getting rid of host
> objects) seems to force towards a general proposal.

One idea: expose [[NativeBrand]] as a private name object available, 
depending on implementation details, only to privileged code.


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