2 package Class::MOP::Class;
7 use Class::MOP::Immutable;
8 use Class::MOP::Instance;
9 use Class::MOP::Method::Wrapped;
12 use Scalar::Util 'blessed', 'weaken';
14 our $VERSION = '0.77';
15 $VERSION = eval $VERSION;
16 our $AUTHORITY = 'cpan:STEVAN';
18 use base 'Class::MOP::Module';
28 $package_name = shift;
31 $package_name = $options{package};
34 (defined $package_name && $package_name && !ref($package_name))
35 || confess "You must pass a package name and it cannot be blessed";
37 return Class::MOP::get_metaclass_by_name($package_name)
38 || $class->construct_class_instance(package => $package_name, @_);
41 # NOTE: (meta-circularity)
42 # this is a special form of &construct_instance
43 # (see below), which is used to construct class
44 # meta-object instances for any Class::MOP::*
45 # class. All other classes will use the more
46 # normal &construct_instance.
47 sub construct_class_instance {
49 my $options = @_ == 1 ? $_[0] : {@_};
50 my $package_name = $options->{package};
51 (defined $package_name && $package_name)
52 || confess "You must pass a package name";
54 # return the metaclass if we have it cached,
55 # and it is still defined (it has not been
56 # reaped by DESTROY yet, which can happen
57 # annoyingly enough during global destruction)
59 if (defined(my $meta = Class::MOP::get_metaclass_by_name($package_name))) {
64 # we need to deal with the possibility
65 # of class immutability here, and then
66 # get the name of the class appropriately
68 ? ($class->is_immutable
69 ? $class->get_mutable_metaclass_name()
73 # now create the metaclass
75 if ($class eq 'Class::MOP::Class') {
77 $meta = $class->_new($options)
81 # it is safe to use meta here because
82 # class will always be a subclass of
83 # Class::MOP::Class, which defines meta
84 $meta = $class->meta->construct_instance($options)
87 # and check the metaclass compatibility
88 $meta->check_metaclass_compatibility();
90 Class::MOP::store_metaclass_by_name($package_name, $meta);
93 # we need to weaken any anon classes
94 # so that they can call DESTROY properly
95 Class::MOP::weaken_metaclass($package_name) if $meta->is_anon_class;
102 my $options = @_ == 1 ? $_[0] : {@_};
105 # inherited from Class::MOP::Package
106 'package' => $options->{package},
109 # since the following attributes will
110 # actually be loaded from the symbol
111 # table, and actually bypass the instance
112 # entirely, we can just leave these things
113 # listed here for reference, because they
114 # should not actually have a value associated
116 'namespace' => \undef,
118 # inherited from Class::MOP::Module
120 'authority' => \undef,
122 # defined in Class::MOP::Class
123 'superclasses' => \undef,
127 'attribute_metaclass' => $options->{'attribute_metaclass'}
128 || 'Class::MOP::Attribute',
129 'method_metaclass' => $options->{'method_metaclass'}
130 || 'Class::MOP::Method',
131 'wrapped_method_metaclass' => $options->{'wrapped_method_metaclass'}
132 || 'Class::MOP::Method::Wrapped',
133 'instance_metaclass' => $options->{'instance_metaclass'}
134 || 'Class::MOP::Instance',
138 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
139 sub update_package_cache_flag {
142 # we can manually update the cache number
143 # since we are actually adding the method
144 # to our cache as well. This avoids us
145 # having to regenerate the method_map.
147 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
150 sub check_metaclass_compatibility {
153 # this is always okay ...
154 return if ref($self) eq 'Class::MOP::Class' &&
155 $self->instance_metaclass eq 'Class::MOP::Instance';
157 my @class_list = $self->linearized_isa;
158 shift @class_list; # shift off $self->name
160 foreach my $superclass_name (@class_list) {
161 my $super_meta = Class::MOP::get_metaclass_by_name($superclass_name) || next;
164 # we need to deal with the possibility
165 # of class immutability here, and then
166 # get the name of the class appropriately
168 = $super_meta->is_immutable
169 ? $super_meta->get_mutable_metaclass_name()
172 ($self->isa($super_meta_type))
173 || confess $self->name . "->meta => (" . (ref($self)) . ")" .
174 " is not compatible with the " .
175 $superclass_name . "->meta => (" . ($super_meta_type) . ")";
177 # we also need to check that instance metaclasses
178 # are compatibile in the same the class.
179 ($self->instance_metaclass->isa($super_meta->instance_metaclass))
180 || confess $self->name . "->meta->instance_metaclass => (" . ($self->instance_metaclass) . ")" .
181 " is not compatible with the " .
182 $superclass_name . "->meta->instance_metaclass => (" . ($super_meta->instance_metaclass) . ")";
186 # backwards compat for stevan's inability to spell ;)
187 sub check_metaclass_compatability {
189 $self->check_metaclass_compatibility(@_);
196 # this should be sufficient, if you have a
197 # use case where it is not, write a test and
199 my $ANON_CLASS_SERIAL = 0;
202 # we need a sufficiently annoying prefix
203 # this should suffice for now, this is
204 # used in a couple of places below, so
205 # need to put it up here for now.
206 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
210 no warnings 'uninitialized';
211 $self->name =~ /^$ANON_CLASS_PREFIX/;
214 sub create_anon_class {
215 my ($class, %options) = @_;
216 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
217 return $class->create($package_name, %options);
221 # this will only get called for
222 # anon-classes, all other calls
223 # are assumed to occur during
224 # global destruction and so don't
225 # really need to be handled explicitly
229 return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
231 no warnings 'uninitialized';
232 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
233 # Moose does a weird thing where it replaces the metaclass for
234 # class when fixing metaclass incompatibility. In that case,
235 # we don't want to clean out the namespace now. We can detect
236 # that because Moose will explicitly update the singleton
237 # cache in Class::MOP.
238 my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
239 return if $current_meta ne $self;
241 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
243 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
244 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
246 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
251 # creating classes with MOP ...
