Re: Reduce context parameter
On Mon, Jan 7, 2013 at 11:59 PM, Rick Waldron waldron.r...@gmail.com wrote: The initialVal argument is _optional_ and undefined is valid — how would you decide if what was passed should be initial value or thisArg? I see. Well, ship has sailed. Thanks. - peter ...(Could have specced the context parameter to be second, to be ignored if undefined, and the accumulator third.) ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
As I said: 'undefined' and 'not provided' have a complex relationship in the ES spec. The ship has sailed, but the turd is the shiniest turd you've ever seen. On Tuesday, January 8, 2013, Peter van der Zee wrote: On Mon, Jan 7, 2013 at 11:59 PM, Rick Waldron waldron.r...@gmail.comjavascript:; wrote: The initialVal argument is _optional_ and undefined is valid — how would you decide if what was passed should be initial value or thisArg? I see. Well, ship has sailed. Thanks. - peter ...(Could have specced the context parameter to be second, to be ignored if undefined, and the accumulator third.) ___ es-discuss mailing list es-discuss@mozilla.org javascript:; https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nl wrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
I know this doesn't answer your question, but Function.prototype.bind makes thisArg obsolete. Regarding the origin story, there is some discussion here: https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html Rick On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi andrea.giammar...@gmail.com wrote: I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nl wrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
Rick you know bind is that slow and it costs on GC if used massively ;-) I use a lot the second argument in Array#extras and I feel Peter van der Zee here: reduce/Right should have had that too br On Mon, Jan 7, 2013 at 1:10 PM, Rick Waldron waldron.r...@gmail.com wrote: I know this doesn't answer your question, but Function.prototype.bind makes thisArg obsolete. Regarding the origin story, there is some discussion here: https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html Rick On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi andrea.giammar...@gmail.com wrote: I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nl wrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
On Monday, January 7, 2013, Andrea Giammarchi wrote:
Rick you know bind is that slow and it costs on GC if used massively ;-)
This is not my problem, implementors should optimize. bind() would only
occur once per method call.
I use a lot the second argument in Array#extras and I feel Peter van der
Zee here: reduce/Right should have had that too
The initialVal argument is _optional_ and undefined is valid — how would
you decide if what was passed should be initial value or thisArg?
Rick
br
On Mon, Jan 7, 2013 at 1:10 PM, Rick Waldron
waldron.r...@gmail.comjavascript:_e({}, 'cvml', 'waldron.r...@gmail.com');
wrote:
I know this doesn't answer your question, but Function.prototype.bind
makes thisArg obsolete.
Regarding the origin story, there is some discussion here:
https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html
Rick
On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi
andrea.giammar...@gmail.com javascript:_e({}, 'cvml',
'andrea.giammar...@gmail.com'); wrote:
I think to increase confusion with other Array#extras :D
and since we have this specced as it is now, a third parameter for the
context could add even more confusion later on 3
I know, I should not have answered that ...
On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee
e...@qfox.nljavascript:_e({}, 'cvml', 'e...@qfox.nl');
wrote:
Mostly out of curiosity; why do Array#reduce and reduceRight have no
context parameter?
- peter
___
es-discuss mailing list
es-discuss@mozilla.org javascript:_e({}, 'cvml',
'es-discuss@mozilla.org');
https://mail.mozilla.org/listinfo/es-discuss
___
es-discuss mailing list
es-discuss@mozilla.org javascript:_e({}, 'cvml',
'es-discuss@mozilla.org');
https://mail.mozilla.org/listinfo/es-discuss
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
The impediment that I recall during ES3.1 days was the accumulator parameter to reduce/reduceRight, which wants to come immediately after the callback function. Both are mandatory, whereas |thisValue| (context, shudder) is optional. So accumulator won. As for .bind's cost, let's remember Knuth: http://en.wikipedia.org/wiki/Program_optimization#When_to_optimize. /be Andrea Giammarchi wrote: Rick you know bind is that slow and it costs on GC if used massively ;-) I use a lot the second argument in Array#extras and I feel Peter van der Zee here: reduce/Right should have had that too br On Mon, Jan 7, 2013 at 1:10 PM, Rick Waldron waldron.r...@gmail.com mailto:waldron.r...@gmail.com wrote: I know this doesn't answer your question, but Function.prototype.bind makes thisArg obsolete. Regarding the origin story, there is some discussion here: https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html Rick On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi andrea.giammar...@gmail.com mailto:andrea.giammar...@gmail.com wrote: I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nl mailto:e...@qfox.nl wrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org mailto:es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org mailto:es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
thisArg could have been third optional argument leaving current implementation as it is but making thisArg possible, IMHO lucky me I don't use Array#reduce that much neither I need the thisArg so far so ... OK for me On Mon, Jan 7, 2013 at 2:59 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, January 7, 2013, Andrea Giammarchi wrote: Rick you know bind is that slow and it costs on GC if used massively ;-) This is not my problem, implementors should optimize. bind() would only occur once per method call. I use a lot the second argument in Array#extras and I feel Peter van der Zee here: reduce/Right should have had that too The initialVal argument is _optional_ and undefined is valid — how would you decide if what was passed should be initial value or thisArg? Rick br On Mon, Jan 7, 2013 at 1:10 PM, Rick Waldron waldron.r...@gmail.comwrote: I know this doesn't answer your question, but Function.prototype.bind makes thisArg obsolete. Regarding the origin story, there is some discussion here: https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html Rick On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi andrea.giammar...@gmail.com wrote: I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nl wrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
