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 = '0.74';
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 'instance_metaclass' => $options->{'instance_metaclass'} || 'Class::MOP::Instance',
131 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
132 sub update_package_cache_flag {
135 # we can manually update the cache number
136 # since we are actually adding the method
137 # to our cache as well. This avoids us
138 # having to regenerate the method_map.
140 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
143 sub check_metaclass_compatibility {
146 # this is always okay ...
147 return if ref($self) eq 'Class::MOP::Class' &&
148 $self->instance_metaclass eq 'Class::MOP::Instance';
150 my @class_list = $self->linearized_isa;
151 shift @class_list; # shift off $self->name
153 foreach my $class_name (@class_list) {
154 my $meta = Class::MOP::get_metaclass_by_name($class_name) || next;
157 # we need to deal with the possibility
158 # of class immutability here, and then
159 # get the name of the class appropriately
160 my $meta_type = ($meta->is_immutable
161 ? $meta->get_mutable_metaclass_name()
164 ($self->isa($meta_type))
165 || confess $self->name . "->meta => (" . (ref($self)) . ")" .
166 " is not compatible with the " .
167 $class_name . "->meta => (" . ($meta_type) . ")";
169 # we also need to check that instance metaclasses
170 # are compatibile in the same the class.
171 ($self->instance_metaclass->isa($meta->instance_metaclass))
172 || confess $self->name . "->meta->instance_metaclass => (" . ($self->instance_metaclass) . ")" .
173 " is not compatible with the " .
174 $class_name . "->meta->instance_metaclass => (" . ($meta->instance_metaclass) . ")";
178 # backwards compat for stevan's inability to spell ;)
179 sub check_metaclass_compatability {
181 $self->check_metaclass_compatibility(@_);
188 # this should be sufficient, if you have a
189 # use case where it is not, write a test and
191 my $ANON_CLASS_SERIAL = 0;
194 # we need a sufficiently annoying prefix
195 # this should suffice for now, this is
196 # used in a couple of places below, so
197 # need to put it up here for now.
198 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
202 no warnings 'uninitialized';
203 $self->name =~ /^$ANON_CLASS_PREFIX/;
206 sub create_anon_class {
207 my ($class, %options) = @_;
208 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
209 return $class->create($package_name, %options);
213 # this will only get called for
214 # anon-classes, all other calls
215 # are assumed to occur during
216 # global destruction and so don't
217 # really need to be handled explicitly
221 return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
223 no warnings 'uninitialized';
224 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
225 # Moose does a weird thing where it replaces the metaclass for
226 # class when fixing metaclass incompatibility. In that case,
227 # we don't want to clean out the namespace now. We can detect
228 # that because Moose will explicitly update the singleton
229 # cache in Class::MOP.
230 my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
231 return if $current_meta ne $self;
233 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
235 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
236 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
238 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
243 # creating classes with MOP ...
246 my ( $class, @args ) = @_;
248 unshift @args, 'package' if @args % 2 == 1;
250 my (%options) = @args;
251 my $package_name = $options{package};
253 (ref $options{superclasses} eq 'ARRAY')
254 || confess "You must pass an ARRAY ref of superclasses"
255 if exists $options{superclasses};
257 (ref $options{attributes} eq 'ARRAY')
258 || confess "You must pass an ARRAY ref of attributes"
259 if exists $options{attributes};
261 (ref $options{methods} eq 'HASH')
262 || confess "You must pass a HASH ref of methods"
263 if exists $options{methods};
265 $class->SUPER::create(%options);
267 my (%initialize_options) = @args;
268 delete @initialize_options{qw(
276 my $meta = $class->initialize( $package_name => %initialize_options );
279 $meta->add_method('meta' => sub {
280 $class->initialize(ref($_[0]) || $_[0]);
283 $meta->superclasses(@{$options{superclasses}})
284 if exists $options{superclasses};
286 # process attributes first, so that they can
287 # install accessors, but locally defined methods
288 # can then overwrite them. It is maybe a little odd, but
289 # I think this should be the order of things.
290 if (exists $options{attributes}) {
291 foreach my $attr (@{$options{attributes}}) {
292 $meta->add_attribute($attr);
295 if (exists $options{methods}) {
296 foreach my $method_name (keys %{$options{methods}}) {
297 $meta->add_method($method_name, $options{methods}->{$method_name});
306 # all these attribute readers will be bootstrapped
307 # away in the Class::MOP bootstrap section
309 sub get_attribute_map { $_[0]->{'attributes'} }
310 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
311 sub method_metaclass { $_[0]->{'method_metaclass'} }
312 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
317 my $class_name = $self->name;
319 my $current = Class::MOP::check_package_cache_flag($class_name);
321 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
322 return $self->{'methods'} ||= {};
325 $self->{_package_cache_flag} = $current;
327 my $map = $self->{'methods'} ||= {};
329 my $method_metaclass = $self->method_metaclass;
331 my $all_code = $self->get_all_package_symbols('CODE');
333 foreach my $symbol (keys %{ $all_code }) {
334 my $code = $all_code->{$symbol};
336 next if exists $map->{$symbol} &&
337 defined $map->{$symbol} &&
338 $map->{$symbol}->body == $code;
340 my ($pkg, $name) = Class::MOP::get_code_info($code);
343 # in 5.10 constant.pm the constants show up
344 # as being in the right package, but in pre-5.10
345 # they show up as constant::__ANON__ so we
346 # make an exception here to be sure that things
347 # work as expected in both.
