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 = '0.76';
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,
117 # inherited from Class::MOP::Module
119 'authority' => \undef,
120 # defined in Class::MOP::Class
121 'superclasses' => \undef,
125 'attribute_metaclass' => $options->{'attribute_metaclass'} || 'Class::MOP::Attribute',
126 'method_metaclass' => $options->{'method_metaclass'} || 'Class::MOP::Method',
127 'wrapped_method_metaclass' => $options->{'wrapped_method_metaclass'} || 'Class::MOP::Method::Wrapped',
128 'instance_metaclass' => $options->{'instance_metaclass'} || 'Class::MOP::Instance',
132 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
133 sub update_package_cache_flag {
136 # we can manually update the cache number
137 # since we are actually adding the method
138 # to our cache as well. This avoids us
139 # having to regenerate the method_map.
141 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
144 sub check_metaclass_compatibility {
147 # this is always okay ...
148 return if ref($self) eq 'Class::MOP::Class' &&
149 $self->instance_metaclass eq 'Class::MOP::Instance';
151 my @class_list = $self->linearized_isa;
152 shift @class_list; # shift off $self->name
154 foreach my $class_name (@class_list) {
155 my $meta = Class::MOP::get_metaclass_by_name($class_name) || next;
158 # we need to deal with the possibility
159 # of class immutability here, and then
160 # get the name of the class appropriately
161 my $meta_type = ($meta->is_immutable
162 ? $meta->get_mutable_metaclass_name()
165 ($self->isa($meta_type))
166 || confess $self->name . "->meta => (" . (ref($self)) . ")" .
167 " is not compatible with the " .
168 $class_name . "->meta => (" . ($meta_type) . ")";
170 # we also need to check that instance metaclasses
171 # are compatibile in the same the class.
172 ($self->instance_metaclass->isa($meta->instance_metaclass))
173 || confess $self->name . "->meta->instance_metaclass => (" . ($self->instance_metaclass) . ")" .
174 " is not compatible with the " .
175 $class_name . "->meta->instance_metaclass => (" . ($meta->instance_metaclass) . ")";
179 # backwards compat for stevan's inability to spell ;)
180 sub check_metaclass_compatability {
182 $self->check_metaclass_compatibility(@_);
189 # this should be sufficient, if you have a
190 # use case where it is not, write a test and
192 my $ANON_CLASS_SERIAL = 0;
195 # we need a sufficiently annoying prefix
196 # this should suffice for now, this is
197 # used in a couple of places below, so
198 # need to put it up here for now.
199 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
203 no warnings 'uninitialized';
204 $self->name =~ /^$ANON_CLASS_PREFIX/;
207 sub create_anon_class {
208 my ($class, %options) = @_;
209 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
210 return $class->create($package_name, %options);
214 # this will only get called for
215 # anon-classes, all other calls
216 # are assumed to occur during
217 # global destruction and so don't
218 # really need to be handled explicitly
222 return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
224 no warnings 'uninitialized';
225 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
226 # Moose does a weird thing where it replaces the metaclass for
227 # class when fixing metaclass incompatibility. In that case,
228 # we don't want to clean out the namespace now. We can detect
229 # that because Moose will explicitly update the singleton
230 # cache in Class::MOP.
231 my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
232 return if $current_meta ne $self;
234 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
236 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
237 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
239 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
244 # creating classes with MOP ...
247 my ( $class, @args ) = @_;
249 unshift @args, 'package' if @args % 2 == 1;
251 my (%options) = @args;
252 my $package_name = $options{package};
254 (ref $options{superclasses} eq 'ARRAY')
255 || confess "You must pass an ARRAY ref of superclasses"
256 if exists $options{superclasses};
258 (ref $options{attributes} eq 'ARRAY')
259 || confess "You must pass an ARRAY ref of attributes"
260 if exists $options{attributes};
262 (ref $options{methods} eq 'HASH')
263 || confess "You must pass a HASH ref of methods"
264 if exists $options{methods};
266 $class->SUPER::create(%options);
268 my (%initialize_options) = @args;
269 delete @initialize_options{qw(
277 my $meta = $class->initialize( $package_name => %initialize_options );
280 $meta->add_method('meta' => sub {
281 $class->initialize(ref($_[0]) || $_[0]);
284 $meta->superclasses(@{$options{superclasses}})
285 if exists $options{superclasses};
287 # process attributes first, so that they can
288 # install accessors, but locally defined methods
289 # can then overwrite them. It is maybe a little odd, but
290 # I think this should be the order of things.
291 if (exists $options{attributes}) {
292 foreach my $attr (@{$options{attributes}}) {
293 $meta->add_attribute($attr);
296 if (exists $options{methods}) {
297 foreach my $method_name (keys %{$options{methods}}) {
298 $meta->add_method($method_name, $options{methods}->{$method_name});
307 # all these attribute readers will be bootstrapped
308 # away in the Class::MOP bootstrap section
310 sub get_attribute_map { $_[0]->{'attributes'} }
311 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
312 sub method_metaclass { $_[0]->{'method_metaclass'} }
313 sub wrapped_method_metaclass { $_[0]->{'wrapped_method_metaclass'} }
314 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
319 my $class_name = $self->name;
321 my $current = Class::MOP::check_package_cache_flag($class_name);
323 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
324 return $self->{'methods'} ||= {};
327 $self->{_package_cache_flag} = $current;
329 my $map = $self->{'methods'} ||= {};
331 my $method_metaclass = $self->method_metaclass;
333 my $all_code = $self->get_all_package_symbols('CODE');
335 foreach my $symbol (keys %{ $all_code }) {
336 my $code = $all_code->{$symbol};
338 next if exists $map->{$symbol} &&
339 defined $map->{$symbol} &&
340 $map->{$symbol}->body == $code;
342 my ($pkg, $name) = Class::MOP::get_code_info($code);
345 # in 5.10 constant.pm the constants show up
346 # as being in the right package, but in pre-5.10
347 # they show up as constant::__ANON__ so we
348 # make an exception here to be sure that things
349 # work as expected in both.