254 my ( $class, @args ) = @_;
256 unshift @args, 'package' if @args % 2 == 1;
258 my (%options) = @args;
259 my $package_name = $options{package};
261 (ref $options{superclasses} eq 'ARRAY')
262 || confess "You must pass an ARRAY ref of superclasses"
263 if exists $options{superclasses};
265 (ref $options{attributes} eq 'ARRAY')
266 || confess "You must pass an ARRAY ref of attributes"
267 if exists $options{attributes};
269 (ref $options{methods} eq 'HASH')
270 || confess "You must pass a HASH ref of methods"
271 if exists $options{methods};
273 $class->SUPER::create(%options);
275 my (%initialize_options) = @args;
276 delete @initialize_options{qw(
284 my $meta = $class->initialize( $package_name => %initialize_options );
287 $meta->add_method('meta' => sub {
288 $class->initialize(ref($_[0]) || $_[0]);
291 $meta->superclasses(@{$options{superclasses}})
292 if exists $options{superclasses};
294 # process attributes first, so that they can
295 # install accessors, but locally defined methods
296 # can then overwrite them. It is maybe a little odd, but
297 # I think this should be the order of things.
298 if (exists $options{attributes}) {
299 foreach my $attr (@{$options{attributes}}) {
300 $meta->add_attribute($attr);
303 if (exists $options{methods}) {
304 foreach my $method_name (keys %{$options{methods}}) {
305 $meta->add_method($method_name, $options{methods}->{$method_name});
314 # all these attribute readers will be bootstrapped
315 # away in the Class::MOP bootstrap section
317 sub get_attribute_map { $_[0]->{'attributes'} }
318 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
319 sub method_metaclass { $_[0]->{'method_metaclass'} }
320 sub wrapped_method_metaclass { $_[0]->{'wrapped_method_metaclass'} }
321 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
326 my $class_name = $self->name;
328 my $current = Class::MOP::check_package_cache_flag($class_name);
330 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
331 return $self->{'methods'} ||= {};
334 $self->{_package_cache_flag} = $current;
336 my $map = $self->{'methods'} ||= {};
338 my $method_metaclass = $self->method_metaclass;
340 my $all_code = $self->get_all_package_symbols('CODE');
342 foreach my $symbol (keys %{ $all_code }) {
343 my $code = $all_code->{$symbol};
345 next if exists $map->{$symbol} &&
346 defined $map->{$symbol} &&
347 $map->{$symbol}->body == $code;
349 my ($pkg, $name) = Class::MOP::get_code_info($code);
352 # in 5.10 constant.pm the constants show up
353 # as being in the right package, but in pre-5.10
354 # they show up as constant::__ANON__ so we
355 # make an exception here to be sure that things
356 # work as expected in both.
358 unless ($pkg eq 'constant' && $name eq '__ANON__') {
359 next if ($pkg || '') ne $class_name ||
360 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
363 $map->{$symbol} = $method_metaclass->wrap(
365 associated_metaclass => $self,
366 package_name => $class_name,
374 # Instance Construction & Cloning
380 # we need to protect the integrity of the
381 # Class::MOP::Class singletons here, so we
382 # delegate this to &construct_class_instance
383 # which will deal with the singletons
384 return $class->construct_class_instance(@_)
385 if $class->name->isa('Class::MOP::Class');
386 return $class->construct_instance(@_);
389 sub construct_instance {
391 my $params = @_ == 1 ? $_[0] : {@_};
392 my $meta_instance = $class->get_meta_instance();
393 my $instance = $meta_instance->create_instance();
394 foreach my $attr ($class->compute_all_applicable_attributes()) {
395 $attr->initialize_instance_slot($meta_instance, $instance, $params);
398 # this will only work for a HASH instance type
399 if ($class->is_anon_class) {
400 (Scalar::Util::reftype($instance) eq 'HASH')
401 || confess "Currently only HASH based instances are supported with instance of anon-classes";
403 # At some point we should make this official
404 # as a reserved slot name, but right now I am
405 # going to keep it here.
406 # my $RESERVED_MOP_SLOT = '__MOP__';
407 $instance->{'__MOP__'} = $class;
413 sub get_meta_instance {
415 $self->{'_meta_instance'} ||= $self->create_meta_instance();
418 sub create_meta_instance {
421 my $instance = $self->instance_metaclass->new(
422 associated_metaclass => $self,
423 attributes => [ $self->compute_all_applicable_attributes() ],
426 $self->add_meta_instance_dependencies()
427 if $instance->is_dependent_on_superclasses();
434 my $instance = shift;
435 (blessed($instance) && $instance->isa($class->name))
436 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
439 # we need to protect the integrity of the
440 # Class::MOP::Class singletons here, they
441 # should not be cloned.