349 unless ($pkg eq 'constant' && $name eq '__ANON__') {
350 next if ($pkg || '') ne $class_name ||
351 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
354 $map->{$symbol} = $method_metaclass->wrap(
356 associated_metaclass => $self,
357 package_name => $class_name,
365 # Instance Construction & Cloning
371 # we need to protect the integrity of the
372 # Class::MOP::Class singletons here, so we
373 # delegate this to &construct_class_instance
374 # which will deal with the singletons
375 return $class->construct_class_instance(@_)
376 if $class->name->isa('Class::MOP::Class');
377 return $class->construct_instance(@_);
380 sub construct_instance {
382 my $params = @_ == 1 ? $_[0] : {@_};
383 my $meta_instance = $class->get_meta_instance();
384 my $instance = $meta_instance->create_instance();
385 foreach my $attr ($class->compute_all_applicable_attributes()) {
386 $attr->initialize_instance_slot($meta_instance, $instance, $params);
389 # this will only work for a HASH instance type
390 if ($class->is_anon_class) {
391 (Scalar::Util::reftype($instance) eq 'HASH')
392 || confess "Currently only HASH based instances are supported with instance of anon-classes";
394 # At some point we should make this official
395 # as a reserved slot name, but right now I am
396 # going to keep it here.
397 # my $RESERVED_MOP_SLOT = '__MOP__';
398 $instance->{'__MOP__'} = $class;
404 sub get_meta_instance {
406 $self->{'_meta_instance'} ||= $self->create_meta_instance();
409 sub create_meta_instance {
412 my $instance = $self->instance_metaclass->new(
413 associated_metaclass => $self,
414 attributes => [ $self->compute_all_applicable_attributes() ],
417 $self->add_meta_instance_dependencies()
418 if $instance->is_dependent_on_superclasses();
425 my $instance = shift;
426 (blessed($instance) && $instance->isa($class->name))
427 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
430 # we need to protect the integrity of the
431 # Class::MOP::Class singletons here, they
432 # should not be cloned.
433 return $instance if $instance->isa('Class::MOP::Class');
434 $class->clone_instance($instance, @_);
438 my ($class, $instance, %params) = @_;
440 || confess "You can only clone instances, ($instance) is not a blessed instance";
441 my $meta_instance = $class->get_meta_instance();
442 my $clone = $meta_instance->clone_instance($instance);
443 foreach my $attr ($class->compute_all_applicable_attributes()) {
444 if ( defined( my $init_arg = $attr->init_arg ) ) {
445 if (exists $params{$init_arg}) {
446 $attr->set_value($clone, $params{$init_arg});
453 sub rebless_instance {
454 my ($self, $instance, %params) = @_;
457 if ($instance->can('meta')) {
458 ($instance->meta->isa('Class::MOP::Class'))
459 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
460 $old_metaclass = $instance->meta;
463 $old_metaclass = $self->initialize(ref($instance));
466 my $meta_instance = $self->get_meta_instance();
468 $self->name->isa($old_metaclass->name)
469 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
472 $meta_instance->rebless_instance_structure($instance, $self);
474 foreach my $attr ( $self->compute_all_applicable_attributes ) {
475 if ( $attr->has_value($instance) ) {
476 if ( defined( my $init_arg = $attr->init_arg ) ) {
477 $params{$init_arg} = $attr->get_value($instance)
478 unless exists $params{$init_arg};
481 $attr->set_value($instance, $attr->get_value($instance));
486 foreach my $attr ($self->compute_all_applicable_attributes) {
487 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
497 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
500 @{$self->get_package_symbol($var_spec)} = @supers;
503 # on 5.8 and below, we need to call
504 # a method to get Perl to detect
505 # a cycle in the class hierarchy
506 my $class = $self->name;
510 # we need to check the metaclass
511 # compatibility here so that we can
512 # be sure that the superclass is
513 # not potentially creating an issues
514 # we don't know about
516 $self->check_metaclass_compatibility();
517 $self->update_meta_instance_dependencies();
519 @{$self->get_package_symbol($var_spec)};
525 my $super_class = $self->name;
527 if ( Class::MOP::HAVE_ISAREV() ) {
528 return @{ $super_class->mro::get_isarev() };
532 my $find_derived_classes;
533 $find_derived_classes = sub {
534 my ($outer_class) = @_;
536 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
539 for my $symbol ( keys %$symbol_table_hashref ) {
540 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
541 my $inner_class = $1;
543 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
547 ? "${outer_class}::$inner_class"
550 if ( $class->isa($super_class) and $class ne $super_class ) {
551 push @derived_classes, $class;
554 next SYMBOL if $class eq 'main'; # skip 'main::*'
556 $find_derived_classes->($class);
560 my $root_class = q{};
561 $find_derived_classes->($root_class);
563 undef $find_derived_classes;
565 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
567 return @derived_classes;
573 return @{ mro::get_linear_isa( (shift)->name ) };
576 sub class_precedence_list {
578 my $name = $self->name;
580 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
582 # We need to check for circular inheritance here
583 # if we are are not on 5.10, cause 5.8 detects it
584 # late. This will do nothing if all is well, and
585 # blow up otherwise. Yes, it's an ugly hack, better
586 # suggestions are welcome.
