#!/usr/bin/perl
# regindbench - which is faster, regexp for fixed text patterns or index()?

use strict;
use Benchmark qw/:all/;

sub random { int rand shift }
my @letters=('A'..'Z');
my $nLetters=scalar @letters;
my $text=join('',map { $letters[random($nLetters)] } 0..9999);    # 10,000 chars
my ($pat,@pats);
map {
   do {
      $pat=join('',map { $letters[random($nLetters)] } 0..4);  # 5 char patterns
   } until index($text,$pat)==-1;    # which never match
   push @pats,$pat;
} 0..99;

sub via_regexp {
   map { die "via_regexp $_ found\n" if $text=~/$_/ } @pats;
}

sub via_index {
   map { die "via_index $_ found\n" if index($text,$_)>-1 } @pats;
}

cmpthese(100000,{regexp=>\&via_regexp,index=>\&via_index});

exit;

__END__

Perl 5.8.8 using

100000 iterations on a 3 GHz 64-bit Intel QuadCore
running Fedora Core 7 (6000 bogomips per core)

        Rate  index regexp
index  370/s     --   -47%
regexp 695/s    88%     --