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Groups > comp.lang.c > #12705

Re: John McCarthy died today.

From Kaz Kylheku <kaz@kylheku.com>
Newsgroups comp.lang.c
Subject Re: John McCarthy died today.
Date 2011-11-04 17:58 +0000
Organization A noiseless patient Spider
Message-ID <20111104135545.861@kylheku.com> (permalink)
References (1 earlier) <j8hdc9$tbd$1@news.albasani.net> <slrnjaof9n.1aaf.willem@toad.stack.nl> <j90aoo$jom$1@news.albasani.net> <20111104115106.357@kylheku.com> <4EB40FC0.8090206@verizon.net>

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On 2011-11-04, James Kuyper <jameskuyper@verizon.net> wrote:
> On 11/04/2011 11:53 AM, Kaz Kylheku wrote:
>> On 2011-11-04, Ark <akhasin@macroexpressions.com> wrote:
>>> The fact that in 
>>> C (and descendants) the assignment operator is an expression is indeed 
>>> unfortunate and has lead to innumerable bugs stemming from clever 
>>> coding. 
>> 
>> This is the consequence of how the operator is spelled, not what kind
>> of expression it is. Doh!
>
> I thought it was a consequence of the grammar, not the spelling of the
> operator. The problem is due entirely to the fact that there is such a
> thing in C as an expression that performs assignment, while C has no
> such thing as an assignment statement - the closest it comes is an
> expression-statement where the relevant expression is an assignment
> expression. Those facts are completely independent of the spelling of
> the assignment operator.

Which problem?

I'm thinking of  accidental assignments:

  if (defence_condition = UNDER_NUCLEAR_ATTACK)
    launch_full_counterstrike();

This problem is caused by the similarity of == and =, but, sure, it would also
go away if you couldn't have an assignment in that context.

Other languages have assignment expressions, but programmers don't make these
mistakes.
  
  ;; Lisp

  ;; actually wanted EQ, but wrote SETF? Vanishingly unlikely.

  (when (setf defence-condition :under-nuclear-attack) ...)