351 unless ($pkg eq 'constant' && $name eq '__ANON__') {
352 next if ($pkg || '') ne $class_name ||
353 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
356 $map->{$symbol} = $method_metaclass->wrap(
358 associated_metaclass => $self,
359 package_name => $class_name,
367 # Instance Construction & Cloning
373 # we need to protect the integrity of the
374 # Class::MOP::Class singletons here, so we
375 # delegate this to &construct_class_instance
376 # which will deal with the singletons
377 return $class->construct_class_instance(@_)
378 if $class->name->isa('Class::MOP::Class');
379 return $class->construct_instance(@_);
382 sub construct_instance {
384 my $params = @_ == 1 ? $_[0] : {@_};
385 my $meta_instance = $class->get_meta_instance();
386 my $instance = $meta_instance->create_instance();
387 foreach my $attr ($class->compute_all_applicable_attributes()) {
388 $attr->initialize_instance_slot($meta_instance, $instance, $params);
391 # this will only work for a HASH instance type
392 if ($class->is_anon_class) {
393 (Scalar::Util::reftype($instance) eq 'HASH')
394 || confess "Currently only HASH based instances are supported with instance of anon-classes";
396 # At some point we should make this official
397 # as a reserved slot name, but right now I am
398 # going to keep it here.
399 # my $RESERVED_MOP_SLOT = '__MOP__';
400 $instance->{'__MOP__'} = $class;
406 sub get_meta_instance {
408 $self->{'_meta_instance'} ||= $self->create_meta_instance();
411 sub create_meta_instance {
414 my $instance = $self->instance_metaclass->new(
415 associated_metaclass => $self,
416 attributes => [ $self->compute_all_applicable_attributes() ],
419 $self->add_meta_instance_dependencies()
420 if $instance->is_dependent_on_superclasses();
427 my $instance = shift;
428 (blessed($instance) && $instance->isa($class->name))
429 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
432 # we need to protect the integrity of the
433 # Class::MOP::Class singletons here, they
434 # should not be cloned.
435 return $instance if $instance->isa('Class::MOP::Class');
436 $class->clone_instance($instance, @_);
440 my ($class, $instance, %params) = @_;
442 || confess "You can only clone instances, ($instance) is not a blessed instance";
443 my $meta_instance = $class->get_meta_instance();
444 my $clone = $meta_instance->clone_instance($instance);
445 foreach my $attr ($class->compute_all_applicable_attributes()) {
446 if ( defined( my $init_arg = $attr->init_arg ) ) {
447 if (exists $params{$init_arg}) {
448 $attr->set_value($clone, $params{$init_arg});
455 sub rebless_instance {
456 my ($self, $instance, %params) = @_;
459 if ($instance->can('meta')) {
460 ($instance->meta->isa('Class::MOP::Class'))
461 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
462 $old_metaclass = $instance->meta;
465 $old_metaclass = $self->initialize(ref($instance));
468 my $meta_instance = $self->get_meta_instance();
470 $self->name->isa($old_metaclass->name)
471 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
474 $meta_instance->rebless_instance_structure($instance, $self);
476 foreach my $attr ( $self->compute_all_applicable_attributes ) {
477 if ( $attr->has_value($instance) ) {
478 if ( defined( my $init_arg = $attr->init_arg ) ) {
479 $params{$init_arg} = $attr->get_value($instance)
480 unless exists $params{$init_arg};
483 $attr->set_value($instance, $attr->get_value($instance));
488 foreach my $attr ($self->compute_all_applicable_attributes) {
489 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
499 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
502 @{$self->get_package_symbol($var_spec)} = @supers;
505 # on 5.8 and below, we need to call
506 # a method to get Perl to detect
507 # a cycle in the class hierarchy
508 my $class = $self->name;
512 # we need to check the metaclass
513 # compatibility here so that we can
514 # be sure that the superclass is
515 # not potentially creating an issues
516 # we don't know about
518 $self->check_metaclass_compatibility();
519 $self->update_meta_instance_dependencies();
521 @{$self->get_package_symbol($var_spec)};
527 my $super_class = $self->name;
529 if ( Class::MOP::HAVE_ISAREV() ) {
530 return @{ $super_class->mro::get_isarev() };
534 my $find_derived_classes;
535 $find_derived_classes = sub {
536 my ($outer_class) = @_;
538 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
541 for my $symbol ( keys %$symbol_table_hashref ) {
542 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
543 my $inner_class = $1;
545 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
549 ? "${outer_class}::$inner_class"
552 if ( $class->isa($super_class) and $class ne $super_class ) {
553 push @derived_classes, $class;
556 next SYMBOL if $class eq 'main'; # skip 'main::*'
558 $find_derived_classes->($class);
562 my $root_class = q{};
563 $find_derived_classes->($root_class);
565 undef $find_derived_classes;
567 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
569 return @derived_classes;
575 return @{ mro::get_linear_isa( (shift)->name ) };
578 sub class_precedence_list {
580 my $name = $self->name;
582 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
584 # We need to check for circular inheritance here
585 # if we are are not on 5.10, cause 5.8 detects it
586 # late. This will do nothing if all is well, and
587 # blow up otherwise. Yes, it's an ugly hack, better
588 # suggestions are welcome.
