gistfile1.txt

#!/usr/bin/perl

use Benchmark qw( cmpthese );
 
sub nostcmp {
    my ($a_char, $a_num) = split '_', $a;
    my ($b_char, $b_num) = split '_', $b;
    return $a_char cmp $b_char
             ||
        $a_num <=> $b_num;
}

sub nost {
   return sort nostcmp @_;
}
 
sub st {
    return
       map $_->[0],
        sort { $a->[1] cmp $b->[1] || $a->[2] <=> $b->[2] }
         map [ $_, split /_/ ],
          @_;
}


my %tests = (
   nost => 'my @sorted = nost(@list);',
   st   => 'my @sorted = st(@list);',
);


$_ = 'use strict; use warnings; our @list; ' . $_
   for values %tests;

{
   local our @list = qw(B_5 A_11 C_0 A_10 A_1);
   cmpthese(-3, \%tests);
}

{
   local our @list = qw(B_5 A_11 C_0 A_10 A_1);
   @lists = (@lists)x100;
   cmpthese(-3, \%tests);
}

__END__
        Rate   st nost
st   92589/s   --  -7%
nost 99653/s   8%   --

        Rate   st nost
st   93349/s   --  -6%
nost 99817/s   7%   --