I know that it is well-known that tr is faster than m//, nevertheless I thought I write my first Benchmark.pm-using, aehmm, well, benchmark :-) 

#!/usr/bin/perl -w

use strict;
use Benchmark qw(:all);

my @rands = qw (A---B-B---B---D----F----G----H----J----K-----L---F-D--
+F---G--H---_R_-f-F-ff-----f
    ----F----G--
    ----F----G------F----G------F----G--
    ----F----G------F----G------F----G------F----G--
    ----F----G------F----G------F----G------F----G-----F----G---
    ----F----G-----F----G---
    ----F----G------F----G------F----G--);

my $max = @rands;

cmpthese(1000000, {
        'tr' => sub {
                $_ = $rands[int(rand($max))];
                my $x = tr/-//;
        },
        'm//' => sub {
                $_ = $rands[int(rand($max))];
                my $x = () = $_ =~ /-/g;
        },
    }
);

[download]

I'd be glad to hear if I did something considerably stupid here :-), under this proviso the (well known!) results: 

__END__
Benchmark: timing 1000000 iterations of m//, tr...
       m//: 57 wallclock secs (54.53 usr +  0.07 sys = 54.60 CPU) @ 18
+315.02/s (n=1000000)
        tr:  1 wallclock secs ( 1.92 usr +  0.00 sys =  1.92 CPU) @ 52
+0833.33/s (n=1000000)
        Rate   m//    tr
m//  18315/s    --  -96%
tr  520833/s 2744%    --

[download]

Quite impressive difference, isn't it?

regards,
tomte

In reply to Re: counting regex hits Benchamark by Tomte
in thread counting regex hits by Becky

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