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Re: What a stupid gcc!

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On 06/19/2012 04:13 PM, BartC wrote:
...
> I started my comments in this thread about the disadvantages of just 
> declaring variables anywhere as needed.
> 
> Then I found out about block scopes and all the extra hassle they introduce, 
> making such declarations even more problematic. (And why is a block so 
> special anyway? Surely it's only used when you need two or more statements 
> instead of one.)

What makes blocks special is their use as function bodies, and as the
code controlled by selection statements (if, switch) and iteration
statements (while, do-while, and for). There are not many good reasons
for creating a block other than those. Those reasons alone are
sufficient to give most code a fair number of distinct blocks.

The relevance to variable scope is that it is commonplace, when using
blocks for those purposes, to have variables which are needed only in a
particular block, and by declaring them inside such blocks and having
their scope restricted to those blocks, you reduce the likelihood of
interfering with the definitions of variables in other blocks.

> I'm sorry if no-one else can see the problems (duplicate declarations, 
> clutter, separating related variables, scattered declarations, trickier 
> editing because you have to keep moving the declarations around, worrying 
> about scope, shadowing, anonymity, etc).

More accurately, I see most of the problems you've raised as positive
features. Duplicate definitions are good, precisely because they're
often not duplicates, but two different definitions of variables with
different meanings that should not be confused with each other, even if
you happened to make the mistake of giving them the same name.
Separating variables is good precisely because, if the appropriate scope
of those variables is in fact different, then they are usually
unrelated. If you tend to have a lot of related variables working
together with the same minimal scope, your program will often be
improved by putting those variables together in an aggregate: an array
or struct. Declarations are scattered to be close to their point of use,
where they're easier to find. Making editing difficult by requiring you
to move the declarations around is a good thing, because if you're doing
it a lot, something's wrong - you should give careful thought to each
such move. Having scope to worry about is a good thing - it means that
you can use a variable without worrying about the possibility that it
has already been used with some different meaning somewhere else in the
code. I've had to work on systems where all variables had global scope -
it's a nightmare.

