Tom - Been following the proxy work for quite a while and, as the original requestor for __noSuchMethod__ to be added to Spidermonkey, I have been keen to see the functionality as I describe here:
https://bugzilla.mozilla.org/show_bug.cgi?id=683218#c8 I'm not sure as to whether direct proxies would solve that problem for me. AFAICT, they wouldn't... Comments? Cheers, - Bill On Oct 17, 2011, at 2:15 PM, Tom Van Cutsem wrote: > Hi, > > A couple of weeks ago, Mark and I sat together to work on a number of open > issues with proxies, in particular, how to make proxies work better with > non-configurable properties and non-extensible objects. The result is what we > call "direct proxies": in our new proposal, a proxy is always a wrapper for > another "target" object. By slightly shifting our perspective on proxies in > this way, many of the earlier open issues go away, and the overhead of > proxies may be substantially reduced in some cases. > > I just finished a first draft of the strawman: > <http://wiki.ecmascript.org/doku.php?id=strawman:direct_proxies>. Feedback > welcome. > > A prototype implementation that builds upon FF7 proxies is available also: > <http://code.google.com/p/es-lab/source/browse/trunk/src/proxies/DirectProxies.js> > (note: I still need to thoroughly test this code, but it's otherwise an > accurate description of the semantics of direct proxies in terms of current > proxies.) > > Mark and I will present this proposal in detail at the TC39 November meeting. > In the meantime, it may use some es-discuss eyeballs. > > To whet your appetite, some advantages of direct proxies w.r.t. the current > proposal: > - Enable emulation of non-configurable properties. > - Enable emulation of non-extensible, sealed and frozen objects. > - Proxies inherit [[Class]] from target. Enables faithful wrapping of Host > objects, Arrays, etc. > - “Fixing” a proxy (i.e. stopping the handler from trapping), is decoupled > from “protecting” a proxy (making it non-extensible, sealed or frozen). > - No need to distinguish between object and function proxies anymore. > - All traps become optional. > - Wrapping an existing object using a direct proxy creates less overhead, no > need to pass through an explicit ForwardingHandler anymore. > - Proxies can't violate non-configurability / non-extensibility invariants. > This in turn enables safe transformation of regular objects into proxies > (Proxy.attach) > - The default forwarding handler becomes a stateless singleton object. > > Also, thanks to David Bruant for being an early sounding board and providing > some useful API tweaks. > > Cheers, > Tom > _______________________________________________ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss
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