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Re: Give alert if form checkbox array is empty

Newsgroups comp.lang.javascript
Date 2016-01-22 10:45 -0800
References (1 earlier) <n7njvu$51k$1@news.albasani.net> <mu00ablmp9s6ronvrrejt2npfp5uffhpc5@4ax.com> <1851504.v7CTRd67sv@PointedEars.de> <5278c17a-a0e3-4772-9a96-2b20a6479804@googlegroups.com> <1954447.mWofGQDR9d@PointedEars.de>
Message-ID <60f55799-39cf-4e12-9f54-706d61363f3b@googlegroups.com> (permalink)
Subject Re: Give alert if form checkbox array is empty
From Scott Sauyet <scott.sauyet@gmail.com>

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Thomas 'PointedEars' Lahn wrote:
> Scott Sauyet wrote:
>> Thomas 'PointedEars' Lahn wrote:

>>> Keep in mind that the built-in implementation of an algorithm is
>>> naturally always the most efficient one to use as it is, at best,
>>> provided in machine code already.
>> 
>> Nonsense.  This is a complete non sequitur.
> 
> It is not.  Machine code is compiled already; script code is not.  So the 
> time to interpret script code or to compile script code to machine code has 
> to be taken into account.

So, taking into account the time to compile a script, how much more 
efficient is the native `Array.prototype.map` method than the one 
supplied by lodash [1]? 

Does this question sound like claptrap to anyone else? It certainly does 
to me. Because the answer will certainly depend on the API differences 
between the pure function supplied by lodash and that of the native 
method, on the number of times the function is called, on the 
optimizations performed by the engine on its native implementation, and 
on the optimizations that the lodash version might be able to take 
advantage of on a given engine. 

But Thomas, you want to point to the fact that it's precompiled as 
enough to outweigh all of these factors. That is pure nonsense. 

 
>> One can write a horrible implementation of an algorithm; the fact that
>> it's available immediately in machine code does not make it more efficient
>> to use than one written better.
> 
> One must start from the assumption that the developers of script engines 
> know what they are doing, without assuming any optimizations on their part.

Why must one start from that assumption?

The writers of script engines are developers like any other, subject to 
the same foibles as anyone else, and subject to constraints from a 
specification that may not be relevant to ones own interests. 


>> Many people have written implementations of functions such as `map`,
>> `reduce`, and `filter` more efficient for many uses than their native
>> counterparts on `Array.prototype`.
> 
> Now *that* is a non sequitur.  And you want to cite evidence.

Do you believe that applies to people who post such ill-supported 
propositions as this: 

| One must start from the assumption that the developers of script 
| engines know what they are doing, without assuming any optimizations
| on their part.

or this:

| Keep in mind that the built-in implementation of an algorithm is
| naturally always the most efficient one to use as it is, at best,
| provided in machine code already.

?

But a very quick search of the Web found many benchmarks, including this 
fairly recent one: 

    <https://jsperf.com/native-vs-array-js-vs-underscore/182>

which demonstrates very different performance characteristics across 
many engines, but finds none in which the native `map` is the fastest. 