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What a stupid gcc! zgene <nospam@nospam.com> - 2012-06-13 21:41 +0000
  Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-13 18:01 -0400
    Re: What a stupid gcc! Noob <root@127.0.0.1> - 2012-06-14 13:00 +0200
      Re: What a stupid gcc! Nomen Nescio <nobody@dizum.com> - 2012-06-14 14:33 +0200
        Re: What a stupid gcc! Rui Maciel <rui.maciel@gmail.com> - 2012-06-14 14:46 +0100
        Re: What a stupid gcc! Noob <root@127.0.0.1> - 2012-06-14 18:19 +0200
  Re: What a stupid gcc! Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-13 18:06 -0400
  Re: What a stupid gcc! jt@toerring.de (Jens Thoms Toerring) - 2012-06-13 22:19 +0000
    Re: What a stupid gcc! Rui Maciel <rui.maciel@gmail.com> - 2012-06-14 09:47 +0100
      Re: What a stupid gcc! Rui Maciel <rui.maciel@gmail.com> - 2012-06-14 14:37 +0100
  Re: What a stupid gcc! Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2012-06-13 17:05 -0600
  Re: What a stupid gcc! Nick Bowler <nbowler@draconx.ca> - 2012-06-14 00:09 +0000
  Re: What a stupid gcc! Varun Tewari <tewari.varun@gmail.com> - 2012-06-14 03:14 -0700
    Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-14 06:56 -0400
    Re: What a stupid gcc! Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-06-17 07:18 +0000
      Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-17 11:47 +0100
        Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-17 09:31 -0400
          Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-18 12:34 +0100
            Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-18 08:18 -0400
              Re: What a stupid gcc! gwowen <gwowen@gmail.com> - 2012-06-18 05:42 -0700
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-18 09:39 -0400
              Re: What a stupid gcc! Rich Webb <bbew.ar@mapson.nozirev.ten> - 2012-06-18 09:06 -0400
                Re: What a stupid gcc! ImpalerCore <jadill33@gmail.com> - 2012-06-18 07:18 -0700
            Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-19 00:13 -0700
              Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-19 11:28 +0100
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 07:30 -0400
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-20 00:16 -0700
        Re: What a stupid gcc! Rui Maciel <rui.maciel@gmail.com> - 2012-06-17 15:52 +0100
        Re: What a stupid gcc! Noob <root@localhost> - 2012-06-18 09:07 +0200
        Re: What a stupid gcc! Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-06-18 09:03 +0000
        Re: What a stupid gcc! Andrew Smallshaw <andrews@sdf.lonestar.org> - 2012-06-18 16:02 +0000
          Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-18 19:40 +0100
            Re: What a stupid gcc! Noob <root@localhost> - 2012-06-18 23:52 +0200
            Re: What a stupid gcc! Ike Naar <ike@iceland.freeshell.org> - 2012-06-18 23:09 +0000
              Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-19 01:30 +0100
                Re: What a stupid gcc! Ian Collins <ian-news@hotmail.com> - 2012-06-19 13:03 +1200
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 06:34 -0400
                Re: What a stupid gcc! Ike Naar <ike@sverige.freeshell.org> - 2012-06-19 08:43 +0000
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-19 11:00 +0100
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 07:05 -0400
                Re: What a stupid gcc! Ian Collins <ian-news@hotmail.com> - 2012-06-19 23:21 +1200
                Re: What a stupid gcc! Ian Collins <ian-news@hotmail.com> - 2012-06-19 23:22 +1200
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-19 13:45 +0100
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-19 15:23 +0100
                Re: What a stupid gcc! Ike Naar <ike@iceland.freeshell.org> - 2012-06-19 16:14 +0000
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-19 18:01 +0100
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 13:59 -0400
                Re: What a stupid gcc! Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2012-06-19 15:29 -0600
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-19 18:22 +0100
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-19 21:13 +0100
                Re: What a stupid gcc! Lew Pitcher <lpitcher@teksavvy.com> - 2012-06-19 16:27 -0400
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 16:38 -0400
                Re: What a stupid gcc! Kenneth Brody <kenbrody@spamcop.net> - 2012-06-20 09:47 -0400
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-19 22:44 +0100
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-21 01:39 -0700
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-21 10:55 +0100
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-21 04:11 -0700
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-21 12:36 +0100
                Re: What a stupid gcc! David Brown <david@westcontrol.removethisbit.com> - 2012-06-21 15:33 +0200
                Re: What a stupid gcc! Andrew Smallshaw <andrews@sdf.lonestar.org> - 2012-06-21 14:15 +0000
                Re: What a stupid gcc! Kenneth Brody <kenbrody@spamcop.net> - 2012-06-20 09:37 -0400
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-20 14:54 +0100
                Re: What a stupid gcc! Kenneth Brody <kenbrody@spamcop.net> - 2012-06-20 18:19 -0400
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-21 00:13 +0100
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-21 02:09 +0100
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-21 02:05 -0700
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-21 11:49 +0100
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-21 14:24 +0100
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-22 00:38 -0700
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-22 13:37 +0100
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-21 01:57 -0700
                Re: What a stupid gcc! "BartC" <bc@freeuk.com> - 2012-06-21 11:46 +0100
                Re: What a stupid gcc! Kenneth Brody <kenbrody@spamcop.net> - 2012-06-21 14:37 -0400
                Re: What a stupid gcc! Andrew Smallshaw <andrews@sdf.lonestar.org> - 2012-06-21 19:38 +0000
                Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-21 01:41 -0700
                Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-21 12:28 +0100
              Re: What a stupid gcc! Kaz Kylheku <kaz@kylheku.com> - 2012-06-19 15:05 +0000
        Re: What a stupid gcc! Ian Collins <ian-news@hotmail.com> - 2012-06-19 09:37 +1200
          Re: What a stupid gcc! ImpalerCore <jadill33@gmail.com> - 2012-06-18 15:18 -0700
          Re: What a stupid gcc! Paul J Gans <gansno@panix.com> - 2012-06-18 23:21 +0000
            Re: What a stupid gcc! Ian Collins <ian-news@hotmail.com> - 2012-06-19 11:26 +1200
              Re: What a stupid gcc! Paul J Gans <gansno@panix.com> - 2012-06-19 01:46 +0000
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 07:19 -0400
                Re: What a stupid gcc! Stephen Sprunk <stephen@sprunk.org> - 2012-06-19 08:01 -0500
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 09:25 -0400
                Re: What a stupid gcc! Les Cargill <lcargill99@comcast.com> - 2012-06-19 12:57 -0500
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-19 14:59 -0400
            Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-19 01:36 +0100
              Re: What a stupid gcc! Paul J Gans <gansno@panix.com> - 2012-06-19 01:48 +0000
          Re: What a stupid gcc! Les Cargill <lcargill99@comcast.com> - 2012-06-18 19:50 -0500
          Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-19 00:19 -0700
            Re: What a stupid gcc! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-19 12:56 +0100
              Re: What a stupid gcc! nick_keighley_nospam@hotmail.com - 2012-06-20 00:26 -0700
                Re: What a stupid gcc! James Kuyper <jameskuyper@verizon.net> - 2012-06-20 06:31 -0400
      Re: What a stupid gcc! Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2012-06-18 00:18 -0600
        Re: What a stupid gcc! Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-06-18 09:15 +0000
  Re: What a stupid gcc! Kaz Kylheku <kaz@kylheku.com> - 2012-06-14 23:21 +0000

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