Re: non-scalar hash key

pack is a bit faster than join:

use strict;
use warnings;
use Benchmark qw(:all) ;

my @foo = qw/1 2 3 4 5 6/;
my %bar = (pack('b', @foo) => 'elephants');

my @baz = qw/1 2 3 4 5 6/;

print $bar{pack('b', @baz)} . "\n";

cmpthese(-5, {
    'join' => sub { join('', qw/1 2 3 4 5 6/) },
    'pack' => sub { pack('b', qw/1 2 3 4 5 6/) },
});
[download]

prints:

% perl test.pl
elephants
          Rate join pack
join 1002841/s   -- -53%
pack 2119814/s 111%   --
%
[download]

Comment on Re: non-scalar hash key Select or Download Code

Replies are listed 'Best First'.
Re^2: non-scalar hash key by tweetiepooh (Hermit) on Jun 17, 2009 at 16:14 UTC
Nice but not in the gold `use strict; use warnings; use Benchmark qw(:all) ; my @foo = qw/1 2 3 4 5 6/; my %bar = (pack('b', @foo) => 'elephants'); my @baz = qw/1 a 4 6 7/; print $bar{pack('b', @baz)} . "\n";` [download] Also outputs "elephants".	[reply] [d/l]
Re^3: non-scalar hash key by Arunbear (Prior) on Jun 18, 2009 at 10:05 UTC
True, and it is fixed by the "L*" template mentioned in Re^2: non-scalar hash key	[reply]
Re^2: non-scalar hash key by kdejonghe (Novice) on Jun 17, 2009 at 13:06 UTC
It is indeed. Thank you very much. I pack as follows though: `my $p = pack('L*', @$pa);` [download] because it's an integer array. I also think it uses less memory. But that I still have test. Thanks again. Seems like this is the only thing to do apart from implementing my own hash algorithm.	[reply] [d/l]