  [1]: <https://lodash.com/docs#map>


  -- Scott

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Thread

Give alert if form checkbox array is empty Bunyip <bunyip@koalanet.com.au> - 2016-01-20 13:28 +1000
  Re: Give alert if form checkbox array is empty JJ <jj4public@vfemail.net> - 2016-01-20 12:30 +0700
    Re: Give alert if form checkbox array is empty Bunyip <bunyip@koalanet.com.au> - 2016-01-20 17:55 +1000
      Re: Give alert if form checkbox array is empty JJ <jj4public@vfemail.net> - 2016-01-20 19:29 +0700
        Re: Give alert if form checkbox array is empty "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-01-20 13:46 +0100
  Re: Give alert if form checkbox array is empty Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2016-01-20 08:23 +0000
    Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-20 15:52 +0100
      Re: Give alert if form checkbox array is empty Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2016-01-20 15:43 +0000
        Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-20 17:15 +0100
          Re: Give alert if form checkbox array is empty Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-01-20 17:53 +0000
            Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-20 20:39 +0100
              Re: Give alert if form checkbox array is empty Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-01-20 22:46 +0000
          Re: Give alert if form checkbox array is empty Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2016-01-21 07:53 +0000
            Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-21 10:52 +0100
              Re: Give alert if form checkbox array is empty Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2016-01-21 10:26 +0000
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-22 00:07 +0100
  Re: Give alert if form checkbox array is empty Stefan Weiss <krewecherl@gmail.com> - 2016-01-20 10:28 +0100
    Re: Give alert if form checkbox array is empty Bunyip <bunyip@koalanet.com.au> - 2016-01-21 08:05 +1000
      Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-21 00:59 +0100
        Re: Give alert if form checkbox array is empty Stefan Weiss <krewecherl@gmail.com> - 2016-01-21 03:17 +0100
          Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-21 08:54 +0100
            Re: Give alert if form checkbox array is empty Stefan Weiss <krewecherl@gmail.com> - 2016-01-21 12:17 +0100
        Re: Give alert if form checkbox array is empty John Harris <niam@jghnorth.org.uk.invalid> - 2016-01-21 14:16 +0000
        Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-21 19:52 -0800
          Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-22 09:48 +0100
            Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-22 10:45 -0800
              Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-23 19:41 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-24 17:51 -0800
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-25 19:46 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-27 11:09 -0800
        Re: Give alert if form checkbox array is empty Dr J R Stockton <reply1600@merlyn.demon.co.uk.invalid> - 2016-01-23 22:22 +0000
        Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-27 11:06 -0800
          Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-28 14:46 +0100
            Re: Give alert if form checkbox array is empty Gene Wirchenko <genew@telus.net> - 2016-01-28 10:30 -0800
              Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-28 20:06 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-28 23:32 -0800
                Re: Give alert if form checkbox array is empty "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-01-29 09:05 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-29 06:02 -0800
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-29 20:54 +0100
                Re: Give alert if form checkbox array is empty John Harris <niam@jghnorth.org.uk.invalid> - 2016-01-29 10:36 +0000
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-02-09 04:39 +0100
                Re: Give alert if form checkbox array is empty John Harris <niam@jghnorth.org.uk.invalid> - 2016-02-09 18:07 +0000
                Re: Give alert if form checkbox array is empty Gene Wirchenko <genew@telus.net> - 2016-01-29 09:32 -0800
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-29 20:34 +0100
                Re: Give alert if form checkbox array is empty Aleksandro <aleksandro@gmx.com> - 2016-01-29 16:50 -0300
                Re: Give alert if form checkbox array is empty Stefan Weiss <krewecherl@gmail.com> - 2016-01-30 03:31 +0100
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-30 04:19 +0100
                Re: Give alert if form checkbox array is empty Stefan Weiss <krewecherl@gmail.com> - 2016-01-30 05:01 +0100
              Re: Give alert if form checkbox array is empty Aleksandro <aleksandro@gmx.com> - 2016-01-28 16:39 -0300
            Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-29 06:04 -0800
              Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-29 20:54 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-29 14:55 -0800
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-30 04:55 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-30 15:48 -0800
                Re: Give alert if form checkbox array is empty Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-01-31 21:02 +0100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-01-31 13:08 -0800
                Re: Give alert if form checkbox array is empty Andrew Poulos <ap_prog@hotmail.com> - 2016-02-01 12:28 +1100
                Re: Give alert if form checkbox array is empty Scott Sauyet <scott.sauyet@gmail.com> - 2016-02-01 17:58 -0800
  Re: Give alert if form checkbox array is empty "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-01-20 06:25 -0800
  Re: Give alert if form checkbox array is empty Aleksandro <aleksandro@gmx.com> - 2016-01-20 12:54 -0300

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