442 return $instance if $instance->isa('Class::MOP::Class');
443 $class->clone_instance($instance, @_);
447 my ($class, $instance, %params) = @_;
449 || confess "You can only clone instances, ($instance) is not a blessed instance";
450 my $meta_instance = $class->get_meta_instance();
451 my $clone = $meta_instance->clone_instance($instance);
452 foreach my $attr ($class->compute_all_applicable_attributes()) {
453 if ( defined( my $init_arg = $attr->init_arg ) ) {
454 if (exists $params{$init_arg}) {
455 $attr->set_value($clone, $params{$init_arg});
462 sub rebless_instance {
463 my ($self, $instance, %params) = @_;
466 if ($instance->can('meta')) {
467 ($instance->meta->isa('Class::MOP::Class'))
468 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
469 $old_metaclass = $instance->meta;
472 $old_metaclass = $self->initialize(ref($instance));
475 my $meta_instance = $self->get_meta_instance();
477 $self->name->isa($old_metaclass->name)
478 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
481 $meta_instance->rebless_instance_structure($instance, $self);
483 foreach my $attr ( $self->compute_all_applicable_attributes ) {
484 if ( $attr->has_value($instance) ) {
485 if ( defined( my $init_arg = $attr->init_arg ) ) {
486 $params{$init_arg} = $attr->get_value($instance)
487 unless exists $params{$init_arg};
490 $attr->set_value($instance, $attr->get_value($instance));
495 foreach my $attr ($self->compute_all_applicable_attributes) {
496 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
506 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
509 @{$self->get_package_symbol($var_spec)} = @supers;
512 # on 5.8 and below, we need to call
513 # a method to get Perl to detect
514 # a cycle in the class hierarchy
515 my $class = $self->name;
519 # we need to check the metaclass
520 # compatibility here so that we can
521 # be sure that the superclass is
522 # not potentially creating an issues
523 # we don't know about
525 $self->check_metaclass_compatibility();
526 $self->update_meta_instance_dependencies();
528 @{$self->get_package_symbol($var_spec)};
534 my $super_class = $self->name;
536 if ( Class::MOP::HAVE_ISAREV() ) {
537 return @{ $super_class->mro::get_isarev() };
541 my $find_derived_classes;
542 $find_derived_classes = sub {
543 my ($outer_class) = @_;
545 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
548 for my $symbol ( keys %$symbol_table_hashref ) {
549 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
550 my $inner_class = $1;
552 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
556 ? "${outer_class}::$inner_class"
559 if ( $class->isa($super_class) and $class ne $super_class ) {
560 push @derived_classes, $class;
563 next SYMBOL if $class eq 'main'; # skip 'main::*'
565 $find_derived_classes->($class);
569 my $root_class = q{};
570 $find_derived_classes->($root_class);
572 undef $find_derived_classes;
574 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
576 return @derived_classes;
582 return @{ mro::get_linear_isa( (shift)->name ) };
585 sub class_precedence_list {
587 my $name = $self->name;
589 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
591 # We need to check for circular inheritance here
592 # if we are are not on 5.10, cause 5.8 detects it
593 # late. This will do nothing if all is well, and
594 # blow up otherwise. Yes, it's an ugly hack, better
595 # suggestions are welcome.
597 ($name || return)->isa('This is a test for circular inheritance')
600 # if our mro is c3, we can
601 # just grab the linear_isa
602 if (mro::get_mro($name) eq 'c3') {
603 return @{ mro::get_linear_isa($name) }
607 # we can't grab the linear_isa for dfs
608 # since it has all the duplicates
613 $self->initialize($_)->class_precedence_list()
614 } $self->superclasses()
621 sub wrap_method_body {
622 my ( $self, %args ) = @_;
624 ('CODE' eq ref $args{body})
625 || confess "Your code block must be a CODE reference";
627 $self->method_metaclass->wrap(
628 package_name => $self->name,
634 my ($self, $method_name, $method) = @_;
635 (defined $method_name && $method_name)
636 || confess "You must define a method name";
639 if (blessed($method)) {
640 $body = $method->body;
641 if ($method->package_name ne $self->name) {
642 $method = $method->clone(
643 package_name => $self->name,
645 ) if $method->can('clone');
650 $method = $self->wrap_method_body( body => $body, name => $method_name );
653 $method->attach_to_class($self);
655 # This used to call get_method_map, which meant we would build all
656 # the method objects for the class just because we added one
657 # method. This is hackier, but quicker too.
658 $self->{methods}{$method_name} = $method;
660 my $full_method_name = ($self->name . '::' . $method_name);
661 $self->add_package_symbol(
662 { sigil => '&', type => 'CODE', name => $method_name },
663 Class::MOP::subname($full_method_name => $body)
668 my $fetch_and_prepare_method = sub {
669 my ($self, $method_name) = @_;
670 my $wrapped_metaclass = $self->wrapped_method_metaclass;
672 my $method = $self->get_method($method_name);
673 # if we dont have local ...
675 # try to find the next method
676 $method = $self->find_next_method_by_name($method_name);
677 # die if it does not exist
679 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
680 # and now make sure to wrap it
681 # even if it is already wrapped
682 # because we need a new sub ref
683 $method = $wrapped_metaclass->wrap($method);
686 # now make sure we wrap it properly
687 $method = $wrapped_metaclass->wrap($method)
688 unless $method->isa($wrapped_metaclass);
690 $self->add_method($method_name => $method);
694 sub add_before_method_modifier {
695 my ($self, $method_name, $method_modifier) = @_;
696 (defined $method_name && $method_name)
697 || confess "You must pass in a method name";
698 my $method = $fetch_and_prepare_method->($self, $method_name);
699 $method->add_before_modifier(
700 Class::MOP::subname(':before' => $method_modifier)
704 sub add_after_method_modifier {
705 my ($self, $method_name, $method_modifier) = @_;
706 (defined $method_name && $method_name)
707 || confess "You must pass in a method name";
708 my $method = $fetch_and_prepare_method->($self, $method_name);
709 $method->add_after_modifier(
710 Class::MOP::subname(':after' => $method_modifier)
714 sub add_around_method_modifier {
715 my ($self, $method_name, $method_modifier) = @_;
716 (defined $method_name && $method_name)
717 || confess "You must pass in a method name";
718 my $method = $fetch_and_prepare_method->($self, $method_name);
719 $method->add_around_modifier(
720 Class::MOP::subname(':around' => $method_modifier)
725 # the methods above used to be named like this:
726 # ${pkg}::${method}:(before|after|around)
727 # but this proved problematic when using one modifier
728 # to wrap multiple methods (something which is likely
729 # to happen pretty regularly IMO). So instead of naming
730 # it like this, I have chosen to just name them purely
731 # with their modifier names, like so:
732 # :(before|after|around)
733 # The fact is that in a stack trace, it will be fairly
734 # evident from the context what method they are attached
735 # to, and so don't need the fully qualified name.
