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MRO::Define - Define your own method resolution order


    # define your mro
    use mro;
    use MRO::Define;
    MRO::Define::register_mro(your_mro => sub { ... });

    # use your mro somewhere else
    use mro 'your_mro';


With recent versions of perl it is possible to change the method resolution order (mro) of a given class either by using use mro as shown in the synopsis, or by using the mro::set_mro.

Perl itself comes with two MROs by default. The traditional Perl default MRO (depth first search, DFS) and C3 MRO.

This module allows you to define custom method resolution orders in addition to those perl already has.


register_mro ($name, $resolve_callback)

This function allows registering of custom method resolution orders. Your MRO needs to have a $name as well as a $resolve_callback that will get invoked when a method trying to be resolved using your MRO. The resolve callback is expected to return an array reference of package names that will be used for the method lookup.


Florian Ragwitz <>


This software is copyright (c) 2013 by Florian Ragwitz.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.