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 = '0.65';
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 return if Class::MOP::does_metaclass_exist($self->name);
232 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
234 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
235 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
237 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
242 # creating classes with MOP ...
245 my ( $class, @args ) = @_;
247 unshift @args, 'package' if @args % 2 == 1;
249 my (%options) = @args;
250 my $package_name = $options{package};
252 (defined $package_name && $package_name)
253 || confess "You must pass a package name";
255 (ref $options{superclasses} eq 'ARRAY')
256 || confess "You must pass an ARRAY ref of superclasses"
257 if exists $options{superclasses};
259 (ref $options{attributes} eq 'ARRAY')
260 || confess "You must pass an ARRAY ref of attributes"
261 if exists $options{attributes};
263 (ref $options{methods} eq 'HASH')
264 || confess "You must pass an HASH ref of methods"
265 if exists $options{methods};
267 my $code = "package $package_name;";
268 $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';"
269 if exists $options{version};
270 $code .= "\$$package_name\:\:AUTHORITY = '" . $options{authority} . "';"
271 if exists $options{authority};
274 confess "creation of $package_name failed : $@" if $@;
276 my $meta = $class->initialize($package_name);
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'} }
315 # this is a prime canidate for conversion to XS
319 my $current = Class::MOP::check_package_cache_flag($self->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 $class_name = $self->name;
330 my $method_metaclass = $self->method_metaclass;
332 my %all_code = $self->get_all_package_symbols('CODE');
334 foreach my $symbol (keys %all_code) {
335 my $code = $all_code{$symbol};
337 next if exists $map->{$symbol} &&
338 defined $map->{$symbol} &&
339 $map->{$symbol}->body == $code;
341 my ($pkg, $name) = Class::MOP::get_code_info($code);
344 # in 5.10 constant.pm the constants show up
345 # as being in the right package, but in pre-5.10
346 # they show up as constant::__ANON__ so we
347 # make an exception here to be sure that things
348 # work as expected in both.
350 unless ($pkg eq 'constant' && $name eq '__ANON__') {
351 next if ($pkg || '') ne $class_name ||
352 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
355 $map->{$symbol} = $method_metaclass->wrap(
357 associated_metaclass => $self,
358 package_name => $class_name,
366 # Instance Construction & Cloning
372 # we need to protect the integrity of the
373 # Class::MOP::Class singletons here, so we
374 # delegate this to &construct_class_instance
375 # which will deal with the singletons
376 return $class->construct_class_instance(@_)
377 if $class->name->isa('Class::MOP::Class');
378 return $class->construct_instance(@_);
381 sub construct_instance {
383 my $params = @_ == 1 ? $_[0] : {@_};
384 my $meta_instance = $class->get_meta_instance();
385 my $instance = $meta_instance->create_instance();
386 foreach my $attr ($class->compute_all_applicable_attributes()) {
387 $attr->initialize_instance_slot($meta_instance, $instance, $params);
390 # this will only work for a HASH instance type
391 if ($class->is_anon_class) {
392 (Scalar::Util::reftype($instance) eq 'HASH')
393 || confess "Currently only HASH based instances are supported with instance of anon-classes";
395 # At some point we should make this official
396 # as a reserved slot name, but right now I am
397 # going to keep it here.
398 # my $RESERVED_MOP_SLOT = '__MOP__';
399 $instance->{'__MOP__'} = $class;
405 sub get_meta_instance {
407 $self->{'_meta_instance'} ||= $self->create_meta_instance();
410 sub create_meta_instance {
413 my $instance = $self->instance_metaclass->new(
414 associated_metaclass => $self,
415 attributes => [ $self->compute_all_applicable_attributes() ],
418 $self->add_meta_instance_dependencies()
419 if $instance->is_dependent_on_superclasses();
426 my $instance = shift;
427 (blessed($instance) && $instance->isa($class->name))
428 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
431 # we need to protect the integrity of the
432 # Class::MOP::Class singletons here, they
433 # should not be cloned.
