use warnings;
use Carp 'confess';
-use Scalar::Util ();
+use Scalar::Util 'weaken';
use Class::MOP::Class;
use Class::MOP::Attribute;
use Class::MOP::Method;
-our $VERSION = '0.30';
+use Class::MOP::Immutable;
+
+our $VERSION = '0.38';
+our $AUTHORITY = 'cpan:STEVAN';
+
+{
+ # Metaclasses are singletons, so we cache them here.
+ # there is no need to worry about destruction though
+ # because they should die only when the program dies.
+ # After all, do package definitions even get reaped?
+ my %METAS;
+
+ # means of accessing all the metaclasses that have
+ # been initialized thus far (for mugwumps obj browser)
+ sub get_all_metaclasses { %METAS }
+ sub get_all_metaclass_instances { values %METAS }
+ sub get_all_metaclass_names { keys %METAS }
+ sub get_metaclass_by_name { $METAS{$_[0]} }
+ sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] }
+ sub weaken_metaclass { weaken($METAS{$_[0]}) }
+ sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} }
+ sub remove_metaclass_by_name { $METAS{$_[0]} = undef }
+
+ # NOTE:
+ # We only cache metaclasses, meaning instances of
+ # Class::MOP::Class. We do not cache instance of
+ # Class::MOP::Package or Class::MOP::Module. Mostly
+ # because I don't yet see a good reason to do so.
+}
+
+sub load_class {
+ my $class = shift;
+ # see if this is already
+ # loaded in the symbol table
+ return 1 if is_class_loaded($class);
+ # otherwise require it ...
+ my $file = $class . '.pm';
+ $file =~ s{::}{/}g;
+ eval { CORE::require($file) };
+ confess "Could not load class ($class) because : $@" if $@;
+ unless (does_metaclass_exist($class)) {
+ eval { Class::MOP::Class->initialize($class) };
+ confess "Could not initialize class ($class) because : $@" if $@;
+ }
+ 1; # return true if it worked
+}
+
+sub is_class_loaded {
+ my $class = shift;
+ no strict 'refs';
+ return 1 if defined ${"${class}::VERSION"} || defined @{"${class}::ISA"};
+ foreach (keys %{"${class}::"}) {
+ next if substr($_, -2, 2) eq '::';
+ return 1 if defined &{"${class}::$_"};
+ }
+ return 0;
+}
+
## ----------------------------------------------------------------------------
## Setting up our environment ...
# any subclass of Class::MOP::* will be able to
# inherit them using &construct_instance
-## Class::MOP::Class
+## --------------------------------------------------------
+## Class::MOP::Package
-Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('$:package' => (
+Class::MOP::Package->meta->add_attribute(
+ Class::MOP::Attribute->new('$!package' => (
reader => {
# NOTE: we need to do this in order
# for the instance meta-object to
# not fall into meta-circular death
- 'name' => sub { (shift)->{'$:package'} }
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ 'name' => \&Class::MOP::Package::name
+ },
+ init_arg => 'package',
+ ))
+);
+
+Class::MOP::Package->meta->add_attribute(
+ Class::MOP::Attribute->new('%!namespace' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'namespace' => \&Class::MOP::Package::namespace
},
- init_arg => ':package',
+ # NOTE:
+ # protect this from silliness
+ init_arg => '!............( DO NOT DO THIS )............!',
+ default => sub { \undef }
))
);
+# NOTE:
+# use the metaclass to construct the meta-package
+# which is a superclass of the metaclass itself :P
+Class::MOP::Package->meta->add_method('initialize' => sub {
+ my $class = shift;
+ my $package_name = shift;
+ $class->meta->new_object('package' => $package_name, @_);
+});
+
+## --------------------------------------------------------
+## Class::MOP::Module
+
+# NOTE:
+# yeah this is kind of stretching things a bit,
+# but truthfully the version should be an attribute
+# of the Module, the weirdness comes from having to
+# stick to Perl 5 convention and store it in the
+# $VERSION package variable. Basically if you just
+# squint at it, it will look how you want it to look.
+# Either as a package variable, or as a attribute of
+# the metaclass, isn't abstraction great :)
+
+Class::MOP::Module->meta->add_attribute(
+ Class::MOP::Attribute->new('$!version' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'version' => \&Class::MOP::Module::version
+ },
+ # NOTE:
+ # protect this from silliness
+ init_arg => '!............( DO NOT DO THIS )............!',
+ default => sub { \undef }
+ ))
+);
+
+# NOTE:
+# By following the same conventions as version here,
+# we are opening up the possibility that people can
+# use the $AUTHORITY in non-Class::MOP modules as
+# well.
