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 $meta->check_metaclass_compatability();
90 Class::MOP::store_metaclass_by_name($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_compatability {
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 compatabile 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) . ")";
182 # this should be sufficient, if you have a
183 # use case where it is not, write a test and
185 my $ANON_CLASS_SERIAL = 0;
188 # we need a sufficiently annoying prefix
189 # this should suffice for now, this is
190 # used in a couple of places below, so
191 # need to put it up here for now.
192 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
196 no warnings 'uninitialized';
197 $self->name =~ /^$ANON_CLASS_PREFIX/;
200 sub create_anon_class {
201 my ($class, %options) = @_;
202 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
203 return $class->create($package_name, %options);
207 # this will only get called for
208 # anon-classes, all other calls
209 # are assumed to occur during
210 # global destruction and so don't
211 # really need to be handled explicitly
215 return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
217 no warnings 'uninitialized';
218 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
219 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
221 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
222 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
224 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
229 # creating classes with MOP ...
232 my ( $class, @args ) = @_;
234 unshift @args, 'package' if @args % 2 == 1;
236 my (%options) = @args;
237 my $package_name = $options{package};
239 (defined $package_name && $package_name)
240 || confess "You must pass a package name";
242 (ref $options{superclasses} eq 'ARRAY')
243 || confess "You must pass an ARRAY ref of superclasses"
244 if exists $options{superclasses};
246 (ref $options{attributes} eq 'ARRAY')
247 || confess "You must pass an ARRAY ref of attributes"
248 if exists $options{attributes};
250 (ref $options{methods} eq 'HASH')
251 || confess "You must pass an HASH ref of methods"
252 if exists $options{methods};
254 my $code = "package $package_name;";
255 $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';"
256 if exists $options{version};
257 $code .= "\$$package_name\:\:AUTHORITY = '" . $options{authority} . "';"
258 if exists $options{authority};
261 confess "creation of $package_name failed : $@" if $@;
263 my $meta = $class->initialize($package_name);
266 $meta->add_method('meta' => sub {
267 $class->initialize(ref($_[0]) || $_[0]);
270 $meta->superclasses(@{$options{superclasses}})
271 if exists $options{superclasses};
273 # process attributes first, so that they can
274 # install accessors, but locally defined methods
275 # can then overwrite them. It is maybe a little odd, but
276 # I think this should be the order of things.
277 if (exists $options{attributes}) {
278 foreach my $attr (@{$options{attributes}}) {
279 $meta->add_attribute($attr);
282 if (exists $options{methods}) {
283 foreach my $method_name (keys %{$options{methods}}) {
284 $meta->add_method($method_name, $options{methods}->{$method_name});
293 # all these attribute readers will be bootstrapped
294 # away in the Class::MOP bootstrap section
296 sub get_attribute_map { $_[0]->{'attributes'} }
297 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
298 sub method_metaclass { $_[0]->{'method_metaclass'} }
299 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
302 # this is a prime canidate for conversion to XS
306 my $current = Class::MOP::check_package_cache_flag($self->name);
308 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
309 return $self->{'methods'} ||= {};
312 $self->{_package_cache_flag} = $current;
314 my $map = $self->{'methods'} ||= {};
316 my $class_name = $self->name;
317 my $method_metaclass = $self->method_metaclass;
319 my %all_code = $self->get_all_package_symbols('CODE');
321 foreach my $symbol (keys %all_code) {
322 my $code = $all_code{$symbol};
324 next if exists $map->{$symbol} &&
325 defined $map->{$symbol} &&
326 $map->{$symbol}->body == $code;
328 my ($pkg, $name) = Class::MOP::get_code_info($code);
331 # in 5.10 constant.pm the constants show up
332 # as being in the right package, but in pre-5.10
333 # they show up as constant::__ANON__ so we
334 # make an exception here to be sure that things
335 # work as expected in both.