588 ($name || return)->isa('This is a test for circular inheritance')
591 # if our mro is c3, we can
592 # just grab the linear_isa
593 if (mro::get_mro($name) eq 'c3') {
594 return @{ mro::get_linear_isa($name) }
598 # we can't grab the linear_isa for dfs
599 # since it has all the duplicates
604 $self->initialize($_)->class_precedence_list()
605 } $self->superclasses()
612 sub wrap_method_body {
613 my ( $self, %args ) = @_;
615 ('CODE' eq ref $args{body})
616 || confess "Your code block must be a CODE reference";
618 $self->method_metaclass->wrap(
619 package_name => $self->name,
625 my ($self, $method_name, $method) = @_;
626 (defined $method_name && $method_name)
627 || confess "You must define a method name";
630 if (blessed($method)) {
631 $body = $method->body;
632 if ($method->package_name ne $self->name) {
633 $method = $method->clone(
634 package_name => $self->name,
636 ) if $method->can('clone');
641 $method = $self->wrap_method_body( body => $body, name => $method_name );
644 $method->attach_to_class($self);
646 # This used to call get_method_map, which meant we would build all
647 # the method objects for the class just because we added one
648 # method. This is hackier, but quicker too.
649 $self->{methods}{$method_name} = $method;
651 my $full_method_name = ($self->name . '::' . $method_name);
652 $self->add_package_symbol(
653 { sigil => '&', type => 'CODE', name => $method_name },
654 Class::MOP::subname($full_method_name => $body)
659 my $fetch_and_prepare_method = sub {
660 my ($self, $method_name) = @_;
662 my $method = $self->get_method($method_name);
663 # if we dont have local ...
665 # try to find the next method
666 $method = $self->find_next_method_by_name($method_name);
667 # die if it does not exist
669 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
670 # and now make sure to wrap it
671 # even if it is already wrapped
672 # because we need a new sub ref
673 $method = Class::MOP::Method::Wrapped->wrap($method);
676 # now make sure we wrap it properly
677 $method = Class::MOP::Method::Wrapped->wrap($method)
678 unless $method->isa('Class::MOP::Method::Wrapped');
680 $self->add_method($method_name => $method);
684 sub add_before_method_modifier {
685 my ($self, $method_name, $method_modifier) = @_;
686 (defined $method_name && $method_name)
687 || confess "You must pass in a method name";
688 my $method = $fetch_and_prepare_method->($self, $method_name);
689 $method->add_before_modifier(
690 Class::MOP::subname(':before' => $method_modifier)
694 sub add_after_method_modifier {
695 my ($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_after_modifier(
700 Class::MOP::subname(':after' => $method_modifier)
704 sub add_around_method_modifier {
705 my ($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_around_modifier(
710 Class::MOP::subname(':around' => $method_modifier)
715 # the methods above used to be named like this:
716 # ${pkg}::${method}:(before|after|around)
717 # but this proved problematic when using one modifier
718 # to wrap multiple methods (something which is likely
719 # to happen pretty regularly IMO). So instead of naming
720 # it like this, I have chosen to just name them purely
721 # with their modifier names, like so:
722 # :(before|after|around)
723 # The fact is that in a stack trace, it will be fairly
724 # evident from the context what method they are attached
725 # to, and so don't need the fully qualified name.
731 $self->add_method(@_);
735 my ($self, $method_name) = @_;
736 (defined $method_name && $method_name)
737 || confess "You must define a method name";
739 exists $self->{methods}{$method_name} || exists $self->get_method_map->{$method_name};
743 my ($self, $method_name) = @_;
744 (defined $method_name && $method_name)
745 || confess "You must define a method name";
748 # I don't really need this here, because
749 # if the method_map is missing a key it
750 # will just return undef for me now
751 # return unless $self->has_method($method_name);
753 return $self->{methods}{$method_name} || $self->get_method_map->{$method_name};
757 my ($self, $method_name) = @_;
758 (defined $method_name && $method_name)
759 || confess "You must define a method name";
761 my $removed_method = delete $self->get_method_map->{$method_name};
763 $self->remove_package_symbol(
764 { sigil => '&', type => 'CODE', name => $method_name }
767 $removed_method->detach_from_class if $removed_method;
769 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
771 return $removed_method;
774 sub get_method_list {
776 keys %{$self->get_method_map};
779 sub find_method_by_name {
780 my ($self, $method_name) = @_;
781 (defined $method_name && $method_name)
782 || confess "You must define a method name to find";
783 foreach my $class ($self->linearized_isa) {
784 # fetch the meta-class ...
785 my $meta = $self->initialize($class);
786 return $meta->get_method($method_name)
787 if $meta->has_method($method_name);
792 sub get_all_methods {
794 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
795 return values %methods;
799 sub compute_all_applicable_methods {
803 class => $_->package_name,
804 code => $_, # sigh, overloading
806 } shift->get_all_methods(@_);
809 sub find_all_methods_by_name {
810 my ($self, $method_name) = @_;
811 (defined $method_name && $method_name)
812 || confess "You must define a method name to find";
814 foreach my $class ($self->linearized_isa) {
815 # fetch the meta-class ...
816 my $meta = $self->initialize($class);
818 name => $method_name,
820 code => $meta->get_method($method_name)
821 } if $meta->has_method($method_name);
826 sub find_next_method_by_name {
827 my ($self, $method_name) = @_;
828 (defined $method_name && $method_name)
829 || confess "You must define a method name to find";
830 my @cpl = $self->linearized_isa;
831 shift @cpl; # discard ourselves
832 foreach my $class (@cpl) {
833 # fetch the meta-class ...