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John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-10-25 00:44 +0000
  Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-10-25 01:27 -0700
  Re: John McCarthy died today. Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-10-25 09:27 +0000
  Re: John McCarthy died today. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-25 11:27 +0100
  Re: John McCarthy died today. Ark <akhasin@macroexpressions.com> - 2011-10-29 13:33 -0400
    Re: John McCarthy died today. Willem <willem@toad.stack.nl> - 2011-10-29 17:51 +0000
      Re: John McCarthy died today. Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-29 21:28 +0300
      Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-10-29 11:57 -0700
        Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-10-30 08:20 -0700
      Re: John McCarthy died today. Ark <akhasin@macroexpressions.com> - 2011-11-04 05:20 -0400
        Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-04 15:53 +0000
          Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-04 12:16 -0400
            Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-04 17:58 +0000
              Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-04 20:49 -0400
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-05 01:55 +0000
                Re: John McCarthy died today. "BartC" <bc@freeuk.com> - 2011-11-07 10:54 +0000
                Re: John McCarthy died today. "Charles Richmond" <netnews@aquaporin4.com> - 2011-11-07 07:36 -0600
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-07 19:49 +0000
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-07 15:49 -0500
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-08 00:38 -0800
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-08 07:05 -0500
                Re: John McCarthy died today. lawrence.jones@siemens.com - 2011-11-08 09:12 -0500
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-08 16:48 +0000
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-08 12:12 -0500
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-08 23:27 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-08 14:10 -0800
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-08 17:16 -0500
                Re: John McCarthy died today. lawrence.jones@siemens.com - 2011-11-09 13:51 -0500
                Re: Looping Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-11-09 19:21 -0700
                Re: Looping Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 02:34 +0000
                Re: John McCarthy died today. Joe Wright <joewwright@comcast.net> - 2011-11-08 17:49 -0500
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-08 16:35 -0800
                Re: John McCarthy died today. Joe Wright <joewwright@comcast.net> - 2011-11-09 01:08 -0500
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-09 01:26 -0800
                Re: John McCarthy died today. Joe Wright <joewwright@comcast.net> - 2011-11-09 08:18 -0500
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-09 05:32 -0800
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-09 01:24 -0800
                Re: John McCarthy died today. Quentin Carbonneaux <qcarbonn@invalid.com> - 2011-11-09 11:59 +0000
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-09 05:34 -0800
                Re: John McCarthy died today. Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-08 18:31 +0200
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-07 14:06 -0800
                Re: John McCarthy died today. "BartC" <bc@freeuk.com> - 2011-11-08 02:01 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-07 23:16 -0800
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-08 05:18 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-07 23:17 -0800
                Re: John McCarthy died today. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-08 01:46 -0800
                Re: John McCarthy died today. "BartC" <bc@freeuk.com> - 2011-11-08 13:02 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-08 14:19 -0800
                Re: John McCarthy died today. Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-11-08 22:23 +0000
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-08 18:13 -0500
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-08 23:38 +0000
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-08 23:18 +0000
                Re: John McCarthy died today. Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-10 12:40 +0200
                Re: John McCarthy died today. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-10 11:39 +0000
                Re: John McCarthy died today. "BartC" <bc@freeuk.com> - 2011-11-10 12:23 +0000
                Re: John McCarthy died today. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-10 05:38 -0800
                Re: John McCarthy died today. Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-10 17:29 +0200
                Re: John McCarthy died today. David Thompson <dave.thompson2@verizon.net> - 2011-11-21 02:39 -0500
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-08 16:34 -0800
                Re: John McCarthy died today. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-09 01:37 -0800
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-09 13:25 -0800
                Re: John McCarthy died today. Ian Collins <ian-news@hotmail.com> - 2011-11-10 10:36 +1300
                Re: John McCarthy died today. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-09 23:47 -0800
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-10 00:21 -0800
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-10 03:04 -0800
                Re: John McCarthy died today. gazelle@shell.xmission.com (Kenny McCormack) - 2011-11-10 15:20 +0000
                Re: John McCarthy died today. Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-11-12 23:22 +0000
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-13 01:44 +0000
                Re: John McCarthy died today. "Charles Richmond" <netnews@aquaporin4.com> - 2011-11-13 04:18 -0600
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-13 16:57 +0000
                Re: John McCarthy died today. Robert Wessel <robertwessel2@yahoo.com> - 2011-11-13 11:59 -0600
                Re: John McCarthy died today. gazelle@shell.xmission.com (Kenny McCormack) - 2011-11-13 18:54 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-13 14:47 -0800
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-14 03:43 +0000
                Re: John McCarthy died today. Ike Naar <ike@sverige.freeshell.org> - 2011-11-14 09:00 +0000
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-14 18:30 +0000
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-14 14:44 -0500
                Re: John McCarthy died today. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-14 20:13 +0000
                Re: John McCarthy died today. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-14 00:21 -0800
                Re: John McCarthy died today. Lauri Alanko <la@iki.fi> - 2011-11-10 15:26 +0000
                Re: John McCarthy died today. Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 01:51 +0000
                Re: John McCarthy died today. Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-11-09 17:15 +0000
                Re: John McCarthy died today. "BartC" <bc@freeuk.com> - 2011-11-09 18:04 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-09 13:31 -0800
                Re: John McCarthy died today. Robert Wessel <robertwessel2@yahoo.com> - 2011-11-09 15:53 -0600
                Re: John McCarthy died today. "BartC" <bc@freeuk.com> - 2011-11-09 22:02 +0000
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-09 14:14 -0800
                Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-09 13:50 -0800
                Re: John McCarthy died today. James Kuyper <jameskuyper@verizon.net> - 2011-11-08 07:10 -0500
          Re: John McCarthy died today. Keith Thompson <kst-u@mib.org> - 2011-11-04 14:51 -0700

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