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From: Greg Herlihy on 5 May 2008 00:52
On May 4, 6:18 pm, Ian Collins <ian-n...(a)hotmail.com> wrote:
>
> gcc -Wall -pedantic -ansi basic.c script.c -lm
> basic.c: In function 'dofor':
> basic.c:870: warning: suggest parentheses around && within ||
> basic.c:873: warning: suggest parentheses around assignment used as
> truth value
> basic.c: In function 'getdimvar':
> basic.c:1932: warning: suggest parentheses around assignment used as
> truth value

These warnings are bogus. It is bad form to insert parentheses where
none are needed in an expression. Unnecessary parentheses simply
highlight the fact that the programmer does must know the order in
which the operators will be evaluated - and therefore has to rely on
parentheses to make up for a deficit of knowledge.

Greg

From: Greg Herlihy on 5 May 2008 00:58
On May 4, 6:18 pm, Ian Collins <ian-n...(a)hotmail.com> wrote:
> Richard Heathfield wrote:
> > Ian Collins said:
>
> >> Bartc wrote:
> >>> "Richard Heathfield" <r...(a)see.sig.invalid> wrote in message
> >>>news:lNydndtwTovn1oPVnZ2dnUVZ8rOdnZ2d(a)bt.com...
>
> > <snip>
>
> >>>> Even after dealing with those two issues, however, compilation reports
> >>>> 32 remaining problems with the code.
>
> >>>> Sorry, but I don't have time to wade through them all.
> >>> I tried 3 different compilers in 5 minutes. 2-3 warnings each but all
> >>> generated a working executable. No mods needed.
>
> >> Same here, he must be hallucinating.
>
> > Yes, that must be it. I must be hallucinating. And so, presumably, is gcc.
>
> gcc -Wall -pedantic -ansi basic.c script.c -lm
> basic.c: In function 'dofor':
> basic.c:870: warning: suggest parentheses around && within ||
> basic.c:873: warning: suggest parentheses around assignment used as
> truth value
> basic.c: In function 'getdimvar':
> basic.c:1932: warning: suggest parentheses around assignment used as
> truth value

These warnings are bogus. It is bad form to insert parentheses where
none are needed in an expression. Unnecessary parentheses in an
expression simply highlight the fact that the programmer must not know
the order in which the operators will be evaluated - and therefore has
to rely on parentheses to make up for a deficit in knowledge.

Greg



From: Richard Heathfield on 5 May 2008 01:11
Greg Herlihy said:

> On May 4, 6:18 pm, Ian Collins <ian-n...(a)hotmail.com> wrote:
>>
>> gcc -Wall -pedantic -ansi basic.c script.c -lm
>> basic.c: In function 'dofor':
>> basic.c:870: warning: suggest parentheses around && within ||
>> basic.c:873: warning: suggest parentheses around assignment used as
>> truth value
>> basic.c: In function 'getdimvar':
>> basic.c:1932: warning: suggest parentheses around assignment used as
>> truth value
>
> These warnings are bogus.

Without looking anything up, please parenthesise this line in such a way as
not to change its meaning:

if(stepval < 0 && initval < toval || stepval > 0 && initval > toval)

After you've done that, you can look stuff up to see whether you got it
right. If you did get it right, award yourself a pat on the back, and
consider the fact that not every C programmer is sufficiently skilled to
follow the above expression properly.

> It is bad form to insert parentheses where none are needed in an
> expression.

I tend to agree, but I also think it's bad form to chain ANDs and ORs
together like that. *Either* parenthesise *or* split the line up. For
example:

negstep = stepval < 0 && initval < toval;
posstep = stepval > 0 && initval > toval;
if(negstep || posstep)

The warning (for Malcolm's newbie-scaring if) rightly points up the fact
that the line is badly written and should be fixed. You don't have to take
its advice on /how/ to fix it, but IMHO the fact that the line is being
diagnosed is not bogus at all.

--
Richard Heathfield <http://www.cpax.org.uk>
Email: -http://www. +rjh@
Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
"Usenet is a strange place" - dmr 29 July 1999
From: Malcolm McLean on 5 May 2008 04:31

"Bartc" <bc(a)freeuk.com> wrote in message
>
> * It is very slow (on one brief test, 40x slower than Python, itself not
> known for it's speed)
>
I've got a much faster semi-compiled version. However I haven't released it.
The problem it it is that much more difficult to modify to add your own
functions.
>
> * The language is very primitive, even for Basic.
>
> Has this ever been commented on?
>
Again, you could add procedures, but this creates major complications.

--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm

From: rossum on 5 May 2008 04:58
On Sun, 4 May 2008 21:58:33 -0700 (PDT), Greg Herlihy <greghe(a)mac.com>
wrote:

>On May 4, 6:18�pm, Ian Collins <ian-n...(a)hotmail.com> wrote:
>> Richard Heathfield wrote:
>> > Ian Collins said:
>>
>> >> Bartc wrote:
>> >>> "Richard Heathfield" <r...(a)see.sig.invalid> wrote in message
>> >>>news:lNydndtwTovn1oPVnZ2dnUVZ8rOdnZ2d(a)bt.com...
>>
>> > <snip>
>>
>> >>>> Even after dealing with those two issues, however, compilation reports
>> >>>> 32 remaining problems with the code.
>>
>> >>>> Sorry, but I don't have time to wade through them all.
>> >>> I tried 3 different compilers in 5 minutes. 2-3 warnings each but all
>> >>> generated a working executable. No mods needed.
>>
>> >> Same here, he must be hallucinating.
>>
>> > Yes, that must be it. I must be hallucinating. And so, presumably, is gcc.
>>
>> gcc -Wall -pedantic -ansi basic.c script.c -lm
>> basic.c: In function 'dofor':
>> basic.c:870: warning: suggest parentheses around && within ||
>> basic.c:873: warning: suggest parentheses around assignment used as
>> truth value
>> basic.c: In function 'getdimvar':
>> basic.c:1932: warning: suggest parentheses around assignment used as
>> truth value
>
>These warnings are bogus. It is bad form to insert parentheses where
>none are needed in an expression. Unnecessary parentheses in an
>expression simply highlight the fact that the programmer must not know
>the order in which the operators will be evaluated - and therefore has
>to rely on parentheses to make up for a deficit in knowledge.
Or alternatively the programmer has decided to make life easier for
the undertrained maintenance programmers who will follow her in
maintaining the code. A few extra parentheses can make code clearer
and easier to maintain.

rossum


>Greg
>
>

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