Re: I think this is an impossible assignment...could you help?

From	blmblm@myrealbox.com <blmblm.myrealbox@gmail.com>
Newsgroups	comp.lang.c
Subject	Re: I think this is an impossible assignment...could you help?
Date	2011-09-05 20:21 +0000
Organization	None
Message-ID	<9ckpavFv7eU1@mid.individual.net> (permalink)
References	<j3jj2t$eq3$1@speranza.aioe.org> <j3obqu$l0f$1@dont-email.me> <9cbg1aFftvU2@mid.individual.net> <j3q9cb$um8$2@dont-email.me>

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In article <j3q9cb$um8$2@dont-email.me>, BartC <bc@freeuk.com> wrote:
> 
> 
> "blmblm@myrealbox.com" <blmblm.myrealbox@gmail.com> wrote in message 
> news:9cbg1aFftvU2@mid.individual.net...
> > In article <j3obqu$l0f$1@dont-email.me>, BartC <bc@freeuk.com> wrote:
> >> "Keith Thompson" <kst-u@mib.org> wrote in message
> >> news:lnfwkgs1k0.fsf@nuthaus.mib.org...
> >> > blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> writes:
> 
> >> >> And then you disallow one legitimate input ....  Well, I guess
> 
> >> > So I can't enter -2147483648.  Oh, darn.  8-)}
> 
> >> I think he meant the -999 that is used to stop the program...
> >
> > I'm not sure who "he" is in this sentence (and for once I'm not just
> > making my usual quibble about the gender of the pronoun).
> 
> It seems I interpreted your "And then" in the wrong way.
> 
> As for "he", that did mean you, but in the absence of clear evidence 
> otherwise, it's often taken to mean "he" or "she". Especially around here..

I don't notice it happening more here than in other newsgroups, but
yeah, it's not unusual usage.  It still bugs me, but I just had that
debate in another newsgroup, and -- eh.  "Get over it", maybe.

> > I'll agree that using some particular value to mean "no more input"
> > doesn't seem as satisfactory as just using end of file, though it's
> > not unusual in a beginning program and maybe not even very bad in
> > that context.
> 
> Yes, at least the user knows that -999 is not an input, but doesn't know 
> that -2147483648 isn't (and nor are most integers for that matter which 
> aren't in the narrow range of LONG_MIN(+1) to LONG_MAX.) But proper range 
> checking would be far too difficult for a beginner's exercise.

Now that you mention range checking .... That's *almost* a valid
argument for using 0x80000000 [*] to mean "invalid", since it's
not a value that's within the range specified by the standard for
"long".  Then again, the fact that it isn't within that range means
it can't be returned from the function without at least impairing
portability ....

Which comes back to the real problem, which is how you signal errors
when all possible return values could be legit.

-- 
B. L. Massingill
ObDisclaimer:  I don't speak for my employers; they return the favor.