434 return $instance if $instance->isa('Class::MOP::Class');
435 $class->clone_instance($instance, @_);
439 my ($class, $instance, %params) = @_;
441 || confess "You can only clone instances, ($instance) is not a blessed instance";
442 my $meta_instance = $class->get_meta_instance();
443 my $clone = $meta_instance->clone_instance($instance);
444 foreach my $attr ($class->compute_all_applicable_attributes()) {
445 if ( defined( my $init_arg = $attr->init_arg ) ) {
446 if (exists $params{$init_arg}) {
447 $attr->set_value($clone, $params{$init_arg});
454 sub rebless_instance {
455 my ($self, $instance, %params) = @_;
458 if ($instance->can('meta')) {
459 ($instance->meta->isa('Class::MOP::Class'))
460 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
461 $old_metaclass = $instance->meta;
464 $old_metaclass = $self->initialize(ref($instance));
467 my $meta_instance = $self->get_meta_instance();
469 $self->name->isa($old_metaclass->name)
470 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
473 $meta_instance->rebless_instance_structure($instance, $self);
475 foreach my $attr ( $self->compute_all_applicable_attributes ) {
476 if ( $attr->has_value($instance) ) {
477 if ( defined( my $init_arg = $attr->init_arg ) ) {
478 $params{$init_arg} = $attr->get_value($instance)
479 unless exists $params{$init_arg};
482 $attr->set_value($instance, $attr->get_value($instance));
487 foreach my $attr ($self->compute_all_applicable_attributes) {
488 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
498 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
501 @{$self->get_package_symbol($var_spec)} = @supers;
503 # we need to check the metaclass
504 # compatibility here so that we can
505 # be sure that the superclass is
506 # not potentially creating an issues
507 # we don't know about
509 $self->check_metaclass_compatibility();
510 $self->update_meta_instance_dependencies();
512 @{$self->get_package_symbol($var_spec)};
518 my $super_class = $self->name;
520 if ( Class::MOP::HAVE_ISAREV() ) {
521 return @{ $super_class->mro::get_isarev() };
525 my $find_derived_classes;
526 $find_derived_classes = sub {
527 my ($outer_class) = @_;
529 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
532 for my $symbol ( keys %$symbol_table_hashref ) {
533 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
534 my $inner_class = $1;
536 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
540 ? "${outer_class}::$inner_class"
543 if ( $class->isa($super_class) and $class ne $super_class ) {
544 push @derived_classes, $class;
547 next SYMBOL if $class eq 'main'; # skip 'main::*'
549 $find_derived_classes->($class);
553 my $root_class = q{};
554 $find_derived_classes->($root_class);
556 undef $find_derived_classes;
558 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
560 return @derived_classes;
566 return @{ mro::get_linear_isa( (shift)->name ) };
569 sub class_precedence_list {
571 my $name = $self->name;
573 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
575 # We need to check for circular inheritance here
576 # if we are are not on 5.10, cause 5.8 detects it
577 # late. This will do nothing if all is well, and
578 # blow up otherwise. Yes, it's an ugly hack, better
579 # suggestions are welcome.
581 ($name || return)->isa('This is a test for circular inheritance')
584 # if our mro is c3, we can
585 # just grab the linear_isa
586 if (mro::get_mro($name) eq 'c3') {
587 return @{ mro::get_linear_isa($name) }
591 # we can't grab the linear_isa for dfs
592 # since it has all the duplicates
597 $self->initialize($_)->class_precedence_list()
598 } $self->superclasses()
605 sub wrap_method_body {
606 my ( $self, %args ) = @_;
608 ('CODE' eq ref $args{body})
609 || confess "Your code block must be a CODE reference";
611 $self->method_metaclass->wrap(
612 package_name => $self->name,
618 my ($self, $method_name, $method) = @_;
619 (defined $method_name && $method_name)
620 || confess "You must define a method name";
623 if (blessed($method)) {
624 $body = $method->body;
625 if ($method->package_name ne $self->name) {
626 $method = $method->clone(
627 package_name => $self->name,
629 ) if $method->can('clone');
634 $method = $self->wrap_method_body( body => $body, name => $method_name );
637 $method->attach_to_class($self);
639 $self->get_method_map->{$method_name} = $method;
641 my $full_method_name = ($self->name . '::' . $method_name);
642 $self->add_package_symbol(
643 { sigil => '&', type => 'CODE', name => $method_name },
644 Class::MOP::subname($full_method_name => $body)
647 $self->update_package_cache_flag; # still valid, since we just added the method to the map, and if it was invalid before that then get_method_map updated it
651 my $fetch_and_prepare_method = sub {
652 my ($self, $method_name) = @_;
654 my $method = $self->get_method($method_name);
655 # if we dont have local ...
657 # try to find the next method
658 $method = $self->find_next_method_by_name($method_name);
659 # die if it does not exist
661 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
662 # and now make sure to wrap it
663 # even if it is already wrapped
664 # because we need a new sub ref
665 $method = Class::MOP::Method::Wrapped->wrap($method);
668 # now make sure we wrap it properly
669 $method = Class::MOP::Method::Wrapped->wrap($method)
670 unless $method->isa('Class::MOP::Method::Wrapped');
672 $self->add_method($method_name => $method);
676 sub add_before_method_modifier {
677 my ($self, $method_name, $method_modifier) = @_;
678 (defined $method_name && $method_name)
679 || confess "You must pass in a method name";
680 my $method = $fetch_and_prepare_method->($self, $method_name);
681 $method->add_before_modifier(
682 Class::MOP::subname(':before' => $method_modifier)
686 sub add_after_method_modifier {
687 my ($self, $method_name, $method_modifier) = @_;
688 (defined $method_name && $method_name)
689 || confess "You must pass in a method name";
690 my $method = $fetch_and_prepare_method->($self, $method_name);
691 $method->add_after_modifier(
692 Class::MOP::subname(':after' => $method_modifier)
696 sub add_around_method_modifier {
697 my ($self, $method_name, $method_modifier) = @_;
698 (defined $method_name && $method_name)
699 || confess "You must pass in a method name";
700 my $method = $fetch_and_prepare_method->($self, $method_name);
701 $method->add_around_modifier(
702 Class::MOP::subname(':around' => $method_modifier)
707 # the methods above used to be named like this:
708 # ${pkg}::${method}:(before|after|around)
709 # but this proved problematic when using one modifier
710 # to wrap multiple methods (something which is likely
711 # to happen pretty regularly IMO). So instead of naming
712 # it like this, I have chosen to just name them purely
713 # with their modifier names, like so:
714 # :(before|after|around)
715 # The fact is that in a stack trace, it will be fairly
716 # evident from the context what method they are attached
717 # to, and so don't need the fully qualified name.