590 ($name || return)->isa('This is a test for circular inheritance')
593 # if our mro is c3, we can
594 # just grab the linear_isa
595 if (mro::get_mro($name) eq 'c3') {
596 return @{ mro::get_linear_isa($name) }
600 # we can't grab the linear_isa for dfs
601 # since it has all the duplicates
606 $self->initialize($_)->class_precedence_list()
607 } $self->superclasses()
614 sub wrap_method_body {
615 my ( $self, %args ) = @_;
617 ('CODE' eq ref $args{body})
618 || confess "Your code block must be a CODE reference";
620 $self->method_metaclass->wrap(
621 package_name => $self->name,
627 my ($self, $method_name, $method) = @_;
628 (defined $method_name && $method_name)
629 || confess "You must define a method name";
632 if (blessed($method)) {
633 $body = $method->body;
634 if ($method->package_name ne $self->name) {
635 $method = $method->clone(
636 package_name => $self->name,
638 ) if $method->can('clone');
643 $method = $self->wrap_method_body( body => $body, name => $method_name );
646 $method->attach_to_class($self);
648 # This used to call get_method_map, which meant we would build all
649 # the method objects for the class just because we added one
650 # method. This is hackier, but quicker too.
651 $self->{methods}{$method_name} = $method;
653 my $full_method_name = ($self->name . '::' . $method_name);
654 $self->add_package_symbol(
655 { sigil => '&', type => 'CODE', name => $method_name },
656 Class::MOP::subname($full_method_name => $body)
661 my $fetch_and_prepare_method = sub {
662 my ($self, $method_name) = @_;
663 my $wrapped_metaclass = $self->wrapped_method_metaclass;
665 my $method = $self->get_method($method_name);
666 # if we dont have local ...
668 # try to find the next method
669 $method = $self->find_next_method_by_name($method_name);
670 # die if it does not exist
672 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
673 # and now make sure to wrap it
674 # even if it is already wrapped
675 # because we need a new sub ref
676 $method = $wrapped_metaclass->wrap($method);
679 # now make sure we wrap it properly
680 $method = $wrapped_metaclass->wrap($method)
681 unless $method->isa($wrapped_metaclass);
683 $self->add_method($method_name => $method);
687 sub add_before_method_modifier {
688 my ($self, $method_name, $method_modifier) = @_;
689 (defined $method_name && $method_name)
690 || confess "You must pass in a method name";
691 my $method = $fetch_and_prepare_method->($self, $method_name);
692 $method->add_before_modifier(
693 Class::MOP::subname(':before' => $method_modifier)
697 sub add_after_method_modifier {
698 my ($self, $method_name, $method_modifier) = @_;
699 (defined $method_name && $method_name)
700 || confess "You must pass in a method name";
701 my $method = $fetch_and_prepare_method->($self, $method_name);
702 $method->add_after_modifier(
703 Class::MOP::subname(':after' => $method_modifier)
707 sub add_around_method_modifier {
708 my ($self, $method_name, $method_modifier) = @_;
709 (defined $method_name && $method_name)
710 || confess "You must pass in a method name";
711 my $method = $fetch_and_prepare_method->($self, $method_name);
712 $method->add_around_modifier(
713 Class::MOP::subname(':around' => $method_modifier)
718 # the methods above used to be named like this:
719 # ${pkg}::${method}:(before|after|around)
720 # but this proved problematic when using one modifier
721 # to wrap multiple methods (something which is likely
722 # to happen pretty regularly IMO). So instead of naming
723 # it like this, I have chosen to just name them purely
724 # with their modifier names, like so:
725 # :(before|after|around)
726 # The fact is that in a stack trace, it will be fairly
727 # evident from the context what method they are attached
728 # to, and so don't need the fully qualified name.
734 $self->add_method(@_);
738 my ($self, $method_name) = @_;
739 (defined $method_name && $method_name)
740 || confess "You must define a method name";
742 exists $self->{methods}{$method_name} || exists $self->get_method_map->{$method_name};
746 my ($self, $method_name) = @_;
747 (defined $method_name && $method_name)
748 || confess "You must define a method name";
750 return $self->{methods}{$method_name} || $self->get_method_map->{$method_name};
754 my ($self, $method_name) = @_;
755 (defined $method_name && $method_name)
756 || confess "You must define a method name";
758 my $removed_method = delete $self->get_method_map->{$method_name};
760 $self->remove_package_symbol(
761 { sigil => '&', type => 'CODE', name => $method_name }
764 $removed_method->detach_from_class if $removed_method;
766 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
768 return $removed_method;
771 sub get_method_list {
773 keys %{$self->get_method_map};
776 sub find_method_by_name {
777 my ($self, $method_name) = @_;
778 (defined $method_name && $method_name)
779 || confess "You must define a method name to find";
780 foreach my $class ($self->linearized_isa) {
781 # fetch the meta-class ...
782 my $meta = $self->initialize($class);
783 return $meta->get_method($method_name)
784 if $meta->has_method($method_name);
789 sub get_all_methods {
791 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
792 return values %methods;
796 sub compute_all_applicable_methods {
800 class => $_->package_name,
801 code => $_, # sigh, overloading
803 } shift->get_all_methods(@_);
806 sub get_all_method_names {
809 grep { $uniq{$_}++ == 0 } map { $_->name } $self->get_all_methods;
812 sub find_all_methods_by_name {
813 my ($self, $method_name) = @_;
814 (defined $method_name && $method_name)
815 || confess "You must define a method name to find";
817 foreach my $class ($self->linearized_isa) {
818 # fetch the meta-class ...