834 my $meta = $self->initialize($class);
835 return $meta->get_method($method_name)
836 if $meta->has_method($method_name);
845 # either we have an attribute object already
846 # or we need to create one from the args provided
847 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
848 # make sure it is derived from the correct type though
849 ($attribute->isa('Class::MOP::Attribute'))
850 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
852 # first we attach our new attribute
853 # because it might need certain information
854 # about the class which it is attached to
855 $attribute->attach_to_class($self);
857 # then we remove attributes of a conflicting
858 # name here so that we can properly detach
859 # the old attr object, and remove any
860 # accessors it would have generated
861 if ( $self->has_attribute($attribute->name) ) {
862 $self->remove_attribute($attribute->name);
864 $self->invalidate_meta_instances();
867 # then onto installing the new accessors
868 $self->get_attribute_map->{$attribute->name} = $attribute;
870 # invalidate package flag here
871 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
873 $self->remove_attribute($attribute->name);
880 sub update_meta_instance_dependencies {
883 if ( $self->{meta_instance_dependencies} ) {
884 return $self->add_meta_instance_dependencies;
888 sub add_meta_instance_dependencies {
891 $self->remove_meta_instance_depdendencies;
893 my @attrs = $self->compute_all_applicable_attributes();
896 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
898 foreach my $class ( @classes ) {
899 $class->add_dependent_meta_instance($self);
902 $self->{meta_instance_dependencies} = \@classes;
905 sub remove_meta_instance_depdendencies {
908 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
909 foreach my $class ( @$classes ) {
910 $class->remove_dependent_meta_instance($self);
920 sub add_dependent_meta_instance {
921 my ( $self, $metaclass ) = @_;
922 push @{ $self->{dependent_meta_instances} }, $metaclass;
925 sub remove_dependent_meta_instance {
926 my ( $self, $metaclass ) = @_;
927 my $name = $metaclass->name;
928 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
931 sub invalidate_meta_instances {
933 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
936 sub invalidate_meta_instance {
938 undef $self->{_meta_instance};
942 my ($self, $attribute_name) = @_;
943 (defined $attribute_name && $attribute_name)
944 || confess "You must define an attribute name";
945 exists $self->get_attribute_map->{$attribute_name};
949 my ($self, $attribute_name) = @_;
950 (defined $attribute_name && $attribute_name)
951 || confess "You must define an attribute name";
952 return $self->get_attribute_map->{$attribute_name}
954 # this will return undef anyway, so no need ...
955 # if $self->has_attribute($attribute_name);
959 sub remove_attribute {
960 my ($self, $attribute_name) = @_;
961 (defined $attribute_name && $attribute_name)
962 || confess "You must define an attribute name";
963 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
964 return unless defined $removed_attribute;
965 delete $self->get_attribute_map->{$attribute_name};
966 $self->invalidate_meta_instances();
967 $removed_attribute->remove_accessors();
968 $removed_attribute->detach_from_class();
969 return $removed_attribute;
972 sub get_attribute_list {
974 keys %{$self->get_attribute_map};
977 sub get_all_attributes {
978 shift->compute_all_applicable_attributes(@_);
981 sub compute_all_applicable_attributes {
983 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
984 return values %attrs;
987 sub find_attribute_by_name {
988 my ($self, $attr_name) = @_;
989 foreach my $class ($self->linearized_isa) {
990 # fetch the meta-class ...
991 my $meta = $self->initialize($class);
992 return $meta->get_attribute($attr_name)
993 if $meta->has_attribute($attr_name);
998 # check if we can reinitialize
1002 # if any local attr is defined
1003 return if $self->get_attribute_list;
1005 # or any non-declared methods
1006 if ( my @methods = values %{ $self->get_method_map } ) {
1007 my $metaclass = $self->method_metaclass;
1008 foreach my $method ( @methods ) {
1009 return if $method->isa("Class::MOP::Method::Generated");
1010 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1019 sub is_mutable { 1 }
1020 sub is_immutable { 0 }
1023 # Why I changed this (groditi)
1024 # - One Metaclass may have many Classes through many Metaclass instances
1025 # - One Metaclass should only have one Immutable Transformer instance
1026 # - Each Class may have different Immutabilizing options
1027 # - Therefore each Metaclass instance may have different Immutabilizing options
1028 # - We need to store one Immutable Transformer instance per Metaclass
1029 # - We need to store one set of Immutable Transformer options per Class
1030 # - Upon make_mutable we may delete the Immutabilizing options
1031 # - We could clean the immutable Transformer instance when there is no more
1032 # immutable Classes of that type, but we can also keep it in case
1033 # another class with this same Metaclass becomes immutable. It is a case
1034 # of trading of storing an instance to avoid unnecessary instantiations of
1035 # Immutable Transformers. You may view this as a memory leak, however
1036 # Because we have few Metaclasses, in practice it seems acceptable
1037 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1038 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1042 my %IMMUTABLE_TRANSFORMERS;
1043 my %IMMUTABLE_OPTIONS;
1045 sub get_immutable_options {
1047 return if $self->is_mutable;
1048 confess "unable to find immutabilizing options"
1049 unless exists $IMMUTABLE_OPTIONS{$self->name};
1050 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1051 delete $options{IMMUTABLE_TRANSFORMER};
1055 sub get_immutable_transformer {
1057 if( $self->is_mutable ){
1058 return $IMMUTABLE_TRANSFORMERS{$self->name} ||= $self->create_immutable_transformer;
1060 confess "unable to find transformer for immutable class"
1061 unless exists $IMMUTABLE_OPTIONS{$self->name};
