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 = '0.71';
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'} }
315 # this is a prime canidate for conversion to XS
319 my $class_name = $self->name;
321 my $current = Class::MOP::check_package_cache_flag($class_name);
323 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
324 return $self->{'methods'} ||= {};
327 $self->{_package_cache_flag} = $current;
329 my $map = $self->{'methods'} ||= {};
331 my $method_metaclass = $self->method_metaclass;
333 my %all_code = $self->get_all_package_symbols('CODE');
335 foreach my $symbol (keys %all_code) {
336 my $code = $all_code{$symbol};
338 next if exists $map->{$symbol} &&
339 defined $map->{$symbol} &&
340 $map->{$symbol}->body == $code;
342 my ($pkg, $name) = Class::MOP::get_code_info($code);
345 # in 5.10 constant.pm the constants show up
346 # as being in the right package, but in pre-5.10
347 # they show up as constant::__ANON__ so we
348 # make an exception here to be sure that things
349 # work as expected in both.
351 unless ($pkg eq 'constant' && $name eq '__ANON__') {
352 next if ($pkg || '') ne $class_name ||
353 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
356 $map->{$symbol} = $method_metaclass->wrap(
358 associated_metaclass => $self,
359 package_name => $class_name,
367 # Instance Construction & Cloning
373 # we need to protect the integrity of the
374 # Class::MOP::Class singletons here, so we
375 # delegate this to &construct_class_instance
376 # which will deal with the singletons
377 return $class->construct_class_instance(@_)
378 if $class->name->isa('Class::MOP::Class');
379 return $class->construct_instance(@_);
382 sub construct_instance {
384 my $params = @_ == 1 ? $_[0] : {@_};
385 my $meta_instance = $class->get_meta_instance();
386 my $instance = $meta_instance->create_instance();
387 foreach my $attr ($class->compute_all_applicable_attributes()) {
388 $attr->initialize_instance_slot($meta_instance, $instance, $params);
391 # this will only work for a HASH instance type
392 if ($class->is_anon_class) {
393 (Scalar::Util::reftype($instance) eq 'HASH')
394 || confess "Currently only HASH based instances are supported with instance of anon-classes";
396 # At some point we should make this official
397 # as a reserved slot name, but right now I am
398 # going to keep it here.
399 # my $RESERVED_MOP_SLOT = '__MOP__';
400 $instance->{'__MOP__'} = $class;
406 sub get_meta_instance {
408 $self->{'_meta_instance'} ||= $self->create_meta_instance();
411 sub create_meta_instance {
414 my $instance = $self->instance_metaclass->new(
415 associated_metaclass => $self,
416 attributes => [ $self->compute_all_applicable_attributes() ],
419 $self->add_meta_instance_dependencies()
420 if $instance->is_dependent_on_superclasses();
427 my $instance = shift;
428 (blessed($instance) && $instance->isa($class->name))
429 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
432 # we need to protect the integrity of the
433 # Class::MOP::Class singletons here, they
434 # should not be cloned.
435 return $instance if $instance->isa('Class::MOP::Class');
436 $class->clone_instance($instance, @_);
440 my ($class, $instance, %params) = @_;
442 || confess "You can only clone instances, ($instance) is not a blessed instance";
443 my $meta_instance = $class->get_meta_instance();
444 my $clone = $meta_instance->clone_instance($instance);
445 foreach my $attr ($class->compute_all_applicable_attributes()) {
446 if ( defined( my $init_arg = $attr->init_arg ) ) {
447 if (exists $params{$init_arg}) {
448 $attr->set_value($clone, $params{$init_arg});
455 sub rebless_instance {
456 my ($self, $instance, %params) = @_;
459 if ($instance->can('meta')) {
460 ($instance->meta->isa('Class::MOP::Class'))
461 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
462 $old_metaclass = $instance->meta;
465 $old_metaclass = $self->initialize(ref($instance));
468 my $meta_instance = $self->get_meta_instance();
470 $self->name->isa($old_metaclass->name)
471 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
474 $meta_instance->rebless_instance_structure($instance, $self);
476 foreach my $attr ( $self->compute_all_applicable_attributes ) {
477 if ( $attr->has_value($instance) ) {
478 if ( defined( my $init_arg = $attr->init_arg ) ) {
479 $params{$init_arg} = $attr->get_value($instance)
480 unless exists $params{$init_arg};
483 $attr->set_value($instance, $attr->get_value($instance));
488 foreach my $attr ($self->compute_all_applicable_attributes) {
489 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
499 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
502 @{$self->get_package_symbol($var_spec)} = @supers;
505 # on 5.8 and below, we need to call
506 # a method to get Perl to detect
507 # a cycle in the class hierarchy
508 my $class = $self->name;
512 # we need to check the metaclass
513 # compatibility here so that we can
514 # be sure that the superclass is
515 # not potentially creating an issues
516 # we don't know about
518 $self->check_metaclass_compatibility();
519 $self->update_meta_instance_dependencies();
521 @{$self->get_package_symbol($var_spec)};
527 my $super_class = $self->name;
529 if ( Class::MOP::HAVE_ISAREV() ) {
530 return @{ $super_class->mro::get_isarev() };
534 my $find_derived_classes;
535 $find_derived_classes = sub {
536 my ($outer_class) = @_;
538 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
541 for my $symbol ( keys %$symbol_table_hashref ) {
542 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
543 my $inner_class = $1;
545 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
549 ? "${outer_class}::$inner_class"
552 if ( $class->isa($super_class) and $class ne $super_class ) {
553 push @derived_classes, $class;
556 next SYMBOL if $class eq 'main'; # skip 'main::*'
558 $find_derived_classes->($class);
562 my $root_class = q{};
563 $find_derived_classes->($root_class);
565 undef $find_derived_classes;
567 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
569 return @derived_classes;
575 return @{ mro::get_linear_isa( (shift)->name ) };
578 sub class_precedence_list {
580 my $name = $self->name;
582 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
584 # We need to check for circular inheritance here
585 # if we are are not on 5.10, cause 5.8 detects it
586 # late. This will do nothing if all is well, and
587 # blow up otherwise. Yes, it's an ugly hack, better
588 # suggestions are welcome.
