On Tue, Sep 27, 2011 at 2:43 PM, Brendan Eich <[email protected]> wrote: > On Sep 27, 2011, at 6:11 AM, Sean Eagan wrote: > >> On Mon, Sep 26, 2011 at 4:47 PM, Xavier MONTILLET >> <[email protected]> wrote: >>> Normally, you use an object for optional arguments. >> >> This is probably the most common case in practice, however... >> >>> And there is no good reason not to since you don't care about the order of >>> the arguments. >> >> There are two good reasons: >> >> * it's more concise since you don't have to prefix each argument >> access with the the object argument name + ".", however, destructuring >> now helps here >> * library author does not need to introduce argument names, the >> callback author can use whatever names they want, such as an >> abbreviations for example >> >> Also, there are existing and future in-language APIs which receive >> multiple argument callbacks, for example: >> >> * Array.prototype methods >> * Proxy traps > > Trailing formal parameters do not need to be declared if not used in JS. > > Holes in parameter lists have some uses as you point out, but they're rare > enough that I don't think we should add parameter list holes.
I agree, but it seems like holes in parameter lists would be no more rare than holes in destructuring lists... [a, , c] = arr; ...so it seems strange to add it to one but not the other. Thanks, Sean Eagan _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
