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Re: LangWart: Method congestion from mutate multiplicty

Newsgroups comp.lang.python
Date 2013-02-09 19:54 -0800
References <680e50a4-6569-49cf-b369-0be450545d50@googlegroups.com> <5115c455$0$6574$c3e8da3$5496439d@news.astraweb.com>
Message-ID <d405822d-2252-4a85-8ab2-38ca88963d91@googlegroups.com> (permalink)
Subject Re: LangWart: Method congestion from mutate multiplicty
From Rick Johnson <rantingrickjohnson@gmail.com>

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On Friday, February 8, 2013 9:36:52 PM UTC-6, Steven D'Aprano wrote:
> Rick Johnson wrote:
> 
> > The solution is simple. Do not offer the "copy-mutate" methods and force
> > all mutation to happen in-place:
> > 
> > py> l = [1,2,3]
> > py> l.reverse
> > py> l
> > [3,2,1]
> > 
> > If the user wants a "mutated copy" he should explicitly create a new
> > object and then apply the correct mutator method:
> > 
> > py> a1 = [1,2,3]
> > py> a2 = list(a1).reverse()
> 
> Oh wow, Rick has re-discovered programming in Python during the mid to late
> 1990s!
> 
> [...snip: long-winded, rambling, and sarcastic response simply to convey 
> that Python lists have had a "reversed" method for some time...]

Steven, i am quite aware of the Python list method "reversed" --which returns a copy of the current list object in reversed order--, my point is that these types of "copy-mutate" methods superfluously pollute the object namespace. Do you really want "method pairs" like these:

 sort, sorted
 reverse, reversed

Hell, why stop there:

 append, appended
 flatten, flattened
 insert, inserted
 map, mapped
 filter, filtered
 reduce, reduced
 extend, extended
 freeze, frozen
 set, sat|setted
 unique, uniqued

Is this really what you prefer? Where does the madness end Steven? At what point do you say enough is enough? And what happens if you fail to catch the infection early enough? Steven, this is a /real/ problem which has the potential to go viral!

My point was this: All mutate methods should mutate "in-place", if the programmer wishes to create a mutated copy of the object, then the programmer should /explicitly/ create a copy of the object and then apply the correct mutator method to the copy. 

 NO: reversed = lst.reversed() # Python
YES: reversed = list(lst).reverse() # Python

 NO: reversed = a.reverse() # Ruby
YES: reversed = Array.new(a).reverse!() # Ruby

This is about consistency and keeping the number of methods from spiraling out of control because we feel the need to automate /every/ task for the programmer, when in actuality, we are doing more harm than good.

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LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-08 17:50 -0800
  Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-09 14:36 +1100
    Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-09 19:54 -0800
      Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-10 15:20 +1100
      Re: LangWart: Method congestion from mutate multiplicty Mark Janssen <dreamingforward@gmail.com> - 2013-02-09 20:53 -0800
        Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 01:29 +1100
          Re: LangWart: Method congestion from mutate multiplicty Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-02-10 14:03 -0500
            Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 11:11 +1100
          Re: LangWart: Method congestion from mutate multiplicty Mark Janssen <dreamingforward@gmail.com> - 2013-02-10 13:28 -0800
            Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 11:10 +1100
              Re: LangWart: Method congestion from mutate multiplicty Mark Janssen <dreamingforward@gmail.com> - 2013-02-10 17:14 -0800
          Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-11 08:51 +1100
          Re: LangWart: Method congestion from mutate multiplicty Mark Janssen <dreamingforward@gmail.com> - 2013-02-10 14:01 -0800
      Re: LangWart: Method congestion from mutate multiplicty Terry Reedy <tjreedy@udel.edu> - 2013-02-10 03:39 -0500
        Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 10:45 -0800
          Re: LangWart: Method congestion from mutate multiplicty Terry Reedy <tjreedy@udel.edu> - 2013-02-10 16:44 -0500
          Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 11:11 +1100
        Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 10:45 -0800
      Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-10 22:29 +1100
        Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-11 00:24 +1100
          Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 01:00 +1100
        Re: LangWart: Method congestion from mutate multiplicty Tim Chase <python.list@tim.thechases.com> - 2013-02-10 07:52 -0600
        Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 15:59 -0800
          Re: LangWart: Method congestion from mutate multiplicty Tim Chase <python.list@tim.thechases.com> - 2013-02-10 18:12 -0600
            Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 17:24 -0800
            Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 17:24 -0800
          Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 11:36 +1100
            Re: LangWart: Method congestion from mutate multiplicty MRAB <python@mrabarnett.plus.com> - 2013-02-11 02:03 +0000
            Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-11 04:53 -0800
              Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-12 00:27 +1100
                Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-11 20:55 -0800
                Re: LangWart: Method congestion from mutate multiplicty Mark Janssen <dreamingforward@gmail.com> - 2013-02-11 21:28 -0800
                Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-12 12:46 -0800
                Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-12 12:46 -0800
                Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-11 20:55 -0800
          Re: LangWart: Method congestion from mutate multiplicty alex23 <wuwei23@gmail.com> - 2013-02-10 18:05 -0800
            Re: LangWart: Method congestion from mutate multiplicty Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-02-11 07:19 +0000
            Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-11 18:24 +1100
            Re: LangWart: Method congestion from mutate multiplicty Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-02-11 07:35 +0000
            Re: LangWart: Method congestion from mutate multiplicty Tim Chase <tim@thechases.com> - 2013-02-11 06:04 -0600
            Re: LangWart: Method congestion from mutate multiplicty Serhiy Storchaka <storchaka@gmail.com> - 2013-02-11 19:07 +0200
      Re: LangWart: Method congestion from mutate multiplicty Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-10 13:30 +0000
        Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 16:25 -0800
          Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-11 11:42 +1100
        Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 16:25 -0800
      Re: LangWart: Method congestion from mutate multiplicty Mark Janssen <dreamingforward@gmail.com> - 2013-02-10 10:45 -0800
    Re: LangWart: Method congestion from mutate multiplicty 88888 Dihedral <dihedral88888@googlemail.com> - 2013-02-10 06:33 -0800
  Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-09 15:51 +1100
    Re: LangWart: Method congestion from mutate multiplicty alex23 <wuwei23@gmail.com> - 2013-02-10 17:56 -0800
      Re: LangWart: Method congestion from mutate multiplicty Chris Angelico <rosuav@gmail.com> - 2013-02-12 19:06 +1100
  Re: LangWart: Method congestion from mutate multiplicty Neil Hodgson <nhodgson@iinet.net.au> - 2013-02-10 20:53 +1100
    Re: LangWart: Method congestion from mutate multiplicty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-10 22:30 +1100
    Re: LangWart: Method congestion from mutate multiplicty Rick Johnson <rantingrickjohnson@gmail.com> - 2013-02-10 10:55 -0800
      Re: LangWart: Method congestion from mutate multiplicty Neil Hodgson <nhodgson@iinet.net.au> - 2013-02-11 08:57 +1100

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