1062 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1065 sub make_immutable {
1069 my $transformer = $self->get_immutable_transformer;
1070 $transformer->make_metaclass_immutable($self, \%options);
1071 $IMMUTABLE_OPTIONS{$self->name} =
1072 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1074 if( exists $options{debug} && $options{debug} ){
1075 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1076 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1084 return if $self->is_mutable;
1085 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1086 confess "unable to find immutabilizing options" unless ref $options;
1087 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1088 $transformer->make_metaclass_mutable($self, $options);
1093 sub create_immutable_transformer {
1095 my $class = Class::MOP::Immutable->new($self, {
1096 read_only => [qw/superclasses/],
1103 remove_package_symbol
1106 class_precedence_list => 'ARRAY',
1107 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
1108 get_all_methods => 'ARRAY',
1109 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
1110 compute_all_applicable_attributes => 'ARRAY',
1111 get_meta_instance => 'SCALAR',
1112 get_method_map => 'SCALAR',
1115 # this is ugly, but so are typeglobs,
1116 # so whattayahgonnadoboutit
1119 add_package_symbol => sub {
1120 my $original = shift;
1121 confess "Cannot add package symbols to an immutable metaclass"
1122 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1124 # This is a workaround for a bug in 5.8.1 which thinks that
1125 # goto $original->body
1126 # is trying to go to a label
1127 my $body = $original->body;
1143 Class::MOP::Class - Class Meta Object
1147 # assuming that class Foo
1148 # has been defined, you can
1150 # use this for introspection ...
1152 # add a method to Foo ...
1153 Foo->meta->add_method('bar' => sub { ... })
1155 # get a list of all the classes searched
1156 # the method dispatcher in the correct order
1157 Foo->meta->class_precedence_list()
1159 # remove a method from Foo
1160 Foo->meta->remove_method('bar');
1162 # or use this to actually create classes ...
1164 Class::MOP::Class->create('Bar' => (
1166 superclasses => [ 'Foo' ],
1168 Class::MOP:::Attribute->new('$bar'),
1169 Class::MOP:::Attribute->new('$baz'),
1172 calculate_bar => sub { ... },
1173 construct_baz => sub { ... }
1179 This is the largest and currently most complex part of the Perl 5
1180 meta-object protocol. It controls the introspection and
1181 manipulation of Perl 5 classes (and it can create them too). The
1182 best way to understand what this module can do, is to read the
1183 documentation for each of it's methods.
1187 B<Class::MOP::Class> is a subclass of L<Class::MOP::Module>
1191 =head2 Self Introspection
1197 This will return a B<Class::MOP::Class> instance which is related
1198 to this class. Thereby allowing B<Class::MOP::Class> to actually
1201 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1202 bootstrap this module by installing a number of attribute meta-objects
1203 into it's metaclass. This will allow this class to reap all the benifits
1204 of the MOP when subclassing it.
1208 =head2 Class construction
1210 These methods will handle creating B<Class::MOP::Class> objects,
1211 which can be used to both create new classes, and analyze
1212 pre-existing classes.
1214 This module will internally store references to all the instances
1215 you create with these methods, so that they do not need to be
1216 created any more than nessecary. Basically, they are singletons.
1220 =item B<create ($package_name,
1221 version =E<gt> ?$version,
1222 authority =E<gt> ?$authority,
1223 superclasses =E<gt> ?@superclasses,
1224 methods =E<gt> ?%methods,
1225 attributes =E<gt> ?%attributes)>
1227 This returns a B<Class::MOP::Class> object, bringing the specified
1228 C<$package_name> into existence and adding any of the C<$version>,
1229 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1232 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1233 methods =E<gt> ?%methods,
1234 attributes =E<gt> ?%attributes)>
1236 This will create an anonymous class, it works much like C<create> but
1237 it does not need a C<$package_name>. Instead it will create a suitably
1238 unique package name for you to stash things into.
1240 On very important distinction is that anon classes are destroyed once
1241 the metaclass they are attached to goes out of scope. In the DESTROY
1242 method, the created package will be removed from the symbol table.
1244 It is also worth noting that any instances created with an anon-class
1245 will keep a special reference to the anon-meta which will prevent the
1246 anon-class from going out of scope until all instances of it have also
1247 been destroyed. This however only works for HASH based instance types,
1248 as we use a special reserved slot (C<__MOP__>) to store this.
1250 =item B<initialize ($package_name, %options)>
1252 This initializes and returns returns a B<Class::MOP::Class> object
1253 for a given a C<$package_name>.
1255 =item B<construct_class_instance (%options)>
1257 This will construct an instance of B<Class::MOP::Class>, it is
1258 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1259 to use C<construct_instance> once all the bootstrapping is done. This
1260 method is used internally by C<initialize> and should never be called
1261 from outside of that method really.
1263 =item B<check_metaclass_compatibility>
1265 This method is called as the very last thing in the
1266 C<construct_class_instance> method. This will check that the
1267 metaclass you are creating is compatible with the metaclasses of all
1268 your ancestors. For more inforamtion about metaclass compatibility
1269 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1271 =item B<update_package_cache_flag>
1273 This will reset the package cache flag for this particular metaclass
1274 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1275 function. This is very rarely needed from outside of C<Class::MOP::Class>
1276 but in some cases you might want to use it, so it is here.
