On Sep 8, 2006, at 6:48 PM, A. Pagaltzis wrote:
* Chris Dolan <[EMAIL PROTECTED]> [2006-09-08 17:10]:
Why did you use "local"? Shouldn't the following work?
sub flatten_copy {
my $s = shift;
ref $s eq 'SCALAR' ? "$$s" : "$s";
}
Works the same. I often use `local $_` in tiny functions that
mangle just a single value. Matter of taste/style.
Ahh, I see -- cargo cult. ;-)
Changing the topic a little bit... I've always suspected there was a
speed difference between local and my. So, I just benchmarked the
two versions, and "my" wins by a wide margin:
% perl test.pl
Rate local my
local 467290/s -- -33%
my 699301/s 50% --
% perl -v
This is perl, v5.8.6 built for darwin-thread-multi-2level
(with 2 registered patches, see perl -V for more detail)
============= test.pl ==============
#!/usr/bin/perl -w
use strict;
use Benchmark qw(cmpthese);
my $s = 'foo';
$_ = 'foo';
cmpthese(1_000_000, {
'local' => sub {
flatten_copy_local('bar');
},
'my' => sub {
flatten_copy_my('bar');
},
});
sub flatten_copy_local {
local $_ = shift;
ref $_ eq 'SCALAR' ? "$$_" : "$_";
}
sub flatten_copy_my {
my $s = shift;
ref $s eq 'SCALAR' ? "$$s" : "$s";
}
========================================
--
Chris Dolan, Software Developer, Clotho Advanced Media Inc.
608-294-7900, fax 294-7025, 1435 E Main St, Madison WI 53703
vCard: http://www.chrisdolan.net/ChrisDolan.vcf
Clotho Advanced Media, Inc. - Creators of MediaLandscape Software
(http://www.media-landscape.com/) and partners in the revolutionary
Croquet project (http://www.opencroquet.org/)
