7 use Scalar::Util 'blessed';
9 use Sub::Name 'subname';
13 our $VERSION = '0.07';
14 our $AUTHORITY = 'cpan:STEVAN';
18 use Moose::Meta::Role;
19 use Moose::Util::TypeConstraints;
22 my ( $CALLER, %METAS );
27 return $METAS{$role} if exists $METAS{$role};
29 # make a subtype for each Moose class
32 => where { $_->does($role) }
33 => optimize_as { blessed($_[0]) && $_[0]->can('does') && $_[0]->does($role) }
34 unless find_type_constraint($role);
37 if ($role->can('meta')) {
38 $meta = $role->meta();
39 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
40 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
43 $meta = Moose::Meta::Role->initialize($role);
44 $meta->alias_method('meta' => sub { $meta });
47 return $METAS{$role} = $meta;
53 my $meta = _find_meta();
54 return subname 'Moose::Role::extends' => sub {
55 confess "Moose::Role does not currently support 'extends'"
59 my $meta = _find_meta();
60 return subname 'Moose::Role::with' => sub (@) {
62 confess "Must specify at least one role" unless @roles;
63 Class::MOP::load_class($_) for @roles;
64 ($_->can('meta') && $_->meta->isa('Moose::Meta::Role'))
65 || confess "You can only consume roles, $_ is not a Moose role"
67 if (scalar @roles == 1) {
68 $roles[0]->meta->apply($meta);
71 Moose::Meta::Role->combine(
72 map { $_->meta } @roles
78 my $meta = _find_meta();
79 return subname 'Moose::Role::requires' => sub (@) {
80 confess "Must specify at least one method" unless @_;
81 $meta->add_required_methods(@_);
85 my $meta = _find_meta();
86 return subname 'Moose::Role::excludes' => sub (@) {
87 confess "Must specify at least one role" unless @_;
88 $meta->add_excluded_roles(@_);
92 my $meta = _find_meta();
93 return subname 'Moose::Role::has' => sub ($;%) {
94 my ($name, %options) = @_;
95 $meta->add_attribute($name, %options)
99 my $meta = _find_meta();
100 return subname 'Moose::Role::before' => sub (@&) {
102 $meta->add_before_method_modifier($_, $code) for @_;
106 my $meta = _find_meta();
107 return subname 'Moose::Role::after' => sub (@&) {
109 $meta->add_after_method_modifier($_, $code) for @_;
113 my $meta = _find_meta();
114 return subname 'Moose::Role::around' => sub (@&) {
116 $meta->add_around_method_modifier($_, $code) for @_;
122 $Moose::SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"};
124 my $meta = _find_meta();
125 return subname 'Moose::Role::super' => sub {};
128 my $meta = _find_meta();
129 return subname 'Moose::Role::override' => sub ($&) {
130 my ($name, $code) = @_;
131 $meta->add_override_method_modifier($name, $code);
135 my $meta = _find_meta();
136 return subname 'Moose::Role::inner' => sub {
137 confess "Moose::Role cannot support 'inner'";
141 my $meta = _find_meta();
142 return subname 'Moose::Role::augment' => sub {
143 confess "Moose::Role cannot support 'augment'";
147 return \&Carp::confess;
150 return \&Scalar::Util::blessed;
154 my $exporter = Sub::Exporter::build_exporter({
155 exports => \%exports,
163 ref $_[1] && defined $_[1]->{into} ? $_[1]->{into}
165 && defined $_[1]->{into_level} ? caller( $_[1]->{into_level} )
172 # we should never export to main
173 return if $CALLER eq 'main';
188 Moose::Role - The Moose Role
193 use Moose::Role; # automatically turns on strict and warnings
198 my ($self, $other) = @_;
199 !$self->equal($other);
202 # ... then in your classes
205 use Moose; # automatically turns on strict and warnings
210 my ($self, $other) = @_;
211 $self->as_float == $other->as_float;
216 Role support in Moose is pretty solid at this point. However, the best
217 documentation is still the the test suite. It is fairly safe to assume Perl 6
218 style behavior and then either refer to the test suite, or ask questions on
219 #moose if something doesn't quite do what you expect.
221 We are planning writing some more documentation in the near future, but nothing
224 =head1 EXPORTED FUNCTIONS
226 Moose::Role currently supports all of the functions that L<Moose> exports, but
227 differs slightly in how some items are handled (see L<CAVEATS> below for
230 Moose::Role also offers two role-specific keyword exports:
234 =item B<requires (@method_names)>
236 Roles can require that certain methods are implemented by any class which
239 =item B<excludes (@role_names)>
241 Roles can C<exclude> other roles, in effect saying "I can never be combined
242 with these C<@role_names>". This is a feature which should not be used
249 Role support has only a few caveats:
255 Roles cannot use the C<extends> keyword; it will throw an exception for now.
256 The same is true of the C<augment> and C<inner> keywords (not sure those
257 really make sense for roles). All other Moose keywords will be I<deferred>
258 so that they can be applied to the consuming class.
262 Role composition does its best to B<not> be order-sensitive when it comes to
263 conflict resolution and requirements detection. However, it is order-sensitive
264 when it comes to method modifiers. All before/around/after modifiers are
265 included whenever a role is composed into a class, and then applied in the order
266 in which the roles are used. This also means that there is no conflict for
267 before/around/after modifiers.
269 In most cases, this will be a non-issue; however, it is something to keep in
270 mind when using method modifiers in a role. You should never assume any
275 The C<requires> keyword currently only works with actual methods. A method
276 modifier (before/around/after and override) will not count as a fufillment
277 of the requirement, and neither will an autogenerated accessor for an attribute.
279 It is likely that attribute accessors will eventually be allowed to fufill those
280 requirements, or we will introduce a C<requires_attr> keyword of some kind
281 instead. This decision has not yet been finalized.
287 All complex software has bugs lurking in it, and this module is no
288 exception. If you find a bug please either email me, or add the bug
293 Stevan Little E<lt>stevan@iinteractive.comE<gt>
295 Christian Hansen E<lt>chansen@cpan.orgE<gt>
297 =head1 COPYRIGHT AND LICENSE
299 Copyright 2006-2008 by Infinity Interactive, Inc.
301 L<http://www.iinteractive.com>
303 This library is free software; you can redistribute it and/or modify
304 it under the same terms as Perl itself.