7 use Scalar::Util 'blessed';
9 use Sub::Name 'subname';
14 our $VERSION = '0.08';
15 our $AUTHORITY = 'cpan:STEVAN';
20 use Moose::Meta::Role;
21 use Moose::Util::TypeConstraints;
24 my ( $CALLER, %METAS );
29 return $METAS{$role} if exists $METAS{$role};
31 # make a subtype for each Moose class
32 role_type $role unless find_type_constraint($role);
35 if ($role->can('meta')) {
36 $meta = $role->meta();
37 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
38 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
41 $meta = Moose::Meta::Role->initialize($role);
42 $meta->alias_method('meta' => sub { $meta });
45 return $METAS{$role} = $meta;
51 my $meta = _find_meta();
52 return subname 'Moose::Role::extends' => sub {
53 confess "Moose::Role does not currently support 'extends'"
57 my $meta = _find_meta();
58 return subname 'Moose::Role::with' => sub (@) {
59 Moose::Util::apply_all_roles($meta, @_)
63 my $meta = _find_meta();
64 return subname 'Moose::Role::requires' => sub (@) {
65 confess "Must specify at least one method" unless @_;
66 $meta->add_required_methods(@_);
70 my $meta = _find_meta();
71 return subname 'Moose::Role::excludes' => sub (@) {
72 confess "Must specify at least one role" unless @_;
73 $meta->add_excluded_roles(@_);
77 my $meta = _find_meta();
78 return subname 'Moose::Role::has' => sub ($;%) {
79 my ($name, %options) = @_;
80 $meta->add_attribute($name, %options)
84 my $meta = _find_meta();
85 return subname 'Moose::Role::before' => sub (@&) {
87 $meta->add_before_method_modifier($_, $code) for @_;
91 my $meta = _find_meta();
92 return subname 'Moose::Role::after' => sub (@&) {
94 $meta->add_after_method_modifier($_, $code) for @_;
98 my $meta = _find_meta();
99 return subname 'Moose::Role::around' => sub (@&) {
101 $meta->add_around_method_modifier($_, $code) for @_;
104 # see Moose.pm for discussion
106 return subname 'Moose::Role::super' => sub { return unless $Moose::SUPER_BODY; $Moose::SUPER_BODY->(@Moose::SUPER_ARGS) }
109 # return subname 'Moose::Role::next' => sub { @_ = @Moose::SUPER_ARGS; goto \&next::method };
112 my $meta = _find_meta();
113 return subname 'Moose::Role::override' => sub ($&) {
114 my ($name, $code) = @_;
115 $meta->add_override_method_modifier($name, $code);
119 my $meta = _find_meta();
120 return subname 'Moose::Role::inner' => sub {
121 confess "Moose::Role cannot support 'inner'";
125 my $meta = _find_meta();
126 return subname 'Moose::Role::augment' => sub {
127 confess "Moose::Role cannot support 'augment'";
131 return \&Carp::confess;
134 return \&Scalar::Util::blessed;
138 my $exporter = Sub::Exporter::build_exporter({
139 exports => \%exports,
147 ref $_[1] && defined $_[1]->{into} ? $_[1]->{into}
149 && defined $_[1]->{into_level} ? caller( $_[1]->{into_level} )
152 # this works because both pragmas set $^H (see perldoc perlvar)
153 # which affects the current compilation - i.e. the file who use'd
154 # us - which is why we don't need to do anything special to make
155 # it affect that file rather than this one (which is already compiled)
160 # we should never export to main
161 return if $CALLER eq 'main';
176 Moose::Role - The Moose Role
181 use Moose::Role; # automatically turns on strict and warnings
186 my ($self, $other) = @_;
187 !$self->equal($other);
190 # ... then in your classes
193 use Moose; # automatically turns on strict and warnings
198 my ($self, $other) = @_;
199 $self->as_float == $other->as_float;
204 Role support in Moose is pretty solid at this point. However, the best
205 documentation is still the the test suite. It is fairly safe to assume Perl 6
206 style behavior and then either refer to the test suite, or ask questions on
207 #moose if something doesn't quite do what you expect.
209 We are planning writing some more documentation in the near future, but nothing
212 =head1 EXPORTED FUNCTIONS
214 Moose::Role currently supports all of the functions that L<Moose> exports, but
215 differs slightly in how some items are handled (see L<CAVEATS> below for
218 Moose::Role also offers two role-specific keyword exports:
222 =item B<requires (@method_names)>
224 Roles can require that certain methods are implemented by any class which
227 =item B<excludes (@role_names)>
229 Roles can C<exclude> other roles, in effect saying "I can never be combined
230 with these C<@role_names>". This is a feature which should not be used
237 Role support has only a few caveats:
243 Roles cannot use the C<extends> keyword; it will throw an exception for now.
244 The same is true of the C<augment> and C<inner> keywords (not sure those
245 really make sense for roles). All other Moose keywords will be I<deferred>
246 so that they can be applied to the consuming class.
250 Role composition does its best to B<not> be order-sensitive when it comes to
251 conflict resolution and requirements detection. However, it is order-sensitive
252 when it comes to method modifiers. All before/around/after modifiers are
253 included whenever a role is composed into a class, and then applied in the order
254 in which the roles are used. This also means that there is no conflict for
255 before/around/after modifiers.
257 In most cases, this will be a non-issue; however, it is something to keep in
258 mind when using method modifiers in a role. You should never assume any
263 The C<requires> keyword currently only works with actual methods. A method
264 modifier (before/around/after and override) will not count as a fufillment
265 of the requirement, and neither will an autogenerated accessor for an attribute.
267 It is likely that attribute accessors will eventually be allowed to fufill those
268 requirements, or we will introduce a C<requires_attr> keyword of some kind
269 instead. This decision has not yet been finalized.
275 All complex software has bugs lurking in it, and this module is no
276 exception. If you find a bug please either email me, or add the bug
281 Stevan Little E<lt>stevan@iinteractive.comE<gt>
283 Christian Hansen E<lt>chansen@cpan.orgE<gt>
285 =head1 COPYRIGHT AND LICENSE
287 Copyright 2006-2008 by Infinity Interactive, Inc.
289 L<http://www.iinteractive.com>
291 This library is free software; you can redistribute it and/or modify
292 it under the same terms as Perl itself.