Re: gcc needs a curly bracket matching/counting function

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.lang.c
Subject	Re: gcc needs a curly bracket matching/counting function
Date	2016-12-21 15:10 +0100
Organization	A noiseless patient Spider
Message-ID	<o3e2ee$lkq$1@dont-email.me> (permalink)
References	(2 earlier) <o3a8if$1rg$1@dont-email.me> <o3bb4h$c6k$1@dont-email.me> <a29a909d-f76e-4625-a687-1acbc8586aa3@googlegroups.com> <o3dnlv$6qt$1@dont-email.me> <o3dtgo$rau$1@dont-email.me>

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On 21/12/16 13:46, BartC wrote:
> On 21/12/2016 11:07, David Brown wrote:
>> On 20/12/16 14:35, Rick C. Hodgin wrote:
>>> On Tuesday, December 20, 2016 at 8:20:47 AM UTC-5, Bart wrote:
>>>> On 20/12/2016 03:30, DFS wrote:
>>>>
>>>>> I'd rather the compiler do at least a quick count for me.
>>>>
>>>> The compiler is handicapped by the language. This has the right number
>>>> of { and } braces and compiles fine:
>>>>
>>>>      if (a) {
>>>>          if (b)
>>>>              puts("B1");
>>>>              puts("B2");
>>>>          }
>>
>> C gives you the ability to write code in an ugly, confusing and
>> error-prone manner.  So do all programming languages I have ever seen.
> 
> In the syntax I normally use, this example is impossible to write
> without invoking an error.

As I said, the details vary from language to language.  But no language
is immune from programmers who write confusing code.  Languages, tools,
coding standards, programmer education and good practice all combine to
reduce the risk of such errors.  For historical reasons, C has a number
of ways to make silly mistakes that many other languages don't have -
this is one of them.  But a decent editor can make this slightly harder
to type (since you get used to indents being generated automatically).
Good tools (gcc 6 spots this, as will many linters and more advanced C
static error checkers).  No coding standard would accept such code.  And
of course if the programmer has been taught properly and is used to
writing code sensibly, then it is very unlikely that they will make such
a mistake.

Mistakes of all sorts /do/ happen, with /all/ programming languages.
Don't pretend that any particular language eliminates typos, bad design,
poor programming habits, or other errors - a  good language design can
greatly reduce the risk of /some/ types programming errors, but that is
all.  And don't confuse weaknesses in a language design with an
inability or unwillingness to use tools to help write correct code.
Just because C /lets/ you write this sort of thing, does not make it any
less /your/ fault if you write it.

Personally, I would have been happier if the C language insisted on
brackets on "if", "while", and "for" statements - it would reduce other
people's mistakes.  (I don't make such mistakes.  I make /other/
mistakes in my coding, but I don't get brackets and indentation wrong.)
 But I can also understand that some people are happy that they are
optional.

> 
>> The details of how you can write confusing and bad code with legal
>> syntax varies from language to language, but it is always possible.
>>
>> You avoid this particular problem with a simple rule - a for, if or
>> while statement should always have brackets.
> 
> Unfortunately that doesn't always work, as the language won't not
> cooperate.

It /always/ works, because the language does not prevent you writing
correct code.

The language does not stop you writing incorrect code, but that's
another matter entirely.

> 
> If you forget the braces, it won't tell you as it knows nothing about
> your rule, unless it can't match them. You can also put in extra braces,
> and that's OK provided the extra brace is matched elsewhere.

It is not the language's job to make sure your code is correct - it is
/your/ job.  And if you can't do it reliably on your own, then it is
/your/ job to make sure you have appropriate tools to help.

> 
> It doesn't help that the same } brace can close an if-block, for-block,
> while-block, do-block, switch-block, function-block, a data-block, and
> just a block-block.

That works just fine.

> 
> So it's a language design issue; it's not true that all languages are
> the same. Not regarding this block-delimiting anyway.

As I said, /all/ languages let you write incorrect or confusing code,
but the details vary.

There are a few things about C that make it easier than necessary to
write incorrect code - this is one of them.  Others include the
automatic fall-through in switch cases, and that "if (x = y)" is legal
code.  But it is still not hard to avoid these potential problems.

> 
> And people aren't going to follow the rule as it's far too tempting to
> just write:
> 
>     if (!fp) return 0;

Many people (including me) see that as fine - /if/ there are no "else"
clauses involved.

> 
> (leaving this open to brace-matching and dangling else problems).
> 
>   And you need a consistent
>> bracing and indenting style - I recommend the One True Brace Style as a
>> starting point, but variations are possible.
> 
> Yes, everyone uses /their own/ consistent style!
> 

You can use existing styles and coding standards, or make your own -
that is up to you.  The point is that having a consistent style is the
key to clear coding her - the details of that style do not matter much.