819 my $meta = $self->initialize($class);
821 name => $method_name,
823 code => $meta->get_method($method_name)
824 } if $meta->has_method($method_name);
829 sub find_next_method_by_name {
830 my ($self, $method_name) = @_;
831 (defined $method_name && $method_name)
832 || confess "You must define a method name to find";
833 my @cpl = $self->linearized_isa;
834 shift @cpl; # discard ourselves
835 foreach my $class (@cpl) {
836 # fetch the meta-class ...
837 my $meta = $self->initialize($class);
838 return $meta->get_method($method_name)
839 if $meta->has_method($method_name);
848 # either we have an attribute object already
849 # or we need to create one from the args provided
850 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
851 # make sure it is derived from the correct type though
852 ($attribute->isa('Class::MOP::Attribute'))
853 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
855 # first we attach our new attribute
856 # because it might need certain information
857 # about the class which it is attached to
858 $attribute->attach_to_class($self);
860 # then we remove attributes of a conflicting
861 # name here so that we can properly detach
862 # the old attr object, and remove any
863 # accessors it would have generated
864 if ( $self->has_attribute($attribute->name) ) {
865 $self->remove_attribute($attribute->name);
867 $self->invalidate_meta_instances();
870 # then onto installing the new accessors
871 $self->get_attribute_map->{$attribute->name} = $attribute;
873 # invalidate package flag here
874 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
876 $self->remove_attribute($attribute->name);
883 sub update_meta_instance_dependencies {
886 if ( $self->{meta_instance_dependencies} ) {
887 return $self->add_meta_instance_dependencies;
891 sub add_meta_instance_dependencies {
894 $self->remove_meta_instance_depdendencies;
896 my @attrs = $self->compute_all_applicable_attributes();
899 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
901 foreach my $class ( @classes ) {
902 $class->add_dependent_meta_instance($self);
905 $self->{meta_instance_dependencies} = \@classes;
908 sub remove_meta_instance_depdendencies {
911 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
912 foreach my $class ( @$classes ) {
913 $class->remove_dependent_meta_instance($self);
923 sub add_dependent_meta_instance {
924 my ( $self, $metaclass ) = @_;
925 push @{ $self->{dependent_meta_instances} }, $metaclass;
928 sub remove_dependent_meta_instance {
929 my ( $self, $metaclass ) = @_;
930 my $name = $metaclass->name;
931 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
934 sub invalidate_meta_instances {
936 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
939 sub invalidate_meta_instance {
941 undef $self->{_meta_instance};
945 my ($self, $attribute_name) = @_;
946 (defined $attribute_name && $attribute_name)
947 || confess "You must define an attribute name";
948 exists $self->get_attribute_map->{$attribute_name};
952 my ($self, $attribute_name) = @_;
953 (defined $attribute_name && $attribute_name)
954 || confess "You must define an attribute name";
955 return $self->get_attribute_map->{$attribute_name}
957 # this will return undef anyway, so no need ...
958 # if $self->has_attribute($attribute_name);
962 sub remove_attribute {
963 my ($self, $attribute_name) = @_;
964 (defined $attribute_name && $attribute_name)
965 || confess "You must define an attribute name";
966 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
967 return unless defined $removed_attribute;
968 delete $self->get_attribute_map->{$attribute_name};
969 $self->invalidate_meta_instances();
970 $removed_attribute->remove_accessors();
971 $removed_attribute->detach_from_class();
972 return $removed_attribute;
975 sub get_attribute_list {
977 keys %{$self->get_attribute_map};
980 sub get_all_attributes {
981 shift->compute_all_applicable_attributes(@_);
984 sub compute_all_applicable_attributes {
986 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
987 return values %attrs;
990 sub find_attribute_by_name {
991 my ($self, $attr_name) = @_;
992 foreach my $class ($self->linearized_isa) {
993 # fetch the meta-class ...
994 my $meta = $self->initialize($class);
995 return $meta->get_attribute($attr_name)
996 if $meta->has_attribute($attr_name);
1001 # check if we can reinitialize
1005 # if any local attr is defined
1006 return if $self->get_attribute_list;
1008 # or any non-declared methods
1009 if ( my @methods = values %{ $self->get_method_map } ) {
1010 my $metaclass = $self->method_metaclass;
1011 foreach my $method ( @methods ) {
1012 return if $method->isa("Class::MOP::Method::Generated");
1013 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1022 sub is_mutable { 1 }
1023 sub is_immutable { 0 }
1026 # Why I changed this (groditi)
1027 # - One Metaclass may have many Classes through many Metaclass instances
1028 # - One Metaclass should only have one Immutable Transformer instance
1029 # - Each Class may have different Immutabilizing options
1030 # - Therefore each Metaclass instance may have different Immutabilizing options
1031 # - We need to store one Immutable Transformer instance per Metaclass
1032 # - We need to store one set of Immutable Transformer options per Class
1033 # - Upon make_mutable we may delete the Immutabilizing options
1034 # - We could clean the immutable Transformer instance when there is no more
1035 # immutable Classes of that type, but we can also keep it in case
1036 # another class with this same Metaclass becomes immutable. It is a case
1037 # of trading of storing an instance to avoid unnecessary instantiations of
1038 # Immutable Transformers. You may view this as a memory leak, however
1039 # Because we have few Metaclasses, in practice it seems acceptable
1040 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1041 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1045 my %IMMUTABLE_TRANSFORMERS;
1046 my %IMMUTABLE_OPTIONS;
1048 sub get_immutable_options {
1050 return if $self->is_mutable;
