#!/usr/local/bin/perl -w

use Benchmark;

@long = ('a' x 100, 45);
@short = ('a' x 10, 7);

timethese( -10, {
                 L_ariels => sub { ariels(@long) },
                 L_merlyn => sub { merlyn(@long) },
                 L_nashdj => sub { nashdj(@long) },
                 S_ariels => sub { ariels(@short) },
                 S_merlyn => sub { merlyn(@short) },
                 S_nashdj => sub { nashdj(@short) },
                }
          );

sub ariels {
  my ($str, $rot) = @_;
  scalar reverse ((reverse substr($str,0,$rot)) .
                  (reverse substr($str,$rot))
                 );
}
 
sub merlyn {
  my ($str, $rot) = @_;
  substr($str,$rot) . substr($str, 0, $rot);
}
 
sub nashdj {
  my ($str, $rot) = @_;
  $str =~ s/(.{$rot})(.*)/$2$1/s;
  $str;
}