NAME

Moose::Cookbook::Snack::Keywords - Restricted "keywords" in Moose

DESCRIPTION

Moose exports a number of sugar functions in order to emulate Perl built-in keywords. These can cause clashes with other user-defined functions. This document provides a list of those keywords for easy reference.

The 'meta' keyword

While most collisions can be avoided, you cannot avoid importing a meta method when you use Moose. If you try to override or change what meta does, you could end up breaking Moose internals.

Moose Keywords

If you are using Moose or Moose::Role its best to avoid these keywords:

extends
with
has
before
after
around
super
override
inner
augment
confess
blessed

Moose::Util::TypeConstraints Keywords

If you are using Moose::Util::TypeConstraints its best to avoid these keywords

type
subtype
class_type
role_type
maybe_type
as
where
message
optimize_as
coerce
from
via
enum
find_type_constraint
register_type_constraint

Avoiding collisions

Turning off Moose

To remove the sugar functions Moose exports just add no Moose at the bottom of your code:

  package Thing;
  use Moose;

  # code here

  no Moose;

This will unexport the sugar functions that Moose originally exported. The same will also work for Moose::Role and Moose::Util::TypeConstraints.

Sub::Exporter features

Moose, Moose::Role and Moose::Util::TypeConstraints all use Sub::Exporter to handle all their exporting needs. This means that all the features that Sub::Exporter provides are also available to them.

For instance, with Sub::Exporter you can rename keywords, like so:

  package LOL::Cat;
  use Moose 'has' => { -as => 'i_can_haz' };

  i_can_haz 'cheeseburger' => (
      is      => 'rw',
      trigger => sub { print "NOM NOM" }
  );

  LOL::Cat->new->cheeseburger('KTHNXBYE');

See the Sub::Exporter docs for more information.

namespace::clean

You can also use namespace::clean to clean up your namespace, but you must be careful not to remove meta when doing so:

  package Foo;
  use Moose;
  use namespace::clean -except => 'meta';
  # ...

AUTHOR

John Goulah <jgoulah@cpan.org<gt>

Stevan Little <stevan@iinteractive.com>

COPYRIGHT AND LICENSE

http://www.iinteractive.com

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

CPAN RT