use strict;
use warnings;
-use Scalar::Util ();
+use Scalar::Util 'blessed';
use Carp 'confess';
use Sub::Name 'subname';
-our $VERSION = '0.01';
+use Sub::Exporter;
-use Moose::Meta::Role;
+our $VERSION = '0.05';
-sub import {
- shift;
- my $pkg = caller();
-
- # we should never export to main
- return if $pkg eq 'main';
-
- Moose::Util::TypeConstraints->import($pkg);
-
- my $meta;
- if ($pkg->can('meta')) {
- $meta = $pkg->meta();
- (blessed($meta) && $meta->isa('Moose::Meta::Role'))
- || confess "Whoops, not møøsey enough";
- }
- else {
- $meta = Moose::Meta::Role->new(role_name => $pkg);
- $meta->role_meta->add_method('meta' => sub { $meta })
- }
-
- # NOTE:
- # &alias_method will install the method, but it
- # will not name it with
-
- # handle superclasses
- $meta->role_meta->alias_method('extends' => subname 'Moose::Role::extends' => sub {
- confess "Moose::Role does not currently support 'extends'"
- });
-
- # handle attributes
- $meta->role_meta->alias_method('has' => subname 'Moose::Role::has' => sub {
- my ($name, %options) = @_;
- $meta->add_attribute($name, %options)
- });
-
- # handle method modifers
- $meta->role_meta->alias_method('before' => subname 'Moose::Role::before' => sub {
- my $code = pop @_;
- $meta->add_method_modifier('before' => $_, $code) for @_;
- });
- $meta->role_meta->alias_method('after' => subname 'Moose::Role::after' => sub {
- my $code = pop @_;
- $meta->add_method_modifier('after' => $_, $code) for @_;
- });
- $meta->role_meta->alias_method('around' => subname 'Moose::Role::around' => sub {
- my $code = pop @_;
- $meta->add_method_modifier('around' => $_, $code) for @_;
- });
-
- $meta->role_meta->alias_method('super' => subname 'Moose::Role::super' => sub {});
- $meta->role_meta->alias_method('override' => subname 'Moose::Role::override' => sub {
- my ($name, $code) = @_;
- $meta->add_method_modifier('override' => $name, $code);
- });
+use Moose ();
+
+use Moose::Meta::Role;
+use Moose::Util::TypeConstraints;
+
+{
+ my ( $CALLER, %METAS );
+
+ sub _find_meta {
+ my $role = $CALLER;
+
+ return $METAS{$role} if exists $METAS{$role};
+
+ # make a subtype for each Moose class
+ subtype $role
+ => as 'Role'
+ => where { $_->does($role) }
+ unless find_type_constraint($role);
+
+ my $meta;
+ if ($role->can('meta')) {
+ $meta = $role->meta();
+ (blessed($meta) && $meta->isa('Moose::Meta::Role'))
+ || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
+ }
+ else {
+ $meta = Moose::Meta::Role->initialize($role);
+ $meta->Moose::Meta::Class::add_method('meta' => sub { $meta })
+ }
+
+ return $METAS{$role} = $meta;
+ }
+
- $meta->role_meta->alias_method('inner' => subname 'Moose::Role::inner' => sub {
- confess "Moose::Role does not currently support 'inner'";
- });
- $meta->role_meta->alias_method('augment' => subname 'Moose::Role::augment' => sub {
- confess "Moose::Role does not currently support 'augment'";
- });
-
- # we recommend using these things
- # so export them for them
- $meta->role_meta->alias_method('confess' => \&Carp::confess);
- $meta->role_meta->alias_method('blessed' => \&Scalar::Util::blessed);
+ my %exports = (
+ extends => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::extends' => sub {
+ confess "Moose::Role does not currently support 'extends'"
+ };
+ },
+ with => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::with' => sub (@) {
+ my (@roles) = @_;
+ confess "Must specify at least one role" unless @roles;
+ Moose::_load_all_classes(@roles);
+ ($_->can('meta') && $_->meta->isa('Moose::Meta::Role'))
+ || confess "You can only consume roles, $_ is not a Moose role"
+ foreach @roles;
+ if (scalar @roles == 1) {
+ $roles[0]->meta->apply($meta);
+ }
+ else {
+ Moose::Meta::Role->combine(
+ map { $_->meta } @roles
+ )->apply($meta);
+ }
+ };
+ },
+ requires => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::requires' => sub (@) {
+ confess "Must specify at least one method" unless @_;
+ $meta->add_required_methods(@_);
+ };
+ },
+ excludes => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::excludes' => sub (@) {
+ confess "Must specify at least one role" unless @_;
+ $meta->add_excluded_roles(@_);
+ };
+ },
+ has => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::has' => sub ($;%) {
+ my ($name, %options) = @_;
+ $meta->add_attribute($name, %options)
+ };
+ },
+ before => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::before' => sub (@&) {
+ confess "Moose::Role does not currently support 'before'";
+ };
+ },
+ after => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::after' => sub (@&) {
+ confess "Moose::Role does not currently support 'after'";
+ };
+ },
+ around => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::around' => sub (@&) {
+ confess "Moose::Role does not currently support 'around'";
+ };
+ },
+ super => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::super' => sub {
+ confess "Moose::Role cannot support 'super'";
+ };
+ },
+ override => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::override' => sub ($&) {
