Re: widening multiplication

From	Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: widening multiplication
Date	2020-08-21 12:46 +0100
Organization	A noiseless patient Spider
Message-ID	<87blj46x2c.fsf@bsb.me.uk> (permalink)
References	(16 earlier) <1Ut%G.293556$RF4.155976@fx43.iad> <rhnues$m6b$1@dont-email.me> <6bd1b70e-e118-4570-91dd-01cbceb8fb15n@googlegroups.com> <87k0xs6zy7.fsf@bsb.me.uk> <rhobcs$1f1$1@dont-email.me>

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David Brown <david.brown@hesbynett.no> writes:

> On 21/08/2020 12:44, Ben Bacarisse wrote:
>> Malcolm McLean <malcolm.arthur.mclean@gmail.com> writes:
>> 
>>> On Friday, 21 August 2020 at 08:52:05 UTC+1, David Brown wrote:
>>>>
>>>> (I have nothing against this concept in itself - I merely disagree that 
>>>> it would be a good idea to squeeze it into C, and I want Malcolm to 
>>>> justify claiming it applies to "most programming languages".)
>> 
>> I've restored the quote because the various edits have not done any
>> favours to the discussion.
>> 
>>> Restore the snip and you'll see that that's not quite what I was
>>> saying.
>> 
>> What you said was this:
>> 
>>   "Most programming languages work in more or less the same way, and if
>>   you know one you can follow along another. And you often have to do
>>   that. [...] Ideally, you keep these gotchas to a bare minimum, only
>>   the things so deeply rooted [that] you can't eliminate them from the
>>   language."
>> 
>> And (barring the usual trouble of about talking about "most" of anything
>> as diverse as programming languages) you are essentially correct.  But
>> your words argue against the point you made about the code -- namely
>> that not using a wide multiplication will be a "gotcha", tripping up
>> programmers who know other languages but not C.  A totally unscientific
>> survey of the inside of my head suggests that most languages determine
>> the result of arithmetic expressions from the types for their operands
>> and not from any wider context.
>
> You mean that what Malcolm had been trying (poorly, IMHO) to say was
> that most programming languages work the way C works here, and that this
> is a good thing because it reduces the gotcha's and makes it easier to
> transfer knowledge from one language to another?

Not quite.  I think he was saying that assuming an unknown language is
roughly like the others one has come across is both common and
reasonable.  But I don't think he intended to include C's common
arithmetic type rule in that assessment, but, as you say, let's wait and
see.

> If so, then I too
> agree (with the same proviso about "most languages").  But it is at odds
> with what he was promoting earlier, namely that "c = a * b;" should take
> the type of "c" into account.  I must admit that it didn't occur to me
> that he would be countering his own proposal in this way.

It may be that his specific experience has given a different impression
of what is the norm.

> I'll leave it to Malcolm to try to give a better explanation of what he
> actually meant, or to make it clear that he has changed his mind
> (there's nothing wrong with doing that!).

-- 
Ben.

