Re: sparse (static analyzer) report

Am Samstag, 15. Januar 2005 21:38 schrieb Bruno Wolff III:
> On Sat, Jan 15, 2005 at 10:44:48 -0500,
>
> Greg Stark <gsstark(at)mit(dot)edu> wrote:
> > What I miss most in both C and Java is the lispish ability to write
> > expressions like:
> >
> > foo = bar() || baz() || qux();
>
> Are you sure that C doesn't guarenty short circuit evaluation?
> I don't have my C reference handy, but my memory is that evaluation
> will stop after the first function call that returns true in the
> above expression.
>
C do guaranty short circuit evaluation.

You can also write:

(foo = bar()) || (foo = baz()) || (foo = qux())

this is a valid shortcut, where bar(), baz() and qux() are not evaluated
twice, like in the if-cascade. But it is a ugly style every stylechecker
should have no problems complaining about. Even a compiler would warn about
'=' and '=='-confusion. But you can fix it:

(foo = bar()) != NULL || (foo = baz()) != NULL || foo = qux()) != NULL;

It's short, but not quite that readable.

Tommi