Converting an existing object to a proxy

Brendan Eich brendan at
Fri May 27 02:35:43 PDT 2011

On May 27, 2011, at 2:26 AM, David Bruant wrote:

> Le 27/05/2011 04:13, Mark S. Miller a écrit :
>> On Thu, May 26, 2011 at 5:04 PM, Cormac Flanagan <cormac at> wrote:
>> [documenting/expanding some ideas briefly discussed at today's meeting]
>> The current proxy proposal has a method to create a new proxy:
>> var proxy = Proxy.create(handler, proto);
>> We could extend this proposal to allow an existing object to be
>> converted to a proxy, via:
>> var proxy = Proxy.createFrom(object, handler, proto);
> I am surprised by this proposal since a design goal of proxies was to not be able to turn existing objects into proxies.
> 4th "driving force" of the proxy proposal:
> "security: avoid enabling arbitrary ES objects to be able to intercept the properties of another object"

That is not the same as "avoid turning an object into a proxy", though.

The idea of permitting this "becomes" operation only for extensible objects with configurable properties is crucial.

The motivation is to unify ideas in proxies (in Harmony) with those proposed in


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the es-discuss mailing list