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| From | "BartC" <bc@freeuk.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: What a stupid gcc! |
| Date | 2012-06-21 00:13 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <jrtljp$fdc$1@dont-email.me> (permalink) |
| References | (1 earlier) <0.d63dfcbf17c321e1d55d.20120619182205BST.87pq8vqksi.fsf@bsb.me.uk> <jrqmir$7q2$1@dont-email.me> <28Gdna63UOSAT3zSnZ2dnUVZ_g-dnZ2d@bestweb.net> <jrskm1$jpv$1@dont-email.me> <pOednUXiQILn0X_SnZ2dnUVZ_sudnZ2d@bestweb.net> |
"Kenneth Brody" <kenbrody@spamcop.net> wrote in message
news:pOednUXiQILn0X_SnZ2dnUVZ_sudnZ2d@bestweb.net...
> On 6/20/2012 9:54 AM, BartC wrote:
>> "Kenneth Brody" <kenbrody@spamcop.net> wrote in message
>> news:28Gdna63UOSAT3zSnZ2dnUVZ_g-dnZ2d@bestweb.net...
>>> On 6/19/2012 4:13 PM, BartC wrote:
> [...]
>>>> 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).
>>>
>>> Ahh... So you want all declarations to be global scope, always?
>>
>> No. Function scope, file scope, and project-wide.
>
> So this:
>
> void foo(void)
> {
> int i;
> ...
> }
>
> should (in your opinion) create a variable "i" of type integer with a
> scope of the braces that encloses the declaration (ie: the function
> "foo"), but:
>
> void foo(void)
> {
> ...
> if ( bar )
> {
> int i;
> ...
> }
> ...
> }
>
> should behave differently, and give "i" some scope other than the braces
> that enclose the declaration?
Until a few days ago, I'd never even considered that variables could be
declared local to a block. You second example was, to me, just a convenient
way of declaring 'i' near the place where you started using it, but would
have exactly the same scope as the ones at function level (ie. declared at
the top of the function).
Now it seems the 'i' is limited to it's immediately enclosing braces, which
doesn't appear so useful. Suppose it's an if-else statement, both branches
having code that uses a variable 'i' of the same type; why bother declaring
two distinct versions of it?
> [...]
>>> That eliminates the ability to create a "local" variable within a small
>>> block of code (I can't have a small loop use "int x,y", as that would
>>> simply be the same as the "double x,y" used elsewhere). That eliminates
>>> basically everything useful about scope, because it eliminates scope
>>> entirely.
>>
>> No-one has said anything of the kind. Scope would still exist across
>> modules,
>> across one module, and across one function. I'm saying it doesn't need to
>> be
>> across individual blocks too, given that a typical function is small.
>
> if ( foo.type == MyInteger )
> {
> int num;
> num = foo.integer;
> ... do stuff with int ...
> }
> else if ( foo.type == MyFloat )
> {
> float num;
> num = foo.floating;
> ... do stuff with float ...
> }
I accept that it does allow you to do stuff like this, but it really doesn't
seem a very good idea, using the same identifier for two different types,
within a few lines of each other in the same function.
Imagine you're trying to read such a function, and your eyes jump from one
part of the function to another. First num is a int; fine. Now you jump to
the 'do stuff with float' part, and you have to do a double take. From this
point on, you can't trust anything you see; what type is 'num' going to have
next time you see it? Maybe these are two nested blocks in a loop, and you
break from one to the other. You have to trace the code, character by
character counting blocks, to match the use of 'num' with it's correct
declaration.
Sorry, but these possibilities which everyone else thinks are great, to me
just seem nightmarish.
> [...]
>>> How could one write a "small function" if it couldn't create variables
>>> that are available only within its scope?
>>
>> We're talking about adding extra block scopes to a 10- or 20-line
>> function
>> that already has local variables valid throughout the function.
>>
>> How small a scope do you need: per line, per statement, or per
>> expression?
>
> Why should the scope of a variable declared inside the outermost braces of
> a function be different from a variable within some other set of braces?
> What's difficult about the concept that the scope is the innermost set of
> braces that enclose the declaration?
What is a set of braces? C uses braces to:
- Enclose the statements of a function body (which can't have just one
non-block statement).
- Enclose an initialiser expression or list
- Group several ordinary statements into one. C statements such as while,
for and if only allow one statement in a loop body or each branch of the
'if', so {, } are a mechanism for allowing more than one.
The syntax could have used entirely different symbols for these
requirements. Having a local scope for a function body, that's fine; every
language except Basic has that. But what's so special about a compound
statement that it ought to have it's own private set of variables?
On just about every other occasion where the complexity of a function grows
beyond about 3 lines, I'm constantly told it needs to split into
sub-functions. Now entire, self-contained sub-programs can be created in
each branch of a minor 'if' in a minor 'for' loop in a dusty corner of a
function, and that is perfectly OK?
In a different kind of forum from comp.lang.c, I would almost start to
suspect a wind-up!
--
Bartc
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
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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