Sort::Key::Register(3) tell Sort::Key how to sort new data types.


use Sort::Key::Register Person =>
sub { $_->surname, $_->name },
qw(string string);
use Sort::Key::Register 'Color::Component' => 'integer';
use Sort::Key::Register Color =>
sub { $_->R, $_->G, $_->B },
('Color::Component') x 3;


Sort::Key::Register allows one to register new data types with Sort::Key so that they can be sorted as natively supported ones.

It works as a pragma module and doesn't export any function, all its functionality is provided via "use":

  use Sort::Key::Register ...

To avoid collisions between modules registering types with the same name, you should qualify them with the package name.

  use Sort::Key::Register 'MyPkg::foo' => sub { $_ }, '-int';
  # or using __PACKAGE__:
  use Sort::Key::Register __PACKAGE__, sub { $_ }, '-int';


use Sort::Key::Register $name => \&multikeygen, @keytypes;
registers type $name.

&multikeygen is the multi-key extraction function for the type and @keytypes are the types of the extracted keys.

use Sort::Key::Register $name => $keytype;
this 'use' is useful for simple types that are sorted as another type already registered, maybe changing the direction of the sort (ascending or descending).


Salvador Fandiño, <[email protected]>


Copyright (C) 2005, 2014 by Salvador Fandiño

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.4 or, at your option, any later version of Perl 5 you may have available.