Re: C scope and struct definitions

From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: C scope and struct definitions
Date	2012-06-27 12:11 -0700
Organization	None to speak of
Message-ID	<lny5n83703.fsf@nuthaus.mib.org> (permalink)
References	(5 earlier) <4FEA27EC.70201@loria.fr> <lnobo54oyc.fsf@nuthaus.mib.org> <4FEAA7AC.50101@loria.fr> <jseoui$ufr$1@dont-email.me> <variables-20120627184545@ram.dialup.fu-berlin.de>

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ram@zedat.fu-berlin.de (Stefan Ram) writes:
> James Kuyper <jameskuyper@verizon.net> writes:
>>identifiers themselves do not. Personally, I use the definition "A
>>variable is a named object.".
>
>   That would be too vague for my taste. For example, after
>
> int a[3];
>
>   one might say that »a[1]« was a variable, because someone
>   called it »joe«.

It seems sufficiently obvious to me that "named" means that the object
has a name (which is a single identifier) in the program text.

>   A more important point is: Your definition makes being a
>   variable a property of objects: By your definition, a
>   variable is a /special kind of object/: an object that is
>   /named/. An object is given by a region of storage and a
>   type. Now, when such an object is given, can one determine
>   whether this given object is a variable by your definition?
>   Usually not, because there is no way to find names starting
>   at the object! (At run-time most names are lost, and at
>   compile time there are no objects yet, so names and objects
>   rarely seem to exist at the same time at all.)

Yes, but I don't see that as a problem. In a running program, it doesn't
matter whether a given object is a "variable" or not; there's no need to
have a way to determine this.

We just use the word "variable" to refer to a named object, as in:

    int x; /* define an int variable named "x" */

>   So, my definition would choose a wording more like
>   »A variable is a /pair of a name and an object/, where
>   the name refers to the object[ and ...]«.

Hmm. I've always thought of a "variable" as a kind of
object. Applying it to a "pair of a name and an object", as you
suggest, seems (a) counterintuitive, and (b) not particularly useful.

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
    Will write code for food.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Thread

C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-22 13:30 -0400
  Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-22 14:02 -0400
    Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-22 22:40 +0000
      Re: C scope and struct definitions Ben Pfaff <blp@cs.stanford.edu> - 2012-06-22 15:47 -0700
      Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-22 20:32 -0400
        Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-23 22:06 +0000
          Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-23 16:18 -0700
            Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-25 10:19 -0400
              Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-25 11:51 -0700
          Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-23 19:54 -0400
            Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-24 00:56 +0000
              Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-23 21:48 -0400
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-24 06:03 +0000
                Re: C scope and struct definitions nick_keighley_nospam@hotmail.com - 2012-06-25 00:05 -0700
              Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-23 19:25 -0700
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-24 05:40 +0000
                Re: C scope and struct definitions Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-24 10:47 +0200
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-24 11:00 -0700
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-25 03:53 +0000
                Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-25 01:14 -0400
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-24 22:38 -0700
                Re: C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-25 11:03 -0400
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-26 20:08 +0000
                Re: C scope and struct definitions Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-26 23:21 +0200
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-26 21:47 +0000
                Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-26 18:05 -0400
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-26 16:45 -0700
                Re: C scope and struct definitions Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-27 08:26 +0200
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-27 00:01 -0700
                Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-27 06:57 -0400
                Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-27 15:00 -0400
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-27 14:48 -0700
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-27 16:14 -0700
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-29 09:36 -0700
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-27 16:27 -0700
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-27 12:03 -0700
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-27 12:11 -0700
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-27 15:53 -0700
                Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-26 17:59 -0400
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-26 22:18 +0000
                Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-26 18:33 -0400
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-26 17:22 -0700
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-27 00:03 -0700
                Re: C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-27 14:13 -0400
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-27 12:15 -0700
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-29 09:43 -0700
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-29 11:59 -0700
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-07-01 18:32 -0700
                Re: C scope and struct definitions pacman@kosh.dhis.org (Alan Curry) - 2012-06-27 20:59 +0000
                Re: C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-28 16:42 -0400
            Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-23 20:57 -0400
              Re: C scope and struct definitions Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-23 22:11 -0400
                Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-23 22:51 -0400
                Re: C scope and struct definitions Nick Bowler <nbowler@draconx.ca> - 2012-06-25 17:31 +0000
                Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-25 14:46 -0400
                Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-25 14:43 -0700
                Re: C scope and struct definitions Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-26 13:44 +0200
                Re: C scope and struct definitions Keith Thompson <kst-u@mib.org> - 2012-06-23 20:07 -0700
              Re: C scope and struct definitions Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-24 10:56 +0200
                Re: C scope and struct definitions James Kuyper <jameskuyper@verizon.net> - 2012-06-24 08:29 -0400
              Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-24 10:26 -0700
          Re: C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-25 10:50 -0400
      Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-24 09:23 -0700
        Re: C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-25 11:17 -0400
          Re: C scope and struct definitions Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-25 14:22 -0700
  Re: C scope and struct definitions Kenneth Brody <kenbrody@spamcop.net> - 2012-06-25 11:11 -0400

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