741 $self->add_method(@_);
745 my ($self, $method_name) = @_;
746 (defined $method_name && $method_name)
747 || confess "You must define a method name";
749 exists $self->{methods}{$method_name} || exists $self->get_method_map->{$method_name};
753 my ($self, $method_name) = @_;
754 (defined $method_name && $method_name)
755 || confess "You must define a method name";
757 return $self->{methods}{$method_name} || $self->get_method_map->{$method_name};
761 my ($self, $method_name) = @_;
762 (defined $method_name && $method_name)
763 || confess "You must define a method name";
765 my $removed_method = delete $self->get_method_map->{$method_name};
767 $self->remove_package_symbol(
768 { sigil => '&', type => 'CODE', name => $method_name }
771 $removed_method->detach_from_class if $removed_method;
773 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
775 return $removed_method;
778 sub get_method_list {
780 keys %{$self->get_method_map};
783 sub find_method_by_name {
784 my ($self, $method_name) = @_;
785 (defined $method_name && $method_name)
786 || confess "You must define a method name to find";
787 foreach my $class ($self->linearized_isa) {
788 # fetch the meta-class ...
789 my $meta = $self->initialize($class);
790 return $meta->get_method($method_name)
791 if $meta->has_method($method_name);
796 sub get_all_methods {
798 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
799 return values %methods;
803 sub compute_all_applicable_methods {
807 class => $_->package_name,
808 code => $_, # sigh, overloading
810 } shift->get_all_methods(@_);
813 sub get_all_method_names {
816 grep { $uniq{$_}++ == 0 } map { $_->name } $self->get_all_methods;
819 sub find_all_methods_by_name {
820 my ($self, $method_name) = @_;
821 (defined $method_name && $method_name)
822 || confess "You must define a method name to find";
824 foreach my $class ($self->linearized_isa) {
825 # fetch the meta-class ...
826 my $meta = $self->initialize($class);
828 name => $method_name,
830 code => $meta->get_method($method_name)
831 } if $meta->has_method($method_name);
836 sub find_next_method_by_name {
837 my ($self, $method_name) = @_;
838 (defined $method_name && $method_name)
839 || confess "You must define a method name to find";
840 my @cpl = $self->linearized_isa;
841 shift @cpl; # discard ourselves
842 foreach my $class (@cpl) {
843 # fetch the meta-class ...
844 my $meta = $self->initialize($class);
845 return $meta->get_method($method_name)
846 if $meta->has_method($method_name);
855 # either we have an attribute object already
856 # or we need to create one from the args provided
857 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
858 # make sure it is derived from the correct type though
859 ($attribute->isa('Class::MOP::Attribute'))
860 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
862 # first we attach our new attribute
863 # because it might need certain information
864 # about the class which it is attached to
865 $attribute->attach_to_class($self);
867 # then we remove attributes of a conflicting
868 # name here so that we can properly detach
869 # the old attr object, and remove any
870 # accessors it would have generated
871 if ( $self->has_attribute($attribute->name) ) {
872 $self->remove_attribute($attribute->name);
874 $self->invalidate_meta_instances();
877 # then onto installing the new accessors
878 $self->get_attribute_map->{$attribute->name} = $attribute;
880 # invalidate package flag here
881 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
883 $self->remove_attribute($attribute->name);
890 sub update_meta_instance_dependencies {
893 if ( $self->{meta_instance_dependencies} ) {
894 return $self->add_meta_instance_dependencies;
898 sub add_meta_instance_dependencies {
901 $self->remove_meta_instance_depdendencies;
903 my @attrs = $self->compute_all_applicable_attributes();
906 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
908 foreach my $class ( @classes ) {
909 $class->add_dependent_meta_instance($self);
912 $self->{meta_instance_dependencies} = \@classes;
915 sub remove_meta_instance_depdendencies {
918 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
919 foreach my $class ( @$classes ) {
920 $class->remove_dependent_meta_instance($self);
930 sub add_dependent_meta_instance {
931 my ( $self, $metaclass ) = @_;
932 push @{ $self->{dependent_meta_instances} }, $metaclass;
935 sub remove_dependent_meta_instance {
936 my ( $self, $metaclass ) = @_;
937 my $name = $metaclass->name;
938 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
941 sub invalidate_meta_instances {
943 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
946 sub invalidate_meta_instance {
948 undef $self->{_meta_instance};
952 my ($self, $attribute_name) = @_;
953 (defined $attribute_name && $attribute_name)
954 || confess "You must define an attribute name";
955 exists $self->get_attribute_map->{$attribute_name};
959 my ($self, $attribute_name) = @_;
960 (defined $attribute_name && $attribute_name)
961 || confess "You must define an attribute name";
962 return $self->get_attribute_map->{$attribute_name}
964 # this will return undef anyway, so no need ...
965 # if $self->has_attribute($attribute_name);
969 sub remove_attribute {
970 my ($self, $attribute_name) = @_;
971 (defined $attribute_name && $attribute_name)
972 || confess "You must define an attribute name";
973 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
974 return unless defined $removed_attribute;
975 delete $self->get_attribute_map->{$attribute_name};
976 $self->invalidate_meta_instances();
977 $removed_attribute->remove_accessors();
978 $removed_attribute->detach_from_class();
979 return $removed_attribute;
982 sub get_attribute_list {
984 keys %{$self->get_attribute_map};
987 sub get_all_attributes {
988 shift->compute_all_applicable_attributes(@_);
991 sub compute_all_applicable_attributes {
993 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
994 return values %attrs;
997 sub find_attribute_by_name {
998 my ($self, $attr_name) = @_;
999 foreach my $class ($self->linearized_isa) {
1000 # fetch the meta-class ...