1278 =item B<reset_package_cache_flag>
1280 Clears the package cache flag to announce to the internals that we need
1281 to rebuild the method map.
1283 =item B<add_meta_instance_dependencies>
1285 Registers this class as dependent on its superclasses.
1287 Only superclasses from which this class inherits attributes will be added.
1289 =item B<remove_meta_instance_depdendencies>
1291 Unregisters this class from its superclasses.
1293 =item B<update_meta_instance_dependencies>
1295 Reregisters if necessary.
1297 =item B<add_dependent_meta_instance> $metaclass
1299 Registers the class as having a meta instance dependent on this class.
1301 =item B<remove_dependent_meta_instance> $metaclass
1303 Remove the class from the list of dependent classes.
1305 =item B<invalidate_meta_instances>
1307 Clears the cached meta instance for this metaclass and all of the registered
1308 classes with dependent meta instances.
1310 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1313 =item B<invalidate_meta_instance>
1315 Used by C<invalidate_meta_instances>.
1319 =head2 Object instance construction and cloning
1321 These methods are B<entirely optional>, it is up to you whether you want
1326 =item B<instance_metaclass>
1328 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1329 for more information on the instance metaclasses.
1331 =item B<get_meta_instance>
1333 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1334 of a new instance of the class.
1336 =item B<create_meta_instance>
1338 Called by C<get_meta_instance> if necessary.
1340 =item B<new_object (%params)>
1342 This is a convience method for creating a new object of the class, and
1343 blessing it into the appropriate package as well. Ideally your class
1344 would call a C<new> this method like so:
1347 my ($class, %param) = @_;
1348 $class->meta->new_object(%params);
1351 =item B<construct_instance (%params)>
1353 This method is used to construct an instance structure suitable for
1354 C<bless>-ing into your package of choice. It works in conjunction
1355 with the Attribute protocol to collect all applicable attributes.
1357 This will construct an instance using a HASH ref as storage
1358 (currently only HASH references are supported). This will collect all
1359 the applicable attributes and layout out the fields in the HASH ref,
1360 it will then initialize them using either use the corresponding key
1361 in C<%params> or any default value or initializer found in the
1362 attribute meta-object.
1364 =item B<clone_object ($instance, %params)>
1366 This is a convience method for cloning an object instance, then
1367 blessing it into the appropriate package. This method will call
1368 C<clone_instance>, which performs a shallow copy of the object,
1369 see that methods documentation for more details. Ideally your
1370 class would call a C<clone> this method like so:
1372 sub MyClass::clone {
1373 my ($self, %param) = @_;
1374 $self->meta->clone_object($self, %params);
1377 =item B<clone_instance($instance, %params)>
1379 This method is a compliment of C<construct_instance> (which means if
1380 you override C<construct_instance>, you need to override this one too),
1381 and clones the instance shallowly.
1383 The cloned structure returned is (like with C<construct_instance>) an
1384 unC<bless>ed HASH reference, it is your responsibility to then bless
1385 this cloned structure into the right class (which C<clone_object> will
1388 As of 0.11, this method will clone the C<$instance> structure shallowly,
1389 as opposed to the deep cloning implemented in prior versions. After much
1390 thought, research and discussion, I have decided that anything but basic
1391 shallow cloning is outside the scope of the meta-object protocol. I
1392 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1393 is too I<context-specific> to be part of the MOP.
1395 =item B<rebless_instance($instance, ?%params)>
1397 This will change the class of C<$instance> to the class of the invoking
1398 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1399 itself. You may pass in optional C<%params> which are like constructor
1400 params and will override anything already defined in the instance.
1404 =head2 Informational
1406 These are a few predicate methods for asking information about the class.
1410 =item B<is_anon_class>
1412 This returns true if the class is a C<Class::MOP::Class> created anon class.
1416 This returns true if the class is still mutable.
1418 =item B<is_immutable>
1420 This returns true if the class has been made immutable.
1422 =item B<is_pristine>
1424 Checks whether the class has any data that will be lost if C<reinitialize> is
1429 =head2 Inheritance Relationships
1433 =item B<superclasses (?@superclasses)>
1435 This is a read-write attribute which represents the superclass
1436 relationships of the class the B<Class::MOP::Class> instance is
1437 associated with. Basically, it can get and set the C<@ISA> for you.
1439 =item B<class_precedence_list>
1441 This computes the a list of all the class's ancestors in the same order
1442 in which method dispatch will be done. This is similair to what
1443 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1445 =item B<linearized_isa>
1447 This returns a list based on C<class_precedence_list> but with all
1452 This returns a list of subclasses for this class.
1460 =item B<get_method_map>
1462 Returns a HASH ref of name to CODE reference mapping for this class.
1464 =item B<method_metaclass>
1466 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1467 for more information on the method metaclasses.
1469 =item B<wrap_method_body(%attrs)>
1471 Wrap a code ref (C<$attrs{body>) with C<method_metaclass>.
1473 =item B<add_method ($method_name, $method)>
1475 This will take a C<$method_name> and CODE reference or meta method
1476 objectand install it into the class's package.
1478 You are strongly encouraged to pass a meta method object instead of a
1479 code reference. If you do so, that object gets stored as part of the
1480 class's method map, providing more useful information about the method
1483 When you provide a method object, this method will clone that object
1484 if the object's package name does not match the class name. This lets
1485 us track the original source of any methods added from other classes
1486 (notably Moose roles).