1051 confess "unable to find immutabilizing options"
1052 unless exists $IMMUTABLE_OPTIONS{$self->name};
1053 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1054 delete $options{IMMUTABLE_TRANSFORMER};
1058 sub get_immutable_transformer {
1060 if( $self->is_mutable ){
1061 return $IMMUTABLE_TRANSFORMERS{$self->name} ||= $self->create_immutable_transformer;
1063 confess "unable to find transformer for immutable class"
1064 unless exists $IMMUTABLE_OPTIONS{$self->name};
1065 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1068 sub make_immutable {
1072 my $transformer = $self->get_immutable_transformer;
1073 $transformer->make_metaclass_immutable($self, \%options);
1074 $IMMUTABLE_OPTIONS{$self->name} =
1075 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1077 if( exists $options{debug} && $options{debug} ){
1078 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1079 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1087 return if $self->is_mutable;
1088 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1089 confess "unable to find immutabilizing options" unless ref $options;
1090 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1091 $transformer->make_metaclass_mutable($self, $options);
1096 sub create_immutable_transformer {
1098 my $class = Class::MOP::Immutable->new($self, {
1099 read_only => [qw/superclasses/],
1106 remove_package_symbol
1109 class_precedence_list => 'ARRAY',
1110 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
1111 get_all_methods => 'ARRAY',
1112 get_all_method_names => 'ARRAY',
1113 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
1114 compute_all_applicable_attributes => 'ARRAY',
1115 get_meta_instance => 'SCALAR',
1116 get_method_map => 'SCALAR',
1119 # this is ugly, but so are typeglobs,
1120 # so whattayahgonnadoboutit
1123 add_package_symbol => sub {
1124 my $original = shift;
1125 confess "Cannot add package symbols to an immutable metaclass"
1126 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1128 # This is a workaround for a bug in 5.8.1 which thinks that
1129 # goto $original->body
1130 # is trying to go to a label
1131 my $body = $original->body;
1147 Class::MOP::Class - Class Meta Object
1151 # assuming that class Foo
1152 # has been defined, you can
1154 # use this for introspection ...
1156 # add a method to Foo ...
1157 Foo->meta->add_method('bar' => sub { ... })
1159 # get a list of all the classes searched
1160 # the method dispatcher in the correct order
1161 Foo->meta->class_precedence_list()
1163 # remove a method from Foo
1164 Foo->meta->remove_method('bar');
1166 # or use this to actually create classes ...
1168 Class::MOP::Class->create('Bar' => (
1170 superclasses => [ 'Foo' ],
1172 Class::MOP:::Attribute->new('$bar'),
1173 Class::MOP:::Attribute->new('$baz'),
1176 calculate_bar => sub { ... },
1177 construct_baz => sub { ... }
1183 This is the largest and currently most complex part of the Perl 5
1184 meta-object protocol. It controls the introspection and
1185 manipulation of Perl 5 classes (and it can create them too). The
1186 best way to understand what this module can do, is to read the
1187 documentation for each of it's methods.
1191 B<Class::MOP::Class> is a subclass of L<Class::MOP::Module>
1195 =head2 Self Introspection
1201 This will return a B<Class::MOP::Class> instance which is related
1202 to this class. Thereby allowing B<Class::MOP::Class> to actually
1205 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1206 bootstrap this module by installing a number of attribute meta-objects
1207 into it's metaclass. This will allow this class to reap all the benifits
1208 of the MOP when subclassing it.
1212 =head2 Class construction
1214 These methods will handle creating B<Class::MOP::Class> objects,
1215 which can be used to both create new classes, and analyze
1216 pre-existing classes.
1218 This module will internally store references to all the instances
1219 you create with these methods, so that they do not need to be
1220 created any more than nessecary. Basically, they are singletons.
1224 =item B<create ($package_name,
1225 version =E<gt> ?$version,
1226 authority =E<gt> ?$authority,
1227 superclasses =E<gt> ?@superclasses,
1228 methods =E<gt> ?%methods,
1229 attributes =E<gt> ?%attributes)>
1231 This returns a B<Class::MOP::Class> object, bringing the specified
1232 C<$package_name> into existence and adding any of the C<$version>,
1233 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1236 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1237 methods =E<gt> ?%methods,
1238 attributes =E<gt> ?%attributes)>
1240 This will create an anonymous class, it works much like C<create> but
1241 it does not need a C<$package_name>. Instead it will create a suitably
1242 unique package name for you to stash things into.
1244 On very important distinction is that anon classes are destroyed once
1245 the metaclass they are attached to goes out of scope. In the DESTROY
1246 method, the created package will be removed from the symbol table.
1248 It is also worth noting that any instances created with an anon-class
1249 will keep a special reference to the anon-meta which will prevent the
1250 anon-class from going out of scope until all instances of it have also
1251 been destroyed. This however only works for HASH based instance types,
1252 as we use a special reserved slot (C<__MOP__>) to store this.
1254 =item B<initialize ($package_name, %options)>
1256 This initializes and returns returns a B<Class::MOP::Class> object for
1257 a given a C<$package_name>. If a metaclass already exists for the
1258 package, it simply returns it instead of creating a new one.
1260 =item B<construct_class_instance (%options)>
1262 This will construct an instance of B<Class::MOP::Class>, it is
1263 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1264 to use C<construct_instance> once all the bootstrapping is done. This
1265 method is used internally by C<initialize> and should never be called
1266 from outside of that method really.