337 unless ($pkg eq 'constant' && $name eq '__ANON__') {
338 next if ($pkg || '') ne $class_name ||
339 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
342 $map->{$symbol} = $method_metaclass->wrap(
344 associated_metaclass => $self,
345 package_name => $class_name,
353 # Instance Construction & Cloning
359 # we need to protect the integrity of the
360 # Class::MOP::Class singletons here, so we
361 # delegate this to &construct_class_instance
362 # which will deal with the singletons
363 return $class->construct_class_instance(@_)
364 if $class->name->isa('Class::MOP::Class');
365 return $class->construct_instance(@_);
368 sub construct_instance {
370 my $params = @_ == 1 ? $_[0] : {@_};
371 my $meta_instance = $class->get_meta_instance();
372 my $instance = $meta_instance->create_instance();
373 foreach my $attr ($class->compute_all_applicable_attributes()) {
374 $attr->initialize_instance_slot($meta_instance, $instance, $params);
377 # this will only work for a HASH instance type
378 if ($class->is_anon_class) {
379 (Scalar::Util::reftype($instance) eq 'HASH')
380 || confess "Currently only HASH based instances are supported with instance of anon-classes";
382 # At some point we should make this official
383 # as a reserved slot name, but right now I am
384 # going to keep it here.
385 # my $RESERVED_MOP_SLOT = '__MOP__';
386 $instance->{'__MOP__'} = $class;
392 sub get_meta_instance {
394 $self->{'_meta_instance'} ||= $self->create_meta_instance();
397 sub create_meta_instance {
400 my $instance = $self->instance_metaclass->new(
401 associated_metaclass => $self,
402 attributes => [ $self->compute_all_applicable_attributes() ],
405 $self->add_meta_instance_dependencies()
406 if $instance->is_dependent_on_superclasses();
413 my $instance = shift;
414 (blessed($instance) && $instance->isa($class->name))
415 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
418 # we need to protect the integrity of the
419 # Class::MOP::Class singletons here, they
420 # should not be cloned.
421 return $instance if $instance->isa('Class::MOP::Class');
422 $class->clone_instance($instance, @_);
426 my ($class, $instance, %params) = @_;
428 || confess "You can only clone instances, ($instance) is not a blessed instance";
429 my $meta_instance = $class->get_meta_instance();
430 my $clone = $meta_instance->clone_instance($instance);
431 foreach my $attr ($class->compute_all_applicable_attributes()) {
432 if ( defined( my $init_arg = $attr->init_arg ) ) {
433 if (exists $params{$init_arg}) {
434 $attr->set_value($clone, $params{$init_arg});
441 sub rebless_instance {
442 my ($self, $instance, %params) = @_;
445 if ($instance->can('meta')) {
446 ($instance->meta->isa('Class::MOP::Class'))
447 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
448 $old_metaclass = $instance->meta;
451 $old_metaclass = $self->initialize(ref($instance));
454 my $meta_instance = $self->get_meta_instance();
456 $self->name->isa($old_metaclass->name)
457 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
460 $meta_instance->rebless_instance_structure($instance, $self);
462 foreach my $attr ( $self->compute_all_applicable_attributes ) {
463 if ( $attr->has_value($instance) ) {
464 if ( defined( my $init_arg = $attr->init_arg ) ) {
465 $params{$init_arg} = $attr->get_value($instance)
466 unless exists $params{$init_arg};
469 $attr->set_value($instance, $attr->get_value($instance));
474 foreach my $attr ($self->compute_all_applicable_attributes) {
475 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
485 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
488 @{$self->get_package_symbol($var_spec)} = @supers;
490 # we need to check the metaclass
491 # compatibility here so that we can
492 # be sure that the superclass is
493 # not potentially creating an issues
494 # we don't know about
495 $self->check_metaclass_compatability();
496 $self->update_meta_instance_dependencies();
498 @{$self->get_package_symbol($var_spec)};
504 my $super_class = $self->name;
506 if ( Class::MOP::HAVE_ISAREV() ) {
507 return @{ $super_class->mro::get_isarev() };
511 my $find_derived_classes;
512 $find_derived_classes = sub {
513 my ($outer_class) = @_;
515 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
518 for my $symbol ( keys %$symbol_table_hashref ) {
519 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
520 my $inner_class = $1;
522 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
526 ? "${outer_class}::$inner_class"
529 if ( $class->isa($super_class) and $class ne $super_class ) {
530 push @derived_classes, $class;
533 next SYMBOL if $class eq 'main'; # skip 'main::*'
535 $find_derived_classes->($class);
539 my $root_class = q{};
540 $find_derived_classes->($root_class);
542 undef $find_derived_classes;
544 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
546 return @derived_classes;
552 return @{ mro::get_linear_isa( (shift)->name ) };
555 sub class_precedence_list {
557 my $name = $self->name;
559 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
561 # We need to check for circular inheritance here
562 # if we are are not on 5.10, cause 5.8 detects it
563 # late. This will do nothing if all is well, and
564 # blow up otherwise. Yes, it's an ugly hack, better
565 # suggestions are welcome.