not always, only when thisArg is needed ... Array#reduce(cb, initialValue[, thisArg]) if needed, arr.reduce(cb, undefined, obj) does not look that bad, IMHO again, I m fine with current status ... On Mon, Jan 7, 2013 at 3:14 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, January 7, 2013, Andrea Giammarchi wrote: thisArg could have been third optional argument leaving current implementation as it is but making thisArg possible, IMHO lucky me I don't use Array#reduce that much neither I need the thisArg so far so ... OK for me Sorry, but no—this would force user code to always provide an initialVal, even when it would prefer to use the first item the array—which is the default when initialVal is omitted. Rick On Mon, Jan 7, 2013 at 2:59 PM, Rick Waldron waldron.r...@gmail.comwrote: On Monday, January 7, 2013, Andrea Giammarchi wrote: Rick you know bind is that slow and it costs on GC if used massively ;-) This is not my problem, implementors should optimize. bind() would only occur once per method call. I use a lot the second argument in Array#extras and I feel Peter van der Zee here: reduce/Right should have had that too The initialVal argument is _optional_ and undefined is valid — how would you decide if what was passed should be initial value or thisArg? Rick br On Mon, Jan 7, 2013 at 1:10 PM, Rick Waldron waldron.r...@gmail.comwrote: I know this doesn't answer your question, but Function.prototype.bind makes thisArg obsolete. Regarding the origin story, there is some discussion here: https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html Rick On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi andrea.giammar...@gmail.com wrote: I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nlwrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
On Monday, January 7, 2013, Andrea Giammarchi wrote: not always, only when thisArg is needed ... Array#reduce(cb, initialValue[, thisArg]) if needed, arr.reduce(cb, undefined, obj) does not look that bad, IMHO undefined is a valid initialVal and won't cause reduce to fallback to the first item in the array (I'd that behaviour was desired). Effectively changing this: var array = [2,3,4]; array.reduce(cb.bind(ctx)) To: array.reduce(cb, array[0], ctx); Not worth it. In fact, it's not even clear now what that param is even for... var Rick again, I m fine with current status ... On Mon, Jan 7, 2013 at 3:14 PM, Rick Waldron waldron.r...@gmail.comwrote: On Monday, January 7, 2013, Andrea Giammarchi wrote: thisArg could have been third optional argument leaving current implementation as it is but making thisArg possible, IMHO lucky me I don't use Array#reduce that much neither I need the thisArg so far so ... OK for me Sorry, but no—this would force user code to always provide an initialVal, even when it would prefer to use the first item the array—which is the default when initialVal is omitted. Rick On Mon, Jan 7, 2013 at 2:59 PM, Rick Waldron waldron.r...@gmail.comwrote: On Monday, January 7, 2013, Andrea Giammarchi wrote: Rick you know bind is that slow and it costs on GC if used massively ;-) This is not my problem, implementors should optimize. bind() would only occur once per method call. I use a lot the second argument in Array#extras and I feel Peter van der Zee here: reduce/Right should have had that too The initialVal argument is _optional_ and undefined is valid — how would you decide if what was passed should be initial value or thisArg? Rick br On Mon, Jan 7, 2013 at 1:10 PM, Rick Waldron waldron.r...@gmail.comwrote: I know this doesn't answer your question, but Function.prototype.bind makes thisArg obsolete. Regarding the origin story, there is some discussion here: https://mail.mozilla.org/pipermail/es-discuss/2008-June/006431.html Rick On Mon, Jan 7, 2013 at 3:56 PM, Andrea Giammarchi andrea.giammar...@gmail.com wrote: I think to increase confusion with other Array#extras :D and since we have this specced as it is now, a third parameter for the context could add even more confusion later on 3 I know, I should not have answered that ... On Sun, Jan 6, 2013 at 9:48 AM, Peter van der Zee e...@qfox.nl wrote: Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org h https://mail.mozilla.org/listinfo/es-discuss ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
but this is wrong array.reduce(cb, array[0], ctx); since index 0 will be looped so first call previous and current will be the same ... right ? That's why I've used undefined but I understand your concern so, as it is right now, there's no way to implement the context in both reduce and reduceRight ... Peter van der Zee use bind :D On Mon, Jan 7, 2013 at 3:41 PM, Rick Waldron waldron.r...@gmail.com wrote: array.reduce(cb, array[0], ctx); ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Reduce context parameter
This is why I ended up using $$ArgumentCount and $$HasArgument('name')
primitive magics. The ES spec's usage of argument exists doesn't really
line up with the semantics of default params. The semantics of default
params are better but it's too late to go back and make explicit
undefined's the same as a lack of a parameter for this stuff (I'm sure
someone out there uses array.reduce(cb, undefined) and depends on it).
On Mon, Jan 7, 2013 at 7:34 PM, Rick Waldron waldron.r...@gmail.com wrote:
On Monday, January 7, 2013, Andrea Giammarchi wrote:
but this is wrong
array.reduce(cb, array[0], ctx);
since index 0 will be looped so first call previous and current will be
the same ... right ? That's why I've used undefined but I understand your
concern so, as it is right now, there's no way to implement the context in
both reduce and reduceRight ... Peter van der Zee use bind :D
Yeah, you'd need to mess it up further array.slice(1).reduce... Even less
worth it now
Rick
On Mon, Jan 7, 2013 at 3:41 PM, Rick Waldron waldron.r...@gmail.comwrote:
array.reduce(cb, array[0], ctx);
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Reduce context parameter
Mostly out of curiosity; why do Array#reduce and reduceRight have no context parameter? - peter ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
