Re: Is goto Still Considered Harmful?

From	Kaz Kylheku <kaz@kylheku.com>
Newsgroups	comp.lang.c
Subject	Re: Is goto Still Considered Harmful?
Date	2014-03-25 16:14 +0000
Organization	Aioe.org NNTP Server
Message-ID	<20140325084738.938@kylheku.com> (permalink)
References	(6 earlier) <functions-20140325021135@ram.dialup.fu-berlin.de> <lnr45ql546.fsf@nuthaus.mib.org> <function-20140325154407@ram.dialup.fu-berlin.de> <lgs5h1$td7$2@dont-email.me> <C-functions-20140325163248@ram.dialup.fu-berlin.de>

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On 2014-03-25, Stefan Ram <ram@zedat.fu-berlin.de> wrote:
> James Kuyper <jameskuyper@verizon.net> writes:
>>Yes, but you've been asked to defend an assertion that there is a
>>C-specific preference for short functions.
>
>   My assertion is that in C we (the majority of educated
>   programmers of today) prefer short functions. I do not wish
>   to make any assertion about whether this holds or does not
>   hold for any other language.

I prefer functions not to be "unnecessarily long".

Sometimes "necessarily long" can mean a thousand lines or more.

If a large function is broken up into a small top function which calls many
smaller ones, but those smaller ones have no caller other than the top
function, then the change is pretty much a waste of effort.

Not only that, but C has poor support for dividing logic into functions.
Breaking up a large function into smaller ones can mean changing the structure
of the code in order to simulate the environment passing that naturally occurs
in a language with nested functions.  What were originally nice, local
variables in the original function turn into some ugly structure or structures
that only exists in order to support the fragmentation of the logic into
multiple functions. These can harm the performance of the function, and also
trade back some of the maintainbility improvement arising from the breakup.

So, it is perfectly okay for some complicated, self-contained piece of logic
which offers no re-usable small pieces to any other part of the program to be
be represented as a big function that works with a bunch of local variables.

Breaking up logic into functions should only be done when:

- some of those functions will be called from more than one place, eliminating
  repetitions.

- some of those functions are useful on their own and will end up being
  called by other functions or modules.

- pieces of the original large code were being selectively dispatched by
  a large switch or if/else ladder, so that when the function is broken up,
  a dispatch based on function pointer indirection can streamline the flow
  and possibly even be faster.

Experienced, mature programmers can handle large functions, and large functions
occur in all advanced, real-world projects.

For instance, the function _dl_map_object_from_fd in the glibc dynamic linker:

   https://sourceware.org/git/?p=glibc.git;a=blob;f=elf/dl-load.c

goes from line 919 to 1623. (Commit 9455df...bef85a).

People always wish that the world conform to their own physical and
intellectual limitations.  Grapes that are out of reach must be sour,
thought the Fox.

Maybe the real principle here is "small functions for small minds".