1268 =item B<check_metaclass_compatibility>
1270 This method is called as the very last thing in the
1271 C<construct_class_instance> method. This will check that the
1272 metaclass you are creating is compatible with the metaclasses of all
1273 your ancestors. For more inforamtion about metaclass compatibility
1274 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1276 =item B<update_package_cache_flag>
1278 This will reset the package cache flag for this particular metaclass
1279 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1280 function. This is very rarely needed from outside of C<Class::MOP::Class>
1281 but in some cases you might want to use it, so it is here.
1283 =item B<reset_package_cache_flag>
1285 Clears the package cache flag to announce to the internals that we need
1286 to rebuild the method map.
1288 =item B<add_meta_instance_dependencies>
1290 Registers this class as dependent on its superclasses.
1292 Only superclasses from which this class inherits attributes will be added.
1294 =item B<remove_meta_instance_depdendencies>
1296 Unregisters this class from its superclasses.
1298 =item B<update_meta_instance_dependencies>
1300 Reregisters if necessary.
1302 =item B<add_dependent_meta_instance> $metaclass
1304 Registers the class as having a meta instance dependent on this class.
1306 =item B<remove_dependent_meta_instance> $metaclass
1308 Remove the class from the list of dependent classes.
1310 =item B<invalidate_meta_instances>
1312 Clears the cached meta instance for this metaclass and all of the registered
1313 classes with dependent meta instances.
1315 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1318 =item B<invalidate_meta_instance>
1320 Used by C<invalidate_meta_instances>.
1324 =head2 Object instance construction and cloning
1326 These methods are B<entirely optional>, it is up to you whether you want
1331 =item B<instance_metaclass>
1333 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1334 for more information on the instance metaclasses.
1336 =item B<get_meta_instance>
1338 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1339 of a new instance of the class.
1341 =item B<create_meta_instance>
1343 Called by C<get_meta_instance> if necessary.
1345 =item B<new_object (%params)>
1347 This is a convience method for creating a new object of the class, and
1348 blessing it into the appropriate package as well. Ideally your class
1349 would call a C<new> this method like so:
1352 my ($class, %param) = @_;
1353 $class->meta->new_object(%params);
1356 =item B<construct_instance (%params)>
1358 This method is used to construct an instance structure suitable for
1359 C<bless>-ing into your package of choice. It works in conjunction
1360 with the Attribute protocol to collect all applicable attributes.
1362 This will construct an instance using a HASH ref as storage
1363 (currently only HASH references are supported). This will collect all
1364 the applicable attributes and layout out the fields in the HASH ref,
1365 it will then initialize them using either use the corresponding key
1366 in C<%params> or any default value or initializer found in the
1367 attribute meta-object.
1369 =item B<clone_object ($instance, %params)>
1371 This is a convience method for cloning an object instance, then
1372 blessing it into the appropriate package. This method will call
1373 C<clone_instance>, which performs a shallow copy of the object,
1374 see that methods documentation for more details. Ideally your
1375 class would call a C<clone> this method like so:
1377 sub MyClass::clone {
1378 my ($self, %param) = @_;
1379 $self->meta->clone_object($self, %params);
1382 =item B<clone_instance($instance, %params)>
1384 This method is a compliment of C<construct_instance> (which means if
1385 you override C<construct_instance>, you need to override this one too),
1386 and clones the instance shallowly.
1388 The cloned structure returned is (like with C<construct_instance>) an
1389 unC<bless>ed HASH reference, it is your responsibility to then bless
1390 this cloned structure into the right class (which C<clone_object> will
1393 As of 0.11, this method will clone the C<$instance> structure shallowly,
1394 as opposed to the deep cloning implemented in prior versions. After much
1395 thought, research and discussion, I have decided that anything but basic
1396 shallow cloning is outside the scope of the meta-object protocol. I
1397 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1398 is too I<context-specific> to be part of the MOP.
1400 =item B<rebless_instance($instance, ?%params)>
1402 This will change the class of C<$instance> to the class of the invoking
1403 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1404 itself. You may pass in optional C<%params> which are like constructor
1405 params and will override anything already defined in the instance.
1409 =head2 Informational
1411 These are a few predicate methods for asking information about the class.
1415 =item B<is_anon_class>
1417 This returns true if the class is a C<Class::MOP::Class> created anon class.
1421 This returns true if the class is still mutable.
1423 =item B<is_immutable>
1425 This returns true if the class has been made immutable.
1427 =item B<is_pristine>
1429 Checks whether the class has any data that will be lost if C<reinitialize> is
1434 =head2 Inheritance Relationships
1438 =item B<superclasses (?@superclasses)>
1440 This is a read-write attribute which represents the superclass
1441 relationships of the class the B<Class::MOP::Class> instance is
1442 associated with. Basically, it can get and set the C<@ISA> for you.
1444 =item B<class_precedence_list>
1446 This computes the a list of all the class's ancestors in the same order
1447 in which method dispatch will be done. This is similair to what
1448 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1450 =item B<linearized_isa>
1452 This returns a list based on C<class_precedence_list> but with all
1457 This returns a list of subclasses for this class.
1465 =item B<get_method_map>
1467 Returns a HASH ref of name to L<Class::MOP::Method> instance mapping
1470 =item B<method_metaclass>
1472 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1473 for more information on the method metaclasses.
1475 =item B<wrap_method_body(%attrs)>
1477 Wrap a code ref (C<$attrs{body>) with C<method_metaclass>.
1479 =item B<add_method ($method_name, $method)>
1481 This will take a C<$method_name> and CODE reference or meta method
1482 objectand install it into the class's package.
1484 You are strongly encouraged to pass a meta method object instead of a
1485 code reference. If you do so, that object gets stored as part of the
1486 class's method map, providing more useful information about the method
1489 When you provide a method object, this method will clone that object
1490 if the object's package name does not match the class name. This lets
1491 us track the original source of any methods added from other classes
1492 (notably Moose roles).