723 $self->add_method(@_);
727 my ($self, $method_name) = @_;
728 (defined $method_name && $method_name)
729 || confess "You must define a method name";
731 exists $self->get_method_map->{$method_name};
735 my ($self, $method_name) = @_;
736 (defined $method_name && $method_name)
737 || confess "You must define a method name";
740 # I don't really need this here, because
741 # if the method_map is missing a key it
742 # will just return undef for me now
743 # return unless $self->has_method($method_name);
745 return $self->get_method_map->{$method_name};
749 my ($self, $method_name) = @_;
750 (defined $method_name && $method_name)
751 || confess "You must define a method name";
753 my $removed_method = delete $self->get_method_map->{$method_name};
755 $self->remove_package_symbol(
756 { sigil => '&', type => 'CODE', name => $method_name }
759 $removed_method->detach_from_class if $removed_method;
761 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
763 return $removed_method;
766 sub get_method_list {
768 keys %{$self->get_method_map};
771 sub find_method_by_name {
772 my ($self, $method_name) = @_;
773 (defined $method_name && $method_name)
774 || confess "You must define a method name to find";
775 foreach my $class ($self->linearized_isa) {
776 # fetch the meta-class ...
777 my $meta = $self->initialize($class);
778 return $meta->get_method($method_name)
779 if $meta->has_method($method_name);
784 sub get_all_methods {
786 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
787 return values %methods;
791 sub compute_all_applicable_methods {
795 class => $_->package_name,
796 code => $_, # sigh, overloading
798 } shift->get_all_methods(@_);
801 sub find_all_methods_by_name {
802 my ($self, $method_name) = @_;
803 (defined $method_name && $method_name)
804 || confess "You must define a method name to find";
806 foreach my $class ($self->linearized_isa) {
807 # fetch the meta-class ...
808 my $meta = $self->initialize($class);
810 name => $method_name,
812 code => $meta->get_method($method_name)
813 } if $meta->has_method($method_name);
818 sub find_next_method_by_name {
819 my ($self, $method_name) = @_;
820 (defined $method_name && $method_name)
821 || confess "You must define a method name to find";
822 my @cpl = $self->linearized_isa;
823 shift @cpl; # discard ourselves
824 foreach my $class (@cpl) {
825 # fetch the meta-class ...
826 my $meta = $self->initialize($class);
827 return $meta->get_method($method_name)
828 if $meta->has_method($method_name);
837 # either we have an attribute object already
838 # or we need to create one from the args provided
839 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
840 # make sure it is derived from the correct type though
841 ($attribute->isa('Class::MOP::Attribute'))
842 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
844 # first we attach our new attribute
845 # because it might need certain information
846 # about the class which it is attached to
847 $attribute->attach_to_class($self);
849 # then we remove attributes of a conflicting
850 # name here so that we can properly detach
851 # the old attr object, and remove any
852 # accessors it would have generated
853 if ( $self->has_attribute($attribute->name) ) {
854 $self->remove_attribute($attribute->name);
856 $self->invalidate_meta_instances();
859 # then onto installing the new accessors
860 $self->get_attribute_map->{$attribute->name} = $attribute;
862 # invalidate package flag here
863 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
865 $self->remove_attribute($attribute->name);
872 sub update_meta_instance_dependencies {
875 if ( $self->{meta_instance_dependencies} ) {
876 return $self->add_meta_instance_dependencies;
880 sub add_meta_instance_dependencies {
883 $self->remove_meta_instance_depdendencies;
885 my @attrs = $self->compute_all_applicable_attributes();
888 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
890 foreach my $class ( @classes ) {
891 $class->add_dependent_meta_instance($self);
894 $self->{meta_instance_dependencies} = \@classes;
897 sub remove_meta_instance_depdendencies {
900 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
901 foreach my $class ( @$classes ) {
902 $class->remove_dependent_meta_instance($self);
912 sub add_dependent_meta_instance {
913 my ( $self, $metaclass ) = @_;
914 push @{ $self->{dependent_meta_instances} }, $metaclass;
917 sub remove_dependent_meta_instance {
918 my ( $self, $metaclass ) = @_;
919 my $name = $metaclass->name;
920 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
923 sub invalidate_meta_instances {
925 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
928 sub invalidate_meta_instance {
930 undef $self->{_meta_instance};
934 my ($self, $attribute_name) = @_;
935 (defined $attribute_name && $attribute_name)
936 || confess "You must define an attribute name";
937 exists $self->get_attribute_map->{$attribute_name};
941 my ($self, $attribute_name) = @_;
942 (defined $attribute_name && $attribute_name)
943 || confess "You must define an attribute name";
944 return $self->get_attribute_map->{$attribute_name}
946 # this will return undef anyway, so no need ...
