my %sorts = (
    'case sensitive forward'             => sub { $_[0] cmp $_[1] },
    'case insensitive forward'           => sub { uc $_[0] cmp uc $_[1
+] },
    'case sensitive backward'            => sub { $_[1] cmp $_[0] },
    'case insensitive backward'          => sub { uc $_[1] cmp uc $_[0
+] },
    'case sensitive forward reverse'     => sub { reverse($_[0]) cmp r
+everse($_[1]) },
    'case insensitive forward reverse'   => sub { uc reverse($_[0]) cm
+p uc reverse($_[1]) },
    'case sensitive backward reverse'    => sub { reverse($_[1]) cmp r
+everse($_[0]) },
    'case insensitive backward reverse'  => sub { uc reverse($_[1]) cm
+p uc reverse($_[0]) },
  );

# 5.10+ only
#sub do_sorts { 
#   state %cache; 
#   my $res = $cache{$_[0], $_[1]};
#   return if defined($res);
#   foreach my $sort (@{$_[2]}) { 
#     $res ||= $sorts{$sort}->(@_) 
#   } 
#   $cache{$_[0], $_[1]} = $res 
#}
{
   my %cache;
   sub do_sorts { 
     my ($first, $second, @sort_list) = @_;
     my $res = $cache{$first, $second};
     return $res if defined($res);
     foreach my $sort (@sort_list) { 
       $res ||= $sorts{$sort}->($first, $second);
       last if $res
     } 
     $cache{$first, $second} = $res 
  }
}

my @list = qw(foo Bar baz Fuzz);

print join(', ', sort { do_sorts($a,$b,('case sensitive forward revers
+e')) } @list)."\n";
[download]