590 ($name || return)->isa('This is a test for circular inheritance')
593 # if our mro is c3, we can
594 # just grab the linear_isa
595 if (mro::get_mro($name) eq 'c3') {
596 return @{ mro::get_linear_isa($name) }
600 # we can't grab the linear_isa for dfs
601 # since it has all the duplicates
606 $self->initialize($_)->class_precedence_list()
607 } $self->superclasses()
614 sub wrap_method_body {
615 my ( $self, %args ) = @_;
617 ('CODE' eq ref $args{body})
618 || confess "Your code block must be a CODE reference";
620 $self->method_metaclass->wrap(
621 package_name => $self->name,
627 my ($self, $method_name, $method) = @_;
628 (defined $method_name && $method_name)
629 || confess "You must define a method name";
632 if (blessed($method)) {
633 $body = $method->body;
634 if ($method->package_name ne $self->name) {
635 $method = $method->clone(
636 package_name => $self->name,
638 ) if $method->can('clone');
643 $method = $self->wrap_method_body( body => $body, name => $method_name );
646 $method->attach_to_class($self);
648 # This used to call get_method_map, which meant we would build all
649 # the method objects for the class just because we added one
650 # method. This is hackier, but quicker too.
651 $self->{methods}{$method_name} = $method;
653 my $full_method_name = ($self->name . '::' . $method_name);
654 $self->add_package_symbol(
655 { sigil => '&', type => 'CODE', name => $method_name },
656 Class::MOP::subname($full_method_name => $body)
661 my $fetch_and_prepare_method = sub {
662 my ($self, $method_name) = @_;
664 my $method = $self->get_method($method_name);
665 # if we dont have local ...
667 # try to find the next method
668 $method = $self->find_next_method_by_name($method_name);
669 # die if it does not exist
671 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
672 # and now make sure to wrap it
673 # even if it is already wrapped
674 # because we need a new sub ref
675 $method = Class::MOP::Method::Wrapped->wrap($method);
678 # now make sure we wrap it properly
679 $method = Class::MOP::Method::Wrapped->wrap($method)
680 unless $method->isa('Class::MOP::Method::Wrapped');
682 $self->add_method($method_name => $method);
686 sub add_before_method_modifier {
687 my ($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_before_modifier(
692 Class::MOP::subname(':before' => $method_modifier)
696 sub add_after_method_modifier {
697 my ($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_after_modifier(
702 Class::MOP::subname(':after' => $method_modifier)
706 sub add_around_method_modifier {
707 my ($self, $method_name, $method_modifier) = @_;
708 (defined $method_name && $method_name)
709 || confess "You must pass in a method name";
710 my $method = $fetch_and_prepare_method->($self, $method_name);
711 $method->add_around_modifier(
712 Class::MOP::subname(':around' => $method_modifier)
717 # the methods above used to be named like this:
718 # ${pkg}::${method}:(before|after|around)
719 # but this proved problematic when using one modifier
720 # to wrap multiple methods (something which is likely
721 # to happen pretty regularly IMO). So instead of naming
722 # it like this, I have chosen to just name them purely
723 # with their modifier names, like so:
724 # :(before|after|around)
725 # The fact is that in a stack trace, it will be fairly
726 # evident from the context what method they are attached
727 # to, and so don't need the fully qualified name.