567 ($name || return)->isa('This is a test for circular inheritance')
570 # if our mro is c3, we can
571 # just grab the linear_isa
572 if (mro::get_mro($name) eq 'c3') {
573 return @{ mro::get_linear_isa($name) }
577 # we can't grab the linear_isa for dfs
578 # since it has all the duplicates
583 $self->initialize($_)->class_precedence_list()
584 } $self->superclasses()
591 sub wrap_method_body {
592 my ( $self, %args ) = @_;
594 my $body = delete $args{body}; # delete is for compat
596 ('CODE' eq ref($body))
597 || confess "Your code block must be a CODE reference";
599 $self->method_metaclass->wrap( $body => (
600 package_name => $self->name,
606 my ($self, $method_name, $method) = @_;
607 (defined $method_name && $method_name)
608 || confess "You must define a method name";
611 if (blessed($method)) {
612 $body = $method->body;
613 if ($method->package_name ne $self->name &&
614 $method->name ne $method_name) {
615 warn "Hello there, got something for you."
616 . " Method says " . $method->package_name . " " . $method->name
617 . " Class says " . $self->name . " " . $method_name;
618 $method = $method->clone(
619 package_name => $self->name,
621 ) if $method->can('clone');
626 $method = $self->wrap_method_body( body => $body, name => $method_name );
629 $method->attach_to_class($self);
631 $self->get_method_map->{$method_name} = $method;
633 my $full_method_name = ($self->name . '::' . $method_name);
634 $self->add_package_symbol(
635 { sigil => '&', type => 'CODE', name => $method_name },
636 Class::MOP::subname($full_method_name => $body)
639 $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
643 my $fetch_and_prepare_method = sub {
644 my ($self, $method_name) = @_;
646 my $method = $self->get_method($method_name);
647 # if we dont have local ...
649 # try to find the next method
650 $method = $self->find_next_method_by_name($method_name);
651 # die if it does not exist
653 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
654 # and now make sure to wrap it
655 # even if it is already wrapped
656 # because we need a new sub ref
657 $method = Class::MOP::Method::Wrapped->wrap($method);
660 # now make sure we wrap it properly
661 $method = Class::MOP::Method::Wrapped->wrap($method)
662 unless $method->isa('Class::MOP::Method::Wrapped');
664 $self->add_method($method_name => $method);
668 sub add_before_method_modifier {
669 my ($self, $method_name, $method_modifier) = @_;
670 (defined $method_name && $method_name)
671 || confess "You must pass in a method name";
672 my $method = $fetch_and_prepare_method->($self, $method_name);
673 $method->add_before_modifier(
674 Class::MOP::subname(':before' => $method_modifier)
678 sub add_after_method_modifier {
679 my ($self, $method_name, $method_modifier) = @_;
680 (defined $method_name && $method_name)
681 || confess "You must pass in a method name";
682 my $method = $fetch_and_prepare_method->($self, $method_name);
683 $method->add_after_modifier(
684 Class::MOP::subname(':after' => $method_modifier)
688 sub add_around_method_modifier {
689 my ($self, $method_name, $method_modifier) = @_;
690 (defined $method_name && $method_name)
691 || confess "You must pass in a method name";
692 my $method = $fetch_and_prepare_method->($self, $method_name);
693 $method->add_around_modifier(
694 Class::MOP::subname(':around' => $method_modifier)
699 # the methods above used to be named like this:
700 # ${pkg}::${method}:(before|after|around)
701 # but this proved problematic when using one modifier
702 # to wrap multiple methods (something which is likely
703 # to happen pretty regularly IMO). So instead of naming
704 # it like this, I have chosen to just name them purely
705 # with their modifier names, like so:
706 # :(before|after|around)
707 # The fact is that in a stack trace, it will be fairly
708 # evident from the context what method they are attached
709 # to, and so don't need the fully qualified name.
