use strict;
use Data::Dumper;
use Benchmark qw/timethese cmpthese/;

my @letters = 'A'..'Z';
my @array;

# generate array of 1000 random length random upper/lower
# case strings to feed into the test subs.
foreach (0..1000) {
    my $c = $letters [rand 26];
    $c = int(rand 2) ? uc $c : lc $c;
    push @array, $c x (1 + rand 10);
}

cmpthese( timethese(1000, {
        'Schwartzian' => '&sort_schwartzian',
        'Simple' => '&sort_simple',
    }) );

sub sort_schwartzian
{
    my @sorted =
        map { $_->[0] }
        sort { $a->[1] cmp $b->[1] }
        map { [ $_, uc $_ ] } @array;
}

sub sort_simple
{
    my @sorted = sort { uc($a) cmp uc($b) } @array;
}

##</code><code>##

Benchmark: timing 1000 iterations of Schwartzian, Simple...
Schwartzian: 16 wallclock secs (16.39 CPU) @ 61.01/s (n=1000)
    Simple: 11 wallclock secs (10.95 CPU) @ 91.32/s (n=1000)
              Rate Schwartzian      Simple
Schwartzian 61.0/s          --        -33%
Simple      91.3/s         50%          --