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Groups > comp.lang.c > #100446

Re: Octal

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: Octal
Date 2016-12-28 09:41 -0800
Organization None to speak of
Message-ID <ln1sws54tz.fsf@kst-u.example.com> (permalink)
References (14 earlier) <o4062a$976$1@dont-email.me> <87tw9ogt3s.fsf@bsb.me.uk> <o40b62$ojm$1@dont-email.me> <87inq4ggus.fsf@bsb.me.uk> <390aaa5f-d06a-4b89-b79c-98ca28b8208a@googlegroups.com>

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supercat@casperkitty.com writes:
> On Wednesday, December 28, 2016 at 10:26:28 AM UTC-6, Ben Bacarisse wrote:
>> BartC writes:
>> > The sounds more like a bug in the language definition.
>> 
>> I agree that that point could be debated (not that I want to debate it).
>> I hope that you agree that what "users might reasonably expect" will, on
>> many occasions, include what the language definition says they can
>> expect.
>
> On many occasions it will.  On the other hand, a supposed intention of
> the C Standard was to describe a language consistent with the way existing
> compilers behaved.  If a sloppily-written part of the Standard describes
> rules which make the language less useful and doesn't coincide with how
> existing compilers behave, and if there is no stated rationale for making
> compilers change behavior to match the Standard, which should be presumed
> defective--the Standard, or compilers which continue to behave in a manner
> more useful than what the Standard would prescribe?

You seem to be making an assertion about how pre-ANSI compilers
handled things like 0x123e+3.  Would you care to be more specific?

I do not believe that part of the standard is sloppily written.
I believe it was written carefully and deliberately, with an
understanding of the tradeoffs.  The behavior it requires is
admittedly odd in some rare corner cases, but it is consistent,
and it lets us determine the legality and meaning of anything that
looks like a constant.

As it turns out, the ANSI C Rationale actually discusses the thought
that went into the definition of pp-numbers -- using an example
almost identical to the one we've been arguing about.

https://www.lysator.liu.se/c/rat/c1.html#3-1-8

    The notion of preprocessing numbers has been introduced to
    simplify the description of preprocessing.  It provides a means
    of talking about the tokenization of strings that look like
    numbers, or initial substrings of numbers, prior to their
    semantic interpretation.  In the interests of keeping the
    description simple, occasional spurious forms are scanned as
    preprocessing numbers --- 0x123E+1 is a single token under the
    rules. The Committee felt that it was better to tolerate such
    anomalies than burden the preprocessor with a more exact, and
    exacting, lexical specification.  It felt that this anomaly was
    no worse than the principle under which the characters a+++++b
    are tokenized as a ++ ++ + b (an invalid expression), even though
    the tokenization a ++ + ++ b would yield a syntactically correct
    expression. In both cases, exercise of reasonable precaution
    in coding style avoids surprises.

-- 
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"