1489 This does absolutely nothing special to C<$method>
1490 other than use B<Sub::Name> to make sure it is tagged with the
1491 correct name, and therefore show up correctly in stack traces and
1494 =item B<has_method ($method_name)>
1496 This just provides a simple way to check if the class implements
1497 a specific C<$method_name>. It will I<not> however, attempt to check
1498 if the class inherits the method (use C<UNIVERSAL::can> for that).
1500 This will correctly handle functions defined outside of the package
1501 that use a fully qualified name (C<sub Package::name { ... }>).
1503 This will correctly handle functions renamed with B<Sub::Name> and
1504 installed using the symbol tables. However, if you are naming the
1505 subroutine outside of the package scope, you must use the fully
1506 qualified name, including the package name, for C<has_method> to
1507 correctly identify it.
1509 This will attempt to correctly ignore functions imported from other
1510 packages using B<Exporter>. It breaks down if the function imported
1511 is an C<__ANON__> sub (such as with C<use constant>), which very well
1512 may be a valid method being applied to the class.
1514 In short, this method cannot always be trusted to determine if the
1515 C<$method_name> is actually a method. However, it will DWIM about
1516 90% of the time, so it's a small trade off I think.
1518 =item B<get_method ($method_name)>
1520 This will return a Class::MOP::Method instance related to the specified
1521 C<$method_name>, or return undef if that method does not exist.
1523 The Class::MOP::Method is codifiable, so you can use it like a normal
1524 CODE reference, see L<Class::MOP::Method> for more information.
1526 =item B<find_method_by_name ($method_name)>
1528 This will return a CODE reference of the specified C<$method_name>,
1529 or return undef if that method does not exist.
1531 Unlike C<get_method> this will also look in the superclasses.
1533 =item B<remove_method ($method_name)>
1535 This will attempt to remove a given C<$method_name> from the class.
1536 It will return the CODE reference that it has removed, and will
1537 attempt to use B<Sub::Name> to clear the methods associated name.
1539 =item B<get_method_list>
1541 This will return a list of method names for all I<locally> defined
1542 methods. It does B<not> provide a list of all applicable methods,
1543 including any inherited ones. If you want a list of all applicable
1544 methods, use the C<compute_all_applicable_methods> method.
1546 =item B<get_all_methods>
1548 This will traverse the inheritance heirachy and return a list of all
1549 the applicable L<Class::MOP::Method> objects for this class.
1551 =item B<compute_all_applicable_methods>
1555 This method returns a list of hashes describing the all the methods of the
1558 Use L<get_all_methods>, which is easier/better/faster. This method predates
1559 L<Class::MOP::Method>.
1561 =item B<find_all_methods_by_name ($method_name)>
1563 This will traverse the inheritence hierarchy and locate all methods
1564 with a given C<$method_name>. Similar to
1565 C<compute_all_applicable_methods> it returns a list of HASH references
1566 with the following information; method name (which will always be the
1567 same as C<$method_name>), the name of the class in which the method
1568 lives and a CODE reference for the actual method.
1570 The list of methods produced is a distinct list, meaning there are no
1571 duplicates in it. This is especially useful for things like object
1572 initialization and destruction where you only want the method called
1573 once, and in the correct order.
1575 =item B<find_next_method_by_name ($method_name)>
1577 This will return the first method to match a given C<$method_name> in
1578 the superclasses, this is basically equivalent to calling
1579 C<SUPER::$method_name>, but it can be dispatched at runtime.
1581 =item B<alias_method ($method_name, $method)>
1583 B<NOTE>: This method is now deprecated. Just use C<add_method>
1588 =head2 Method Modifiers
1590 Method modifiers are a concept borrowed from CLOS, in which a method
1591 can be wrapped with I<before>, I<after> and I<around> method modifiers
1592 that will be called everytime the method is called.
1594 =head3 How method modifiers work?
1596 Method modifiers work by wrapping the original method and then replacing
1597 it in the classes symbol table. The wrappers will handle calling all the
1598 modifiers in the appropariate orders and preserving the calling context
1599 for the original method.
1601 Each method modifier serves a particular purpose, which may not be
1602 obvious to users of other method wrapping modules. To start with, the
1603 return values of I<before> and I<after> modifiers are ignored. This is
1604 because thier purpose is B<not> to filter the input and output of the
1605 primary method (this is done with an I<around> modifier). This may seem
1606 like an odd restriction to some, but doing this allows for simple code
1607 to be added at the begining or end of a method call without jeapordizing
1608 the normal functioning of the primary method or placing any extra
1609 responsibility on the code of the modifier. Of course if you have more
1610 complex needs, then use the I<around> modifier, which uses a variation
1611 of continutation passing style to allow for a high degree of flexibility.
1613 Before and around modifiers are called in last-defined-first-called order,
1614 while after modifiers are called in first-defined-first-called order. So
1615 the call tree might looks something like this:
1627 To see examples of using method modifiers, see the following examples
1628 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1629 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1630 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1632 =head3 What is the performance impact?
1634 Of course there is a performance cost associated with method modifiers,
1635 but we have made every effort to make that cost be directly proportional
1636 to the amount of modifier features you utilize.
1638 The wrapping method does it's best to B<only> do as much work as it
1639 absolutely needs to. In order to do this we have moved some of the
1640 performance costs to set-up time, where they are easier to amortize.