715 $self->add_method(@_);
719 my ($self, $method_name) = @_;
720 (defined $method_name && $method_name)
721 || confess "You must define a method name";
723 exists $self->get_method_map->{$method_name};
727 my ($self, $method_name) = @_;
728 (defined $method_name && $method_name)
729 || confess "You must define a method name";
732 # I don't really need this here, because
733 # if the method_map is missing a key it
734 # will just return undef for me now
735 # return unless $self->has_method($method_name);
737 return $self->get_method_map->{$method_name};
741 my ($self, $method_name) = @_;
742 (defined $method_name && $method_name)
743 || confess "You must define a method name";
745 my $removed_method = delete $self->get_method_map->{$method_name};
747 $self->remove_package_symbol(
748 { sigil => '&', type => 'CODE', name => $method_name }
751 $removed_method->detach_from_class if $removed_method;
753 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
755 return $removed_method;
758 sub get_method_list {
760 keys %{$self->get_method_map};
763 sub find_method_by_name {
764 my ($self, $method_name) = @_;
765 (defined $method_name && $method_name)
766 || confess "You must define a method name to find";
767 foreach my $class ($self->linearized_isa) {
768 # fetch the meta-class ...
769 my $meta = $self->initialize($class);
770 return $meta->get_method($method_name)
771 if $meta->has_method($method_name);
776 sub get_all_methods {
778 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
779 return values %methods;
783 sub compute_all_applicable_methods {
787 class => $_->package_name,
788 code => $_, # sigh, overloading
790 } shift->get_all_methods(@_);
793 sub find_all_methods_by_name {
794 my ($self, $method_name) = @_;
795 (defined $method_name && $method_name)
796 || confess "You must define a method name to find";
798 foreach my $class ($self->linearized_isa) {
799 # fetch the meta-class ...
800 my $meta = $self->initialize($class);
802 name => $method_name,
804 code => $meta->get_method($method_name)
805 } if $meta->has_method($method_name);
810 sub find_next_method_by_name {
811 my ($self, $method_name) = @_;
812 (defined $method_name && $method_name)
813 || confess "You must define a method name to find";
814 my @cpl = $self->linearized_isa;
815 shift @cpl; # discard ourselves
816 foreach my $class (@cpl) {
817 # fetch the meta-class ...
818 my $meta = $self->initialize($class);
819 return $meta->get_method($method_name)
820 if $meta->has_method($method_name);
829 # either we have an attribute object already
830 # or we need to create one from the args provided
831 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
832 # make sure it is derived from the correct type though
833 ($attribute->isa('Class::MOP::Attribute'))
834 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
836 # first we attach our new attribute
837 # because it might need certain information
838 # about the class which it is attached to
839 $attribute->attach_to_class($self);
841 # then we remove attributes of a conflicting
842 # name here so that we can properly detach
843 # the old attr object, and remove any
844 # accessors it would have generated
845 if ( $self->has_attribute($attribute->name) ) {
846 $self->remove_attribute($attribute->name);
848 $self->invalidate_meta_instances();
851 # then onto installing the new accessors
852 $self->get_attribute_map->{$attribute->name} = $attribute;
854 # invalidate package flag here
855 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
857 $self->remove_attribute($attribute->name);
864 sub update_meta_instance_dependencies {
867 if ( $self->{meta_instance_dependencies} ) {
868 return $self->add_meta_instance_dependencies;
872 sub add_meta_instance_dependencies {
875 $self->remove_meta_instance_depdendencies;
877 my @attrs = $self->compute_all_applicable_attributes();
880 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
882 foreach my $class ( @classes ) {
883 $class->add_dependent_meta_instance($self);
886 $self->{meta_instance_dependencies} = \@classes;
889 sub remove_meta_instance_depdendencies {
892 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
893 foreach my $class ( @$classes ) {
894 $class->remove_dependent_meta_instance($self);
904 sub add_dependent_meta_instance {
905 my ( $self, $metaclass ) = @_;
906 push @{ $self->{dependent_meta_instances} }, $metaclass;
909 sub remove_dependent_meta_instance {
910 my ( $self, $metaclass ) = @_;
911 my $name = $metaclass->name;
912 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
915 sub invalidate_meta_instances {
917 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
920 sub invalidate_meta_instance {
922 undef $self->{_meta_instance};
926 my ($self, $attribute_name) = @_;
927 (defined $attribute_name && $attribute_name)
928 || confess "You must define an attribute name";
929 exists $self->get_attribute_map->{$attribute_name};
933 my ($self, $attribute_name) = @_;
934 (defined $attribute_name && $attribute_name)
935 || confess "You must define an attribute name";
936 return $self->get_attribute_map->{$attribute_name}
938 # this will return undef anyway, so no need ...