733 $self->add_method(@_);
737 my ($self, $method_name) = @_;
738 (defined $method_name && $method_name)
739 || confess "You must define a method name";
741 exists $self->{methods}{$method_name} || exists $self->get_method_map->{$method_name};
745 my ($self, $method_name) = @_;
746 (defined $method_name && $method_name)
747 || confess "You must define a method name";
750 # I don't really need this here, because
751 # if the method_map is missing a key it
752 # will just return undef for me now
753 # return unless $self->has_method($method_name);
755 return $self->{methods}{$method_name} || $self->get_method_map->{$method_name};
759 my ($self, $method_name) = @_;
760 (defined $method_name && $method_name)
761 || confess "You must define a method name";
763 my $removed_method = delete $self->get_method_map->{$method_name};
765 $self->remove_package_symbol(
766 { sigil => '&', type => 'CODE', name => $method_name }
769 $removed_method->detach_from_class if $removed_method;
771 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
773 return $removed_method;
776 sub get_method_list {
778 keys %{$self->get_method_map};
781 sub find_method_by_name {
782 my ($self, $method_name) = @_;
783 (defined $method_name && $method_name)
784 || confess "You must define a method name to find";
785 foreach my $class ($self->linearized_isa) {
786 # fetch the meta-class ...
787 my $meta = $self->initialize($class);
788 return $meta->get_method($method_name)
789 if $meta->has_method($method_name);
794 sub get_all_methods {
796 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
797 return values %methods;
801 sub compute_all_applicable_methods {
805 class => $_->package_name,
806 code => $_, # sigh, overloading
808 } shift->get_all_methods(@_);
811 sub find_all_methods_by_name {
812 my ($self, $method_name) = @_;
813 (defined $method_name && $method_name)
814 || confess "You must define a method name to find";
816 foreach my $class ($self->linearized_isa) {
817 # fetch the meta-class ...
818 my $meta = $self->initialize($class);
820 name => $method_name,
822 code => $meta->get_method($method_name)
823 } if $meta->has_method($method_name);
828 sub find_next_method_by_name {
829 my ($self, $method_name) = @_;
830 (defined $method_name && $method_name)
831 || confess "You must define a method name to find";
832 my @cpl = $self->linearized_isa;
833 shift @cpl; # discard ourselves
834 foreach my $class (@cpl) {
835 # fetch the meta-class ...
836 my $meta = $self->initialize($class);
837 return $meta->get_method($method_name)
838 if $meta->has_method($method_name);
847 # either we have an attribute object already
848 # or we need to create one from the args provided
849 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
850 # make sure it is derived from the correct type though
851 ($attribute->isa('Class::MOP::Attribute'))
852 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
854 # first we attach our new attribute
855 # because it might need certain information
856 # about the class which it is attached to
857 $attribute->attach_to_class($self);
859 # then we remove attributes of a conflicting
860 # name here so that we can properly detach
861 # the old attr object, and remove any
862 # accessors it would have generated
863 if ( $self->has_attribute($attribute->name) ) {
864 $self->remove_attribute($attribute->name);
866 $self->invalidate_meta_instances();
869 # then onto installing the new accessors
870 $self->get_attribute_map->{$attribute->name} = $attribute;
872 # invalidate package flag here
873 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
875 $self->remove_attribute($attribute->name);
882 sub update_meta_instance_dependencies {
885 if ( $self->{meta_instance_dependencies} ) {
886 return $self->add_meta_instance_dependencies;
890 sub add_meta_instance_dependencies {
893 $self->remove_meta_instance_depdendencies;
895 my @attrs = $self->compute_all_applicable_attributes();
898 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
900 foreach my $class ( @classes ) {
901 $class->add_dependent_meta_instance($self);
904 $self->{meta_instance_dependencies} = \@classes;
907 sub remove_meta_instance_depdendencies {
910 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
911 foreach my $class ( @$classes ) {
912 $class->remove_dependent_meta_instance($self);
922 sub add_dependent_meta_instance {
923 my ( $self, $metaclass ) = @_;
924 push @{ $self->{dependent_meta_instances} }, $metaclass;
927 sub remove_dependent_meta_instance {
928 my ( $self, $metaclass ) = @_;
929 my $name = $metaclass->name;
930 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
933 sub invalidate_meta_instances {
935 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
938 sub invalidate_meta_instance {
940 undef $self->{_meta_instance};
944 my ($self, $attribute_name) = @_;
945 (defined $attribute_name && $attribute_name)
946 || confess "You must define an attribute name";
947 exists $self->get_attribute_map->{$attribute_name};
951 my ($self, $attribute_name) = @_;
952 (defined $attribute_name && $attribute_name)
953 || confess "You must define an attribute name";
954 return $self->get_attribute_map->{$attribute_name}
956 # this will return undef anyway, so no need ...
