Benchmarking with a deck of 13.
              Rate     roger coruscate    fisher   fisher2      list
roger      18931/s        --       -0%       -4%      -21%      -85%
coruscate  18959/s        0%        --       -4%      -20%      -85%
fisher     19747/s        4%        4%        --      -17%      -85%
fisher2    23821/s       26%       26%       21%        --      -82%
list      129419/s      584%      583%      555%      443%        --
Benchmarking with a deck of 52.
             Rate    fisher     roger coruscate   fisher2      list
fisher     4917/s        --       -2%       -3%      -18%      -85%
roger      5021/s        2%        --       -1%      -17%      -85%
coruscate  5062/s        3%        1%        --      -16%      -85%
fisher2    6031/s       23%       20%       19%        --      -82%
list      33210/s      575%      561%      556%      451%        --
Benchmarking with a deck of 1024.
            Rate coruscate    fisher     roger   fisher2      list
coruscate  246/s        --       -2%       -6%      -21%      -86%
fisher     251/s        2%        --       -4%      -19%      -86%
roger      261/s        6%        4%        --      -16%      -85%
fisher2    310/s       26%       23%       19%        --      -82%
list      1767/s      619%      603%      577%      471%        --
Benchmarking with a deck of 50000.
             Rate coruscate    fisher     roger   fisher2      list
coruscate 0.909/s        --      -72%      -73%      -85%      -94%
fisher     3.19/s      251%        --       -7%      -47%      -78%
roger      3.43/s      277%        7%        --      -43%      -76%
fisher2    6.03/s      563%       89%       76%        --      -58%
list       14.3/s     1474%      349%      318%      137%        --


#!/usr/bin/perl

use strict;
use warnings;

use List::Util;
use Benchmark qw /timethese cmpthese/;

our (@cards, @cards2, @tmp);

foreach my $size (qw /13 52 1024 50000/) {

    @cards  = 1 .. $size;
    @cards2 = 1 .. $size;

    print "Benchmarking with a deck of $size.\n";

    cmpthese -10   => {
        roger      =>  '@tmp = roger               @cards',
        coruscate  =>  '@tmp = coruscate           @cards',
        fisher     =>  '@tmp = fisher              @cards',
        fisher2    =>  '       fisher2            \@cards2',
        list       =>  '@tmp = List::Util::shuffle @cards',
    };

}


sub roger {
    my @new = ();

    for (@_) {
        my $i = int rand($#new+1);
        push @new, $new[$i];
        $new[$i] = $_;
    };

    return(@new);
}

sub coruscate {
  my @orig_deck = @_;
  my @new_deck;

  for (0 .. $#orig_deck) {
    my $rand = int(rand $#orig_deck);
    push @new_deck, splice(@orig_deck, $rand, 1);
  }

  return @new_deck;
}
        
        
sub fisher {
    my $i = my @deck = @_;
    while (-- $i) {
        my $j = int rand ($i + 1);
        @deck [$i, $j] = @deck [$j, $i];
    }
    @deck;
}
    

sub fisher2 { 
    my $deck = shift;
    my $i    = @$deck;
    while (-- $i) {   
        my $j = int rand ($i + 1);
        @$deck [$i, $j] = @$deck [$j, $i];
    }
}
__END__