947 # if $self->has_attribute($attribute_name);
951 sub remove_attribute {
952 my ($self, $attribute_name) = @_;
953 (defined $attribute_name && $attribute_name)
954 || confess "You must define an attribute name";
955 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
956 return unless defined $removed_attribute;
957 delete $self->get_attribute_map->{$attribute_name};
958 $self->invalidate_meta_instances();
959 $removed_attribute->remove_accessors();
960 $removed_attribute->detach_from_class();
961 return $removed_attribute;
964 sub get_attribute_list {
966 keys %{$self->get_attribute_map};
969 sub get_all_attributes {
970 shift->compute_all_applicable_attributes(@_);
973 sub compute_all_applicable_attributes {
975 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
976 return values %attrs;
979 sub find_attribute_by_name {
980 my ($self, $attr_name) = @_;
981 foreach my $class ($self->linearized_isa) {
982 # fetch the meta-class ...
983 my $meta = $self->initialize($class);
984 return $meta->get_attribute($attr_name)
985 if $meta->has_attribute($attr_name);
990 # check if we can reinitialize
994 # if any local attr is defined
995 return if $self->get_attribute_list;
997 # or any non-declared methods
998 if ( my @methods = values %{ $self->get_method_map } ) {
999 my $metaclass = $self->method_metaclass;
1000 foreach my $method ( @methods ) {
1001 return if $method->isa("Class::MOP::Method::Generated");
1002 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1011 sub is_mutable { 1 }
1012 sub is_immutable { 0 }
1015 # Why I changed this (groditi)
1016 # - One Metaclass may have many Classes through many Metaclass instances
1017 # - One Metaclass should only have one Immutable Transformer instance
1018 # - Each Class may have different Immutabilizing options
1019 # - Therefore each Metaclass instance may have different Immutabilizing options
1020 # - We need to store one Immutable Transformer instance per Metaclass
1021 # - We need to store one set of Immutable Transformer options per Class
1022 # - Upon make_mutable we may delete the Immutabilizing options
1023 # - We could clean the immutable Transformer instance when there is no more
1024 # immutable Classes of that type, but we can also keep it in case
1025 # another class with this same Metaclass becomes immutable. It is a case
1026 # of trading of storing an instance to avoid unnecessary instantiations of
1027 # Immutable Transformers. You may view this as a memory leak, however
1028 # Because we have few Metaclasses, in practice it seems acceptable
1029 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1030 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1034 my %IMMUTABLE_TRANSFORMERS;
1035 my %IMMUTABLE_OPTIONS;
1037 sub get_immutable_options {
1039 return if $self->is_mutable;
1040 confess "unable to find immutabilizing options"
1041 unless exists $IMMUTABLE_OPTIONS{$self->name};
1042 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1043 delete $options{IMMUTABLE_TRANSFORMER};
1047 sub get_immutable_transformer {
1049 if( $self->is_mutable ){
1050 my $class = ref $self || $self;
1051 return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
1053 confess "unable to find transformer for immutable class"
1054 unless exists $IMMUTABLE_OPTIONS{$self->name};
1055 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1058 sub make_immutable {
1062 my $transformer = $self->get_immutable_transformer;
1063 $transformer->make_metaclass_immutable($self, \%options);
1064 $IMMUTABLE_OPTIONS{$self->name} =
1065 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1067 if( exists $options{debug} && $options{debug} ){
1068 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1069 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1077 return if $self->is_mutable;
1078 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1079 confess "unable to find immutabilizing options" unless ref $options;
1080 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1081 $transformer->make_metaclass_mutable($self, $options);
1086 sub create_immutable_transformer {
1088 my $class = Class::MOP::Immutable->new($self, {
1089 read_only => [qw/superclasses/],
1096 remove_package_symbol
1099 class_precedence_list => 'ARRAY',
1100 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
1101 get_all_methods => 'ARRAY',
1102 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
1103 compute_all_applicable_attributes => 'ARRAY',
1104 get_meta_instance => 'SCALAR',
1105 get_method_map => 'SCALAR',
1108 # this is ugly, but so are typeglobs,
1109 # so whattayahgonnadoboutit
1112 add_package_symbol => sub {
1113 my $original = shift;
1114 confess "Cannot add package symbols to an immutable metaclass"
1115 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1117 # This is a workaround for a bug in 5.8.1 which thinks that
1118 # goto $original->body
1119 # is trying to go to a label
1120 my $body = $original->body;
1136 Class::MOP::Class - Class Meta Object
1140 # assuming that class Foo
1141 # has been defined, you can
1143 # use this for introspection ...
