Solving the "how do I tell whether I have an HTML element?" (or image element, or whatever) problem

Boris Zbarsky bzbarsky at MIT.EDU
Wed Jan 16 11:13:53 PST 2013

On 12/31/12 11:33 PM, Boris Zbarsky wrote:
> 1)  Hack instanceof as Gecko has in the past.  This is actually a bit of
> a pain to implement even in Gecko, without changes to SpiderMonkey,
> because function objects can't have the magic behavior the RHS needs
> above in SpiderMonkey at the moment.

We have decided to go this route in Gecko, I believe, given that Allen 
says this will be describable in ES6.

In the short term that means that our WebIDL interface objects will 
probably not be function objects but reasonable facsimiles.  In the 
longer term we'll probably add a way to have functions have custom 
instanceof behavior to SpiderMonkey.

The next step is presumably getting WebIDL changed accordingly.  With 
that in mind, I would welcome one single representative of another 
browser or browser engine commenting here... ;)


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