1001 my $meta = $self->initialize($class);
1002 return $meta->get_attribute($attr_name)
1003 if $meta->has_attribute($attr_name);
1008 # check if we can reinitialize
1012 # if any local attr is defined
1013 return if $self->get_attribute_list;
1015 # or any non-declared methods
1016 if ( my @methods = values %{ $self->get_method_map } ) {
1017 my $metaclass = $self->method_metaclass;
1018 foreach my $method ( @methods ) {
1019 return if $method->isa("Class::MOP::Method::Generated");
1020 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1029 sub is_mutable { 1 }
1030 sub is_immutable { 0 }
1033 # Why I changed this (groditi)
1034 # - One Metaclass may have many Classes through many Metaclass instances
1035 # - One Metaclass should only have one Immutable Transformer instance
1036 # - Each Class may have different Immutabilizing options
1037 # - Therefore each Metaclass instance may have different Immutabilizing options
1038 # - We need to store one Immutable Transformer instance per Metaclass
1039 # - We need to store one set of Immutable Transformer options per Class
1040 # - Upon make_mutable we may delete the Immutabilizing options
1041 # - We could clean the immutable Transformer instance when there is no more
1042 # immutable Classes of that type, but we can also keep it in case
1043 # another class with this same Metaclass becomes immutable. It is a case
1044 # of trading of storing an instance to avoid unnecessary instantiations of
1045 # Immutable Transformers. You may view this as a memory leak, however
1046 # Because we have few Metaclasses, in practice it seems acceptable
1047 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1048 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1052 my %IMMUTABLE_TRANSFORMERS;
1053 my %IMMUTABLE_OPTIONS;
1055 sub get_immutable_options {
1057 return if $self->is_mutable;
1058 confess "unable to find immutabilizing options"
1059 unless exists $IMMUTABLE_OPTIONS{$self->name};
1060 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1061 delete $options{IMMUTABLE_TRANSFORMER};
1065 sub get_immutable_transformer {
1067 if( $self->is_mutable ){
1068 return $IMMUTABLE_TRANSFORMERS{$self->name} ||= $self->create_immutable_transformer;
1070 confess "unable to find transformer for immutable class"
1071 unless exists $IMMUTABLE_OPTIONS{$self->name};
1072 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1075 sub make_immutable {
1079 my $transformer = $self->get_immutable_transformer;
1080 $transformer->make_metaclass_immutable($self, \%options);
1081 $IMMUTABLE_OPTIONS{$self->name} =
1082 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1084 if( exists $options{debug} && $options{debug} ){
1085 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1086 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1094 return if $self->is_mutable;
1095 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1096 confess "unable to find immutabilizing options" unless ref $options;
1097 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1098 $transformer->make_metaclass_mutable($self, $options);
1103 sub create_immutable_transformer {
1105 my $class = Class::MOP::Immutable->new($self, {
1106 read_only => [qw/superclasses/],
1113 remove_package_symbol
1116 class_precedence_list => 'ARRAY',
1117 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
1118 get_all_methods => 'ARRAY',
1119 get_all_method_names => 'ARRAY',
1120 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
1121 compute_all_applicable_attributes => 'ARRAY',
1122 get_meta_instance => 'SCALAR',
1123 get_method_map => 'SCALAR',
1126 # this is ugly, but so are typeglobs,
1127 # so whattayahgonnadoboutit
1130 add_package_symbol => sub {
1131 my $original = shift;
1132 confess "Cannot add package symbols to an immutable metaclass"
1133 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1135 # This is a workaround for a bug in 5.8.1 which thinks that
1136 # goto $original->body
1137 # is trying to go to a label
1138 my $body = $original->body;
1154 Class::MOP::Class - Class Meta Object
1158 # assuming that class Foo
1159 # has been defined, you can
1161 # use this for introspection ...
1163 # add a method to Foo ...
1164 Foo->meta->add_method('bar' => sub { ... })
1166 # get a list of all the classes searched
1167 # the method dispatcher in the correct order
1168 Foo->meta->class_precedence_list()
1170 # remove a method from Foo
1171 Foo->meta->remove_method('bar');
1173 # or use this to actually create classes ...
1175 Class::MOP::Class->create('Bar' => (
1177 superclasses => [ 'Foo' ],
1179 Class::MOP:::Attribute->new('$bar'),
1180 Class::MOP:::Attribute->new('$baz'),
1183 calculate_bar => sub { ... },
1184 construct_baz => sub { ... }
1190 This is the largest and currently most complex part of the Perl 5
1191 meta-object protocol. It controls the introspection and
1192 manipulation of Perl 5 classes (and it can create them too). The
1193 best way to understand what this module can do, is to read the
1194 documentation for each of it's methods.
1198 B<Class::MOP::Class> is a subclass of L<Class::MOP::Module>
1202 =head2 Self Introspection
1208 This will return a B<Class::MOP::Class> instance which is related
1209 to this class. Thereby allowing B<Class::MOP::Class> to actually
1212 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1213 bootstrap this module by installing a number of attribute meta-objects
1214 into it's metaclass. This will allow this class to reap all the benifits
1215 of the MOP when subclassing it.
1219 =head2 Class construction
1221 These methods will handle creating B<Class::MOP::Class> objects,
1222 which can be used to both create new classes, and analyze
1223 pre-existing classes.
1225 This module will internally store references to all the instances
1226 you create with these methods, so that they do not need to be
1227 created any more than nessecary. Basically, they are singletons.
1231 =item B<create ($package_name,
1232 version =E<gt> ?$version,
1233 authority =E<gt> ?$authority,
1234 superclasses =E<gt> ?@superclasses,
1235 methods =E<gt> ?%methods,
1236 attributes =E<gt> ?%attributes)>
1238 This returns a B<Class::MOP::Class> object, bringing the specified
1239 C<$package_name> into existence and adding any of the C<$version>,
1240 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1243 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1244 methods =E<gt> ?%methods,
1245 attributes =E<gt> ?%attributes)>
1247 This will create an anonymous class, it works much like C<create> but
1248 it does not need a C<$package_name>. Instead it will create a suitably
1249 unique package name for you to stash things into.
1251 On very important distinction is that anon classes are destroyed once
1252 the metaclass they are attached to goes out of scope. In the DESTROY
1253 method, the created package will be removed from the symbol table.