957 # if $self->has_attribute($attribute_name);
961 sub remove_attribute {
962 my ($self, $attribute_name) = @_;
963 (defined $attribute_name && $attribute_name)
964 || confess "You must define an attribute name";
965 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
966 return unless defined $removed_attribute;
967 delete $self->get_attribute_map->{$attribute_name};
968 $self->invalidate_meta_instances();
969 $removed_attribute->remove_accessors();
970 $removed_attribute->detach_from_class();
971 return $removed_attribute;
974 sub get_attribute_list {
976 keys %{$self->get_attribute_map};
979 sub get_all_attributes {
980 shift->compute_all_applicable_attributes(@_);
983 sub compute_all_applicable_attributes {
985 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
986 return values %attrs;
989 sub find_attribute_by_name {
990 my ($self, $attr_name) = @_;
991 foreach my $class ($self->linearized_isa) {
992 # fetch the meta-class ...
993 my $meta = $self->initialize($class);
994 return $meta->get_attribute($attr_name)
995 if $meta->has_attribute($attr_name);
1000 # check if we can reinitialize
1004 # if any local attr is defined
1005 return if $self->get_attribute_list;
1007 # or any non-declared methods
1008 if ( my @methods = values %{ $self->get_method_map } ) {
1009 my $metaclass = $self->method_metaclass;
1010 foreach my $method ( @methods ) {
1011 return if $method->isa("Class::MOP::Method::Generated");
1012 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1021 sub is_mutable { 1 }
1022 sub is_immutable { 0 }
1025 # Why I changed this (groditi)
1026 # - One Metaclass may have many Classes through many Metaclass instances
1027 # - One Metaclass should only have one Immutable Transformer instance
1028 # - Each Class may have different Immutabilizing options
1029 # - Therefore each Metaclass instance may have different Immutabilizing options
1030 # - We need to store one Immutable Transformer instance per Metaclass
1031 # - We need to store one set of Immutable Transformer options per Class
1032 # - Upon make_mutable we may delete the Immutabilizing options
1033 # - We could clean the immutable Transformer instance when there is no more
1034 # immutable Classes of that type, but we can also keep it in case
1035 # another class with this same Metaclass becomes immutable. It is a case
1036 # of trading of storing an instance to avoid unnecessary instantiations of
1037 # Immutable Transformers. You may view this as a memory leak, however
1038 # Because we have few Metaclasses, in practice it seems acceptable
1039 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1040 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1044 my %IMMUTABLE_TRANSFORMERS;
1045 my %IMMUTABLE_OPTIONS;
1047 sub get_immutable_options {
1049 return if $self->is_mutable;
1050 confess "unable to find immutabilizing options"
1051 unless exists $IMMUTABLE_OPTIONS{$self->name};
1052 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1053 delete $options{IMMUTABLE_TRANSFORMER};
1057 sub get_immutable_transformer {
1059 if( $self->is_mutable ){
1060 my $class = ref $self || $self;
1061 return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
1063 confess "unable to find transformer for immutable class"
1064 unless exists $IMMUTABLE_OPTIONS{$self->name};
1065 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1068 sub make_immutable {
1072 my $transformer = $self->get_immutable_transformer;
1073 $transformer->make_metaclass_immutable($self, \%options);
1074 $IMMUTABLE_OPTIONS{$self->name} =
1075 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1077 if( exists $options{debug} && $options{debug} ){
1078 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1079 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1087 return if $self->is_mutable;
1088 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1089 confess "unable to find immutabilizing options" unless ref $options;
1090 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1091 $transformer->make_metaclass_mutable($self, $options);
1096 sub create_immutable_transformer {
1098 my $class = Class::MOP::Immutable->new($self, {
1099 read_only => [qw/superclasses/],
1106 remove_package_symbol
1109 class_precedence_list => 'ARRAY',
1110 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
1111 get_all_methods => 'ARRAY',
1112 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
1113 compute_all_applicable_attributes => 'ARRAY',
1114 get_meta_instance => 'SCALAR',
1115 get_method_map => 'SCALAR',
1118 # this is ugly, but so are typeglobs,
1119 # so whattayahgonnadoboutit
1122 add_package_symbol => sub {
1123 my $original = shift;
1124 confess "Cannot add package symbols to an immutable metaclass"
1125 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1127 # This is a workaround for a bug in 5.8.1 which thinks that
1128 # goto $original->body
1129 # is trying to go to a label
1130 my $body = $original->body;
1146 Class::MOP::Class - Class Meta Object
1150 # assuming that class Foo
1151 # has been defined, you can
1153 # use this for introspection ...
1155 # add a method to Foo ...
1156 Foo->meta->add_method('bar' => sub { ... })
1158 # get a list of all the classes searched
1159 # the method dispatcher in the correct order
1160 Foo->meta->class_precedence_list()
1162 # remove a method from Foo
1163 Foo->meta->remove_method('bar');
1165 # or use this to actually create classes ...
