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
34 => where { Moose::Util::does_role($_, $role) }
35 => optimize_as { blessed($_[0]) && Moose::Util::does_role($_[0], $role) }
36 unless find_type_constraint($role);
39 if ($role->can('meta')) {
40 $meta = $role->meta();
41 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
42 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
45 $meta = Moose::Meta::Role->initialize($role);
46 $meta->alias_method('meta' => sub { $meta });
49 return $METAS{$role} = $meta;
55 my $meta = _find_meta();
56 return subname 'Moose::Role::extends' => sub {
57 confess "Moose::Role does not currently support 'extends'"
61 my $meta = _find_meta();
62 return subname 'Moose::Role::with' => sub (@) {
63 Moose::Util::apply_all_roles($meta, @_)
67 my $meta = _find_meta();
68 return subname 'Moose::Role::requires' => sub (@) {
69 confess "Must specify at least one method" unless @_;
70 $meta->add_required_methods(@_);
74 my $meta = _find_meta();
75 return subname 'Moose::Role::excludes' => sub (@) {
76 confess "Must specify at least one role" unless @_;
77 $meta->add_excluded_roles(@_);
81 my $meta = _find_meta();
82 return subname 'Moose::Role::has' => sub ($;%) {
83 my ($name, %options) = @_;
84 $meta->add_attribute($name, %options)
88 my $meta = _find_meta();
89 return subname 'Moose::Role::before' => sub (@&) {
91 $meta->add_before_method_modifier($_, $code) for @_;
95 my $meta = _find_meta();
96 return subname 'Moose::Role::after' => sub (@&) {
98 $meta->add_after_method_modifier($_, $code) for @_;
102 my $meta = _find_meta();
103 return subname 'Moose::Role::around' => sub (@&) {
105 $meta->add_around_method_modifier($_, $code) for @_;
111 $Moose::SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"};
113 my $meta = _find_meta();
114 return subname 'Moose::Role::super' => sub {};
117 my $meta = _find_meta();
118 return subname 'Moose::Role::override' => sub ($&) {
119 my ($name, $code) = @_;
120 $meta->add_override_method_modifier($name, $code);
124 my $meta = _find_meta();
125 return subname 'Moose::Role::inner' => sub {
126 confess "Moose::Role cannot support 'inner'";
130 my $meta = _find_meta();
131 return subname 'Moose::Role::augment' => sub {
132 confess "Moose::Role cannot support 'augment'";
136 return \&Carp::confess;
139 return \&Scalar::Util::blessed;
143 my $exporter = Sub::Exporter::build_exporter({
144 exports => \%exports,
152 ref $_[1] && defined $_[1]->{into} ? $_[1]->{into}
154 && defined $_[1]->{into_level} ? caller( $_[1]->{into_level} )
157 # this works because both pragmas set $^H (see perldoc perlvar)
158 # which affects the current compilation - i.e. the file who use'd
159 # us - which is why we don't need to do anything special to make
160 # it affect that file rather than this one (which is already compiled)
165 # we should never export to main
166 return if $CALLER eq 'main';
181 Moose::Role - The Moose Role
186 use Moose::Role; # automatically turns on strict and warnings
191 my ($self, $other) = @_;
192 !$self->equal($other);
195 # ... then in your classes
198 use Moose; # automatically turns on strict and warnings
203 my ($self, $other) = @_;
204 $self->as_float == $other->as_float;
209 Role support in Moose is pretty solid at this point. However, the best
210 documentation is still the the test suite. It is fairly safe to assume Perl 6
211 style behavior and then either refer to the test suite, or ask questions on
212 #moose if something doesn't quite do what you expect.
214 We are planning writing some more documentation in the near future, but nothing
217 =head1 EXPORTED FUNCTIONS
219 Moose::Role currently supports all of the functions that L<Moose> exports, but
220 differs slightly in how some items are handled (see L<CAVEATS> below for
223 Moose::Role also offers two role-specific keyword exports:
227 =item B<requires (@method_names)>
229 Roles can require that certain methods are implemented by any class which
232 =item B<excludes (@role_names)>
234 Roles can C<exclude> other roles, in effect saying "I can never be combined
235 with these C<@role_names>". This is a feature which should not be used
242 Role support has only a few caveats:
248 Roles cannot use the C<extends> keyword; it will throw an exception for now.
249 The same is true of the C<augment> and C<inner> keywords (not sure those
250 really make sense for roles). All other Moose keywords will be I<deferred>
251 so that they can be applied to the consuming class.
255 Role composition does its best to B<not> be order-sensitive when it comes to
256 conflict resolution and requirements detection. However, it is order-sensitive
257 when it comes to method modifiers. All before/around/after modifiers are
258 included whenever a role is composed into a class, and then applied in the order
259 in which the roles are used. This also means that there is no conflict for
260 before/around/after modifiers.
262 In most cases, this will be a non-issue; however, it is something to keep in
263 mind when using method modifiers in a role. You should never assume any
268 The C<requires> keyword currently only works with actual methods. A method
269 modifier (before/around/after and override) will not count as a fufillment
270 of the requirement, and neither will an autogenerated accessor for an attribute.
272 It is likely that attribute accessors will eventually be allowed to fufill those
273 requirements, or we will introduce a C<requires_attr> keyword of some kind
274 instead. This decision has not yet been finalized.
280 All complex software has bugs lurking in it, and this module is no
281 exception. If you find a bug please either email me, or add the bug
286 Stevan Little E<lt>stevan@iinteractive.comE<gt>
288 Christian Hansen E<lt>chansen@cpan.orgE<gt>
290 =head1 COPYRIGHT AND LICENSE
292 Copyright 2006-2008 by Infinity Interactive, Inc.
294 L<http://www.iinteractive.com>
296 This library is free software; you can redistribute it and/or modify
297 it under the same terms as Perl itself.