1145 # add a method to Foo ...
1146 Foo->meta->add_method('bar' => sub { ... })
1148 # get a list of all the classes searched
1149 # the method dispatcher in the correct order
1150 Foo->meta->class_precedence_list()
1152 # remove a method from Foo
1153 Foo->meta->remove_method('bar');
1155 # or use this to actually create classes ...
1157 Class::MOP::Class->create('Bar' => (
1159 superclasses => [ 'Foo' ],
1161 Class::MOP:::Attribute->new('$bar'),
1162 Class::MOP:::Attribute->new('$baz'),
1165 calculate_bar => sub { ... },
1166 construct_baz => sub { ... }
1172 This is the largest and currently most complex part of the Perl 5
1173 meta-object protocol. It controls the introspection and
1174 manipulation of Perl 5 classes (and it can create them too). The
1175 best way to understand what this module can do, is to read the
1176 documentation for each of it's methods.
1180 =head2 Self Introspection
1186 This will return a B<Class::MOP::Class> instance which is related
1187 to this class. Thereby allowing B<Class::MOP::Class> to actually
1190 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1191 bootstrap this module by installing a number of attribute meta-objects
1192 into it's metaclass. This will allow this class to reap all the benifits
1193 of the MOP when subclassing it.
1197 =head2 Class construction
1199 These methods will handle creating B<Class::MOP::Class> objects,
1200 which can be used to both create new classes, and analyze
1201 pre-existing classes.
1203 This module will internally store references to all the instances
1204 you create with these methods, so that they do not need to be
1205 created any more than nessecary. Basically, they are singletons.
1209 =item B<create ($package_name,
1210 version =E<gt> ?$version,
1211 authority =E<gt> ?$authority,
1212 superclasses =E<gt> ?@superclasses,
1213 methods =E<gt> ?%methods,
1214 attributes =E<gt> ?%attributes)>
1216 This returns a B<Class::MOP::Class> object, bringing the specified
1217 C<$package_name> into existence and adding any of the C<$version>,
1218 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1221 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1222 methods =E<gt> ?%methods,
1223 attributes =E<gt> ?%attributes)>
1225 This will create an anonymous class, it works much like C<create> but
1226 it does not need a C<$package_name>. Instead it will create a suitably
1227 unique package name for you to stash things into.
1229 On very important distinction is that anon classes are destroyed once
1230 the metaclass they are attached to goes out of scope. In the DESTROY
1231 method, the created package will be removed from the symbol table.
1233 It is also worth noting that any instances created with an anon-class
1234 will keep a special reference to the anon-meta which will prevent the
1235 anon-class from going out of scope until all instances of it have also
1236 been destroyed. This however only works for HASH based instance types,
1237 as we use a special reserved slot (C<__MOP__>) to store this.
1239 =item B<initialize ($package_name, %options)>
1241 This initializes and returns returns a B<Class::MOP::Class> object
1242 for a given a C<$package_name>.
1244 =item B<construct_class_instance (%options)>
1246 This will construct an instance of B<Class::MOP::Class>, it is
1247 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1248 to use C<construct_instance> once all the bootstrapping is done. This
1249 method is used internally by C<initialize> and should never be called
1250 from outside of that method really.
1252 =item B<check_metaclass_compatibility>
1254 This method is called as the very last thing in the
1255 C<construct_class_instance> method. This will check that the
1256 metaclass you are creating is compatible with the metaclasses of all
1257 your ancestors. For more inforamtion about metaclass compatibility
1258 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1260 =item B<update_package_cache_flag>
1262 This will reset the package cache flag for this particular metaclass
1263 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1264 function. This is very rarely needed from outside of C<Class::MOP::Class>
1265 but in some cases you might want to use it, so it is here.
1267 =item B<reset_package_cache_flag>
1269 Clears the package cache flag to announce to the internals that we need
1270 to rebuild the method map.
1272 =item B<add_meta_instance_dependencies>
1274 Registers this class as dependent on its superclasses.
1276 Only superclasses from which this class inherits attributes will be added.
1278 =item B<remove_meta_instance_depdendencies>
1280 Unregisters this class from its superclasses.
1282 =item B<update_meta_instance_dependencies>
1284 Reregisters if necessary.
1286 =item B<add_dependent_meta_instance> $metaclass
1288 Registers the class as having a meta instance dependent on this class.
1290 =item B<remove_dependent_meta_instance> $metaclass
1292 Remove the class from the list of dependent classes.
1294 =item B<invalidate_meta_instances>
1296 Clears the cached meta instance for this metaclass and all of the registered
1297 classes with dependent meta instances.
1299 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1302 =item B<invalidate_meta_instance>
1304 Used by C<invalidate_meta_instances>.
1308 =head2 Object instance construction and cloning
1310 These methods are B<entirely optional>, it is up to you whether you want
1315 =item B<instance_metaclass>
1317 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1318 for more information on the instance metaclasses.
1320 =item B<get_meta_instance>
1322 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1323 of a new instance of the class.