1642 All this said, my benchmarks have indicated the following:
1644 simple wrapper with no modifiers 100% slower
1645 simple wrapper with simple before modifier 400% slower
1646 simple wrapper with simple after modifier 450% slower
1647 simple wrapper with simple around modifier 500-550% slower
1648 simple wrapper with all 3 modifiers 1100% slower
1650 These numbers may seem daunting, but you must remember, every feature
1651 comes with some cost. To put things in perspective, just doing a simple
1652 C<AUTOLOAD> which does nothing but extract the name of the method called
1653 and return it costs about 400% over a normal method call.
1657 =item B<add_before_method_modifier ($method_name, $code)>
1659 This will wrap the method at C<$method_name> and the supplied C<$code>
1660 will be passed the C<@_> arguments, and called before the original
1661 method is called. As specified above, the return value of the I<before>
1662 method modifiers is ignored, and it's ability to modify C<@_> is
1663 fairly limited. If you need to do either of these things, use an
1664 C<around> method modifier.
1666 =item B<add_after_method_modifier ($method_name, $code)>
1668 This will wrap the method at C<$method_name> so that the original
1669 method will be called, it's return values stashed, and then the
1670 supplied C<$code> will be passed the C<@_> arguments, and called.
1671 As specified above, the return value of the I<after> method
1672 modifiers is ignored, and it cannot modify the return values of
1673 the original method. If you need to do either of these things, use an
1674 C<around> method modifier.
1676 =item B<add_around_method_modifier ($method_name, $code)>
1678 This will wrap the method at C<$method_name> so that C<$code>
1679 will be called and passed the original method as an extra argument
1680 at the begining of the C<@_> argument list. This is a variation of
1681 continuation passing style, where the function prepended to C<@_>
1682 can be considered a continuation. It is up to C<$code> if it calls
1683 the original method or not, there is no restriction on what the
1684 C<$code> can or cannot do.
1690 It should be noted that since there is no one consistent way to define
1691 the attributes of a class in Perl 5. These methods can only work with
1692 the information given, and can not easily discover information on
1693 their own. See L<Class::MOP::Attribute> for more details.
1697 =item B<attribute_metaclass>
1699 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1700 for more information on the attribute metaclasses.
1702 =item B<get_attribute_map>
1704 This returns a HASH ref of name to attribute meta-object mapping.
1706 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1708 This stores the C<$attribute_meta_object> (or creates one from the
1709 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1710 instance associated with the given class. Unlike methods, attributes
1711 within the MOP are stored as meta-information only. They will be used
1712 later to construct instances from (see C<construct_instance> above).
1713 More details about the attribute meta-objects can be found in the
1714 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1717 It should be noted that any accessor, reader/writer or predicate
1718 methods which the C<$attribute_meta_object> has will be installed
1719 into the class at this time.
1722 If an attribute already exists for C<$attribute_name>, the old one
1723 will be removed (as well as removing all it's accessors), and then
1726 =item B<has_attribute ($attribute_name)>
1728 Checks to see if this class has an attribute by the name of
1729 C<$attribute_name> and returns a boolean.
1731 =item B<get_attribute ($attribute_name)>
1733 Returns the attribute meta-object associated with C<$attribute_name>,
1734 if none is found, it will return undef.
1736 =item B<remove_attribute ($attribute_name)>
1738 This will remove the attribute meta-object stored at
1739 C<$attribute_name>, then return the removed attribute meta-object.
1742 Removing an attribute will only affect future instances of
1743 the class, it will not make any attempt to remove the attribute from
1744 any existing instances of the class.
1746 It should be noted that any accessor, reader/writer or predicate
1747 methods which the attribute meta-object stored at C<$attribute_name>
1748 has will be removed from the class at this time. This B<will> make
1749 these attributes somewhat inaccessable in previously created
1750 instances. But if you are crazy enough to do this at runtime, then
1751 you are crazy enough to deal with something like this :).
1753 =item B<get_attribute_list>
1755 This returns a list of attribute names which are defined in the local
1756 class. If you want a list of all applicable attributes for a class,
1757 use the C<compute_all_applicable_attributes> method.
1759 =item B<compute_all_applicable_attributes>
1761 =item B<get_all_attributes>
1763 This will traverse the inheritance heirachy and return a list of all
1764 the applicable L<Class::MOP::Attribute> objects for this class.
1766 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1768 =item B<find_attribute_by_name ($attr_name)>
1770 This method will traverse the inheritance heirachy and find the
1771 first attribute whose name matches C<$attr_name>, then return it.
1772 It will return undef if nothing is found.
1776 =head2 Class Immutability
1780 =item B<make_immutable (%options)>
1782 This method will invoke a tranforamtion upon the class which will
1783 make it immutable. Details of this transformation can be found in
1784 the L<Class::MOP::Immutable> documentation.
1786 =item B<make_mutable>
1788 This method will reverse tranforamtion upon the class which
1791 =item B<get_immutable_transformer>
1793 Return a transformer suitable for making this class immutable or, if this
1794 class is immutable, the transformer used to make it immutable.
1796 =item B<get_immutable_options>
1798 If the class is immutable, return the options used to make it immutable.
1800 =item B<create_immutable_transformer>
1802 Create a transformer suitable for making this class immutable
1808 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1810 =head1 COPYRIGHT AND LICENSE
1812 Copyright 2006-2008 by Infinity Interactive, Inc.
1814 L<http://www.iinteractive.com>
1816 This library is free software; you can redistribute it and/or modify
1817 it under the same terms as Perl itself.