Re^3: my $a outside sort block incompatibility

Of course you need to use the appropriate package variables. That said, I recind my suggestion in favour of the OPs use of our.

Not because of any problem with the use of qualified package vars, but because against my expectations, it runs far more quickly. Indeed, unless someone can show me the flaw in my benchmark, I'll be explicitly including our( $a, $b) in all my sorts from now on:

#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

cmpthese -10, {
    "\$a<=>\$b"     => q[my @a = sort{                $b <=> $a   } 1 
+.. 1e6;],
    "\$::a<=>\$::b" => q[my @a = sort{              $::b <=> $::a } 1 
+.. 1e6;],
    "our(\$a,\$b)"  => q[my @a = sort{ our( $a, $b ); $b <=> $a   } 1 
+.. 1e6;],
};

__END__
C:\test>junk2.pl
            s/iter $::a<=>$::b     $a<=>$b  our($a,$b)
$::a<=>$::b   2.09          --         -0%        -77%
$a<=>$b       2.08          0%          --        -77%
our($a,$b)   0.469        344%        343%          --
[download]

UPDATE: I guess it really is time to upgrade. Under 5.10 I get much closer to what I expected:

              Rate  our($a,$b)     $a<=>$b $::a<=>$::b
our($a,$b)  1.75/s          --        -46%        -46%
$a<=>$b     3.24/s         85%          --         -0%
$::a<=>$::b 3.24/s         86%          0%          --
[download]

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Re^4: my $a outside sort block incompatibility by tilly (Archbishop) on Feb 21, 2009 at 15:34 UTC
Interesting. I would assume that is because it is more efficient to access a lexical than a package variable.	[reply]
Re^4: my $a outside sort block incompatibility by massa (Hermit) on Feb 21, 2009 at 17:28 UTC
you know you can `sort { our $a <=> our $b } @x`, huh? :-) IMHO it's prettier... []s, HTH, Massa (κς,πμ,πλ)	[reply] [d/l]