1255 It is also worth noting that any instances created with an anon-class
1256 will keep a special reference to the anon-meta which will prevent the
1257 anon-class from going out of scope until all instances of it have also
1258 been destroyed. This however only works for HASH based instance types,
1259 as we use a special reserved slot (C<__MOP__>) to store this.
1261 =item B<initialize ($package_name, %options)>
1263 This initializes and returns returns a B<Class::MOP::Class> object for
1264 a given a C<$package_name>. If a metaclass already exists for the
1265 package, it simply returns it instead of creating a new one.
1267 =item B<construct_class_instance (%options)>
1269 This will construct an instance of B<Class::MOP::Class>, it is
1270 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1271 to use C<construct_instance> once all the bootstrapping is done. This
1272 method is used internally by C<initialize> and should never be called
1273 from outside of that method really.
1275 =item B<check_metaclass_compatibility>
1277 This method is called as the very last thing in the
1278 C<construct_class_instance> method. This will check that the
1279 metaclass you are creating is compatible with the metaclasses of all
1280 your ancestors. For more inforamtion about metaclass compatibility
1281 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1283 =item B<update_package_cache_flag>
1285 This will reset the package cache flag for this particular metaclass
1286 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1287 function. This is very rarely needed from outside of C<Class::MOP::Class>
1288 but in some cases you might want to use it, so it is here.
1290 =item B<reset_package_cache_flag>
1292 Clears the package cache flag to announce to the internals that we need
1293 to rebuild the method map.
1295 =item B<add_meta_instance_dependencies>
1297 Registers this class as dependent on its superclasses.
1299 Only superclasses from which this class inherits attributes will be added.
1301 =item B<remove_meta_instance_depdendencies>
1303 Unregisters this class from its superclasses.
1305 =item B<update_meta_instance_dependencies>
1307 Reregisters if necessary.
1309 =item B<add_dependent_meta_instance> $metaclass
1311 Registers the class as having a meta instance dependent on this class.
1313 =item B<remove_dependent_meta_instance> $metaclass
1315 Remove the class from the list of dependent classes.
1317 =item B<invalidate_meta_instances>
1319 Clears the cached meta instance for this metaclass and all of the registered
1320 classes with dependent meta instances.
1322 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1325 =item B<invalidate_meta_instance>
1327 Used by C<invalidate_meta_instances>.
1331 =head2 Object instance construction and cloning
1333 These methods are B<entirely optional>, it is up to you whether you want
1338 =item B<instance_metaclass>
1340 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1341 for more information on the instance metaclasses.
1343 =item B<get_meta_instance>
1345 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1346 of a new instance of the class.
1348 =item B<create_meta_instance>
1350 Called by C<get_meta_instance> if necessary.
1352 =item B<new_object (%params)>
1354 This is a convience method for creating a new object of the class, and
1355 blessing it into the appropriate package as well. Ideally your class
1356 would call a C<new> this method like so:
1359 my ($class, %param) = @_;
1360 $class->meta->new_object(%params);
1363 =item B<construct_instance (%params)>
1365 This method is used to construct an instance structure suitable for
1366 C<bless>-ing into your package of choice. It works in conjunction
1367 with the Attribute protocol to collect all applicable attributes.
1369 This will construct an instance using a HASH ref as storage
1370 (currently only HASH references are supported). This will collect all
1371 the applicable attributes and layout out the fields in the HASH ref,
1372 it will then initialize them using either use the corresponding key
1373 in C<%params> or any default value or initializer found in the
1374 attribute meta-object.
1376 =item B<clone_object ($instance, %params)>
1378 This is a convience method for cloning an object instance, then
1379 blessing it into the appropriate package. This method will call
1380 C<clone_instance>, which performs a shallow copy of the object,
1381 see that methods documentation for more details. Ideally your
1382 class would call a C<clone> this method like so:
1384 sub MyClass::clone {
1385 my ($self, %param) = @_;
1386 $self->meta->clone_object($self, %params);
1389 =item B<clone_instance($instance, %params)>
1391 This method is a compliment of C<construct_instance> (which means if
1392 you override C<construct_instance>, you need to override this one too),
1393 and clones the instance shallowly.
1395 The cloned structure returned is (like with C<construct_instance>) an
1396 unC<bless>ed HASH reference, it is your responsibility to then bless
1397 this cloned structure into the right class (which C<clone_object> will
1400 As of 0.11, this method will clone the C<$instance> structure shallowly,
1401 as opposed to the deep cloning implemented in prior versions. After much
1402 thought, research and discussion, I have decided that anything but basic
1403 shallow cloning is outside the scope of the meta-object protocol. I
1404 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1405 is too I<context-specific> to be part of the MOP.
1407 =item B<rebless_instance($instance, ?%params)>
1409 This will change the class of C<$instance> to the class of the invoking
1410 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1411 itself. You may pass in optional C<%params> which are like constructor
1412 params and will override anything already defined in the instance.
1416 =head2 Informational
1418 These are a few predicate methods for asking information about the class.
1422 =item B<is_anon_class>
1424 This returns true if the class is a C<Class::MOP::Class> created anon class.
1428 This returns true if the class is still mutable.
1430 =item B<is_immutable>
1432 This returns true if the class has been made immutable.
1434 =item B<is_pristine>
1436 Checks whether the class has any data that will be lost if C<reinitialize> is
1441 =head2 Inheritance Relationships
1445 =item B<superclasses (?@superclasses)>
1447 This is a read-write attribute which represents the superclass
1448 relationships of the class the B<Class::MOP::Class> instance is
1449 associated with. Basically, it can get and set the C<@ISA> for you.
1451 =item B<class_precedence_list>
1453 This computes the a list of all the class's ancestors in the same order
1454 in which method dispatch will be done. This is similair to what
1455 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1457 =item B<linearized_isa>
1459 This returns a list based on C<class_precedence_list> but with all
1464 This returns a list of subclasses for this class.
1472 =item B<get_method_map>
1474 Returns a HASH ref of name to L<Class::MOP::Method> instance mapping
1477 =item B<method_metaclass>
1479 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1480 for more information on the method metaclasses.