1325 =item B<create_meta_instance>
1327 Called by C<get_meta_instance> if necessary.
1329 =item B<new_object (%params)>
1331 This is a convience method for creating a new object of the class, and
1332 blessing it into the appropriate package as well. Ideally your class
1333 would call a C<new> this method like so:
1336 my ($class, %param) = @_;
1337 $class->meta->new_object(%params);
1340 =item B<construct_instance (%params)>
1342 This method is used to construct an instance structure suitable for
1343 C<bless>-ing into your package of choice. It works in conjunction
1344 with the Attribute protocol to collect all applicable attributes.
1346 This will construct and instance using a HASH ref as storage
1347 (currently only HASH references are supported). This will collect all
1348 the applicable attributes and layout out the fields in the HASH ref,
1349 it will then initialize them using either use the corresponding key
1350 in C<%params> or any default value or initializer found in the
1351 attribute meta-object.
1353 =item B<clone_object ($instance, %params)>
1355 This is a convience method for cloning an object instance, then
1356 blessing it into the appropriate package. This method will call
1357 C<clone_instance>, which performs a shallow copy of the object,
1358 see that methods documentation for more details. Ideally your
1359 class would call a C<clone> this method like so:
1361 sub MyClass::clone {
1362 my ($self, %param) = @_;
1363 $self->meta->clone_object($self, %params);
1366 =item B<clone_instance($instance, %params)>
1368 This method is a compliment of C<construct_instance> (which means if
1369 you override C<construct_instance>, you need to override this one too),
1370 and clones the instance shallowly.
1372 The cloned structure returned is (like with C<construct_instance>) an
1373 unC<bless>ed HASH reference, it is your responsibility to then bless
1374 this cloned structure into the right class (which C<clone_object> will
1377 As of 0.11, this method will clone the C<$instance> structure shallowly,
1378 as opposed to the deep cloning implemented in prior versions. After much
1379 thought, research and discussion, I have decided that anything but basic
1380 shallow cloning is outside the scope of the meta-object protocol. I
1381 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1382 is too I<context-specific> to be part of the MOP.
1384 =item B<rebless_instance($instance, ?%params)>
1386 This will change the class of C<$instance> to the class of the invoking
1387 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1388 itself. You may pass in optional C<%params> which are like constructor
1389 params and will override anything already defined in the instance.
1393 =head2 Informational
1395 These are a few predicate methods for asking information about the class.
1399 =item B<is_anon_class>
1401 This returns true if the class is a C<Class::MOP::Class> created anon class.
1405 This returns true if the class is still mutable.
1407 =item B<is_immutable>
1409 This returns true if the class has been made immutable.
1411 =item B<is_pristine>
1413 Checks whether the class has any data that will be lost if C<reinitialize> is
1418 =head2 Inheritance Relationships
1422 =item B<superclasses (?@superclasses)>
1424 This is a read-write attribute which represents the superclass
1425 relationships of the class the B<Class::MOP::Class> instance is
1426 associated with. Basically, it can get and set the C<@ISA> for you.
1428 =item B<class_precedence_list>
1430 This computes the a list of all the class's ancestors in the same order
1431 in which method dispatch will be done. This is similair to what
1432 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1434 =item B<linearized_isa>
1436 This returns a list based on C<class_precedence_list> but with all
1441 This returns a list of subclasses for this class.
1449 =item B<get_method_map>
1451 Returns a HASH ref of name to CODE reference mapping for this class.
1453 =item B<method_metaclass>
1455 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1456 for more information on the method metaclasses.
1458 =item B<wrap_method_body(%attrs)>
1460 Wrap a code ref (C<$attrs{body>) with C<method_metaclass>.
1462 =item B<add_method ($method_name, $method, %attrs)>
1464 This will take a C<$method_name> and CODE reference or meta method
1465 objectand install it into the class's package.
1467 You are strongly encouraged to pass a meta method object instead of a
1468 code reference. If you do so, that object gets stored as part of the
1469 class's method map, providing more useful information about the method
1472 When you provide a method object, this method will clone that object
1473 if the object's package name does not match the class name. This lets
1474 us track the original source of any methods added from other classes
1475 (notably Moose roles).
1478 This does absolutely nothing special to C<$method>
1479 other than use B<Sub::Name> to make sure it is tagged with the
1480 correct name, and therefore show up correctly in stack traces and
1483 =item B<has_method ($method_name)>
1485 This just provides a simple way to check if the class implements
1486 a specific C<$method_name>. It will I<not> however, attempt to check
1487 if the class inherits the method (use C<UNIVERSAL::can> for that).
1489 This will correctly handle functions defined outside of the package
1490 that use a fully qualified name (C<sub Package::name { ... }>).
1492 This will correctly handle functions renamed with B<Sub::Name> and
1493 installed using the symbol tables. However, if you are naming the
1494 subroutine outside of the package scope, you must use the fully
1495 qualified name, including the package name, for C<has_method> to
1496 correctly identify it.
