> Le 17 janv. 2017 à 23:56, Oriol _ <[email protected]> a écrit :
> 
> See my 
> http://stackoverflow.com/questions/39334278/check-if-object-is-a-constructor-isconstructor
>  
> <http://stackoverflow.com/questions/39334278/check-if-object-is-a-constructor-isconstructor>
> 
> I also thought the `extends` trick could be useful, but it fails 3 of my 
> tests. It doesn't work for bounded normal functions and some proxy objects.

Yes, I missed the fact that subclassing implies a concrete access to the 
`prototype` property of the superclass in order to construct the subclass' 
prototype. That is the root of the failures.

> 
> The proper way is the second one in Claude's post: using a proxy object.
> 
> There is only a problem: it doesn't work for revoked proxies, because they 
> can't be used as a proxy target.
> 
> In my opinion that restriction is somewhat stupid, because you can use a 
> revocable proxy as a proxy target, and revoke it later.
> 
> But I guess it's too late to change that.

It is not too late to change that point, in that the risk of breakage may 
reasonably be judged almost inexistant. The hard part is to convince people 
that the inability to use a revoked proxy as proxy target is troublesome enough 
in order to justify the change. (Also, knowing why there is such a restriction 
may help to judge.)


> Maybe some day we will have `Object.isConstructor`.
> 
> ;Oriol
> 
> _______________________________________________
> es-discuss mailing list
> [email protected] <mailto:[email protected]>
> https://mail.mozilla.org/listinfo/es-discuss 
> <https://mail.mozilla.org/listinfo/es-discuss>
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss

Reply via email to