On Oct 8, 2012, at 10:35 AM, Andreas Rossberg wrote: > On 8 October 2012 19:18, Allen Wirfs-Brock <[email protected]> wrote: >> >> On Oct 8, 2012, at 10:04 AM, Andreas Rossberg wrote: >> >>> On 8 October 2012 18:24, Allen Wirfs-Brock <[email protected]> wrote: >>>> You desugaring would break ES<=5.1 compatibility for: >>>> >>>> (function (p) { >>>> var p; >>>> return typeof p >>>> })("test") >>>> >>>> ES5.1 returns "string", your desugaring returns "undefined" >>> >>> I'm probably just being blind, but I'm not seeing it. Why? >>> >> In ES <= 5.1, function declarations over-write formal parameters. But var >> declarations, without initializer do not assign undefined to already local >> bindings (including formal parameters) that already exist. > > Yes. > >> You desugaring would create a new var declaration in a new scope contours >> that would be initialized to undefined and shadow the like-named formal >> parameter. > > But it creates no new var declarations. Your function would presumably become
Right, I glossed over the fact that both the inner and outer function declaration introduce bindings for the formals Allen _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