1498 This will attempt to correctly ignore functions imported from other
1499 packages using B<Exporter>. It breaks down if the function imported
1500 is an C<__ANON__> sub (such as with C<use constant>), which very well
1501 may be a valid method being applied to the class.
1503 In short, this method cannot always be trusted to determine if the
1504 C<$method_name> is actually a method. However, it will DWIM about
1505 90% of the time, so it's a small trade off I think.
1507 =item B<get_method ($method_name)>
1509 This will return a Class::MOP::Method instance related to the specified
1510 C<$method_name>, or return undef if that method does not exist.
1512 The Class::MOP::Method is codifiable, so you can use it like a normal
1513 CODE reference, see L<Class::MOP::Method> for more information.
1515 =item B<find_method_by_name ($method_name)>
1517 This will return a CODE reference of the specified C<$method_name>,
1518 or return undef if that method does not exist.
1520 Unlike C<get_method> this will also look in the superclasses.
1522 =item B<remove_method ($method_name)>
1524 This will attempt to remove a given C<$method_name> from the class.
1525 It will return the CODE reference that it has removed, and will
1526 attempt to use B<Sub::Name> to clear the methods associated name.
1528 =item B<get_method_list>
1530 This will return a list of method names for all I<locally> defined
1531 methods. It does B<not> provide a list of all applicable methods,
1532 including any inherited ones. If you want a list of all applicable
1533 methods, use the C<compute_all_applicable_methods> method.
1535 =item B<get_all_methods>
1537 This will traverse the inheritance heirachy and return a list of all
1538 the applicable L<Class::MOP::Method> objects for this class.
1540 =item B<compute_all_applicable_methods>
1544 This method returns a list of hashes describing the all the methods of the
1547 Use L<get_all_methods>, which is easier/better/faster. This method predates
1548 L<Class::MOP::Method>.
1550 =item B<find_all_methods_by_name ($method_name)>
1552 This will traverse the inheritence hierarchy and locate all methods
1553 with a given C<$method_name>. Similar to
1554 C<compute_all_applicable_methods> it returns a list of HASH references
1555 with the following information; method name (which will always be the
1556 same as C<$method_name>), the name of the class in which the method
1557 lives and a CODE reference for the actual method.
1559 The list of methods produced is a distinct list, meaning there are no
1560 duplicates in it. This is especially useful for things like object
1561 initialization and destruction where you only want the method called
1562 once, and in the correct order.
1564 =item B<find_next_method_by_name ($method_name)>
1566 This will return the first method to match a given C<$method_name> in
1567 the superclasses, this is basically equivalent to calling
1568 C<SUPER::$method_name>, but it can be dispatched at runtime.
1570 =item B<alias_method ($method_name, $method)>
1572 B<NOTE>: This method is now deprecated. Just use C<add_method>
1577 =head2 Method Modifiers
1579 Method modifiers are a concept borrowed from CLOS, in which a method
1580 can be wrapped with I<before>, I<after> and I<around> method modifiers
1581 that will be called everytime the method is called.
1583 =head3 How method modifiers work?
1585 Method modifiers work by wrapping the original method and then replacing
1586 it in the classes symbol table. The wrappers will handle calling all the
1587 modifiers in the appropariate orders and preserving the calling context
1588 for the original method.
1590 Each method modifier serves a particular purpose, which may not be
1591 obvious to users of other method wrapping modules. To start with, the
1592 return values of I<before> and I<after> modifiers are ignored. This is
1593 because thier purpose is B<not> to filter the input and output of the
1594 primary method (this is done with an I<around> modifier). This may seem
1595 like an odd restriction to some, but doing this allows for simple code
1596 to be added at the begining or end of a method call without jeapordizing
1597 the normal functioning of the primary method or placing any extra
1598 responsibility on the code of the modifier. Of course if you have more
1599 complex needs, then use the I<around> modifier, which uses a variation
1600 of continutation passing style to allow for a high degree of flexibility.
1602 Before and around modifiers are called in last-defined-first-called order,
1603 while after modifiers are called in first-defined-first-called order. So
1604 the call tree might looks something like this:
1614 To see examples of using method modifiers, see the following examples
1615 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1616 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1617 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1619 =head3 What is the performance impact?
1621 Of course there is a performance cost associated with method modifiers,
1622 but we have made every effort to make that cost be directly proportional
1623 to the amount of modifier features you utilize.
1625 The wrapping method does it's best to B<only> do as much work as it
1626 absolutely needs to. In order to do this we have moved some of the
1627 performance costs to set-up time, where they are easier to amortize.
1629 All this said, my benchmarks have indicated the following:
1631 simple wrapper with no modifiers 100% slower
1632 simple wrapper with simple before modifier 400% slower
1633 simple wrapper with simple after modifier 450% slower
1634 simple wrapper with simple around modifier 500-550% slower
1635 simple wrapper with all 3 modifiers 1100% slower
1637 These numbers may seem daunting, but you must remember, every feature
1638 comes with some cost. To put things in perspective, just doing a simple
1639 C<AUTOLOAD> which does nothing but extract the name of the method called
1640 and return it costs about 400% over a normal method call.
