Mouse::Role(3pm)

1Mouse::Role(3)        User Contributed Perl Documentation       Mouse::Role(3)
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NAME

6       Mouse::Role - The Mouse Role
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VERSION

9       This document describes Mouse version v2.5.10
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SYNOPSIS

12           package Comparable;
13           use Mouse::Role; # the package is now a Mouse role
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15           # Declare methods that are required by this role
16           requires qw(compare);
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18           # Define methods this role provides
19           sub equals {
20               my($self, $other) = @_;
21               return $self->compare($other) == 0;
22           }
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24           # and later
25           package MyObject;
26           use Mouse;
27           with qw(Comparable); # Now MyObject can equals()
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29           sub compare {
30               # ...
31           }
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33           my $foo = MyObject->new();
34           my $bar = MyObject->new();
35           $obj->equals($bar); # yes, it is comparable
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DESCRIPTION

38       This module declares the caller class to be a Mouse role.
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40       The concept of roles is documented in Moose::Manual::Roles.  This
41       document serves as API documentation.
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EXPORTED FUNCTIONS

44       Mouse::Role supports all of the functions that Mouse exports, but
45       differs slightly in how some items are handled (see "CAVEATS" below for
46       details).
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48       Mouse::Role also offers two role-specific keywords:
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50   "requires(@method_names)"
51       Roles can require that certain methods are implemented by any class
52       which "does" the role.
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54       Note that attribute accessors also count as methods for the purposes of
55       satisfying the requirements of a role.
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57   "excludes(@role_names)"
58       This is exported but not implemented in Mouse.
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IMPORT AND UNIMPORT

61   import
62       Importing Mouse::Role will give you sugar. "-traits" are also
63       supported.
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65   unimport
66       Please unimport ("no Mouse::Role") so that if someone calls one of the
67       keywords (such as "has") it will break loudly instead breaking subtly.
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CAVEATS

70       Role support has only a few caveats:
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72       •   Roles cannot use the "extends" keyword; it will throw an exception
73           for now.  The same is true of the "augment" and "inner" keywords
74           (not sure those really make sense for roles). All other Mouse
75           keywords will be deferred so that they can be applied to the
76           consuming class.
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78       •   Role composition does its best to not be order-sensitive when it
79           comes to conflict resolution and requirements detection. However,
80           it is order-sensitive when it comes to method modifiers. All
81           before/around/after modifiers are included whenever a role is
82           composed into a class, and then applied in the order in which the
83           roles are used. This also means that there is no conflict for
84           before/around/after modifiers.
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86           In most cases, this will be a non-issue; however, it is something
87           to keep in mind when using method modifiers in a role. You should
88           never assume any ordering.
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