sub sort_em {
  my $src = shift;
  return {
           up => sub { $src->{$a} <=> $src->{$b} },
           down => sub { $src->{$b} <=> $src->{$a} },
         }
}

my %numbers = ( qw( a 5 c 4 d 1 ) );
my $num_sorts = sort_em( \%numbers );

print "UP:\n",
      join( "\n", map { "$_ $numbers{$_}" }
		  sort { $num_sorts->{up}->() } keys %numbers ),
      "\nDOWN\n",
      join( "\n", map { "$_ $numbers{$_}" }
	              sort { $num_sorts->{down}->() } keys %numbers ),
      "\n";