Inside Google we have a few occurrences of arguments.callee. Some of these are from Prototype, MochiKit, jQuery and other third party code.
I agree with Tobie regarding the 2 use cases but there is one more related use case and that is arguments.callee.caller and I know a lot of developers here rely on and that to be able to generate a stack trace. This is crucial for fixing bugs in production systems. SpiderMonkey has the Error.prototype.stack property and if that was supported everywhere I don't think there would be any serious complaints about removing arguments.callee and arguments.callee.caller. On Sat, Sep 13, 2008 at 08:19, Bob Ippolito <[EMAIL PROTECTED]> wrote: > I found it convenient when writing MochiKit for the same reasons that > it's in Prototype but it would be rather simple to change things > around to use named references to functions or whatever else was > appropriate. It occurs 28 times in trunk. > > -bob > > On Fri, Sep 12, 2008 at 5:08 PM, Brendan Eich <[EMAIL PROTECTED]> wrote: >> Great -- good to have library authors / maintainers on this list. >> >> I hold no brief for callee. The only issue in its favor is the cost of >> migrating to strict mode. A new version of Prototype that loses >> internal arguments.callee uses and is otherwise compatible helps. >> >> Dojo and other Ajax folks on the list, please pipe up. >> >> / be >> >> Sent from my iPhone >> >> On Sep 12, 2008, at 6:54 PM, Tobie Langel <[EMAIL PROTECTED]> >> wrote: >> >>> >>> On Sep 11, 2008, at 14:34 , Brendan Eich wrote: >>> >>>> I snipped your words about callee, but it's used quite a bit in Ajax >>>> libraries, e.g, Prototype: >>>> >>>> $ grep -w callee prottype.js >>>> replacement = arguments.callee.prepareReplacement(replacement); >>>> var self = arguments.callee; >>>> parts.add = arguments.callee.addPair; >>>> >>>> (Prototype 1.5.1.1.) >>> >>> In Prototype, arguments.callee is used in two distinct cases: >>> >>> 1) reading a property of the callee, and >>> 2) recursively calling the callee. >>> >>> Case #1 is easily solved by storing the said property in a closure, >>> or by setting it elsewhere (where it probably would be a better fit, >>> anyway). >>> >>> Case #2 is easily solved by using a named function instead. For the >>> particular case where it is used in Prototype, the anonymous >>> function lies inside of a closure, so there is no chance of >>> triggering the JScript scope bug nor of polluting the global >>> namespace when naming it. >>> >>> From what I understand, ES 3.1 strict mode compliance will be opt-in >>> and will require at least slight source code modifications (if only >>> to prepend it with the 'use strict'; expression). So current >>> versions of Prototype (or other libs, for that matter), will not be >>> ES 3.1 'strict' compliant by default. >>> >>> I'm not really worried about modifying Prototype to avoid use of the >>> arguments.callee property. As a matter of fact, we've already done >>> so in a development branch for Caja compliance. >>> >>> Note that jQuery does not use arguments.callee at all. >>> >>> Best, >>> >>> Tobie >>> >>> >>> >>> >>> >> _______________________________________________ >> 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 > -- erik _______________________________________________ Es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
