On Nov 10, 2013, at 2:12 PM, Andrea Giammarchi <[email protected]> wrote:
> I think I've completely missed the `undefined === absent` conversation ... so > if I have an object, and `obj.key = void 0` why `key` would be considered > absent, exactly? `undefined` is a very well described "value", passing stuff > around thinking has a value but getting ignored by signatures and who knows > what else is a door to hell in the real world. > void <expression> simply evaluates expression and sets the return continuation value to undefined. void 0 is identical to |undefined| unless a containing scope has declared a variable named “undefined” locally. void … does not result in a special value. —Oliver > my 2 cents > > > On Sun, Nov 10, 2013 at 1:49 PM, Mark S. Miller <[email protected]> wrote: > On Sun, Nov 10, 2013 at 1:30 PM, K. Gadd <[email protected]> wrote: > JSIL and embind both need arguments.length for efficient method call dispatch > when dealing with overloaded functions. Is it your intent that all such > scenarios must now pay the cost of creating an array (to hold the rest > arguments) and then destructuring it, for every call? At present it's > possible to avoid this overhead in V8 and SpiderMonkey by using > arguments.length + arguments[n] or by using arguments.length + patterned > argument names. > > Hi Katelyn, > > No one is taking arguments away. Perhaps we would if we could but we can't. > So as I said just now to Allen, if you really need to do this, go ahead and > use arguments.length. > > But do you really need to do this? Assuming for a moment that we were all > agreed that the best practice is to treat absence the same as undefined, why > not go with the best practice and be done? > > > > > > On Sun, Nov 10, 2013 at 1:24 PM, David Bruant <[email protected]> wrote: > Le 10/11/2013 22:19, Brendan Eich a écrit : > > On Nov 10, 2013, at 9:12 PM, Andrea Giammarchi <[email protected]> > wrote: > > Not sure why this is so needed though. > Allen's posts make the case: webidl and varargs-style functions. Not all > legacy. > WebIDL creates spec, not code. The language syntax doesn't need to evolve for > that. Allen showed that rest params+destructuring allows self-hosting without > |arguments| > Varargs functions have rest parameters. > > David > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > > > > > -- > Cheers, > --MarkM > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss
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