Re: Christmas Quiz 2022

From	Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups	comp.lang.c
Subject	Re: Christmas Quiz 2022
Date	2022-12-26 13:05 -0800
Organization	None to speak of
Message-ID	<87y1qtq3j3.fsf@nosuchdomain.example.com> (permalink)
References	(3 earlier) <tnshp9$mh7i$1@dont-email.me> <87ili6unpn.fsf@bsb.me.uk> <tnsis8$mh7i$2@dont-email.me> <tnsl3s$mh7i$3@dont-email.me> <86pmc6w8e7.fsf@linuxsc.com>

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Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
> Lew Pitcher <lew.pitcher@digitalfreehold.ca> writes:
>> On Tue, 20 Dec 2022 15:03:36 +0000, Lew Pitcher wrote:
>>> On Tue, 20 Dec 2022 14:57:56 +0000, Ben Bacarisse wrote:
>>
>> [snip]
>>
>>>>> The notable point is that the semicolon between clause-1 and
>>>>> expression-2 is /not/ part of clause-1, but is, instead part of
>>>>> the for statement itself.
>>>>
>>>> But that does not help if the grammar for a declaration still
>>>> includes a semicolon.  I wonder what all the relevant parts of the
>>>> draft you are referring to look like when taken together.
>>>>
>>>>> Because of this, I don't believe that your count can be correct.
>>>>> But, I'm willing to be educated on this :-)
>>>>
>>>> Well, I did add (but then deleted) that the count depends on how
>>>> the grammar is structured.  I should look at a more recent draft
>>>> that will have taken the confirmed C11 text as a starting point.
>>>> I might do that later, but I am in a rush!
>>>
>>> Perhaps I've got an outdated copy of the draft standard, and the
>>> semicolon question was asked and answered in a later release.
>>>
>>> Your explanation sounds valid to me.  'Tis a puzzle to be resolved
>>> later.
>>
>> Oops... I found it.
>>
>> Under 6.8.5 Iteration statements
>> Syntax
>>   ...
>>   for ( expression ; expression ; expression ) statement
>>   for ( declaration expression ; expression ) statement
>>
>> (all expressions are marked optional)
>>
>> Crisis averted.  You are indeed correct, and I've learned something
>> new today.  :-)
>>
>> But, that doesn't explain why 6.8.5.3 ("the for statement") shows
>> the syntax it does.  Perhaps the draft missed something in resolving
>> the text between 6.8.5 and 6.8.5.3.
>
> This line
>
>     for ( clause-1 ; expression-2 ; expression-3 ) statement
>
> in 6.8.5.3 p1 is not syntax.  It may /look/ like syntax, but it
> isn't;  it is simply a template to assist the discussion later in
> the same paragraph and subsequent paragraph (and also in various
> footnotes).  How do we know it isn't syntax?  For starters, it
> isn't labeled 'Syntax', as are all other syntax excerpts in the C
> standard.  (Disclaimer:  I'm pretty sure this is true but I
> didn't check every one.)  Also, none of clause-1, expression-2,
> and expression-3 are defined non-terminals.  They are there to
> serve as reference points for the subsequent discussion, not to
> to be part of the C syntax.
>
> So it seems clear that this non-syntax line is present as a
> deliberate choice, put there to aid the discussion of semantics
> but not as part of the C syntax.

I don't think that's nearly as clear as you think it is.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */

Thread

Christmas Quiz 2022 Roman P <invalid@example.com> - 2022-12-18 20:00 +0000
  Re: Christmas Quiz 2022 Tony Oliver <guinness.tony@gmail.com> - 2022-12-18 13:18 -0800
    Re: Christmas Quiz 2022 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-18 16:48 -0800
    Re: Christmas Quiz 2022 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-18 17:18 -0800
      Re: Christmas Quiz 2022 "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-19 19:39 -0800
    Re: Christmas Quiz 2022 Niles Rogoff <eternal-september@niles.xyz> - 2022-12-27 01:22 -0800
      Re: Christmas Quiz 2022 Öö Tiib <ootiib@hot.ee> - 2022-12-27 01:58 -0800
        Re: Christmas Quiz 2022 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-27 10:25 -0800
      Re: Christmas Quiz 2022 James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-12-27 05:07 -0500
        Re: Christmas Quiz 2022 scott@slp53.sl.home (Scott Lurndal) - 2022-12-27 16:06 +0000
          Re: Christmas Quiz 2022 scott@slp53.sl.home (Scott Lurndal) - 2022-12-27 17:42 +0000
          Re: Christmas Quiz 2022 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-27 13:53 -0800
    Re: Christmas Quiz 2022 Niles Rogoff <eternal-september@niles.xyz> - 2022-12-27 01:24 -0800
      Re: Christmas Quiz 2022 scott@slp53.sl.home (Scott Lurndal) - 2022-12-27 16:07 +0000
  Re: Christmas Quiz 2022 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-18 21:22 +0000
    Re: Christmas Quiz 2022 Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-18 21:40 +0000
    Re: Christmas Quiz 2022 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-18 17:02 -0800
    Re: Christmas Quiz 2022 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-18 17:20 -0800
  Re: Christmas Quiz 2022 red floyd <no.spam.here@its.invalid> - 2022-12-18 13:36 -0800
  Re: Christmas Quiz 2022 "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-18 13:48 -0800
    Re: Christmas Quiz 2022 Siri Cruise <chine.bleu@yahoo.com> - 2022-12-18 14:57 -0800
      Re: Christmas Quiz 2022 "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-18 15:43 -0800
        Re: Christmas Quiz 2022 Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-19 23:40 -0600
      Re: Christmas Quiz 2022 "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-20 14:01 -0800
  Re: Christmas Quiz 2022 Kaz Kylheku <864-117-4973@kylheku.com> - 2022-12-20 13:49 +0000
    Re: Christmas Quiz 2022 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-20 14:33 +0000
      Re: Christmas Quiz 2022 Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-20 14:44 +0000
        Re: Christmas Quiz 2022 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-20 14:57 +0000
          Re: Christmas Quiz 2022 Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-20 15:03 +0000
            Re: Christmas Quiz 2022 David Brown <david.brown@hesbynett.no> - 2022-12-20 16:32 +0100
            Re: Christmas Quiz 2022 Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-20 15:41 +0000
              Re: Christmas Quiz 2022 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-20 10:22 -0800
                Re: for() syntax (Was: Christmas Quiz 2022) Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-20 18:54 +0000
                Re: for() syntax Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-20 12:08 -0800
                Re: for() syntax (Was: Christmas Quiz 2022) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-26 06:48 -0800
                Re: Christmas Quiz 2022 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-26 06:25 -0800
              Re: Christmas Quiz 2022 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-26 06:24 -0800
                Re: Christmas Quiz 2022 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-26 13:05 -0800
  Re: Christmas Quiz 2022 Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-12-20 12:46 -0800
    Re: Christmas Quiz 2022 Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-20 23:49 +0200
      Re: Christmas Quiz 2022 Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-12-20 14:00 -0800
        Re: Christmas Quiz 2022 Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-21 00:13 +0200
          Re: Christmas Quiz 2022 Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-12-20 14:38 -0800
    Re: Christmas Quiz 2022 Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-12-20 21:31 -0800
      Re: Christmas Quiz 2022 David Brown <david.brown@hesbynett.no> - 2022-12-21 12:02 +0100

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