Save Object.observe()! (please) + make WeakMap/WeakSet observable.

[William Edney]

For those interested in using Proxies in the future, here are the
appropriate links to the two remaining holdouts (FF and MS Edge are already
there):

Safari/Webkit/JSC:

https://bugs.webkit.org/show_bug.cgi?id=35731

Chrome/V8:

https://code.google.com/p/v8/issues/detail?id=1543

Bug the appropriate owners ;-).

Cheers,

- Bill


On Tue, Nov 3, 2015 at 4:40 PM, Brendan Eich <brendan.eich at gmail.com> wrote:

> Ah yes, the Smalltalk "become:" message, something that inspired
> SpiderMonkey's "Brain Transplants" -- see the [1] footnote at
> https://brendaneich.com/2010/11/proxy-inception/, and of course the
> bugzilla link, which leads to this:
>
> <https://bugzilla.mozilla.org/user_profile?user_id=1214> Brendan Eich
> [:brendan] 2010-07-19 17:53:44 PDT
>
> Burns:    [saws off the top of Homer's head.  No blood, very clean.
>            The top of Homer's head rolls away.]
>           Smithers, hand me that ice-cream scoop.
> Smithers: Ice-cream scoop?!
> Burns:    Dammit, Smithers, this isn't rocket science, it's brain surgery!
>
> ("If I Only Had a Brain", from "Treehouse of Horror II")
>
> /be
>
>
> On Tue, Nov 3, 2015 at 6:42 AM Matthew Robb <matthewwrobb at gmail.com>
> wrote:
>
>> I probably have a terrible understanding of how this all works at a low
>> level but I feel like a potential solution would be a method of "upgrading"
>> a non-proxy object to be a proxy. The reason accessors are being used as
>> they are now is because you can retro fit them. Maybe what I am suggesting
>> is essentially like swapping out the internal pointer of an object with
>> another object (such as the way live module bindings work). In this way you
>> might upgrade an existing object to behave like a proxy.
>>
>>
>> - Matthew Robb
>>
>> On Tue, Nov 3, 2015 at 3:20 AM, Tom Van Cutsem <tomvc.be at gmail.com>
>> wrote:
>>
>>>
>>> 2015-11-02 23:34 GMT+01:00 Coroutines <coroutines at gmail.com>:
>>>>
>>>> I come from Lua.  In Lua we make proxy objects with metamethods.  You
>>>> create an empty table/object and define a metatable with a __index and
>>>> __newindex to catch accesses and changes when a key/property doesn't
>>>> exist.  I would primarily use this in sandboxes where I wanted to
>>>> track the exact series of operations a user was performing to modify
>>>> their environment (the one I'd stuck them in).
>>>
>>>
>>> For this type of use case, you can use an ES6 Proxy <
>>> https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Proxy>.
>>> You can think of the proxy handler's methods as the 'metamethods' of the
>>> proxy object.
>>>
>>> What O.o would provide beyond Proxy is the ability to observe changes to
>>> already pre-existing objects. However, since you mention you'd start with
>>> an empty table/object, you should be able to create a fresh Proxy and use
>>> that to trace all property accesses.
>>>
>>> Proxies are particularly well-suited when you want to sandbox things,
>>> since you should be in control of the sandboxed environment anyway and can
>>> set-up proxies to intermediate. O.o is particularly well-suited to
>>> scenarios where there are already plenty of pre-existing objects and you
>>> don't know ahead of time which ones to observe and which not.
>>>
>>> Cheers,
>>> Tom
>>>
>>> _______________________________________________
>>> es-discuss mailing list
>>> es-discuss at mozilla.org
>>> https://mail.mozilla.org/listinfo/es-discuss
>>>
>>>
>> _______________________________________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>
> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20151103/b748ce51/attachment-0001.html>