X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FMOP.pm;h=e70592ea865c00a4e1d236bb554a95691458aeda;hb=9c8cda9011b019e4876183222b8793b66bab7546;hp=09220ff8b447e4c929a2e2136bab0b6e8c47b2e0;hpb=8048fe76388270488ccaf9515bbc54a1f28d44fb;p=gitmo%2FClass-MOP.git diff --git a/lib/Class/MOP.pm b/lib/Class/MOP.pm index 09220ff..e70592e 100644 --- a/lib/Class/MOP.pm +++ b/lib/Class/MOP.pm @@ -5,13 +5,70 @@ use strict; 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 = '0.25'; +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 ... @@ -37,95 +94,288 @@ our $VERSION = '0.25'; # any subclass of Class::MOP::* will be able to # inherit them using &construct_instance +## -------------------------------------------------------- +## Class::MOP::Package + +Class::MOP::Package->meta->add_attribute( + Class::MOP::Attribute->new('$!package' => ( + reader => { + # NOTE: we need to do this in order + # for the instance meta-object to + # not fall into meta-circular death + # + # 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 + }, + # 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('$:package' => ( - reader => 'name', - init_arg => ':package', + Class::MOP::Attribute->new('%!attributes' => ( + reader => { + # NOTE: we need to do this in order + # for the instance meta-object to + # not fall into meta-circular death + # + # we just alias the original method + # rather than re-produce it here + 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map + }, + init_arg => 'attributes', + default => sub { {} } )) ); Class::MOP::Class->meta->add_attribute( - Class::MOP::Attribute->new('%:attributes' => ( - reader => 'get_attribute_map', - init_arg => ':attributes', - default => sub { {} } + Class::MOP::Attribute->new('%!methods' => ( + init_arg => 'methods', + reader => { + # NOTE: + # we just alias the original method + # rather than re-produce it here + 'get_method_map' => \&Class::MOP::Class::get_method_map + }, + default => sub { {} } + )) +); + +Class::MOP::Class->meta->add_attribute( + Class::MOP::Attribute->new('@!superclasses' => ( + accessor => { + # NOTE: + # we just alias the original method + # rather than re-produce it here + 'superclasses' => \&Class::MOP::Class::superclasses + }, + # NOTE: + # protect this from silliness + init_arg => '!............( DO NOT DO THIS )............!', + default => sub { \undef } )) ); Class::MOP::Class->meta->add_attribute( - Class::MOP::Attribute->new('$:attribute_metaclass' => ( - reader => 'attribute_metaclass', - init_arg => ':attribute_metaclass', + 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' => ( + 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 + 'instance_metaclass' => \&Class::MOP::Class::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 => 'name' + Class::MOP::Attribute->new('$!name' => ( + init_arg => 'name', + reader => { + # NOTE: we need to do this in order + # for the instance meta-object to + # not fall into meta-circular death + # + # we just alias the original method + # rather than re-produce it here + 'name' => \&Class::MOP::Attribute::name + } )) ); Class::MOP::Attribute->meta->add_attribute( - Class::MOP::Attribute->new('associated_class' => ( - reader => 'associated_class' + Class::MOP::Attribute->new('$!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 + # + # 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('$!accessor' => ( + init_arg => 'accessor', + reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, + predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, )) ); Class::MOP::Attribute->meta->add_attribute( - Class::MOP::Attribute->new('reader' => ( - reader => 'reader', - predicate => 'has_reader', + Class::MOP::Attribute->new('$!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('writer' => ( - reader => 'writer', - predicate => 'has_writer', + Class::MOP::Attribute->new('$!writer' => ( + init_arg => 'writer', + reader => { 'writer' => \&Class::MOP::Attribute::writer }, + predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, )) ); Class::MOP::Attribute->meta->add_attribute( - Class::MOP::Attribute->new('predicate' => ( - reader => 'predicate', - predicate => 'has_predicate', + Class::MOP::Attribute->new('$!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('init_arg' => ( - reader => 'init_arg', - predicate => 'has_init_arg', + Class::MOP::Attribute->new('$!clearer' => ( + init_arg => 'clearer', + reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, + predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, )) ); Class::MOP::Attribute->meta->add_attribute( - Class::MOP::Attribute->new('default' => ( + Class::MOP::Attribute->new('$!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' => ( + 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 @@ -141,6 +391,11 @@ Class::MOP::Attribute->meta->add_method('new' => sub { || 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); @@ -151,6 +406,119 @@ Class::MOP::Attribute->meta->add_method('clone' => sub { $self->meta->clone_object($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__ @@ -161,11 +529,6 @@ __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 @@ -178,6 +541,12 @@ set of extensions to the Perl 5 object system. Every attempt has been 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 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. @@ -323,6 +692,64 @@ See L for more details. =back +=head1 FUNCTIONS + +=head2 Utility functions + +=over 4 + +=item B + +This will load a given C<$class_name> and if it does not have an +already initialized metaclass, then it will intialize one for it. + +=item B + +This will return a boolean depending on if the C<$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) 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 + +This will return an hash of all the metaclass instances that have +been cached by B keyed by the package name. + +=item B + +This will return an array of all the metaclass instances that have +been cached by B. + +=item B + +This will return an array of all the metaclass names that have +been cached by B. + +=item B + +=item B + +=item B + +=item B + +=item B + +=back + =head1 SEE ALSO =head2 Books @@ -383,6 +810,16 @@ L =back +=head2 Articles + +=over 4 + +=item CPAN Module Review of Class::MOP + +L + +=back + =head1 SIMILAR MODULES As I have said above, this module is a class-builder-builder, so it is @@ -398,40 +835,33 @@ All complex software has bugs lurking in it, and this module is no exception. If you find a bug please either email me, or add the bug to cpan-RT. -=head1 CODE COVERAGE - -I use L to test the code coverage of my tests, below is the -L 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 Erob@iinteractive.comE +=item Rob Kinyon Thanks to Rob for actually getting the development of this module kick-started. =back -=head1 AUTHOR +=head1 AUTHORS Stevan Little Estevan@iinteractive.comE +B + +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