Thread

Is goto Still Considered Harmful? Lynn McGuire <lmc@winsim.com> - 2014-03-12 11:02 -0500
  Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-12 12:17 -0400
  Re: Is goto Still Considered Harmful? nospam@see.signature (Richard Maine) - 2014-03-12 09:20 -0700
    Re: Is goto Still Considered Harmful? Lynn McGuire <lmc@winsim.com> - 2014-03-18 16:30 -0500
      Re: Is goto Still Considered Harmful? Geoff <geoff@invalid.invalid> - 2014-03-18 17:36 -0700
        Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-19 07:34 -0400
          Re: Is goto Still Considered Harmful? "BartC" <bc@freeuk.com> - 2014-03-19 12:08 +0000
            Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-19 10:07 -0400
              Re: Is goto Still Considered Harmful? Richard <rgrdev_@gmail.com> - 2014-03-19 17:05 +0100
            Re: Is goto Still Considered Harmful? Lynn McGuire <lmc@winsim.com> - 2014-03-19 12:27 -0500
      Re: Is goto Still Considered Harmful? "Terence" <tbwright@bigpond.net.au> - 2014-03-19 20:35 +1100
        Re: Is goto Still Considered Harmful? Lynn McGuire <lmc@winsim.com> - 2014-03-19 12:26 -0500
  Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-12 16:47 +0000
    Re: Is goto Still Considered Harmful? Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2014-03-12 19:07 +0100
      Re: Is goto Still Considered Harmful? Andrew Cooper <root@127.0.0.1> - 2014-03-12 23:36 +0000
        Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-13 00:23 +0000
          Re: Is goto Still Considered Harmful? Andrew Cooper <root@127.0.0.1> - 2014-03-13 01:18 +0000
            Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-13 02:08 +0000
              Re: Is goto Still Considered Harmful? Andrew Cooper <root@127.0.0.1> - 2014-03-13 02:21 +0000
              Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-13 11:17 +0100
        Re: Is goto Still Considered Harmful? Melzzzzz <mel@zzzzz.invalid> - 2014-03-13 01:53 +0100
      Re: Is goto Still Considered Harmful? Les Cargill <lcargill99@comcast.com> - 2014-03-13 01:46 -0500
    Re: Is goto Still Considered Harmful? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2014-03-13 10:56 +0100
    Re: Is goto Still Considered Harmful? "Nasser M. Abbasi" <nma@12000.org> - 2014-03-16 08:18 -0500
      Re: Is goto Still Considered Harmful? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-16 15:18 +0000
        Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-20 11:36 -0700
  Re: Is goto Still Considered Harmful? "BartC" <bc@freeuk.com> - 2014-03-12 18:50 +0000
    Re: Is goto Still Considered Harmful? <william@wilbur.25thandClement.com> - 2014-03-12 12:49 -0700
    Re: Is goto Still Considered Harmful? "Qolin" <noone@nowhere.com> - 2014-03-12 21:54 +0000
      Re: Is goto Still Considered Harmful? Lynn McGuire <lmc@winsim.com> - 2014-03-12 16:57 -0500
      Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-12 15:36 -0700
        Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-12 19:02 -0400
          Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-12 16:58 -0700
            Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-12 20:09 -0400
        Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-12 16:44 -0700
      Re: Is goto Still Considered Harmful? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-12 23:40 -0500
        Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-13 11:25 +0100
        Re: Is goto Still Considered Harmful? Thomas Jahns <jahns@idontlikespam.dkrz.de> - 2014-03-14 11:24 +0100
          Re: Is goto Still Considered Harmful? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-14 23:32 -0500
          Re: Is goto Still Considered Harmful? Dr Nick <nospam-4@temporary-address.org.uk> - 2014-03-15 13:43 +0000
            Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-15 16:28 +0100
              Re: Is goto Still Considered Harmful? Dr Nick <nospam-4@temporary-address.org.uk> - 2014-03-15 16:01 +0000
                Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-17 08:51 +0100
    Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-13 11:22 +0100
  Re: Is goto Still Considered Harmful? ralph <nt_consulting@yahoo.com> - 2014-03-12 15:34 -0500
  Re: Is goto Still Considered Harmful? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2014-03-12 17:48 -0700
  Re: Is goto Still Considered Harmful? jt@toerring.de (Jens Thoms Toerring) - 2014-03-13 01:06 +0000
    Re: Is goto Still Considered Harmful? wilson <winslole@udayton.edu> - 2014-03-13 03:59 -0400
      Re: Is goto Still Considered Harmful? wilson <winslole@udayton.edu> - 2014-03-13 05:02 -0400
        Re: Is goto Still Considered Harmful? Richard Damon <Richard@Damon-Family.org> - 2014-03-13 08:42 -0400
          Re: Is goto Still Considered Harmful? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-13 14:45 +0000
