NAME

       Sort::Key::Register - tell Sort::Key how to sort new data types.

SYNOPSIS

         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;

DESCRIPTION

       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';

   USAGE
       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).

SEE ALSO

       Sort::Key, Sort::Key::Maker.

AUTHOR

       Salvador Fandiño, <sfandino@yahoo.com>

COPYRIGHT AND LICENSE

       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.