Re: Challenge: tightest code to find-replace a string

From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: Challenge: tightest code to find-replace a string
Date	2014-06-09 08:57 -0700
Organization	None to speak of
Message-ID	<lny4x6m5y4.fsf@nuthaus.mib.org> (permalink)
References	(1 earlier) <replace-20140606202851@ram.dialup.fu-berlin.de> <ln00k4$qb4$1@dont-email.me> <06565dc2-0168-425d-b32e-8db5d93e2a4d@googlegroups.com> <lnbnu3nio9.fsf@nuthaus.mib.org> <2f848f76-4008-414d-bf53-ace7ed92ec52@googlegroups.com>

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Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
> On Sunday, June 8, 2014 11:24:54 PM UTC+1, Keith Thompson wrote:
>> Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
>> > Depends.
>> 
>> > If you're providing a "search and replace" tool for use on
>> > human-readable text, it hardly matters how it handles the overlapping
>> > cases, because it will rarely be called for such, and any reasonable
>> > behaviour is likely to be accepted.
>> 
>> It matters very much if the handling of overlapping cases can trigger an
>> infinite loop.
>>
> it mustn't crash or fail to return on any input. But it probably
> doesn't matter if replace 'abcabc' 'x' called on abcabcabc returns
> xabc xx or even abcabcabc.

Nonsense.

>> And even for use on human-readable text, I fail to see how a precise and
>> unambiguous definition of the behavior is unimportant.
>> 
> The requirement for a function can be something like "makes the space
> invader crash realistically". That's not reducible to a pure
> mathematical specification.

Yes, the requirement for *some* functions can be that vague.

But a string replacement function *can* be specified precisely,
and there's no excuse for not doing so.  And if it doesn't behave
consistently, I'm not interested in using it; I'll just use a
different function that's properly defined.

Are you perhaps assuming that it doesn't matter because
search-and-replace is performed interactively, and therefore the
user can immediately see the results?  Are you familiar with sed?

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Thread

Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-06 00:08 -0400
  Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-06 04:34 -0400
    Re: Challenge: tightest code to find-replace a string Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-06-06 10:04 +0000
    Re: Challenge: tightest code to find-replace a string Mark Storkamp <mstorkamp@yahoo.com> - 2014-06-06 07:27 -0500
    Re: Challenge: tightest code to find-replace a string Robert Wessel <robertwessel2@yahoo.com> - 2014-06-06 11:55 -0500
      Re: Challenge: tightest code to find-replace a string Johannes Bauer <dfnsonfsduifb@gmx.de> - 2014-06-06 20:47 +0200
  Re: Challenge: tightest code to find-replace a string Ike Naar <ike@iceland.freeshell.org> - 2014-06-06 06:05 +0000
    Re: Challenge: tightest code to find-replace a string Noob <root@127.0.0.1> - 2014-06-06 10:17 +0200
      Re: Challenge: tightest code to find-replace a string Ian Collins <ian-news@hotmail.com> - 2014-06-08 21:20 +1200
  Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-06 14:41 +0100
    Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-06 16:29 +0100
      Re: Challenge: tightest code to find-replace a string Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-06-06 17:27 +0000
      Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-06 22:16 +0100
        Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-06 23:26 +0100
          Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-06 23:38 +0100
    Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-06 08:31 -0700
      Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-06 22:12 +0100
    Re: Challenge: tightest code to find-replace a string Chad <cdalten@gmail.com> - 2014-06-07 12:19 -0700
      Re: Challenge: tightest code to find-replace a string Chad <cdalten@gmail.com> - 2014-06-07 13:38 -0700
        Re: Challenge: tightest code to find-replace a string raltbos@xs4all.nl (Richard Bos) - 2014-06-08 10:34 +0000
    Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-07 18:30 -0400
      Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-08 13:09 +0100
        Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-08 12:42 -0400
          Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-09 01:44 +0100
            Re: Challenge: tightest code to find-replace a string Siri Crews <chine.bleu@yahoo.com> - 2014-06-08 22:15 -0700
              Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-09 12:58 +0100
            Re: Challenge: tightest code to find-replace a string Ike Naar <ike@iceland.freeshell.org> - 2014-06-09 06:40 +0000
              Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-09 13:04 +0100
                Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-09 15:27 +0100
                Re: Challenge: tightest code to find-replace a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-06-09 16:22 +0100
                Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-09 18:06 +0100
                Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-09 22:38 +0100
      Re: Challenge: tightest code to find-replace a string Tim Rentsch <txr@alumni.caltech.edu> - 2014-06-10 00:57 -0700
  Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-07 17:36 -0400
    Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-08 09:57 +0100
      Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-08 12:43 -0400
        Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-08 15:27 -0700
        Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-09 10:02 +0100
          Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-09 08:03 -0700
    Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-08 04:43 -0700
      Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-08 13:26 -0400
      Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-08 15:24 -0700
        Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-09 08:39 -0700
          Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-09 08:57 -0700
            Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-09 09:52 -0700
              Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-09 11:25 -0700
                Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-09 13:42 -0700
                Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-09 15:02 -0700
                Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-09 16:04 -0700
                Re: Challenge: tightest code to find-replace a string raltbos@xs4all.nl (Richard Bos) - 2014-06-10 10:23 +0000
          Re: Challenge: tightest code to find-replace a string raltbos@xs4all.nl (Richard Bos) - 2014-06-09 16:57 +0000
            Re: Challenge: tightest code to find-replace a string raltbos@xs4all.nl (Richard Bos) - 2014-06-10 10:06 +0000
  Re: Challenge: tightest code to find-replace a string "Chris M. Thomasson" <no@spam.invalid> - 2014-06-09 12:43 -0700
    Re: Challenge: tightest code to find-replace a string "Chris M. Thomasson" <no@spam.invalid> - 2014-06-09 14:32 -0700
      Re: Challenge: tightest code to find-replace a string "Chris M. Thomasson" <no@spam.invalid> - 2014-06-09 16:09 -0700
      Re: Challenge: tightest code to find-replace a string James Kuyper <jameskuyper@verizon.net> - 2014-06-09 21:35 -0400
    Re: Challenge: tightest code to find-replace a string DFS <nospam@dfs.com> - 2014-06-10 09:39 -0400
      Re: Challenge: tightest code to find-replace a string James Kuyper <jameskuyper@verizon.net> - 2014-06-10 11:26 -0400
      Re: Challenge: tightest code to find-replace a string raltbos@xs4all.nl (Richard Bos) - 2014-06-11 16:16 +0000
      Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-11 09:25 -0700
        Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-11 13:48 -0700
          Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-11 22:04 +0100
            Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-11 14:59 -0700
          Re: Challenge: tightest code to find-replace a string Ike Naar <ike@iceland.freeshell.org> - 2014-06-11 21:35 +0000
          Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-11 14:56 -0700
            Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-12 02:24 -0700
              Re: Challenge: tightest code to find-replace a string Keith Thompson <kst-u@mib.org> - 2014-06-12 09:09 -0700
                Re: Challenge: tightest code to find-replace a string Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-06-13 00:40 -0700
                Re: Challenge: tightest code to find-replace a string "BartC" <bc@freeuk.com> - 2014-06-13 09:17 +0100
  Re: Challenge: tightest code to find-replace a string "Chris M. Thomasson" <no@spam.invalid> - 2014-06-14 13:12 -0700

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