+
+Class::MOP::Module->meta->add_attribute(
+ Class::MOP::Attribute->new('$!authority' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'authority' => \&Class::MOP::Module::authority
+ },
+ # NOTE:
+ # protect this from silliness
+ init_arg => '!............( DO NOT DO THIS )............!',
+ default => sub { \undef }
+ ))
+);
+
+## --------------------------------------------------------
+## Class::MOP::Class
+
Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('%:attributes' => (
- reader => 'get_attribute_map',
- init_arg => ':attributes',
+ Class::MOP::Attribute->new('%!attributes' => (
+ reader => {
+ # NOTE: we need to do this in order
+ # for the instance meta-object to
+ # not fall into meta-circular death
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map
+ },
+ init_arg => 'attributes',
default => sub { {} }
))
);
Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('$:attribute_metaclass' => (
- reader => 'attribute_metaclass',
- init_arg => ':attribute_metaclass',
+ Class::MOP::Attribute->new('%!methods' => (
+ init_arg => 'methods',
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'get_method_map' => \&Class::MOP::Class::get_method_map
+ },
+ default => sub { {} }
+ ))
+);
+
+Class::MOP::Class->meta->add_attribute(
+ Class::MOP::Attribute->new('@!superclasses' => (
+ accessor => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'superclasses' => \&Class::MOP::Class::superclasses
+ },
+ # NOTE:
+ # protect this from silliness
+ init_arg => '!............( DO NOT DO THIS )............!',
+ default => sub { \undef }
+ ))
+);
+
+Class::MOP::Class->meta->add_attribute(
+ Class::MOP::Attribute->new('$!attribute_metaclass' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass
+ },
+ init_arg => 'attribute_metaclass',
default => 'Class::MOP::Attribute',
))
);
Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('$:method_metaclass' => (
- reader => 'method_metaclass',
- init_arg => ':method_metaclass',
+ Class::MOP::Attribute->new('$!method_metaclass' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'method_metaclass' => \&Class::MOP::Class::method_metaclass
+ },
+ init_arg => 'method_metaclass',
default => 'Class::MOP::Method',
))
);
Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('$:instance_metaclass' => (
+ Class::MOP::Attribute->new('$!instance_metaclass' => (
reader => {
# NOTE: we need to do this in order
# for the instance meta-object to
- # not fall into meta-circular death
- 'instance_metaclass' => sub { (shift)->{'$:instance_metaclass'} }
+ # not fall into meta-circular death
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass
},
- init_arg => ':instance_metaclass',
+ init_arg => 'instance_metaclass',
default => 'Class::MOP::Instance',
))
);
+# NOTE:
+# we don't actually need to tie the knot with
+# Class::MOP::Class here, it is actually handled
+# within Class::MOP::Class itself in the
+# construct_class_instance method.
+
+## --------------------------------------------------------
## Class::MOP::Attribute
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('name' => (
- reader => {
+ Class::MOP::Attribute->new('$!name' => (
+ init_arg => 'name',
+ reader => {
# NOTE: we need to do this in order
# for the instance meta-object to
- # not fall into meta-circular death
- 'name' => sub { (shift)->{name} }
+ # not fall into meta-circular death
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ 'name' => \&Class::MOP::Attribute::name
}
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('associated_class' => (
- reader => {
+ Class::MOP::Attribute->new('$!associated_class' => (
+ init_arg => 'associated_class',
+ reader => {
# NOTE: we need to do this in order
# for the instance meta-object to
- # not fall into meta-circular death
- 'associated_class' => sub { (shift)->{associated_class} }
+ # not fall into meta-circular death
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ 'associated_class' => \&Class::MOP::Attribute::associated_class
}
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('accessor' => (
- reader => 'accessor',
- predicate => 'has_accessor',
+ Class::MOP::Attribute->new('$!accessor' => (
+ init_arg => 'accessor',
+ reader => { 'accessor' => \&Class::MOP::Attribute::accessor },
+ predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor },
+ ))
+);
+
+Class::MOP::Attribute->meta->add_attribute(
+ Class::MOP::Attribute->new('$!reader' => (
+ init_arg => 'reader',
+ reader => { 'reader' => \&Class::MOP::Attribute::reader },
+ predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader },
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('reader' => (
- reader => 'reader',
- predicate => 'has_reader',
+ Class::MOP::Attribute->new('$!writer' => (
+ init_arg => 'writer',
+ reader => { 'writer' => \&Class::MOP::Attribute::writer },
+ predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer },
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('writer' => (
- reader => 'writer',
- predicate => 'has_writer',
+ Class::MOP::Attribute->new('$!predicate' => (
+ init_arg => 'predicate',
+ reader => { 'predicate' => \&Class::MOP::Attribute::predicate },
+ predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate },
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('predicate' => (
- reader => 'predicate',
- predicate => 'has_predicate',
+ Class::MOP::Attribute->new('$!clearer' => (
+ init_arg => 'clearer',
+ reader => { 'clearer' => \&Class::MOP::Attribute::clearer },
+ predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer },
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('init_arg' => (
- reader => 'init_arg',
- predicate => 'has_init_arg',
+ Class::MOP::Attribute->new('$!init_arg' => (
+ init_arg => 'init_arg',
+ reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg },
+ predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg },
))
);
Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('default' => (
+ Class::MOP::Attribute->new('$!default' => (
+ init_arg => 'default',
# default has a custom 'reader' method ...
- predicate => 'has_default',
+ predicate => { 'has_default' => \&Class::MOP::Attribute::has_default },
))
);
+Class::MOP::Attribute->meta->add_attribute(
+ Class::MOP::Attribute->new('@!associated_methods' => (
+ init_arg => 'associated_methods',
+ reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods },
+ default => sub { [] }
+ ))
+);
# NOTE: (meta-circularity)
# This should be one of the last things done
|| confess "You must provide a name for the attribute";
$options{init_arg} = $name
if not exists $options{init_arg};
+
+ (Class::MOP::Attribute::is_default_a_coderef(\%options))
+ || confess("References are not allowed as default values, you must ".
+ "wrap then in a CODE reference (ex: sub { [] } and not [])")
+ if exists $options{default} && ref $options{default};
# return the new object
$class->meta->new_object(name => $name, %options);
$self->meta->clone_object($self, @_);
});
+## --------------------------------------------------------
+## Class::MOP::Method
+
+Class::MOP::Method->meta->add_attribute(
+ Class::MOP::Attribute->new('&!body' => (
+ init_arg => 'body',
+ reader => { 'body' => \&Class::MOP::Method::body },
+ ))
+);
+
+## --------------------------------------------------------
+## Class::MOP::Method::Wrapped
+
+# NOTE:
+# the way this item is initialized, this
+# really does not follow the standard
+# practices of attributes, but we put
+# it here for completeness
+Class::MOP::Method::Wrapped->meta->add_attribute(
+ Class::MOP::Attribute->new('%!modifier_table')
+);
+
+## --------------------------------------------------------
+## Class::MOP::Method::Accessor
+
+Class::MOP::Method::Accessor->meta->add_attribute(
+ Class::MOP::Attribute->new('$!attribute' => (
+ init_arg => 'attribute',
+ reader => {
+ 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute
+ },
+ ))
+);
+
+Class::MOP::Method::Accessor->meta->add_attribute(
+ Class::MOP::Attribute->new('$!accessor_type' => (
+ init_arg => 'accessor_type',
+ reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type },
+ ))
+);
+
+Class::MOP::Method::Accessor->meta->add_attribute(
+ Class::MOP::Attribute->new('$!is_inline' => (
+ init_arg => 'is_inline',
+ reader => { 'is_inline' => \&Class::MOP::Method::Accessor::is_inline },
+ ))
+);
+
+## --------------------------------------------------------
+## Class::MOP::Method::Constructor
+
+Class::MOP::Method::Constructor->meta->add_attribute(
+ Class::MOP::Attribute->new('%!options' => (
+ init_arg => 'options',
+ reader => {
+ 'options' => \&Class::MOP::Method::Constructor::options
+ },
+ ))
+);
+
+Class::MOP::Method::Constructor->meta->add_attribute(
+ Class::MOP::Attribute->new('$!associated_metaclass' => (
+ init_arg => 'metaclass',
+ reader => {
+ 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass
+ },
+ ))
+);
+
+## --------------------------------------------------------
+## Class::MOP::Instance
+
+# NOTE:
+# these don't yet do much of anything, but are just
+# included for completeness
+
+Class::MOP::Instance->meta->add_attribute(
+ Class::MOP::Attribute->new('$!meta')
+);
+
+Class::MOP::Instance->meta->add_attribute(
+ Class::MOP::Attribute->new('@!slots')
+);
+
+## --------------------------------------------------------
+## Now close all the Class::MOP::* classes
+
+# NOTE:
+# we don't need to inline the
+# constructors or the accessors
+# this only lengthens the compile
+# time of the MOP, and gives us
+# no actual benefits.
