On Wed, May 18, 2011 at 7:38 AM, Brendan Eich <bren...@mozilla.com> wrote:
> On May 18, 2011, at 7:28 AM, Tom Van Cutsem wrote: > > > Proxies do coerce all property names to strings, e.g. proxy[obj] will > trigger the 'get' trap with 'obj' coerced to a String. This is not actually > enforced by the proxy spec, but rather by ES5 (e.g. [[Get]] assumes that its > argument P is bound to a property name (a String)). At one point we > suggested removing this restriction, so that "proxy[obj]" would give the get > trap direct access to obj (which would be particularly useful when > intercepting numeric indices on array-like proxies). IIRC, we didn't pursue > this option since engines rely on property names being strings in other > places, and widening the type of property names to cover arbitrary objects > would be problematic. > > SpiderMonkey has a wider internal property name type, which can accomodate > at least int and object names. The int case is an optimization, commonly > done. The object case is for E4X and perhaps private names. > > Oliver wrote in the thread at the time that he thought allowing any value > to be used as a property name (in brackets) and passed through uncoerced to > proxies was implementable without trouble for JavaScriptCore, IIRC. > That's the opposite of my memory, but it was a long time ago. Oliver? > > /be > > _______________________________________________ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss > -- Cheers, --MarkM
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