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From: James Kanze on 30 Apr 2010 21:21
On Apr 25, 8:02 am, Juha Nieminen <nos...(a)thanks.invalid> wrote:
> In comp.lang.c++ red floyd <no.spam.h...(a)its.invalid> wrote:

> > As a purely stylistic matter, my empty loops always look like:

> > for ( begin_expr; test_expr; next_expr)
> > /* do nothing */ ;

> No, the proper way of writing an empty loop is:

> for(begin_expr; test_expr; next_expr) {}

> The empty block makes it explicitly clear that it's intended
> to be empty, and not just a typo. (The empty block could also
> be put in the next line, below the 'for', if so desired. A
> matter of style.)

I'd argue that it's more than just a question of style. What
the loop controls is on a line (or lines) after the loop, and if
it controls nothing, there should be a line which is clearly
"nothing". Either:
for (begin_expr; test_expr; next_expr)
;
or
for (begin_expr; test_expr; next_expr) {
}
(or whatever your coding guideline says with regards to the
placement of the braces).

--
James Kanze
From: James Kanze on 30 Apr 2010 21:26
On Apr 28, 8:26 am, Nick Keighley <nick_keighley_nos...(a)hotmail.com>
wrote:
> On 25 Apr, 08:02, Juha Nieminen <nos...(a)thanks.invalid> wrote:

[...]
> > The empty block makes it explicitly clear that it's intended to be empty,
> > and not just a typo. (The empty block could also be put in the next line,
> > below the 'for', if so desired. A matter of style.)

> for (begin_expr; test_expr; next_expr)
> ;

> is my usual form. And I cam across this and was taken with it

> for (begin_expr; test_expr; next_expr)
> continue;

> (the place I'd comtemplate a continue)

I'll bet the programmer who invented that one was an
ex-Fortran'er.

--
James Kanze
From: Sjouke Burry on 30 Apr 2010 21:57
James Kanze wrote:
> On Apr 28, 8:26 am, Nick Keighley <nick_keighley_nos...(a)hotmail.com>
> wrote:
>> On 25 Apr, 08:02, Juha Nieminen <nos...(a)thanks.invalid> wrote:
>
> [...]
>>> The empty block makes it explicitly clear that it's intended to be empty,
>>> and not just a typo. (The empty block could also be put in the next line,
>>> below the 'for', if so desired. A matter of style.)
>
>> for (begin_expr; test_expr; next_expr)
>> ;
>
>> is my usual form. And I cam across this and was taken with it
>
>> for (begin_expr; test_expr; next_expr)
>> continue;
>
>> (the place I'd comtemplate a continue)
>
> I'll bet the programmer who invented that one was an
> ex-Fortran'er.
>
> --
> James Kanze
Fortran uses cycle to get to the end of a loop.
From: Moi on 1 May 2010 04:24
On Wed, 28 Apr 2010 05:18:41 +1000, Lie Ryan wrote:

> On 04/25/10 16:19, red floyd wrote:
>> On 4/24/2010 5:54 PM, Andrew Poelstra wrote:
>>
>>> The alternative here, using the loop structure, would be:
>>>
>>> for(i = 0; i< 10&& arr[i].state != READY; ++i)
>>> ;
>>> /* now use arr[i], or if i is 10, indicate failure. */
>>>
>>>
>> As a purely stylistic matter, my empty loops always look like:
>>
>>
>> for ( begin_expr; test_expr; next_expr)
>> /* do nothing */ ;
>>
>> That is, I always explicitly comment the empty loop so that it's clear
>> that I wanted the loop to be empty.
>>
>>
> Stylistically, I would put an empty { } to the side, containing a single
> space:
>
> for ( begin_expr; test_expr; next_expr) { }
>
> instead of semicolons. Most brace-language programmer would
> unconsciously filter out semicolons from the end of lines, while { } is
> much more visible since it's more unusual to open a block only to close
> it again.

Personally I tend to use:

for ( begin_expr; test_expr; next_expr) {;}

, which immediately makes clear that the empty loop is intended.

AvK
From: Phil Carmody on 1 May 2010 05:49
James Kanze <james.kanze(a)gmail.com> writes:
> On Apr 25, 8:02 am, Juha Nieminen <nos...(a)thanks.invalid> wrote:
>> In comp.lang.c++ red floyd <no.spam.h...(a)its.invalid> wrote:
>
>> > As a purely stylistic matter, my empty loops always look like:
>
>> > for ( begin_expr; test_expr; next_expr)
>> > /* do nothing */ ;
>
>> No, the proper way of writing an empty loop is:
>
>> for(begin_expr; test_expr; next_expr) {}
>
>> The empty block makes it explicitly clear that it's intended
>> to be empty, and not just a typo. (The empty block could also
>> be put in the next line, below the 'for', if so desired. A
>> matter of style.)
>
> I'd argue that it's more than just a question of style. What
> the loop controls is on a line (or lines) after the loop,

Bollocks. What the loop controls is the statement that follows
it. (Or in the case of a do-while, the statement between the do
and the while.) By the time the C parser is interpreting the
loop construct, there's no such thing as a 'line'.

You're addressing _nothing_ but style, stop pretending otherwise.

However, thanks for making me peek into the documentation itself,
I've discovered a horribly misleading sentence in the standard,
so shall propose a correction.

Phil
--
I find the easiest thing to do is to k/f myself and just troll away
-- David Melville on r.a.s.f1
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