On Tue, Jul 31, 2001 at 04:00:44PM +0200, Marc A. Lehmann wrote:
> Optimizing sort in this manner to gain speed is IMHO a very bad idea, as
> this optimizes sort but leaves all other functions unoptimized.
Abigail already corrected the mislogic here...
Anyhow, you should get a fairly large increase in both memory and
performance with a good inplace sort over large lists. $a and $b are
aliases, not copies (AFAIK) but Perl has to go and allocate all the
extra memory to make a new array and copies of each scalar to return
from sort() and that eats time and memory.
> The only advantage I'd see is that inplace sort is shorter to write (which
> would be in the spirit of perl), but I think the nasty consequences of not
> being able to do in-place sorts everywhere:
>
> sub test {
> if (xxx) {
> sort inplace; # how do I do that?
> }
> (); # by adding smileys???
> }
>
> without very strange syntax. And it doesn't look very perl'ish as well.
This is the kind of thing I was worried about. Of course, it can be
gotten around fairly simply:
use constant NOTHING => undef;
sub foo {
if( xxx ) {
sort inplace;
}
return NOTHING;
}
so rather than simply falling off the end of the function you can put
an explicit return statement in. I usually remember to do this, but
it's not as common an idiom as it should be.
--
Michael G. Schwern <[EMAIL PROTECTED]> http://www.pobox.com/~schwern/
Perl6 Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Nature is pissed.
http://www.unamerican.com/