1644 =item B<add_before_method_modifier ($method_name, $code)>
1646 This will wrap the method at C<$method_name> and the supplied C<$code>
1647 will be passed the C<@_> arguments, and called before the original
1648 method is called. As specified above, the return value of the I<before>
1649 method modifiers is ignored, and it's ability to modify C<@_> is
1650 fairly limited. If you need to do either of these things, use an
1651 C<around> method modifier.
1653 =item B<add_after_method_modifier ($method_name, $code)>
1655 This will wrap the method at C<$method_name> so that the original
1656 method will be called, it's return values stashed, and then the
1657 supplied C<$code> will be passed the C<@_> arguments, and called.
1658 As specified above, the return value of the I<after> method
1659 modifiers is ignored, and it cannot modify the return values of
1660 the original method. If you need to do either of these things, use an
1661 C<around> method modifier.
1663 =item B<add_around_method_modifier ($method_name, $code)>
1665 This will wrap the method at C<$method_name> so that C<$code>
1666 will be called and passed the original method as an extra argument
1667 at the begining of the C<@_> argument list. This is a variation of
1668 continuation passing style, where the function prepended to C<@_>
1669 can be considered a continuation. It is up to C<$code> if it calls
1670 the original method or not, there is no restriction on what the
1671 C<$code> can or cannot do.
1677 It should be noted that since there is no one consistent way to define
1678 the attributes of a class in Perl 5. These methods can only work with
1679 the information given, and can not easily discover information on
1680 their own. See L<Class::MOP::Attribute> for more details.
1684 =item B<attribute_metaclass>
1686 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1687 for more information on the attribute metaclasses.
1689 =item B<get_attribute_map>
1691 This returns a HASH ref of name to attribute meta-object mapping.
1693 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1695 This stores the C<$attribute_meta_object> (or creates one from the
1696 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1697 instance associated with the given class. Unlike methods, attributes
1698 within the MOP are stored as meta-information only. They will be used
1699 later to construct instances from (see C<construct_instance> above).
1700 More details about the attribute meta-objects can be found in the
1701 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1704 It should be noted that any accessor, reader/writer or predicate
1705 methods which the C<$attribute_meta_object> has will be installed
1706 into the class at this time.
1709 If an attribute already exists for C<$attribute_name>, the old one
1710 will be removed (as well as removing all it's accessors), and then
1713 =item B<has_attribute ($attribute_name)>
1715 Checks to see if this class has an attribute by the name of
1716 C<$attribute_name> and returns a boolean.
1718 =item B<get_attribute ($attribute_name)>
1720 Returns the attribute meta-object associated with C<$attribute_name>,
1721 if none is found, it will return undef.
1723 =item B<remove_attribute ($attribute_name)>
1725 This will remove the attribute meta-object stored at
1726 C<$attribute_name>, then return the removed attribute meta-object.
1729 Removing an attribute will only affect future instances of
1730 the class, it will not make any attempt to remove the attribute from
1731 any existing instances of the class.
1733 It should be noted that any accessor, reader/writer or predicate
1734 methods which the attribute meta-object stored at C<$attribute_name>
1735 has will be removed from the class at this time. This B<will> make
1736 these attributes somewhat inaccessable in previously created
1737 instances. But if you are crazy enough to do this at runtime, then
1738 you are crazy enough to deal with something like this :).
1740 =item B<get_attribute_list>
1742 This returns a list of attribute names which are defined in the local
1743 class. If you want a list of all applicable attributes for a class,
1744 use the C<compute_all_applicable_attributes> method.
1746 =item B<compute_all_applicable_attributes>
1748 =item B<get_all_attributes>
1750 This will traverse the inheritance heirachy and return a list of all
1751 the applicable L<Class::MOP::Attribute> objects for this class.
1753 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1755 =item B<find_attribute_by_name ($attr_name)>
1757 This method will traverse the inheritance heirachy and find the
1758 first attribute whose name matches C<$attr_name>, then return it.
1759 It will return undef if nothing is found.
1763 =head2 Class Immutability
1767 =item B<make_immutable (%options)>
1769 This method will invoke a tranforamtion upon the class which will
1770 make it immutable. Details of this transformation can be found in
1771 the L<Class::MOP::Immutable> documentation.
1773 =item B<make_mutable>
1775 This method will reverse tranforamtion upon the class which
1778 =item B<get_immutable_transformer>
1780 Return a transformer suitable for making this class immutable or, if this
1781 class is immutable, the transformer used to make it immutable.
1783 =item B<get_immutable_options>
1785 If the class is immutable, return the options used to make it immutable.
1787 =item B<create_immutable_transformer>
1789 Create a transformer suitable for making this class immutable
1795 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1797 =head1 COPYRIGHT AND LICENSE
1799 Copyright 2006-2008 by Infinity Interactive, Inc.
1801 L<http://www.iinteractive.com>
1803 This library is free software; you can redistribute it and/or modify
1804 it under the same terms as Perl itself.