1167 Class::MOP::Class->create('Bar' => (
1169 superclasses => [ 'Foo' ],
1171 Class::MOP:::Attribute->new('$bar'),
1172 Class::MOP:::Attribute->new('$baz'),
1175 calculate_bar => sub { ... },
1176 construct_baz => sub { ... }
1182 This is the largest and currently most complex part of the Perl 5
1183 meta-object protocol. It controls the introspection and
1184 manipulation of Perl 5 classes (and it can create them too). The
1185 best way to understand what this module can do, is to read the
1186 documentation for each of it's methods.
1190 =head2 Self Introspection
1196 This will return a B<Class::MOP::Class> instance which is related
1197 to this class. Thereby allowing B<Class::MOP::Class> to actually
1200 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1201 bootstrap this module by installing a number of attribute meta-objects
1202 into it's metaclass. This will allow this class to reap all the benifits
1203 of the MOP when subclassing it.
1207 =head2 Class construction
1209 These methods will handle creating B<Class::MOP::Class> objects,
1210 which can be used to both create new classes, and analyze
1211 pre-existing classes.
1213 This module will internally store references to all the instances
1214 you create with these methods, so that they do not need to be
1215 created any more than nessecary. Basically, they are singletons.
1219 =item B<create ($package_name,
1220 version =E<gt> ?$version,
1221 authority =E<gt> ?$authority,
1222 superclasses =E<gt> ?@superclasses,
1223 methods =E<gt> ?%methods,
1224 attributes =E<gt> ?%attributes)>
1226 This returns a B<Class::MOP::Class> object, bringing the specified
1227 C<$package_name> into existence and adding any of the C<$version>,
1228 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1231 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1232 methods =E<gt> ?%methods,
1233 attributes =E<gt> ?%attributes)>
1235 This will create an anonymous class, it works much like C<create> but
1236 it does not need a C<$package_name>. Instead it will create a suitably
1237 unique package name for you to stash things into.
1239 On very important distinction is that anon classes are destroyed once
1240 the metaclass they are attached to goes out of scope. In the DESTROY
1241 method, the created package will be removed from the symbol table.
1243 It is also worth noting that any instances created with an anon-class
1244 will keep a special reference to the anon-meta which will prevent the
1245 anon-class from going out of scope until all instances of it have also
1246 been destroyed. This however only works for HASH based instance types,
1247 as we use a special reserved slot (C<__MOP__>) to store this.
1249 =item B<initialize ($package_name, %options)>
1251 This initializes and returns returns a B<Class::MOP::Class> object
1252 for a given a C<$package_name>.
1254 =item B<construct_class_instance (%options)>
1256 This will construct an instance of B<Class::MOP::Class>, it is
1257 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1258 to use C<construct_instance> once all the bootstrapping is done. This
1259 method is used internally by C<initialize> and should never be called
1260 from outside of that method really.
1262 =item B<check_metaclass_compatibility>
1264 This method is called as the very last thing in the
1265 C<construct_class_instance> method. This will check that the
1266 metaclass you are creating is compatible with the metaclasses of all
1267 your ancestors. For more inforamtion about metaclass compatibility
1268 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1270 =item B<update_package_cache_flag>
1272 This will reset the package cache flag for this particular metaclass
1273 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1274 function. This is very rarely needed from outside of C<Class::MOP::Class>
1275 but in some cases you might want to use it, so it is here.
1277 =item B<reset_package_cache_flag>
1279 Clears the package cache flag to announce to the internals that we need
1280 to rebuild the method map.
1282 =item B<add_meta_instance_dependencies>
1284 Registers this class as dependent on its superclasses.
1286 Only superclasses from which this class inherits attributes will be added.
1288 =item B<remove_meta_instance_depdendencies>
1290 Unregisters this class from its superclasses.
1292 =item B<update_meta_instance_dependencies>
1294 Reregisters if necessary.
1296 =item B<add_dependent_meta_instance> $metaclass
1298 Registers the class as having a meta instance dependent on this class.
1300 =item B<remove_dependent_meta_instance> $metaclass
1302 Remove the class from the list of dependent classes.
1304 =item B<invalidate_meta_instances>
1306 Clears the cached meta instance for this metaclass and all of the registered
1307 classes with dependent meta instances.
1309 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1312 =item B<invalidate_meta_instance>
1314 Used by C<invalidate_meta_instances>.
1318 =head2 Object instance construction and cloning
1320 These methods are B<entirely optional>, it is up to you whether you want
1325 =item B<instance_metaclass>
1327 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1328 for more information on the instance metaclasses.
1330 =item B<get_meta_instance>
1332 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1333 of a new instance of the class.
1335 =item B<create_meta_instance>
1337 Called by C<get_meta_instance> if necessary.
1339 =item B<new_object (%params)>
1341 This is a convience method for creating a new object of the class, and
1342 blessing it into the appropriate package as well. Ideally your class
1343 would call a C<new> this method like so:
1346 my ($class, %param) = @_;
1347 $class->meta->new_object(%params);
1350 =item B<construct_instance (%params)>
1352 This method is used to construct an instance structure suitable for
1353 C<bless>-ing into your package of choice. It works in conjunction
1354 with the Attribute protocol to collect all applicable attributes.