+ confess "Moose::Role cannot support 'override'";
+ };
+ },
+ inner => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::inner' => sub {
+ confess "Moose::Role cannot support 'inner'";
+ };
+ },
+ augment => sub {
+ my $meta = _find_meta();
+ return subname 'Moose::Role::augment' => sub {
+ confess "Moose::Role cannot support 'augment'";
+ };
+ },
+ confess => sub {
+ return \&Carp::confess;
+ },
+ blessed => sub {
+ return \&Scalar::Util::blessed;
+ }
+ );
+
+ my $exporter = Sub::Exporter::build_exporter({
+ exports => \%exports,
+ groups => {
+ default => [':all']
+ }
+ });
+
+ sub import {
+ $CALLER = caller();
+
+ strict->import;
+ warnings->import;
+
+ # we should never export to main
+ return if $CALLER eq 'main';
+
+ goto $exporter;
+ };
+
}
1;
use warnings;
use Moose::Role;
- sub equal { confess "equal must be implemented" }
+ requires 'equal';
sub no_equal {
my ($self, $other) = @_;
sub equal {
my ($self, $other) = @_;
- $other->as_float == $other->as_float;
+ $self->as_float == $other->as_float;
}
=head1 DESCRIPTION
-This is currently a very early release of Perl 6 style Roles for
-Moose, it should be considered experimental and incomplete.
+Role support in Moose is coming along quite well. It's best documentation
+is still the the test suite, but it is fairly safe to assume Perl 6 style
+behavior, and then either refer to the test suite, or ask questions on
+#moose if something doesn't quite do what you expect. More complete
+documentation is planned and will be included with the next official
+(non-developer) release.
-This feature is being actively developed, but $work is currently
-preventing me from paying as much attention to it as I would like.
-So I am releasing it in hopes people will help me on this I<hint hint>.
+=head1 EXPORTED FUNCTIONS
-If you are interested in helping, please come to #moose on irc.perl.org
-and we can talk.
-
-=head1 CAVEATS
+Currently Moose::Role supports all of the functions that L<Moose> exports,
+but differs slightly in how some items are handled (see L<CAVEATS> below
+for details).
-Currently, the role support has a number of caveats. They are as follows:
+Moose::Role also offers two role specific keyword exports:
=over 4
-=item *
+=item B<requires (@method_names)>
-There is no support for Roles consuming other Roles. The details of this
-are not totally worked out yet, but it will mostly follow what is set out
-in the Perl 6 Synopsis 12.
+Roles can require that certain methods are implemented by any class which
+C<does> the role.
-=item *
+=item B<excludes (@role_names)>
-At this time classes I<can> consume more than one Role, but they are simply
-applied one after another in the order you ask for them. This is incorrect
-behavior, the roles should be merged first, and conflicts determined, etc.
-However, if your roles do not have any conflicts, then things will work just
-fine.
+Roles can C<exclude> other roles, in effect saying "I can never be combined
+with these C<@role_names>". This is a feature which should not be used
+lightly.
-=item *
+=back
+
+=head1 CAVEATS
+
+The role support now has only a few caveats. They are as follows:
-I want to have B<required> methods, which is unlike Perl 6 roles, and more
-like the original Traits on which roles are based. This would be similar
-in behavior to L<Class::Trait>. These are not yet implemented or course.
+=over 4
=item *
really make sense for roles). All other Moose keywords will be I<deferred>
so that they can be applied to the consuming class.
-=back
+=item *
+
+Role composition does it's best to B<not> be order sensitive when it comes
+to conflict resolution and requirements detection. However, it is order
+sensitive when it comes to method modifiers. All before/around/after modifiers
+are included whenever a role is composed into a class, and then are applied
+in the order the roles are used. This too means that there is no conflict for
+before/around/after modifiers as well.
-Basically thats all I can think of for now, I am sure there are more though.
+In most cases, this will be a non issue, however it is something to keep in
+mind when using method modifiers in a role. You should never assume any
+ordering.
+
+=item *
+
+The C<requires> keyword currently only works with actual methods. A method
+modifier (before/around/after and override) will not count as a fufillment
+of the requirement, and neither will an autogenerated accessor for an attribute.
+
+It is likely that the attribute accessors will eventually be allowed to fufill
+those requirements, either that or we will introduce a C<requires_attr> keyword
+of some kind instead. This descision has not yet been finalized.
+
+=back
=head1 BUGS
Stevan Little E<lt>stevan@iinteractive.comE<gt>
+Christian Hansen E<lt>chansen@cpan.orgE<gt>
+
=head1 COPYRIGHT AND LICENSE
Copyright 2006 by Infinity Interactive, Inc.
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
-=cut
\ No newline at end of file
+=cut