#!/usr/bin/perl

use Benchmark 'cmpthese';
use warnings;

@array = (  'a'..'z' );
$value = 'z';
my $res;
my $position;

print "for(): ".traditional()."\tforeach: ".for_each()."\tmap: ".maptohash()."\n";

cmpthese ( 10000, { for_loop =>  '$res = traditional()',
                         map => '$res = maptohash()',
                    for_each => '$res = for_each()',
                  }
 );

sub traditional{
    for ($position=0; $position <= $#array; $position++) {
        last if ($array[$position] eq $value);
    }
    return $position;
}

sub for_each{
    for our $position ( 0..$#array ) {
         last if ($array[$position] eq $value) ;
    }
    return $position;
}

sub maptohash{
    %indexed = map{ $array[$_], $_ } (0..$#array);
    return $indexed{$value};
}

 %perl foo.pl                                   [7:41pm]
for(): 25       foreach: 25     map: 25
            Rate      map for_loop for_each
map       5100/s       --     -40%     -72%
for_loop  8477/s      66%       --     -53%
for_each 18028/s     254%     113%       --