> From: Claude Pache <[email protected]> > To: Axel Rauschmayer <[email protected]> > Cc: Erik Arvidsson <[email protected]>, es-discuss list < [email protected]> > Date: Sat, 27 Dec 2014 09:04:43 +0100 > Subject: Re: Throwing when symbol *wrappers* are converted to primitives > > > Le 27 déc. 2014 à 08:41, Claude Pache <[email protected]> a écrit : > > > > I guess that V8 follows an old version of the spec draft. That particular behaviour was modified in Rev 28. See: > > > > https://bugs.ecmascript.org/show_bug.cgi?id=3252 > > > > —Claude > > In fact, that bug was for the particular case of wrapped symbol used as property key. For the more general case of converting a Symbol wrapper object back into a primitive value, I believe that behaviour also changed during the life in the spec draft, but I am too lazy to find when. (Note that the current draft defines Symbol.prototype[@@toPrimitive], and AFAIK, V8 doesn't implement @@toPrimitive yet.) > > —Claude > > > > > Le 27 déc. 2014 à 08:17, Axel Rauschmayer <[email protected]> a écrit : > > > >> This is current V8 behavior: > >> > >> ``` > >> > let obj = {}; > >> > obj[Object(Symbol())] = true; > >> TypeError: Cannot convert object to primitive value > >> > >> > '' + Object(Symbol()) > >> TypeError: Cannot convert a Symbol wrapper object to a primitive value > >> ``` > >> > >> Both exceptions make a lot of sense, but I don’t see that in the spec. The way I’d expect it to happen is via `Symbol.prototype[@@toPrimitive]` – it would always throw. But that’s not the case. > >> > >> https://people.mozilla.org/~jorendorff/es6-draft.html#sec-symbol.prototype-@@toprimitive > >> > >> -- > >> Dr. Axel Rauschmayer > >> [email protected] > >> rauschma.de > >> > >> > >> > >> _______________________________________________ > >> es-discuss mailing list > >> [email protected] > >> https://mail.mozilla.org/listinfo/es-discuss
AFAICT from the GitHub mirror, V8 does not.
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