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



NAME

Moose::Cookbook::Snack::Keywords - Restricted ``keywords'' in Moose


VERSION

version 2.1605


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

use Moose adds a method called meta to your class. If this conflicts with a method or function you are using, you can rename it, or prevent it from being installed entirely. To do this, pass the -meta_name option when you use Moose. For instance:

  # install it under a different name
  use Moose -meta_name => 'moose_meta';
  # don't install it at all
  use Moose -meta_name => undef;

Moose Keywords

If you are using Moose or the Moose::Role manpage it is best to avoid these keywords:

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

Moose::Util::TypeConstraints Keywords

If you are using the Moose::Util::TypeConstraints manpage it is best to avoid these keywords:

type
subtype
class_type
role_type
maybe_type
duck_type
as
where
message
inline_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 the Moose::Role manpage and the Moose::Util::TypeConstraints manpage.

Sub::Exporter features

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

For instance, with the Sub::Exporter manpage 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 the Sub::Exporter manpage docs for more information.

namespace::autoclean and namespace::clean

You can also use the namespace::autoclean manpage to clean up your namespace. This will remove all imported functions from your namespace. Note that if you are importing functions that are intended to be used as methods (this includes the overload manpage, due to internal implementation details), it will remove these as well.

Another option is to use the namespace::clean manpage directly, but you must be careful not to remove meta when doing so:

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


SEE ALSO

Moose
the Moose::Role manpage
the Moose::Util::TypeConstraints manpage
the Sub::Exporter manpage
the namespace::autoclean manpage
the namespace::clean manpage


AUTHORS


COPYRIGHT AND LICENSE

This software is copyright (c) 2006 by Infinity Interactive, Inc.

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

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