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



my $test = shift;

my $sort = {
    'numbers' => sub { $_[0] <=> $_[1] },
    'letters' => sub { "$_[0]" cmp "$_[1]" },
};

my @test = qw/1 2 3 4 a b 0 10 9 100/;

print sort {$sort->{$test}->($a,$b)} @test;