#!/usr/bin/perl
                                                           
use strict;
use warnings;

use Benchmark qw/timethese cmpthese/;
   
my @letters = ('A' .. 'Z', 'a' .. 'z');
   
my $size  = 1_000;
my $max_l = 1_000;

my @array = map {join "" => map {$letters [rand @letters]} 1 .. 1 + rand $max_l}
                                                           1 .. $size;
        
my (@st_sorted, @simple_sorted, @grt_sorted);
 
cmpthese -10 => {
   Schwartzian  => \&sort_schwartzian,
   Simple       => \&sort_simple,
   GRT          => \&sort_grt,
};

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

sub sort_simple { 
    @simple_sorted = sort {uc ($a) cmp uc ($b)} @array;
}
                                                           
sub sort_grt {
    @grt_sorted =
        map {substr $_ => $max_l}
        sort
        map {uc () . ("\0" x ($max_l - length)) . $_} @array;
}
   
die "Unequal" unless "@st_sorted" eq "@simple_sorted" &&
                     "@st_sorted" eq "@grt_sorted";
__END__
              Rate      Simple Schwartzian         GRT
Simple      8.99/s          --        -78%        -81%
Schwartzian 40.7/s        353%          --        -15%
GRT         48.2/s        436%         18%          --