1356 This will construct and instance using a HASH ref as storage
1357 (currently only HASH references are supported). This will collect all
1358 the applicable attributes and layout out the fields in the HASH ref,
1359 it will then initialize them using either use the corresponding key
1360 in C<%params> or any default value or initializer found in the
1361 attribute meta-object.
1363 =item B<clone_object ($instance, %params)>
1365 This is a convience method for cloning an object instance, then
1366 blessing it into the appropriate package. This method will call
1367 C<clone_instance>, which performs a shallow copy of the object,
1368 see that methods documentation for more details. Ideally your
1369 class would call a C<clone> this method like so:
1371 sub MyClass::clone {
1372 my ($self, %param) = @_;
1373 $self->meta->clone_object($self, %params);
1376 =item B<clone_instance($instance, %params)>
1378 This method is a compliment of C<construct_instance> (which means if
1379 you override C<construct_instance>, you need to override this one too),
1380 and clones the instance shallowly.
1382 The cloned structure returned is (like with C<construct_instance>) an
1383 unC<bless>ed HASH reference, it is your responsibility to then bless
1384 this cloned structure into the right class (which C<clone_object> will
1387 As of 0.11, this method will clone the C<$instance> structure shallowly,
1388 as opposed to the deep cloning implemented in prior versions. After much
1389 thought, research and discussion, I have decided that anything but basic
1390 shallow cloning is outside the scope of the meta-object protocol. I
1391 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1392 is too I<context-specific> to be part of the MOP.
1394 =item B<rebless_instance($instance, ?%params)>
1396 This will change the class of C<$instance> to the class of the invoking
1397 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1398 itself. You may pass in optional C<%params> which are like constructor
1399 params and will override anything already defined in the instance.
1403 =head2 Informational
1405 These are a few predicate methods for asking information about the class.
1409 =item B<is_anon_class>
1411 This returns true if the class is a C<Class::MOP::Class> created anon class.
1415 This returns true if the class is still mutable.
1417 =item B<is_immutable>
1419 This returns true if the class has been made immutable.
1421 =item B<is_pristine>
1423 Checks whether the class has any data that will be lost if C<reinitialize> is
1428 =head2 Inheritance Relationships
1432 =item B<superclasses (?@superclasses)>
1434 This is a read-write attribute which represents the superclass
1435 relationships of the class the B<Class::MOP::Class> instance is
1436 associated with. Basically, it can get and set the C<@ISA> for you.
1438 =item B<class_precedence_list>
1440 This computes the a list of all the class's ancestors in the same order
1441 in which method dispatch will be done. This is similair to what
1442 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1444 =item B<linearized_isa>
1446 This returns a list based on C<class_precedence_list> but with all
1451 This returns a list of subclasses for this class.
1459 =item B<get_method_map>
1461 Returns a HASH ref of name to CODE reference mapping for this class.
1463 =item B<method_metaclass>
1465 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1466 for more information on the method metaclasses.
1468 =item B<wrap_method_body(%attrs)>
1470 Wrap a code ref (C<$attrs{body>) with C<method_metaclass>.
1472 =item B<add_method ($method_name, $method)>
1474 This will take a C<$method_name> and CODE reference or meta method
1475 objectand install it into the class's package.
1477 You are strongly encouraged to pass a meta method object instead of a
1478 code reference. If you do so, that object gets stored as part of the
1479 class's method map, providing more useful information about the method
1482 When you provide a method object, this method will clone that object
1483 if the object's package name does not match the class name. This lets
1484 us track the original source of any methods added from other classes
1485 (notably Moose roles).
1488 This does absolutely nothing special to C<$method>
1489 other than use B<Sub::Name> to make sure it is tagged with the
1490 correct name, and therefore show up correctly in stack traces and
1493 =item B<has_method ($method_name)>
1495 This just provides a simple way to check if the class implements
1496 a specific C<$method_name>. It will I<not> however, attempt to check
1497 if the class inherits the method (use C<UNIVERSAL::can> for that).
1499 This will correctly handle functions defined outside of the package
1500 that use a fully qualified name (C<sub Package::name { ... }>).
1502 This will correctly handle functions renamed with B<Sub::Name> and
1503 installed using the symbol tables. However, if you are naming the
1504 subroutine outside of the package scope, you must use the fully
1505 qualified name, including the package name, for C<has_method> to
1506 correctly identify it.
1508 This will attempt to correctly ignore functions imported from other
1509 packages using B<Exporter>. It breaks down if the function imported
1510 is an C<__ANON__> sub (such as with C<use constant>), which very well
1511 may be a valid method being applied to the class.
1513 In short, this method cannot always be trusted to determine if the
1514 C<$method_name> is actually a method. However, it will DWIM about
1515 90% of the time, so it's a small trade off I think.