    Re: Is goto Still Considered Harmful? Louis Krupp <lkrupp@nospam.pssw.com.invalid> - 2014-03-13 07:42 -0600
      Re: Is goto Still Considered Harmful? Richard <rgrdev_@gmail.com> - 2014-03-13 14:56 +0100
  Re: Is goto Still Considered Harmful? Wolfgang Kilian <kilian@invalid.com> - 2014-03-13 09:10 +0100
  Re: Is goto Still Considered Harmful? mark.bluemel@gmail.com - 2014-03-13 08:02 -0700
  Re: Is goto Still Considered Harmful? Thomas Koenig <tkoenig@netcologne.de> - 2014-03-13 21:09 +0000
    Re: Is goto Still Considered Harmful? "Qolin" <noone@nowhere.com> - 2014-03-13 21:24 +0000
      Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-13 22:36 +0000
        Re: Is goto Still Considered Harmful? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-13 23:02 -0500
          Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-14 04:07 +0000
            Re: Is goto Still Considered Harmful? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-13 23:56 -0500
          Re: Is goto Still Considered Harmful? helbig@astro.multiCLOTHESvax.de (Phillip Helbig---undress to reply) - 2014-03-14 09:17 +0000
    Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-13 22:42 +0000
      Re: Is goto Still Considered Harmful? "James Van Buskirk" <not_valid@comcast.net> - 2014-03-13 17:13 -0600
        Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-13 16:46 -0700
          Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-14 01:17 +0000
            Re: Is goto Still Considered Harmful? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-13 23:04 -0500
              Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-14 10:41 +0100
                Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-14 09:55 +0000
                Re: Is goto Still Considered Harmful? David Brown <david.brown@hesbynett.no> - 2014-03-14 13:16 +0100
                Re: Is goto Still Considered Harmful? Seebs <usenet-nospam@seebs.net> - 2014-03-18 21:08 +0000
                Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-18 17:41 -0400
        Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-14 00:45 +0000
          Re: Is goto Still Considered Harmful? "James Van Buskirk" <not_valid@comcast.net> - 2014-03-13 21:40 -0600
            Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-14 01:02 -0400
              Re: Is goto Still Considered Harmful? "James Van Buskirk" <not_valid@comcast.net> - 2014-03-14 10:36 -0600
                Re: Is goto Still Considered Harmful? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-14 17:30 +0000
                Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-14 13:51 -0400
                Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-14 13:12 -0700
                Re: Is goto Still Considered Harmful? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 06:46 -0700
            Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-14 05:29 +0000
              Re: Is goto Still Considered Harmful? "James Van Buskirk" <not_valid@comcast.net> - 2014-03-14 10:47 -0600
                Re: Is goto Still Considered Harmful? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-14 17:43 +0000
                Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-14 13:52 -0400
            Re: Is goto Still Considered Harmful? Stephen Sprunk <stephen@sprunk.org> - 2014-03-16 17:15 -0500
              Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-16 16:04 -0700
    Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-14 05:11 +0000
      Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-14 06:00 +0000
  Re: Is goto Still Considered Harmful? "Terence" <tbwright@bigpond.net.au> - 2014-03-14 08:32 +1100
    Re: Is goto Still Considered Harmful? Richard Damon <Richard@Damon-Family.org> - 2014-03-14 23:10 -0400
  Re: Is goto Still Considered Harmful? Rosario193 <Rosario@invalid.invalid> - 2014-03-14 02:18 +0100
    Re: Is goto Still Considered Harmful? Lynn McGuire <lmc@winsim.com> - 2014-03-18 16:14 -0500
  Re: Is goto Still Considered Harmful? John Bode <jfbode1029@gmail.com> - 2014-03-24 07:52 -0700
    Re: Is goto Still Considered Harmful? Ken Brody <kenbrody@spamcop.net> - 2014-03-24 11:20 -0400
      Re: Is goto Still Considered Harmful? "BartC" <bc@freeuk.com> - 2014-03-24 17:08 +0000
      Re: Is goto Still Considered Harmful? Ken Brody <kenbrody@spamcop.net> - 2014-03-25 14:06 -0400
        Re: Is goto Still Considered Harmful? Lowell Gilbert <lgusenet@be-well.ilk.org> - 2014-03-26 13:31 -0400
    Re: Is goto Still Considered Harmful? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-24 16:31 +0000
    Re: Is goto Still Considered Harmful? "BartC" <bc@freeuk.com> - 2014-03-24 16:46 +0000
      Re: Is goto Still Considered Harmful? John Bode <jfbode1029@gmail.com> - 2014-03-24 16:10 -0700
        Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-24 17:19 -0700
          Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-25 02:56 -0700