Thread

I think this is an impossible assignment...could you help? Jack <spamtrap@trashcan.invalid> - 2011-08-30 21:01 +0000
  Re: I think this is an impossible assignment...could you help? Ian Collins <ian-news@hotmail.com> - 2011-08-31 09:18 +1200
    Re: I think this is an impossible assignment...could you help? Jack <spamtrap@trashcan.invalid> - 2011-08-30 21:20 +0000
      Re: I think this is an impossible assignment...could you help? Ian Collins <ian-news@hotmail.com> - 2011-08-31 10:34 +1200
  Re: I think this is an impossible assignment...could you help? John Gordon <gordon@panix.com> - 2011-08-30 21:29 +0000
    Re: I think this is an impossible assignment...could you help? Jack <spamtrap@trashcan.invalid> - 2011-08-30 21:43 +0000
      Re: I think this is an impossible assignment...could you help? John Gordon <gordon@panix.com> - 2011-08-30 22:16 +0000
        Re: I think this is an impossible assignment...could you help? William Ahern <william@wilbur.25thandClement.com> - 2011-08-30 16:26 -0700
        Re: I think this is an impossible assignment...could you help? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-30 21:44 -0400
          Re: I think this is an impossible assignment...could you help? John Gordon <gordon@panix.com> - 2011-08-31 02:03 +0000
            Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-08-31 08:56 -0700
              Re: I think this is an impossible assignment...could you help? John Gordon <gordon@panix.com> - 2011-08-31 16:15 +0000
                Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-08-31 09:20 -0700
                Re: I think this is an impossible assignment...could you help? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-31 21:15 -0400
                Re: I think this is an impossible assignment...could you help? James Kuyper <jameskuyper@verizon.net> - 2011-08-31 22:18 -0400
                Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-01 15:06 +0000
                Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-01 15:04 +0000
                Re: I think this is an impossible assignment...could you help? John Gordon <gordon@panix.com> - 2011-09-01 15:20 +0000
                Re: I think this is an impossible assignment...could you help? David Thompson <dave.thompson2@verizon.net> - 2011-09-06 01:20 -0400
      Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-08-30 16:37 -0700
      Re: I think this is an impossible assignment...could you help? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-31 00:51 +0100
        Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-08-31 13:28 +0000
          Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-01 15:03 +0000
            Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-01 08:49 -0700
              Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-02 07:46 +0000
            Re: I think this is an impossible assignment...could you help? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-01 21:30 -0400
              Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-02 07:48 +0000
      Re: I think this is an impossible assignment...could you help? Ian Collins <ian-news@hotmail.com> - 2011-08-31 11:58 +1200
      Re: I think this is an impossible assignment...could you help? Ike Naar <ike@sverige.freeshell.org> - 2011-08-31 07:27 +0000
  Re: I think this is an impossible assignment...could you help? "BartC" <bc@freeuk.com> - 2011-08-31 10:37 +0100
    Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-08-31 13:29 +0000
      Re: I think this is an impossible assignment...could you help? "BartC" <bc@freeuk.com> - 2011-08-31 18:41 +0100
        Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-01 15:05 +0000
      Re: I think this is an impossible assignment...could you help? Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-02 01:42 -0700
    Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-08-31 09:15 -0700
      Re: I think this is an impossible assignment...could you help? "BartC" <bc@freeuk.com> - 2011-08-31 18:36 +0100
        Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-08-31 11:44 -0700
      Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-01 15:05 +0000
        Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-01 08:51 -0700
          Re: I think this is an impossible assignment...could you help? "BartC" <bc@freeuk.com> - 2011-09-01 17:26 +0100
            Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-02 07:47 +0000
              Re: I think this is an impossible assignment...could you help? "BartC" <bc@freeuk.com> - 2011-09-02 10:56 +0100
                Re: I think this is an impossible assignment...could you help? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-09-05 20:21 +0000
                Re: I think this is an impossible assignment...could you help? "Bartc" <bc@freeuk.com> - 2011-09-09 13:59 +0100
    Re: I think this is an impossible assignment...could you help? "BartC" <bc@freeuk.com> - 2011-09-02 10:43 +0100
  Re: I think this is an impossible assignment...could you help? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-09-01 12:02 -0600
    Re: I think this is an impossible assignment...could you help? James Kuyper <jameskuyper@verizon.net> - 2011-09-01 15:12 -0400
      Re: I think this is an impossible assignment...could you help? sandeep <nospam@nospam.com> - 2011-09-01 19:36 +0000
      Re: I think this is an impossible assignment...could you help? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-09-01 14:53 -0600
        Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-01 16:01 -0700
          Re: I think this is an impossible assignment...could you help? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-09-01 17:22 -0600
            Re: I think this is an impossible assignment...could you help? pete <pfiland@mindspring.com> - 2011-09-01 19:39 -0400
            Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-01 16:39 -0700
              Re: I think this is an impossible assignment...could you help? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-09-01 18:51 -0600
                Re: I think this is an impossible assignment...could you help? pete <pfiland@mindspring.com> - 2011-09-01 22:27 -0400
                Re: I think this is an impossible assignment...could you help? James Kuyper <jameskuyper@verizon.net> - 2011-09-01 22:53 -0400
                Re: I think this is an impossible assignment...could you help? Kenneth Brody <kenbrody@spamcop.net> - 2011-09-02 10:45 -0400
                Re: I think this is an impossible assignment...could you help? James Kuyper <jameskuyper@verizon.net> - 2011-09-02 11:02 -0400
                Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-02 08:05 -0700
                Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-02 08:17 -0700
                Re: I think this is an impossible assignment...could you help? Willem <willem@toad.stack.nl> - 2011-09-02 15:18 +0000
                Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-02 08:42 -0700
            Re: I think this is an impossible assignment...could you help? James Kuyper <jameskuyper@verizon.net> - 2011-09-01 23:21 -0400
          Re: I think this is an impossible assignment...could you help? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-01 21:53 -0400
            Re: I think this is an impossible assignment...could you help? James Kuyper <jameskuyper@verizon.net> - 2011-09-01 23:09 -0400
    Re: I think this is an impossible assignment...could you help? Michael Press <rubrum@pacbell.net> - 2011-09-01 21:43 -0700
    Re: I think this is an impossible assignment...could you help? Keith Thompson <kst-u@mib.org> - 2011-09-02 08:32 -0700

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