1517 =item B<get_method ($method_name)>
1519 This will return a Class::MOP::Method instance related to the specified
1520 C<$method_name>, or return undef if that method does not exist.
1522 The Class::MOP::Method is codifiable, so you can use it like a normal
1523 CODE reference, see L<Class::MOP::Method> for more information.
1525 =item B<find_method_by_name ($method_name)>
1527 This will return a CODE reference of the specified C<$method_name>,
1528 or return undef if that method does not exist.
1530 Unlike C<get_method> this will also look in the superclasses.
1532 =item B<remove_method ($method_name)>
1534 This will attempt to remove a given C<$method_name> from the class.
1535 It will return the CODE reference that it has removed, and will
1536 attempt to use B<Sub::Name> to clear the methods associated name.
1538 =item B<get_method_list>
1540 This will return a list of method names for all I<locally> defined
1541 methods. It does B<not> provide a list of all applicable methods,
1542 including any inherited ones. If you want a list of all applicable
1543 methods, use the C<compute_all_applicable_methods> method.
1545 =item B<get_all_methods>
1547 This will traverse the inheritance heirachy and return a list of all
1548 the applicable L<Class::MOP::Method> objects for this class.
1550 =item B<compute_all_applicable_methods>
1554 This method returns a list of hashes describing the all the methods of the
1557 Use L<get_all_methods>, which is easier/better/faster. This method predates
1558 L<Class::MOP::Method>.
1560 =item B<find_all_methods_by_name ($method_name)>
1562 This will traverse the inheritence hierarchy and locate all methods
1563 with a given C<$method_name>. Similar to
1564 C<compute_all_applicable_methods> it returns a list of HASH references
1565 with the following information; method name (which will always be the
1566 same as C<$method_name>), the name of the class in which the method
1567 lives and a CODE reference for the actual method.
1569 The list of methods produced is a distinct list, meaning there are no
1570 duplicates in it. This is especially useful for things like object
1571 initialization and destruction where you only want the method called
1572 once, and in the correct order.
1574 =item B<find_next_method_by_name ($method_name)>
1576 This will return the first method to match a given C<$method_name> in
1577 the superclasses, this is basically equivalent to calling
1578 C<SUPER::$method_name>, but it can be dispatched at runtime.
1580 =item B<alias_method ($method_name, $method)>
1582 B<NOTE>: This method is now deprecated. Just use C<add_method>
1587 =head2 Method Modifiers
1589 Method modifiers are a concept borrowed from CLOS, in which a method
1590 can be wrapped with I<before>, I<after> and I<around> method modifiers
1591 that will be called everytime the method is called.
1593 =head3 How method modifiers work?
1595 Method modifiers work by wrapping the original method and then replacing
1596 it in the classes symbol table. The wrappers will handle calling all the
1597 modifiers in the appropariate orders and preserving the calling context
1598 for the original method.
1600 Each method modifier serves a particular purpose, which may not be
1601 obvious to users of other method wrapping modules. To start with, the
1602 return values of I<before> and I<after> modifiers are ignored. This is
1603 because thier purpose is B<not> to filter the input and output of the
1604 primary method (this is done with an I<around> modifier). This may seem
1605 like an odd restriction to some, but doing this allows for simple code
1606 to be added at the begining or end of a method call without jeapordizing
1607 the normal functioning of the primary method or placing any extra
1608 responsibility on the code of the modifier. Of course if you have more
1609 complex needs, then use the I<around> modifier, which uses a variation
1610 of continutation passing style to allow for a high degree of flexibility.
1612 Before and around modifiers are called in last-defined-first-called order,
1613 while after modifiers are called in first-defined-first-called order. So
1614 the call tree might looks something like this:
1624 To see examples of using method modifiers, see the following examples
1625 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1626 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1627 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1629 =head3 What is the performance impact?
1631 Of course there is a performance cost associated with method modifiers,
1632 but we have made every effort to make that cost be directly proportional
1633 to the amount of modifier features you utilize.
1635 The wrapping method does it's best to B<only> do as much work as it
1636 absolutely needs to. In order to do this we have moved some of the
1637 performance costs to set-up time, where they are easier to amortize.
1639 All this said, my benchmarks have indicated the following:
1641 simple wrapper with no modifiers 100% slower
1642 simple wrapper with simple before modifier 400% slower
1643 simple wrapper with simple after modifier 450% slower
1644 simple wrapper with simple around modifier 500-550% slower
1645 simple wrapper with all 3 modifiers 1100% slower
1647 These numbers may seem daunting, but you must remember, every feature
1648 comes with some cost. To put things in perspective, just doing a simple
1649 C<AUTOLOAD> which does nothing but extract the name of the method called
1650 and return it costs about 400% over a normal method call.