Thread

gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-19 20:38 -0500
  Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 01:59 +0000
    Re: gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-19 22:30 -0500
      Re: gcc needs a curly bracket matching/counting function Robert Spanjaard <spamtrap@arumes.com> - 2016-12-20 11:46 +0100
      Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 13:20 +0000
        Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 13:30 +0000
        Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-20 05:35 -0800
          Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 12:07 +0100
            Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 12:46 +0000
              Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 15:10 +0100
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 17:10 +0000
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 19:50 +0100
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 20:15 +0000
                Re: gcc needs a curly bracket matching/counting function Ike Naar <ike@iceland.freeshell.org> - 2016-12-21 22:36 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 23:46 +0000
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-22 01:54 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 12:16 +0000
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-22 13:06 +0000
                Re: gcc needs a curly bracket matching/counting function asetofsymbols@gmail.com - 2016-12-22 05:25 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 13:34 +0000
                Re: gcc needs a curly bracket matching/counting function asetofsymbols@gmail.com - 2016-12-22 08:16 -0800
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-22 09:30 -0800
                Re: gcc needs a curly bracket matching/counting function luser droog <luser.droog@gmail.com> - 2016-12-22 09:40 -0800
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 05:33 -0800
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 05:41 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 14:53 +0000
                Re: gcc needs a curly bracket matching/counting function asetofsymbols@gmail.com - 2016-12-22 08:11 -0800
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 08:27 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 16:48 +0000
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 09:27 -0800
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-22 20:12 +0000
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 12:18 -0800
              Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-21 09:04 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 17:24 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-21 09:41 -0800
                Re: gcc needs a curly bracket matching/counting function Ian Collins <ian-news@hotmail.com> - 2016-12-22 18:10 +1300
                Re: gcc needs a curly bracket matching/counting function Ian Collins <ian-news@hotmail.com> - 2016-12-29 14:50 +1300
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-02 02:07 -0800
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2017-01-02 11:16 +0100
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:40 -0800
            Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-21 08:52 -0800
              Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 20:16 +0100
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-22 09:41 +0100
      Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 17:04 +0000
        Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 18:46 +0000
          Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 21:55 +0000
        Re: gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-20 13:52 -0500
          Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 19:09 +0000
          Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 19:14 +0000
            Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 12:16 -0800
              Re: gcc needs a curly bracket matching/counting function Gareth Owen <gwowen@gmail.com> - 2016-12-20 20:53 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 13:51 -0800
                Re: gcc needs a curly bracket matching/counting function Gareth Owen <gwowen@gmail.com> - 2016-12-29 18:49 +0000
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:36 -0800
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-29 12:44 +0100
              Re: gcc needs a curly bracket matching/counting function bart4858@gmail.com - 2016-12-20 13:25 -0800
                Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 13:39 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 21:58 +0000
                Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 14:05 -0800
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 22:17 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2017-01-26 19:03 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 14:31 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 23:21 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 15:51 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 00:38 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2017-01-26 19:11 +0000
    Re: gcc needs a curly bracket matching/counting function mark.bluemel@gmail.com - 2016-12-20 00:50 -0800
  gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-19 18:11 -0800
    Re: gcc needs a curly bracket matching/counting function fir <profesor.fir@gmail.com> - 2016-12-20 03:00 -0800
      Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 03:50 -0800
        Re: gcc needs a curly bracket matching/counting function fir <profesor.fir@gmail.com> - 2016-12-20 05:20 -0800
    Re: gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-20 13:46 -0500
      Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 18:59 +0000
      Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 19:02 +0000
        Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 12:13 -0800
          Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 20:25 +0000
      Re: gcc needs a curly bracket matching/counting function Robert Spanjaard <spamtrap@arumes.com> - 2016-12-20 20:35 +0100
  Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-20 08:56 +0100
  Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 02:26 -0800
    Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 10:41 +0000
      Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 02:52 -0800
        Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 11:00 +0000
          Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 03:19 -0800
            Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 11:31 +0000
            Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 17:21 +0000
              Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 17:49 +0000
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 12:25 +0100
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-29 01:14 -0800
    Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 09:07 -0800
      Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 17:14 +0000
        Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 09:33 -0800
          Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 17:39 +0000
          Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-20 09:45 -0800
      Re: gcc needs a curly bracket matching/counting function gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-20 17:56 +0000
        Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-20 10:01 -0800
    Re: gcc needs a curly bracket matching/counting function Ian Collins <ian-news@hotmail.com> - 2016-12-21 07:44 +1300
  Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 10:46 +0000
  Re: gcc needs a curly bracket matching/counting function Ike Naar <ike@iceland.freeshell.org> - 2016-12-20 22:00 +0000
    Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:39 -0800
  Re: gcc needs a curly bracket matching/counting function Ken Brody <kenbrody@spamcop.net> - 2016-12-22 12:12 -0500
  Re: gcc needs a curly bracket matching/counting function Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-12-22 12:59 -0700
  Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:10 -0800

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