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Re: Restricted unsigned integer range would have been better?

Message-ID	<50191E78.CDB@mindspring.com> (permalink)
Date	2012-08-01 08:18 -0400
From	pete <pfiland@mindspring.com>
Organization	PF
Newsgroups	comp.lang.c
Subject	Re: Restricted unsigned integer range would have been better?
References	(7 earlier) <te-dnWYbGZ2hqIvNnZ2dnUVZ8sCdnZ2d@lyse.net> <MPG.2a8225bcdb731a4798968a@news.eternal-september.org> <5018AE22.152C@mindspring.com> <P4Odncjoya6Oe4XNnZ2dnUVZ8iSdnZ2d@lyse.net> <0.41a5266becbe1d48f128.20120801125152BST.87r4rq4yp3.fsf@bsb.me.uk>

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Ben Bacarisse wrote:
> 
> David Brown <david@westcontrol.removethisbit.com> writes:
> 
> > On 01/08/2012 06:18, pete wrote:
> >> Philip Lantz wrote:
> >>>
> >>> David Brown wrote:
> >>>> Les Cargill wrote:
> >>>>> Keith Thompson wrote:
> >>>>>> Les Cargill writes:
> >>>>>>> Type conversions must be made explicit.
> >>>>>>
> >>>>>> I presume that's meant as advice, not a language rule.
> >>>>>
> >>>>> Sorry - yes, it's advice.
> >>>>
> >>>> Good advice.
> >>>>
> >>>> For my work, it is more than advice - it is a style rule,
> >>>> and I enforce
> >>>> it with compiler warnings (-Wconversion -Wsign-conversion in gcc).
> >>>
> >>> Do you really? Would you use casts in situations like these?
> >>>    1. char c = 'x';
> >>>    2. int *p = malloc(N * sizeof *p);
> >>>    3. free(p);
> >>>    4. printf("%c\n", c);
> >>>    5. while (*s != '\0')
> >>>           n = n * 10 + (*s - '0');
> >>>
> >>> I would find them to be undesirable clutter.
> >>
> >> I was thinking the same thing.
> >>
> >> And I think you meant to imply
> >> that (*s) is an expression of type char.
> >>
> >> If n is of type int and also not negative,
> >> then you could write without having to use parentheses
> >>      n = n * 10 - '0' + *s;
> >> with no possibility of overflow.
> 
> I don't understand that.  Did you mean "and also unsigned" rather than
> "and also not negative"?

No. 
It reminded me of a line from a toy atoi 
that I once wrote as an exercise.



int 
a_toi(const char *nptr)
{
    int n;

    n = 0;
    while (isspace(*nptr)) {
        ++nptr;
    }
    if (*nptr != '-') {
        if (*nptr == '+') {
            ++nptr;
        }
        while (isdigit(*nptr)) {
            n = 10 * n - '0' + *nptr++;
        }
    } else {
        ++nptr;
        while (isdigit(*nptr)) {
            n = 10 * n + '0' - *nptr++;
        } 
    }
    return n;
}