1654 =item B<add_before_method_modifier ($method_name, $code)>
1656 This will wrap the method at C<$method_name> and the supplied C<$code>
1657 will be passed the C<@_> arguments, and called before the original
1658 method is called. As specified above, the return value of the I<before>
1659 method modifiers is ignored, and it's ability to modify C<@_> is
1660 fairly limited. If you need to do either of these things, use an
1661 C<around> method modifier.
1663 =item B<add_after_method_modifier ($method_name, $code)>
1665 This will wrap the method at C<$method_name> so that the original
1666 method will be called, it's return values stashed, and then the
1667 supplied C<$code> will be passed the C<@_> arguments, and called.
1668 As specified above, the return value of the I<after> method
1669 modifiers is ignored, and it cannot modify the return values of
1670 the original method. If you need to do either of these things, use an
1671 C<around> method modifier.
1673 =item B<add_around_method_modifier ($method_name, $code)>
1675 This will wrap the method at C<$method_name> so that C<$code>
1676 will be called and passed the original method as an extra argument
1677 at the begining of the C<@_> argument list. This is a variation of
1678 continuation passing style, where the function prepended to C<@_>
1679 can be considered a continuation. It is up to C<$code> if it calls
1680 the original method or not, there is no restriction on what the
1681 C<$code> can or cannot do.
1687 It should be noted that since there is no one consistent way to define
1688 the attributes of a class in Perl 5. These methods can only work with
1689 the information given, and can not easily discover information on
1690 their own. See L<Class::MOP::Attribute> for more details.
1694 =item B<attribute_metaclass>
1696 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1697 for more information on the attribute metaclasses.
1699 =item B<get_attribute_map>
1701 This returns a HASH ref of name to attribute meta-object mapping.
1703 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1705 This stores the C<$attribute_meta_object> (or creates one from the
1706 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1707 instance associated with the given class. Unlike methods, attributes
1708 within the MOP are stored as meta-information only. They will be used
1709 later to construct instances from (see C<construct_instance> above).
1710 More details about the attribute meta-objects can be found in the
1711 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1714 It should be noted that any accessor, reader/writer or predicate
1715 methods which the C<$attribute_meta_object> has will be installed
1716 into the class at this time.
1719 If an attribute already exists for C<$attribute_name>, the old one
1720 will be removed (as well as removing all it's accessors), and then
1723 =item B<has_attribute ($attribute_name)>
1725 Checks to see if this class has an attribute by the name of
1726 C<$attribute_name> and returns a boolean.
1728 =item B<get_attribute ($attribute_name)>
1730 Returns the attribute meta-object associated with C<$attribute_name>,
1731 if none is found, it will return undef.
1733 =item B<remove_attribute ($attribute_name)>
1735 This will remove the attribute meta-object stored at
1736 C<$attribute_name>, then return the removed attribute meta-object.
1739 Removing an attribute will only affect future instances of
1740 the class, it will not make any attempt to remove the attribute from
1741 any existing instances of the class.
1743 It should be noted that any accessor, reader/writer or predicate
1744 methods which the attribute meta-object stored at C<$attribute_name>
1745 has will be removed from the class at this time. This B<will> make
1746 these attributes somewhat inaccessable in previously created
1747 instances. But if you are crazy enough to do this at runtime, then
1748 you are crazy enough to deal with something like this :).
1750 =item B<get_attribute_list>
1752 This returns a list of attribute names which are defined in the local
1753 class. If you want a list of all applicable attributes for a class,
1754 use the C<compute_all_applicable_attributes> method.
1756 =item B<compute_all_applicable_attributes>
1758 =item B<get_all_attributes>
1760 This will traverse the inheritance heirachy and return a list of all
1761 the applicable L<Class::MOP::Attribute> objects for this class.
1763 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1765 =item B<find_attribute_by_name ($attr_name)>
1767 This method will traverse the inheritance heirachy and find the
1768 first attribute whose name matches C<$attr_name>, then return it.
1769 It will return undef if nothing is found.
1773 =head2 Class Immutability
1777 =item B<make_immutable (%options)>
1779 This method will invoke a tranforamtion upon the class which will
1780 make it immutable. Details of this transformation can be found in
1781 the L<Class::MOP::Immutable> documentation.
1783 =item B<make_mutable>
1785 This method will reverse tranforamtion upon the class which
1788 =item B<get_immutable_transformer>
1790 Return a transformer suitable for making this class immutable or, if this
1791 class is immutable, the transformer used to make it immutable.
1793 =item B<get_immutable_options>
1795 If the class is immutable, return the options used to make it immutable.
1797 =item B<create_immutable_transformer>
1799 Create a transformer suitable for making this class immutable
1805 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1807 =head1 COPYRIGHT AND LICENSE
1809 Copyright 2006-2008 by Infinity Interactive, Inc.
1811 L<http://www.iinteractive.com>
1813 This library is free software; you can redistribute it and/or modify
1814 it under the same terms as Perl itself.