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| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: global/static variables & loops |
| Date | 2012-02-15 16:00 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <jhh6d5$aps$1@dont-email.me> (permalink) |
| References | (5 earlier) <87d39g9fgm.fsf@huddi.jernurt.dk> <jhgt9t$hkn$1@dont-email.me> <878vk3ao7m.fsf@huddi.jernurt.dk> <jhh2sd$kt1$1@dont-email.me> <87y5s396wj.fsf@huddi.jernurt.dk> |
On 02/15/2012 03:30 PM, Anders Wegge Keller wrote:
> James Kuyper <jameskuyper@verizon.net> writes:
>
>> On 02/15/2012 02:30 PM, Anders Wegge Keller wrote:
>
>>> If it quacks like a duck, walks like a duck and swims like a duck, it
>>> probably is a duck, no matter how you dress it up.
>>
>> Well, that works both ways - labeling it a prejudice doesn't make it
>> cease to be a well-justified judgment.
>
> Yoy have missed the point. I'm talking about cases like
>
> int debug_level;
>
> versus:
>
> static int debug_level
> int get_debug_level(void) { return debug_level; }
> void set_debug_level(int lvl) { debug_level = lvl; }
That's just a global dressed up in fancy clothes. It has all of the
disadvantages of a global, while being unnecessarily more complicated
than defining a global. If the setter function at least implemented some
kind of validity test on the new level, the example would make a little
more sense, but I had not considered that you were arguing against this
kind of idea.
> I'm not trying to justify "All data should be global", as you seem to
> imply. I'm questioning "No data should be global". There is a world
> between those two statements.
I'd argue for "little, if any, data should be global". The only objects
that should have external linkage are those which will be used almost
everywhere in a program, and in my experience there aren't many of
those. If there are, poor design is usually to blame. To take your
example, I could quite easily imagine wanting to have different debug
levels in different parts of the program, which would make a single
global debug level inappropriate.
..
> Try implementing GNU ls without globals. I know that the whole lot
> are statics, since the code is in just one TU, but imagine something
> of a similar magnitude then. The first few levels of functions will
> have prototypes of several pages.
I don't have time to implement the entirety of ls; if the sheer
complexity of ls is your point, then I won't be able to address it
directly. If there's some particular feature of ls that you think
requires use of globals, I could possibly spare time to implement a
simplified version providing only that feature.
--
James Kuyper
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global/static variables & loops Rob Janecek <robs@invalid.com> - 2012-02-14 19:56 +0000
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-14 12:42 -0800
Re: global/static variables & loops Stephen Sprunk <stephen@sprunk.org> - 2012-02-14 15:01 -0600
Re: global/static variables & loops Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-14 20:35 -0500
Re: global/static variables & loops Philip Lantz <prl@canterey.us> - 2012-02-14 21:18 -0800
Re: global/static variables & loops pete <pfiland@mindspring.com> - 2012-02-15 00:53 -0500
Re: global/static variables & loops Jonathan Leffler <jleffler@earthlink.net> - 2012-02-18 21:15 -0800
Re: global/static variables & loops Kaz Kylheku <kaz@kylheku.com> - 2012-02-19 06:05 +0000
Re: global/static variables & loops Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-22 03:15 +0200
Re: global/static variables & loops Shao Miller <sha0.miller@gmail.com> - 2012-02-19 04:14 -0500
Re: global/static variables & loops Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-19 12:32 +0000
Re: Array 'typedef's and exclusive use of '->' versus '.' Shao Miller <sha0.miller@gmail.com> - 2012-02-19 17:00 -0500
Re: Array 'typedef's and exclusive use of '->' versus '.' Keith Thompson <kst-u@mib.org> - 2012-02-19 16:43 -0800
Re: Array 'typedef's and exclusive use of '->' versus '.' Shao Miller <sha0.miller@gmail.com> - 2012-02-19 20:32 -0500
Re: Array 'typedef's and exclusive use of '->' versus '.' Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-22 03:27 +0200
Re: Array 'typedef's and exclusive use of '->' versus '.' Shao Miller <sha0.miller@gmail.com> - 2012-02-25 02:19 -0500
Re: Array 'typedef's and exclusive use of '->' versus '.' Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-25 10:14 +0200
Re: global/static variables & loops "BartC" <bc@freeuk.com> - 2012-02-15 10:47 +0000
Re: global/static variables & loops Kaz Kylheku <kaz@kylheku.com> - 2012-02-15 11:42 +0000
Re: global/static variables & loops "BartC" <bc@freeuk.com> - 2012-02-15 12:54 +0000
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-15 05:17 -0800
Re: global/static variables & loops Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-22 03:28 +0200
Re: global/static variables & loops August Karlstrom <fusionfile@gmail.com> - 2012-02-15 15:19 +0100
Re: global/static variables & loops Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-22 03:12 +0200
Re: global/static variables & loops Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-02-15 01:23 -0800
Re: global/static variables & loops August Karlstrom <fusionfile@gmail.com> - 2012-02-15 14:03 +0100
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-15 05:20 -0800
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 08:41 -0500
Re: global/static variables & loops Kaz Kylheku <kaz@kylheku.com> - 2012-02-16 00:20 +0000
Re: global/static variables & loops Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-15 21:02 -0500
Re: global/static variables & loops "BartC" <bc@freeuk.com> - 2012-02-16 10:03 +0000
Re: global/static variables & loops Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-16 07:58 -0500
Re: global/static variables & loops Markus Wichmann <nullplan@gmx.net> - 2012-02-19 20:44 +0100
Re: global/static variables & loops Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-19 15:37 -0500
Re: global/static variables & loops Kaz Kylheku <kaz@kylheku.com> - 2012-02-22 05:01 +0000
Re: global/static variables & loops Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-22 08:12 -0500
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 15:55 +0100
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 11:05 -0500
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-15 09:13 -0800
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 18:25 +0100
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 13:25 -0500
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-15 10:51 -0800
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 14:45 -0500
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 20:47 +0100
Re: global/static variables & loops Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-02-16 04:45 -0800
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-16 14:25 +0100
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-16 08:10 -0800
Re: global/static variables & loops Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-02-17 00:59 -0800
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 20:30 +0100
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 15:00 -0500
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 21:30 +0100
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 16:00 -0500
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 23:10 +0100
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-15 15:50 -0800
Re: global/static variables & loops James Kuyper <jameskuyper@verizon.net> - 2012-02-15 19:50 -0500
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-16 14:36 +0100
Re: global/static variables & loops Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-02-16 03:29 -0800
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-15 23:37 +0100
Re: global/static variables & loops Kaz Kylheku <kaz@kylheku.com> - 2012-02-16 00:23 +0000
Re: global/static variables & loops Anders Wegge Keller <wegge@wegge.dk> - 2012-02-16 01:29 +0100
Re: global/static variables & loops Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-15 21:20 -0500
Re: global/static variables & loops Shao Miller <sha0.miller@gmail.com> - 2012-02-15 22:24 -0500
Re: global/static variables & loops Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-16 01:08 -0800
Re: global/static variables & loops Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-02-16 03:17 -0800
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