1495 This does absolutely nothing special to C<$method>
1496 other than use B<Sub::Name> to make sure it is tagged with the
1497 correct name, and therefore show up correctly in stack traces and
1500 =item B<has_method ($method_name)>
1502 This just provides a simple way to check if the class implements
1503 a specific C<$method_name>. It will I<not> however, attempt to check
1504 if the class inherits the method (use C<UNIVERSAL::can> for that).
1506 This will correctly handle functions defined outside of the package
1507 that use a fully qualified name (C<sub Package::name { ... }>).
1509 This will correctly handle functions renamed with B<Sub::Name> and
1510 installed using the symbol tables. However, if you are naming the
1511 subroutine outside of the package scope, you must use the fully
1512 qualified name, including the package name, for C<has_method> to
1513 correctly identify it.
1515 This will attempt to correctly ignore functions imported from other
1516 packages using B<Exporter>. It breaks down if the function imported
1517 is an C<__ANON__> sub (such as with C<use constant>), which very well
1518 may be a valid method being applied to the class.
1520 In short, this method cannot always be trusted to determine if the
1521 C<$method_name> is actually a method. However, it will DWIM about
1522 90% of the time, so it's a small trade off I think.
1524 =item B<get_method ($method_name)>
1526 This will return a Class::MOP::Method instance related to the specified
1527 C<$method_name>, or return undef if that method does not exist.
1529 The Class::MOP::Method is codifiable, so you can use it like a normal
1530 CODE reference, see L<Class::MOP::Method> for more information.
1532 =item B<find_method_by_name ($method_name)>
1534 This will return a L<Class::MOP::Method> instance for the specified
1535 C<$method_name>, or return undef if that method does not exist.
1537 Unlike C<get_method> this will also look in the superclasses.
1539 =item B<remove_method ($method_name)>
1541 This will attempt to remove a given C<$method_name> from the class.
1542 It will return the L<Class::MOP::Method> instance that it has removed,
1543 and will attempt to use B<Sub::Name> to clear the methods associated
1546 =item B<get_method_list>
1548 This will return a list of method names for all I<locally> defined
1549 methods. It does B<not> provide a list of all applicable methods,
1550 including any inherited ones. If you want a list of all applicable
1551 methods, use the C<compute_all_applicable_methods> method.
1553 =item B<get_all_methods>
1555 This will traverse the inheritance heirachy and return a list of all
1556 the applicable L<Class::MOP::Method> objects for this class.
1558 =item B<compute_all_applicable_methods>
1562 This method returns a list of hashes describing the all the methods of the
1565 Use L<get_all_methods>, which is easier/better/faster. This method predates
1566 L<Class::MOP::Method>.
1568 =item B<get_all_method_names>
1570 This will traverse the inheritance heirachy and return a list of all the
1571 applicable method names for this class. Duplicate names are removed, but the
1572 order the methods come out is not defined.
1574 =item B<find_all_methods_by_name ($method_name)>
1576 This will traverse the inheritence hierarchy and locate all methods
1577 with a given C<$method_name>. Similar to
1578 C<compute_all_applicable_methods> it returns a list of HASH references
1579 with the following information; method name (which will always be the
1580 same as C<$method_name>), the name of the class in which the method
1581 lives and a CODE reference for the actual method.
1583 The list of methods produced is a distinct list, meaning there are no
1584 duplicates in it. This is especially useful for things like object
1585 initialization and destruction where you only want the method called
1586 once, and in the correct order.
1588 =item B<find_next_method_by_name ($method_name)>
1590 This will return the first method to match a given C<$method_name> in
1591 the superclasses, this is basically equivalent to calling
1592 C<SUPER::$method_name>, but it can be dispatched at runtime.
1594 =item B<alias_method ($method_name, $method)>
1596 B<NOTE>: This method is now deprecated. Just use C<add_method>
1601 =head2 Method Modifiers
1603 Method modifiers are a concept borrowed from CLOS, in which a method
1604 can be wrapped with I<before>, I<after> and I<around> method modifiers
1605 that will be called everytime the method is called.
1607 =head3 How method modifiers work?
1609 Method modifiers work by wrapping the original method and then replacing
1610 it in the classes symbol table. The wrappers will handle calling all the
1611 modifiers in the appropariate orders and preserving the calling context
1612 for the original method.
1614 Each method modifier serves a particular purpose, which may not be
1615 obvious to users of other method wrapping modules. To start with, the
1616 return values of I<before> and I<after> modifiers are ignored. This is
1617 because thier purpose is B<not> to filter the input and output of the
1618 primary method (this is done with an I<around> modifier). This may seem
1619 like an odd restriction to some, but doing this allows for simple code
1620 to be added at the begining or end of a method call without jeapordizing
1621 the normal functioning of the primary method or placing any extra
1622 responsibility on the code of the modifier. Of course if you have more
1623 complex needs, then use the I<around> modifier, which uses a variation
1624 of continutation passing style to allow for a high degree of flexibility.
1626 Before and around modifiers are called in last-defined-first-called order,
1627 while after modifiers are called in first-defined-first-called order. So
1628 the call tree might looks something like this:
1640 To see examples of using method modifiers, see the following examples
1641 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1642 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1643 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1645 =head3 What is the performance impact?
1647 Of course there is a performance cost associated with method modifiers,
1648 but we have made every effort to make that cost be directly proportional
1649 to the amount of modifier features you utilize.
1651 The wrapping method does it's best to B<only> do as much work as it
1652 absolutely needs to. In order to do this we have moved some of the
1653 performance costs to set-up time, where they are easier to amortize.
