On Saturday, June 9, 2012 at 11:53 PM, Erik Arvidsson wrote:
> Don't you want to use arguments.length instead of function.length? > On Jun 9, 2012 6:53 PM, "Irakli Gozalishvili" <[email protected] > (mailto:[email protected])> wrote: > > I just noticed strange behavior in spider monkey implementation of rest > > arguments: > > > > (function(a, b, ...rest) {}).length // => 2 I agree that this is strange, I would expect 3, as there are three formally named parameters. Rick > > > > I think ignoring `rest` in length is pretty counter intuitive. For example > > I have small utility function that > > I use to dispatch depending on argument length. > > > > var sum = dispatcher([ > > function() { return 0 }, > > function(x) { return x }, > > function(x, y) { return x + y }, > > function(x, y, z) { return Array.prototype.slice.call(arguments, > > 1).reduce(sum, x) } > > ]) > > > > This behavior of rest would obviously break assumptions made by this > > library. That being said I don't think `3` would be any better. Maybe such > > functions length should be: > > > > - Infinity ? > > - 2.5 ? > > > > That way libraries would be able to handle them in a nice way: > > > > var sum = dispatcher([ > > () => 0, > > (x) => x, > > (x, y) => x + y, > > (x, ...rest) => rest.reduce(sum, x) > > ]) > > > > > > Regards > > -- > > Irakli Gozalishvili > > Web: http://www.jeditoolkit.com/ > > > > > > _______________________________________________ > > es-discuss mailing list > > [email protected] (mailto:[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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