Thread

widening multiplication jacobnavia <jacob@jacob.remcomp.fr> - 2020-08-17 22:11 +0200
  Re: widening multiplication Eric Sosman <esosman@comcast-dot-net.invalid> - 2020-08-17 16:30 -0400
    Re: widening multiplication jacobnavia <jacob@jacob.remcomp.fr> - 2020-08-18 09:27 +0200
  Re: widening multiplication Andrey Tarasevich <andreytarasevich@hotmail.com> - 2020-08-17 13:33 -0700
    Re: widening multiplication jacobnavia <jacob@jacob.remcomp.fr> - 2020-08-18 09:24 +0200
    Re: widening multiplication Andrey Tarasevich <andreytarasevich@hotmail.com> - 2020-08-21 14:47 -0700
  Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-17 21:52 +0100
    Re: widening multiplication jacobnavia <jacob@jacob.remcomp.fr> - 2020-08-18 09:22 +0200
  Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-17 14:10 -0700
    Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-17 22:33 +0100
      Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-17 15:13 -0700
      Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 11:33 +0200
    Re: widening multiplication jacobnavia <jacob@jacob.remcomp.fr> - 2020-08-18 09:20 +0200
  Re: widening multiplication scott@slp53.sl.home (Scott Lurndal) - 2020-08-17 21:38 +0000
    Re: widening multiplication jacobnavia <jacob@jacob.remcomp.fr> - 2020-08-18 09:19 +0200
  Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 11:31 +0200
    Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-18 05:00 -0700
      Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 15:10 +0200
    Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-18 12:31 +0000
      Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 15:15 +0200
        Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-18 06:53 -0700
          Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 16:14 +0200
            Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-18 07:24 -0700
              Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 22:41 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-18 14:24 -0700
                Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-18 22:54 +0100
                Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-18 15:18 -0700
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-18 15:54 -0700
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-18 15:38 -0700
                Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-19 07:03 +0000
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 09:24 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 02:13 -0700
                Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-19 10:43 +0000
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 12:50 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 07:30 -0700
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 07:44 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 17:35 +0200
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-19 10:13 -0700
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 14:30 -0700
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-19 15:07 -0700
                Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-19 22:13 +0000
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 15:49 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-20 11:31 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-20 03:47 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-20 13:21 +0200
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-20 08:20 -0400
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-21 09:51 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-21 02:51 -0700
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-21 11:44 +0100
                Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-21 12:17 +0100
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-21 13:36 +0200
                Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-21 13:15 +0100
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-21 11:04 -0700
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-21 08:30 -0400
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-21 13:32 +0200
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-21 12:46 +0100
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-21 07:43 -0700
                Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-21 16:13 +0100
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-21 20:15 +0200
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-21 20:14 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-21 16:37 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 15:38 +0200
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-22 01:02 +0100
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-22 04:57 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 16:11 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-22 08:46 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 18:33 +0200
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-22 13:44 -0400
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-22 12:48 -0700
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-22 21:45 +0100
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-22 05:20 -0700
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-22 10:16 -0400
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-22 08:59 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 19:04 +0200
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-22 13:59 -0400
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 23:01 +0200
                Re: widening multiplication Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-08-23 07:42 -0700
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-22 22:12 +0100
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-23 13:31 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-23 04:53 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-23 14:22 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-23 06:47 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-23 16:25 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-23 07:42 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-24 09:10 +0200
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-24 02:06 -0700
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-23 13:10 -0400
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-23 16:16 +0100
                Re: widening multiplication Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-22 22:02 +0100
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-22 18:14 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-23 14:27 +0200
                Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-21 05:58 -0700
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-19 19:15 -0400
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 16:48 -0700
                Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-19 23:39 +0100
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 15:51 -0700
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-19 15:56 -0700
                Re: widening multiplication Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-08-19 16:04 -0700
                Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-19 18:04 -0700
                Re: widening multiplication antispam@math.uni.wroc.pl - 2020-08-20 00:13 +0000
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-20 10:06 +0200
                Re: widening multiplication Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2020-08-20 11:26 +0200
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-20 13:25 +0200
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-19 07:41 -0400
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 15:08 +0200
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-19 10:29 -0400
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 17:41 +0200
                Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-19 13:34 -0400
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 20:21 +0200
                Re: widening multiplication Siri Cruise <chine.bleu@yahoo.com> - 2020-08-18 15:16 -0700
                Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 09:32 +0200
        Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-18 11:11 -0400
          Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-18 22:45 +0200
  Re: widening multiplication Daniel Hyde <Daniel.Hyde71@gmail.com> - 2020-08-19 20:17 +0200
    Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-19 15:20 -0400
      Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-19 20:59 +0000
        Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-19 17:28 -0400
          Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-19 22:43 +0100
    Re: widening multiplication Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2020-08-19 21:38 +0200
      Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-19 21:47 +0200
      Re: widening multiplication Daniel Hyde <Daniel.Hyde71@gmail.com> - 2020-08-20 12:24 +0200
        Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-20 08:14 -0400
          Re: widening multiplication Daniel Hyde <Daniel.Hyde71@gmail.com> - 2020-08-20 14:20 +0200
            Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-20 10:39 -0700
    Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-19 15:55 -0400
      Re: widening multiplication Daniel Hyde <Daniel.Hyde71@gmail.com> - 2020-08-22 12:30 +0200
        Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-22 05:09 -0700
          Re: widening multiplication Daniel Hyde <Daniel.Hyde71@gmail.com> - 2020-08-22 17:15 +0200
            Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 19:06 +0200
              Re: widening multiplication Richard Harnden <richard.nospam@gmail.com> - 2020-08-22 19:06 +0100
                Re: widening multiplication Bonita Montero <Bonita.Montero@gmail.com> - 2020-08-22 20:28 +0200
                Re: widening multiplication Bonita Montero <Bonita.Montero@gmail.com> - 2020-08-23 01:36 +0200
                Re: widening multiplication "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-08-22 18:15 -0700
                Re: widening multiplication Bonita Montero <Bonita.Montero@gmail.com> - 2020-08-23 11:16 +0200
                Re: widening multiplication "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-08-23 21:05 -0700
              Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-22 12:45 -0700
            Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-22 11:47 -0700
        Re: widening multiplication Richard Damon <Richard@Damon-Family.org> - 2020-08-22 10:21 -0400
          Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-22 16:18 +0100
            Re: widening multiplication David Brown <david.brown@hesbynett.no> - 2020-08-22 19:16 +0200
        Re: widening multiplication Kaz Kylheku <793-849-0957@kylheku.com> - 2020-08-23 04:38 +0000
          Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-23 08:22 -0400
            Re: widening multiplication Kaz Kylheku <793-849-0957@kylheku.com> - 2020-08-24 03:00 +0000
              Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-23 23:54 -0400
                Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-24 06:19 +0000
                Re: widening multiplication James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-08-24 09:45 -0400
                Re: widening multiplication Kaz Kylheku <793-849-0957@kylheku.com> - 2020-08-24 14:47 +0000
                Re: widening multiplication "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-08-24 12:14 -0700
                Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-24 08:40 -0700
                Re: widening multiplication Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-26 18:06 +0000
          Re: widening multiplication Daniel Hyde <Daniel.Hyde71@gmail.com> - 2020-08-23 17:55 +0200
            Re: widening multiplication Bart <bc@freeuk.com> - 2020-08-23 17:38 +0100
    Re: widening multiplication Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-19 13:15 -0700
  Re: widening multiplication rick.c.hodgin@gmail.com - 2020-08-23 08:03 -0700

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