1655 All this said, my benchmarks have indicated the following:
1657 simple wrapper with no modifiers 100% slower
1658 simple wrapper with simple before modifier 400% slower
1659 simple wrapper with simple after modifier 450% slower
1660 simple wrapper with simple around modifier 500-550% slower
1661 simple wrapper with all 3 modifiers 1100% slower
1663 These numbers may seem daunting, but you must remember, every feature
1664 comes with some cost. To put things in perspective, just doing a simple
1665 C<AUTOLOAD> which does nothing but extract the name of the method called
1666 and return it costs about 400% over a normal method call.
1670 =item B<add_before_method_modifier ($method_name, $code)>
1672 This will wrap the method at C<$method_name> and the supplied C<$code>
1673 will be passed the C<@_> arguments, and called before the original
1674 method is called. As specified above, the return value of the I<before>
1675 method modifiers is ignored, and it's ability to modify C<@_> is
1676 fairly limited. If you need to do either of these things, use an
1677 C<around> method modifier.
1679 =item B<add_after_method_modifier ($method_name, $code)>
1681 This will wrap the method at C<$method_name> so that the original
1682 method will be called, it's return values stashed, and then the
1683 supplied C<$code> will be passed the C<@_> arguments, and called.
1684 As specified above, the return value of the I<after> method
1685 modifiers is ignored, and it cannot modify the return values of
1686 the original method. If you need to do either of these things, use an
1687 C<around> method modifier.
1689 =item B<add_around_method_modifier ($method_name, $code)>
1691 This will wrap the method at C<$method_name> so that C<$code>
1692 will be called and passed the original method as an extra argument
1693 at the begining of the C<@_> argument list. This is a variation of
1694 continuation passing style, where the function prepended to C<@_>
1695 can be considered a continuation. It is up to C<$code> if it calls
1696 the original method or not, there is no restriction on what the
1697 C<$code> can or cannot do.
1703 It should be noted that since there is no one consistent way to define
1704 the attributes of a class in Perl 5. These methods can only work with
1705 the information given, and can not easily discover information on
1706 their own. See L<Class::MOP::Attribute> for more details.
1710 =item B<attribute_metaclass>
1712 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1713 for more information on the attribute metaclasses.
1715 =item B<get_attribute_map>
1717 This returns a HASH ref of name to attribute meta-object mapping.
1719 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1721 This stores the C<$attribute_meta_object> (or creates one from the
1722 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1723 instance associated with the given class. Unlike methods, attributes
1724 within the MOP are stored as meta-information only. They will be used
1725 later to construct instances from (see C<construct_instance> above).
1726 More details about the attribute meta-objects can be found in the
1727 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1730 It should be noted that any accessor, reader/writer or predicate
1731 methods which the C<$attribute_meta_object> has will be installed
1732 into the class at this time.
1735 If an attribute already exists for C<$attribute_name>, the old one
1736 will be removed (as well as removing all it's accessors), and then
1739 =item B<has_attribute ($attribute_name)>
1741 Checks to see if this class has an attribute by the name of
1742 C<$attribute_name> and returns a boolean.
1744 =item B<get_attribute ($attribute_name)>
1746 Returns the attribute meta-object associated with C<$attribute_name>,
1747 if none is found, it will return undef.
1749 =item B<remove_attribute ($attribute_name)>
1751 This will remove the attribute meta-object stored at
1752 C<$attribute_name>, then return the removed attribute meta-object.
1755 Removing an attribute will only affect future instances of
1756 the class, it will not make any attempt to remove the attribute from
1757 any existing instances of the class.
1759 It should be noted that any accessor, reader/writer or predicate
1760 methods which the attribute meta-object stored at C<$attribute_name>
1761 has will be removed from the class at this time. This B<will> make
1762 these attributes somewhat inaccessable in previously created
1763 instances. But if you are crazy enough to do this at runtime, then
1764 you are crazy enough to deal with something like this :).
1766 =item B<get_attribute_list>
1768 This returns a list of attribute names which are defined in the local
1769 class. If you want a list of all applicable attributes for a class,
1770 use the C<compute_all_applicable_attributes> method.
1772 =item B<compute_all_applicable_attributes>
1774 =item B<get_all_attributes>
1776 This will traverse the inheritance heirachy and return a list of all
1777 the applicable L<Class::MOP::Attribute> objects for this class.
1779 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1781 =item B<find_attribute_by_name ($attr_name)>
1783 This method will traverse the inheritance heirachy and find the
1784 first attribute whose name matches C<$attr_name>, then return it.
1785 It will return undef if nothing is found.
1789 =head2 Class Immutability
1793 =item B<make_immutable (%options)>
1795 This method will invoke a tranforamtion upon the class which will
1796 make it immutable. Details of this transformation can be found in
1797 the L<Class::MOP::Immutable> documentation.
1799 =item B<make_mutable>
1801 This method will reverse tranforamtion upon the class which
1804 =item B<get_immutable_transformer>
1806 Return a transformer suitable for making this class immutable or, if this
1807 class is immutable, the transformer used to make it immutable.
1809 =item B<get_immutable_options>
1811 If the class is immutable, return the options used to make it immutable.
1813 =item B<create_immutable_transformer>
1815 Create a transformer suitable for making this class immutable
1821 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1823 =head1 COPYRIGHT AND LICENSE
1825 Copyright 2006-2008 by Infinity Interactive, Inc.
1827 L<http://www.iinteractive.com>
1829 This library is free software; you can redistribute it and/or modify
1830 it under the same terms as Perl itself.