-- 
pete

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Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-23 01:32 -0600
Re: Restricted unsigned integer range would have been better? "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-07-23 01:45 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 00:19 -0600
Re: Restricted unsigned integer range would have been better? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-07-24 11:25 +0100
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 16:22 -0600
Re: Restricted unsigned integer range would have been better? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-07-25 01:53 +0100
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 21:43 -0600
Re: Restricted unsigned integer range would have been better? "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-07-24 16:29 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 21:53 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-24 23:24 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-25 01:12 -0600
Re: Restricted unsigned integer range would have been better? Nobody <nobody@nowhere.com> - 2012-07-23 10:37 +0100
Re: Restricted unsigned integer range would have been better? Andre <lodwig@pathme.de> - 2012-07-23 11:46 +0200
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-23 11:33 +0100
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-23 23:48 -0600
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-24 10:43 +0100
Re: Restricted unsigned integer range would have been better? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-24 02:58 -0700
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-24 12:04 +0100
Re: Restricted unsigned integer range would have been better? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-24 05:32 -0700
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-24 14:20 +0100
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-24 18:41 +0100
Re: Restricted unsigned integer range would have been better? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-24 12:37 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 16:15 -0600
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 16:05 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-24 23:28 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-25 01:13 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-25 01:26 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-25 05:43 -0600
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-07-24 15:10 +0200
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-24 16:23 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-24 23:40 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-25 01:32 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-25 01:29 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-25 05:45 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-25 12:35 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-26 00:12 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-26 01:42 -0700
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-07-25 09:31 +0200
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-25 06:28 -0600
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-07-25 16:28 +0200
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-25 17:17 +0100
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-07-26 12:07 +0200
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-26 14:06 +0100
Re: Restricted unsigned integer range would have been better? James Kuyper <jameskuyper@verizon.net> - 2012-07-26 09:45 -0400
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-07-30 09:01 +0200
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-26 00:09 -0600
Re: Restricted unsigned integer range would have been better? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-26 00:52 -0700
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-07-26 20:35 -0400
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-26 22:35 -0600
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-07-27 09:19 -0400
Re: Restricted unsigned integer range would have been better? Les Cargill <lcargill99@comcast.com> - 2012-07-27 12:51 -0500
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-27 16:19 -0700
Re: Restricted unsigned integer range would have been better? Les Cargill <lcargill99@comcast.com> - 2012-07-27 18:47 -0500
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-07-30 09:10 +0200
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-07-31 17:26 -1000
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-08-01 00:18 -0400
Re: Restricted unsigned integer range would have been better? "io_x" <a@b.c.invalid> - 2012-08-01 10:19 +0200
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-08-01 10:09 +0200
Re: Restricted unsigned integer range would have been better? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-01 12:51 +0100
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-08-01 08:18 -0400
Re: Restricted unsigned integer range would have been better? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-01 14:22 +0100
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-08-01 09:57 -0400
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-08-01 11:35 -0400
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 11:43 -0700
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-09-08 10:13 -0400
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-09-22 23:39 -0700
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-09-22 23:45 -0700
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-17 13:52 -0800
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-17 13:45 -0800
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-12-17 19:51 -0500
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-12-28 11:11 -0800
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-29 11:31 -0800
Re: Restricted unsigned integer range would have been better? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-29 23:59 +0000
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-02 10:01 -0800
Re: Restricted unsigned integer range would have been better? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2013-01-05 12:00 +0200
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2013-01-02 13:07 -0800
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-03 12:10 -0800
Re: Restricted unsigned integer range would have been better? James Kuyper <jameskuyper@verizon.net> - 2013-01-05 12:26 -0500
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-09-22 23:35 -0700
Re: Restricted unsigned integer range would have been better? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-17 14:02 -0800
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-08-01 10:06 +0200
Re: Restricted unsigned integer range would have been better? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-01 12:46 +0100
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-08-02 08:19 -1000
Re: Restricted unsigned integer range would have been better? Philip Lantz <prl@canterey.us> - 2012-08-02 08:17 -1000
Re: Restricted unsigned integer range would have been better? David Brown <david@westcontrol.removethisbit.com> - 2012-08-03 08:04 +0200
Re: Restricted unsigned integer range would have been better? "io_x" <a@b.c.invalid> - 2012-08-03 09:40 +0200
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-27 22:27 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-07-28 01:31 -0700
Re: Restricted unsigned integer range would have been better? "BartC" <bc@freeuk.com> - 2012-07-28 10:52 +0100
Re: Restricted unsigned integer range would have been better? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-28 03:31 -0700
Re: Restricted unsigned integer range would have been better? pete <pfiland@mindspring.com> - 2012-07-28 00:05 -0400
Re: Restricted unsigned integer range would have been better? Les Cargill <lcargill99@comcast.com> - 2012-07-27 23:22 -0500
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-27 22:35 -0600
Re: Restricted unsigned integer range would have been better? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-08-04 08:43 -0700
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-08-04 16:40 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-04 22:58 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-08-04 23:10 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-05 01:16 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-08-05 02:25 -0700
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-05 03:35 -0600
Re: Restricted unsigned integer range would have been better? Keith Thompson <kst-u@mib.org> - 2012-08-05 12:16 -0700
Re: Restricted unsigned integer range would have been better? gazelle@shell.xmission.com (Kenny McCormack) - 2012-08-05 19:56 +0000
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-06 01:12 -0600
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-06 01:07 -0600
Re: Restricted unsigned integer range would have been better? gazelle@shell.xmission.com (Kenny McCormack) - 2012-08-05 13:33 +0000
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-06 01:13 -0600
Re: Restricted unsigned integer range would have been better? "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-04 22:54 -0600

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