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Octal BartC <bc@freeuk.com> - 2016-12-27 14:08 +0000
  Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 06:19 -0800
    Re: Octal BartC <bc@freeuk.com> - 2016-12-27 14:58 +0000
      Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 07:07 -0800
        Re: Octal BartC <bc@freeuk.com> - 2016-12-27 15:22 +0000
          Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 07:37 -0800
            Re: Octal BartC <bc@freeuk.com> - 2016-12-27 16:24 +0000
              Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 08:30 -0800
              Re: Octal supercat@casperkitty.com - 2016-12-27 09:10 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 09:35 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 10:47 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:03 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 12:27 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:44 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 13:37 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 16:38 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 17:53 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-27 20:26 -0600
                Re: Octal supercat@casperkitty.com - 2016-12-27 18:48 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-27 22:20 -0600
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 18:41 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 19:19 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-29 14:52 +1300
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 18:41 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:54 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-27 17:44 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:17 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-27 22:39 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-28 11:49 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-27 23:09 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-28 12:32 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 00:51 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-28 14:00 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 01:13 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-27 20:04 -0600
                Re: Octal supercat@casperkitty.com - 2016-12-27 18:45 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-29 13:35 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-29 14:49 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-29 15:33 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-30 12:35 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-13 15:19 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-13 15:32 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-14 12:35 +1300
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-13 15:51 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-13 18:25 -0800
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-01-14 06:21 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-14 14:00 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 23:08 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 23:02 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-13 18:52 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 23:46 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-16 01:46 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-31 08:33 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 17:19 -0800
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 09:39 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 11:02 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 12:13 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 11:41 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:31 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 17:39 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 22:05 +0100
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 12:01 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 20:05 +0000
                Re: Octal asetofsymbols@gmail.com - 2016-12-28 11:20 -0800
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 12:01 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 12:30 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 13:51 +0100
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 16:26 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-28 08:40 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:41 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 18:04 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 19:36 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 19:42 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-29 00:34 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-28 11:04 -0800
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 12:09 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 16:46 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 00:56 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 17:52 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 11:27 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 12:09 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-28 08:17 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 17:02 +0000
                Re: Octal Ike Naar <ike@iceland.freeshell.org> - 2016-12-28 17:25 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 17:45 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:21 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-28 09:27 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:23 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-28 11:18 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:19 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 15:54 +0000
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-29 12:57 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 10:01 +1300
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 10:44 +0100
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 17:32 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 17:03 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-29 16:26 -0600
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 11:31 +1300
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-29 16:58 -0600
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 11:59 +1300
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 09:00 +1300
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 10:21 +0100
                Re: Octal asetofsymbols@gmail.com - 2016-12-30 01:29 -0800
                Re: Octal asetofsymbols@gmail.com - 2016-12-30 01:29 -0800
                Re: Octal asetofsymbols@gmail.com - 2016-12-30 01:36 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 11:52 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 17:10 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-29 05:52 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 19:51 -0600
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 21:09 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 10:15 +1300
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-29 13:53 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 12:07 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 13:04 +0000
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-30 05:31 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 15:00 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 15:55 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2017-01-01 16:00 +0100
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 08:33 +1300
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 09:02 +1300
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 09:38 +1300
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-01-01 13:59 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-01 14:24 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-01 15:51 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 13:09 +1300
                Re: Octal supercat@casperkitty.com - 2017-01-01 16:50 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 14:24 +1300
                Re: Octal David Brown <david.brown@hesbynett.no> - 2017-01-02 01:53 +0100
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 14:15 +1300
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-02 02:28 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 06:24 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 17:53 +0000
                Re: Octal luser droog <luser.droog@gmail.com> - 2016-12-30 10:01 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 09:57 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-30 13:50 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 11:09 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-30 14:46 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 12:28 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-30 16:01 -0800
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-30 14:48 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 22:51 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-30 15:20 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 12:34 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 23:40 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 22:12 +0000
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 21:38 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 12:04 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 13:42 +0100
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 08:59 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-29 12:23 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 10:56 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 22:09 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 12:27 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 21:18 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 20:46 +0000
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 20:55 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 14:54 -0600
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 15:44 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 19:39 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 15:04 -0600
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 19:52 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-29 09:36 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 18:02 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 16:17 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2017-01-01 16:09 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 20:02 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 12:32 -0800
                Re: Octal Richard Heathfield <rjh@cpax.org.uk> - 2016-12-29 13:45 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 17:16 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:04 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-02 02:26 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-02 12:35 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-12 23:22 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-13 10:04 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-14 00:45 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:59 -0800
                Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 09:45 -0800
        Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-27 17:14 +0100
          Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 08:23 -0800
            Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 10:37 +0100
              Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-28 03:07 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 12:25 +0100
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 11:58 +0000
                Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-28 04:35 -0800
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 17:31 +0000
                Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-28 09:38 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 15:12 -0600
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 12:01 -0800
              Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:20 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 13:39 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 12:29 +0100
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 22:20 +0100
      Re: Octal Noob <root@127.0.0.1> - 2016-12-28 13:02 +0100
        Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 13:30 +0100
        Re: Octal BartC <bc@freeuk.com> - 2016-12-28 13:25 +0000
  Re: Octal Manfred <noname@invalid.add> - 2016-12-27 15:19 +0100
    Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 08:37 -0800
      Re: Octal Manfred <noname@invalid.add> - 2016-12-27 18:43 +0100
        Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:07 -0800
    Re: Octal Manfred <noname@invalid.add> - 2016-12-27 18:21 +0100
  Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-27 15:28 +0100
  Re: Octal BGB <cr88192@hotmail.com> - 2016-12-27 11:42 -0600

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