use strict;
use warnings;
use Benchmark qw(cmpthese);

cmpthese(
	100000,
	{
		'ahash' => sub {
			my $pat = {qw(a - b = c ~ d ^)}->{substr($0, 0, 1)};
		}, 
		'tr'    => sub {
			(my $pat = substr($0, 0, 1)) =~ tr/abcd/-=~^/;
		},
	},
);