+
+$_->meta->make_immutable(
+ inline_constructor => 0,
+ inline_accessors => 0,
+) for qw/
+ Class::MOP::Package
+ Class::MOP::Module
+ Class::MOP::Class
+
+ Class::MOP::Attribute
+ Class::MOP::Method
+ Class::MOP::Instance
+
+ Class::MOP::Object
+
+ Class::MOP::Method::Accessor
+ Class::MOP::Method::Constructor
+ Class::MOP::Method::Wrapped
+/;
+
1;
__END__
Class::MOP - A Meta Object Protocol for Perl 5
-=head1 SYNOPSIS
-
- # ... This will come later, for now see
- # the other SYNOPSIS for more information
-
=head1 DESCRIPTON
This module is an attempt to create a meta object protocol for the
made for these tools to keep to the spirit of the Perl 5 object
system that we all know and love.
+This documentation is admittedly sparse on details, as time permits
+I will try to improve them. For now, I suggest looking at the items
+listed in the L<SEE ALSO> section for more information. In particular
+the book "The Art of the Meta Object Protocol" was very influential
+in the development of this system.
+
=head2 What is a Meta Object Protocol?
A meta object protocol is an API to an object system.
=back
+=head1 FUNCTIONS
+
+=head2 Utility functions
+
+=over 4
+
+=item B<load_class ($class_name)>
+
+This will load a given C<$class_name> and if it does not have an
+already initialized metaclass, then it will intialize one for it.
+
+=item B<is_class_loaded ($class_name)>
+
+This will return a boolean depending on if the C<$class_name> has
+been loaded.
+
+NOTE: This does a basic check of the symbol table to try and
+determine as best it can if the C<$class_name> is loaded, it
+is probably correct about 99% of the time.
+
+=back
+
+=head2 Metaclass cache functions
+
+Class::MOP holds a cache of metaclasses, the following are functions
+(B<not methods>) which can be used to access that cache. It is not
+recommended that you mess with this, bad things could happen. But if
+you are brave and willing to risk it, go for it.
+
+=over 4
+
+=item B<get_all_metaclasses>
+
+This will return an hash of all the metaclass instances that have
+been cached by B<Class::MOP::Class> keyed by the package name.
+
+=item B<get_all_metaclass_instances>
+
+This will return an array of all the metaclass instances that have
+been cached by B<Class::MOP::Class>.
+
+=item B<get_all_metaclass_names>
+
+This will return an array of all the metaclass names that have
+been cached by B<Class::MOP::Class>.
+
+=item B<get_metaclass_by_name ($name)>
+
+=item B<store_metaclass_by_name ($name, $meta)>
+
+=item B<weaken_metaclass ($name)>
+
+=item B<does_metaclass_exist ($name)>
+
+=item B<remove_metaclass_by_name ($name)>
+
+=back
+
=head1 SEE ALSO
=head2 Books
=back
+=head2 Articles
+
+=over 4
+
+=item CPAN Module Review of Class::MOP
+
+L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html>
+
+=back
+
=head1 SIMILAR MODULES
As I have said above, this module is a class-builder-builder, so it is
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
-=head1 CODE COVERAGE
-
-I use L<Devel::Cover> to test the code coverage of my tests, below is the
-L<Devel::Cover> report on this module's test suite.
-
- ---------------------------- ------ ------ ------ ------ ------ ------ ------
- File stmt bran cond sub pod time total
- ---------------------------- ------ ------ ------ ------ ------ ------ ------
- Class/MOP.pm 100.0 100.0 100.0 100.0 n/a 9.6 100.0
- Class/MOP/Attribute.pm 100.0 100.0 91.7 73.8 100.0 28.4 92.1
- Class/MOP/Class.pm 100.0 93.5 82.3 98.2 100.0 56.6 95.7
- Class/MOP/Method.pm 100.0 64.3 52.9 80.0 100.0 3.5 85.3
- metaclass.pm 100.0 100.0 80.0 100.0 n/a 1.9 97.4
- ---------------------------- ------ ------ ------ ------ ------ ------ ------
- Total 100.0 90.8 79.7 86.2 100.0 100.0 93.6
- ---------------------------- ------ ------ ------ ------ ------ ------ ------
-
=head1 ACKNOWLEDGEMENTS
=over 4
-=item Rob Kinyon E<lt>rob@iinteractive.comE<gt>
+=item Rob Kinyon
Thanks to Rob for actually getting the development of this module kick-started.
=back
-=head1 AUTHOR
+=head1 AUTHORS
Stevan Little E<lt>stevan@iinteractive.comE<gt>
+B<with contributions from:>
+
+Brandon (blblack) Black
+
+Guillermo (groditi) Roditi
+
+Rob (robkinyon) Kinyon
+
+Yuval (nothingmuch) Kogman
+
=head1 COPYRIGHT AND LICENSE
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006, 2007 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
projects / gitmo/Class-MOP.git / blobdiff