1482 =item B<wrap_method_body(%attrs)>
1484 Wrap a code ref (C<$attrs{body>) with C<method_metaclass>.
1486 =item B<add_method ($method_name, $method)>
1488 This will take a C<$method_name> and CODE reference or meta method
1489 objectand install it into the class's package.
1491 You are strongly encouraged to pass a meta method object instead of a
1492 code reference. If you do so, that object gets stored as part of the
1493 class's method map, providing more useful information about the method
1496 When you provide a method object, this method will clone that object
1497 if the object's package name does not match the class name. This lets
1498 us track the original source of any methods added from other classes
1499 (notably Moose roles).
1502 This does absolutely nothing special to C<$method>
1503 other than use B<Sub::Name> to make sure it is tagged with the
1504 correct name, and therefore show up correctly in stack traces and
1507 =item B<has_method ($method_name)>
1509 This just provides a simple way to check if the class implements
1510 a specific C<$method_name>. It will I<not> however, attempt to check
1511 if the class inherits the method (use C<UNIVERSAL::can> for that).
1513 This will correctly handle functions defined outside of the package
1514 that use a fully qualified name (C<sub Package::name { ... }>).
1516 This will correctly handle functions renamed with B<Sub::Name> and
1517 installed using the symbol tables. However, if you are naming the
1518 subroutine outside of the package scope, you must use the fully
1519 qualified name, including the package name, for C<has_method> to
1520 correctly identify it.
1522 This will attempt to correctly ignore functions imported from other
1523 packages using B<Exporter>. It breaks down if the function imported
1524 is an C<__ANON__> sub (such as with C<use constant>), which very well
1525 may be a valid method being applied to the class.
1527 In short, this method cannot always be trusted to determine if the
1528 C<$method_name> is actually a method. However, it will DWIM about
1529 90% of the time, so it's a small trade off I think.
1531 =item B<get_method ($method_name)>
1533 This will return a Class::MOP::Method instance related to the specified
1534 C<$method_name>, or return undef if that method does not exist.
1536 The Class::MOP::Method is codifiable, so you can use it like a normal
1537 CODE reference, see L<Class::MOP::Method> for more information.
1539 =item B<find_method_by_name ($method_name)>
1541 This will return a L<Class::MOP::Method> instance for the specified
1542 C<$method_name>, or return undef if that method does not exist.
1544 Unlike C<get_method> this will also look in the superclasses.
1546 =item B<remove_method ($method_name)>
1548 This will attempt to remove a given C<$method_name> from the class.
1549 It will return the L<Class::MOP::Method> instance that it has removed,
1550 and will attempt to use B<Sub::Name> to clear the methods associated
1553 =item B<get_method_list>
1555 This will return a list of method names for all I<locally> defined
1556 methods. It does B<not> provide a list of all applicable methods,
1557 including any inherited ones. If you want a list of all applicable
1558 methods, use the C<compute_all_applicable_methods> method.
1560 =item B<get_all_methods>
1562 This will traverse the inheritance hierarchy and return a list of all
1563 the applicable L<Class::MOP::Method> objects for this class.
1565 =item B<compute_all_applicable_methods>
1569 This method returns a list of hashes describing the all the methods of the
1572 Use L<get_all_methods>, which is easier/better/faster. This method predates
1573 L<Class::MOP::Method>.
1575 =item B<get_all_method_names>
1577 This will traverse the inheritance hierarchy and return a list of all the
1578 applicable method names for this class. Duplicate names are removed, but the
1579 order the methods come out is not defined.
1581 =item B<find_all_methods_by_name ($method_name)>
1583 This will traverse the inheritence hierarchy and locate all methods
1584 with a given C<$method_name>. Similar to
1585 C<compute_all_applicable_methods> it returns a list of HASH references
1586 with the following information; method name (which will always be the
1587 same as C<$method_name>), the name of the class in which the method
1588 lives and a CODE reference for the actual method.
1590 The list of methods produced is a distinct list, meaning there are no
1591 duplicates in it. This is especially useful for things like object
1592 initialization and destruction where you only want the method called
1593 once, and in the correct order.
1595 =item B<find_next_method_by_name ($method_name)>
1597 This will return the first method to match a given C<$method_name> in
1598 the superclasses, this is basically equivalent to calling
1599 C<SUPER::$method_name>, but it can be dispatched at runtime.
1601 =item B<alias_method ($method_name, $method)>
1603 B<NOTE>: This method is now deprecated. Just use C<add_method>
1608 =head2 Method Modifiers
1610 Method modifiers are a concept borrowed from CLOS, in which a method
1611 can be wrapped with I<before>, I<after> and I<around> method modifiers
1612 that will be called everytime the method is called.
1614 =head3 How method modifiers work?
1616 Method modifiers work by wrapping the original method and then replacing
1617 it in the classes symbol table. The wrappers will handle calling all the
1618 modifiers in the appropariate orders and preserving the calling context
1619 for the original method.
1621 Each method modifier serves a particular purpose, which may not be
1622 obvious to users of other method wrapping modules. To start with, the
1623 return values of I<before> and I<after> modifiers are ignored. This is
1624 because thier purpose is B<not> to filter the input and output of the
1625 primary method (this is done with an I<around> modifier). This may seem
1626 like an odd restriction to some, but doing this allows for simple code
1627 to be added at the begining or end of a method call without jeapordizing
1628 the normal functioning of the primary method or placing any extra
1629 responsibility on the code of the modifier. Of course if you have more
1630 complex needs, then use the I<around> modifier, which uses a variation
1631 of continutation passing style to allow for a high degree of flexibility.
1633 Before and around modifiers are called in last-defined-first-called order,
1634 while after modifiers are called in first-defined-first-called order. So
1635 the call tree might looks something like this:
1647 To see examples of using method modifiers, see the following examples
1648 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1649 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1650 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1652 =head3 What is the performance impact?
