1206584 - make WeakSet/WeakMap Object.observe()'able

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, enhancement)

Description

[Coroutines]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.93 Safari/537.36

Steps to reproduce:

(feature request?/proposal?)


Actual results:

(in my head this went splendidly)


Expected results:

I have a feature request/proposal for Javascript in Firefox.  I'm not sure if I'm filing this properly, there are a lot of projects and I ahd trouble navigating bugzilla?

Anyway.

WeakSets and WeakMaps can't be Object.observe()'d - I wish this were possible so I could provide finalizers.  I want to call a function when something is collected.  WeakSet/Map are the only source of weak references we have - I can't see any other way provide callbacks for broken weak references.

This might be a proposal for ES7.  I'm probably in the wrong place.

Comment 1

[Boris Zbarsky [:bzbarsky]]

> This might be a proposal for ES7.  I'm probably in the wrong place.

Indeed.  You want to mail [e-mail] with spec proposals for ES.

But note that there is quite a bit of discussion there in the past about whether it's OK to expose finalizers, even the post-mortem kind you presumably want here, and people are pretty wary of exposing it.  This is why WeakSets/WeakMaps can't be enumerated, for example...

This bug as filed is wontfix, since Object.observe is not happening.  See https://mail.mozilla.org/pipermail/es-discuss/2015-November/044684.html