Are Private name and Weak Map the same feature? and the Assoc API

Tom Van Cutsem at
Mon Dec 19 07:56:22 PST 2011

2011/12/19 David Bruant <bruant.d at>

> Le 19/12/2011 11:03, Tom Van Cutsem a écrit :
> > (...)
> > Separate getPrivate/setPrivate traps would avoid this confusion:
> > (...)
> One thing that is unsaid in the current proposal is whether private
> names can be used with Object.defineProperty and
> Object.getOwnPropertyDescriptor. I think that private getters and
> setters would be awesome.
> But it would mean that the "private handler API" would need to be extend
> to 'definePrivateProperty', 'getOwnPrivatePropertyDescriptor' (and
> 'deletePrivate' as well)

Good point. That is indeed a major drawback of separating out all private
name handling in parallel traps.

I think I don't have a problem with widening the type of the name parameter
of all of these traps from String to Object. Then a proxy handler can at
least test whether it is intercepting a private name or a normal property.
The only thing I'm worried about at this point is that there has to be a
simple way for the proxy to say "I'm not interested in intercepting this
private name, just forward it to my target". Otherwise I'm afraid most
proxies will wrongly forward a private name access as a normal property
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