1654 Of course there is a performance cost associated with method modifiers,
1655 but we have made every effort to make that cost be directly proportional
1656 to the amount of modifier features you utilize.
1658 The wrapping method does it's best to B<only> do as much work as it
1659 absolutely needs to. In order to do this we have moved some of the
1660 performance costs to set-up time, where they are easier to amortize.
1662 All this said, my benchmarks have indicated the following:
1664 simple wrapper with no modifiers 100% slower
1665 simple wrapper with simple before modifier 400% slower
1666 simple wrapper with simple after modifier 450% slower
1667 simple wrapper with simple around modifier 500-550% slower
1668 simple wrapper with all 3 modifiers 1100% slower
1670 These numbers may seem daunting, but you must remember, every feature
1671 comes with some cost. To put things in perspective, just doing a simple
1672 C<AUTOLOAD> which does nothing but extract the name of the method called
1673 and return it costs about 400% over a normal method call.
1677 =item B<add_before_method_modifier ($method_name, $code)>
1679 This will wrap the method at C<$method_name> and the supplied C<$code>
1680 will be passed the C<@_> arguments, and called before the original
1681 method is called. As specified above, the return value of the I<before>
1682 method modifiers is ignored, and it's ability to modify C<@_> is
1683 fairly limited. If you need to do either of these things, use an
1684 C<around> method modifier.
1686 =item B<add_after_method_modifier ($method_name, $code)>
1688 This will wrap the method at C<$method_name> so that the original
1689 method will be called, it's return values stashed, and then the
1690 supplied C<$code> will be passed the C<@_> arguments, and called.
1691 As specified above, the return value of the I<after> method
1692 modifiers is ignored, and it cannot modify the return values of
1693 the original method. If you need to do either of these things, use an
1694 C<around> method modifier.
1696 =item B<add_around_method_modifier ($method_name, $code)>
1698 This will wrap the method at C<$method_name> so that C<$code>
1699 will be called and passed the original method as an extra argument
1700 at the begining of the C<@_> argument list. This is a variation of
1701 continuation passing style, where the function prepended to C<@_>
1702 can be considered a continuation. It is up to C<$code> if it calls
1703 the original method or not, there is no restriction on what the
1704 C<$code> can or cannot do.
1710 It should be noted that since there is no one consistent way to define
1711 the attributes of a class in Perl 5. These methods can only work with
1712 the information given, and can not easily discover information on
1713 their own. See L<Class::MOP::Attribute> for more details.
1717 =item B<attribute_metaclass>
1719 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1720 for more information on the attribute metaclasses.
1722 =item B<get_attribute_map>
1724 This returns a HASH ref of name to attribute meta-object mapping.
1726 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1728 This stores the C<$attribute_meta_object> (or creates one from the
1729 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1730 instance associated with the given class. Unlike methods, attributes
1731 within the MOP are stored as meta-information only. They will be used
1732 later to construct instances from (see C<construct_instance> above).
1733 More details about the attribute meta-objects can be found in the
1734 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1737 It should be noted that any accessor, reader/writer or predicate
1738 methods which the C<$attribute_meta_object> has will be installed
1739 into the class at this time.
1742 If an attribute already exists for C<$attribute_name>, the old one
1743 will be removed (as well as removing all it's accessors), and then
1746 =item B<has_attribute ($attribute_name)>
1748 Checks to see if this class has an attribute by the name of
1749 C<$attribute_name> and returns a boolean.
1751 =item B<get_attribute ($attribute_name)>
1753 Returns the attribute meta-object associated with C<$attribute_name>,
1754 if none is found, it will return undef.
1756 =item B<remove_attribute ($attribute_name)>
1758 This will remove the attribute meta-object stored at
1759 C<$attribute_name>, then return the removed attribute meta-object.
1762 Removing an attribute will only affect future instances of
1763 the class, it will not make any attempt to remove the attribute from
1764 any existing instances of the class.
1766 It should be noted that any accessor, reader/writer or predicate
1767 methods which the attribute meta-object stored at C<$attribute_name>
1768 has will be removed from the class at this time. This B<will> make
1769 these attributes somewhat inaccessable in previously created
1770 instances. But if you are crazy enough to do this at runtime, then
1771 you are crazy enough to deal with something like this :).
1773 =item B<get_attribute_list>
1775 This returns a list of attribute names which are defined in the local
1776 class. If you want a list of all applicable attributes for a class,
1777 use the C<compute_all_applicable_attributes> method.
1779 =item B<compute_all_applicable_attributes>
1781 =item B<get_all_attributes>
1783 This will traverse the inheritance hierarchy and return a list of all
1784 the applicable L<Class::MOP::Attribute> objects for this class.
1786 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1788 =item B<find_attribute_by_name ($attr_name)>
1790 This method will traverse the inheritance hierarchy and find the
1791 first attribute whose name matches C<$attr_name>, then return it.
1792 It will return undef if nothing is found.
1796 =head2 Class Immutability
1800 =item B<make_immutable (%options)>
1802 This method will invoke a tranforamtion upon the class which will
1803 make it immutable. Details of this transformation can be found in
1804 the L<Class::MOP::Immutable> documentation.
1806 =item B<make_mutable>
1808 This method will reverse tranforamtion upon the class which
1811 =item B<get_immutable_transformer>
1813 Return a transformer suitable for making this class immutable or, if this
1814 class is immutable, the transformer used to make it immutable.
1816 =item B<get_immutable_options>
1818 If the class is immutable, return the options used to make it immutable.
1820 =item B<create_immutable_transformer>
1822 Create a transformer suitable for making this class immutable
1828 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1830 =head1 COPYRIGHT AND LICENSE
1832 Copyright 2006-2008 by Infinity Interactive, Inc.
1834 L<http://www.iinteractive.com>
1836 This library is free software; you can redistribute it and/or modify
1837 it under the same terms as Perl itself.