          Re: Is goto Still Considered Harmful? Keith Thompson <kst-u@mib.org> - 2014-03-25 07:34 -0700
            Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-25 10:57 -0400
              Re: Is goto Still Considered Harmful? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-25 16:09 +0000
              Re: Is goto Still Considered Harmful? Kaz Kylheku <kaz@kylheku.com> - 2014-03-25 16:14 +0000
                Re: Is goto Still Considered Harmful? Ian Collins <ian-news@hotmail.com> - 2014-03-26 08:06 +1300
                Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-25 12:49 -0700
                Re: Is goto Still Considered Harmful? Stephen Sprunk <stephen@sprunk.org> - 2014-03-31 14:05 -0500
                Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-31 15:20 -0400
                Re: Is goto Still Considered Harmful? Stephen Sprunk <stephen@sprunk.org> - 2014-04-04 14:56 -0500
                Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-04-04 17:11 -0400
                Re: Is goto Still Considered Harmful? Ian Collins <ian-news@hotmail.com> - 2014-04-05 12:03 +1300
                Re: Is goto Still Considered Harmful? ralph <nt_consulting@yahoo.com> - 2014-04-05 00:17 -0500
                Re: Is goto Still Considered Harmful? Ian Collins <ian-news@hotmail.com> - 2014-04-05 20:14 +1300
                Re: Is goto Still Considered Harmful? Stephen Sprunk <stephen@sprunk.org> - 2014-04-09 14:30 -0500
                Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-04-09 16:37 -0400
                Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-04-09 14:01 -0700
                Re: Is goto Still Considered Harmful? Richard <rgrdev_@gmail.com> - 2014-04-05 15:21 +0100
                Re: Is goto Still Considered Harmful? Ian Collins <ian-news@hotmail.com> - 2014-04-01 11:04 +1300
                Re: Is goto Still Considered Harmful? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-04-01 02:45 +0300
                Re: Is goto Still Considered Harmful? Ian Collins <ian-news@hotmail.com> - 2014-04-01 13:03 +1300
                Re: Is goto Still Considered Harmful? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-05-22 12:01 +0300
                Re: Is goto Still Considered Harmful? Ian Collins <ian-news@hotmail.com> - 2014-05-22 21:22 +1200
                Re: Is goto Still Considered Harmful? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-05-22 11:53 +0300
              Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-31 12:10 -0400
                Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-31 10:39 -0700
                Re: Is goto Still Considered Harmful? Stephen Sprunk <stephen@sprunk.org> - 2014-03-31 13:42 -0500
                Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-31 15:16 -0700
                Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-04-01 00:24 -0700
                Re: Is goto Still Considered Harmful? Richard Damon <Richard@Damon-Family.org> - 2014-04-01 08:26 -0400
                Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-04-01 06:50 -0700
                Re: Are setters Stil Considered Harmful? (was: Is goto Still Considered Harmful?) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-04-02 10:49 -0700
            Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-25 19:30 +0000
              Re: Is goto Still Considered Harmful? Ken Brody <kenbrody@spamcop.net> - 2014-03-27 09:33 -0400
            Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-25 19:37 +0000
        Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-25 00:30 -0400
        Re: Is goto Still Considered Harmful? John Bode <jfbode1029@gmail.com> - 2014-03-27 11:47 -0700
          Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-27 20:39 -0400
            Re: Is goto Still Considered Harmful? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-28 01:40 +0000
          Re: Is goto Still Considered Harmful? Richard <rgrdev_@gmail.com> - 2014-03-28 10:09 +0100
            Re: Is goto Still Considered Harmful? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-28 09:48 +0000
            Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-28 03:24 -0700
              Re: Is goto Still Considered Harmful? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-28 18:52 +0000
              Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-30 02:45 -0700
    Re: Is goto Still Considered Harmful? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-03-24 12:53 -0700
    Re: Is goto Still Considered Harmful? John Bode <jfbode1029@gmail.com> - 2014-03-24 15:02 -0700
      Re: Is goto Still Considered Harmful? James Kuyper <jameskuyper@verizon.net> - 2014-03-24 19:11 -0400
  Re: Is goto Still Considered Harmful? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 05:56 -0700

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