939 # if $self->has_attribute($attribute_name);
943 sub remove_attribute {
944 my ($self, $attribute_name) = @_;
945 (defined $attribute_name && $attribute_name)
946 || confess "You must define an attribute name";
947 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
948 return unless defined $removed_attribute;
949 delete $self->get_attribute_map->{$attribute_name};
950 $self->invalidate_meta_instances();
951 $removed_attribute->remove_accessors();
952 $removed_attribute->detach_from_class();
953 return $removed_attribute;
956 sub get_attribute_list {
958 keys %{$self->get_attribute_map};
961 sub get_all_attributes {
962 shift->compute_all_applicable_attributes(@_);
965 sub compute_all_applicable_attributes {
967 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
968 return values %attrs;
971 sub find_attribute_by_name {
972 my ($self, $attr_name) = @_;
973 foreach my $class ($self->linearized_isa) {
974 # fetch the meta-class ...
975 my $meta = $self->initialize($class);
976 return $meta->get_attribute($attr_name)
977 if $meta->has_attribute($attr_name);
982 # check if we can reinitialize
986 # if any local attr is defined
987 return if $self->get_attribute_list;
989 # or any non-declared methods
990 if ( my @methods = values %{ $self->get_method_map } ) {
991 my $metaclass = $self->method_metaclass;
992 foreach my $method ( @methods ) {
993 return if $method->isa("Class::MOP::Method::Generated");
994 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1003 sub is_mutable { 1 }
1004 sub is_immutable { 0 }
1007 # Why I changed this (groditi)
1008 # - One Metaclass may have many Classes through many Metaclass instances
1009 # - One Metaclass should only have one Immutable Transformer instance
1010 # - Each Class may have different Immutabilizing options
1011 # - Therefore each Metaclass instance may have different Immutabilizing options
1012 # - We need to store one Immutable Transformer instance per Metaclass
1013 # - We need to store one set of Immutable Transformer options per Class
1014 # - Upon make_mutable we may delete the Immutabilizing options
1015 # - We could clean the immutable Transformer instance when there is no more
1016 # immutable Classes of that type, but we can also keep it in case
1017 # another class with this same Metaclass becomes immutable. It is a case
1018 # of trading of storing an instance to avoid unnecessary instantiations of
1019 # Immutable Transformers. You may view this as a memory leak, however
1020 # Because we have few Metaclasses, in practice it seems acceptable
1021 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1022 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1026 my %IMMUTABLE_TRANSFORMERS;
1027 my %IMMUTABLE_OPTIONS;
1029 sub get_immutable_options {
1031 return if $self->is_mutable;
1032 confess "unable to find immutabilizing options"
1033 unless exists $IMMUTABLE_OPTIONS{$self->name};
1034 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1035 delete $options{IMMUTABLE_TRANSFORMER};
1039 sub get_immutable_transformer {
1041 if( $self->is_mutable ){
1042 my $class = ref $self || $self;
1043 return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
1045 confess "unable to find transformer for immutable class"
1046 unless exists $IMMUTABLE_OPTIONS{$self->name};
1047 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1050 sub make_immutable {
1054 my $transformer = $self->get_immutable_transformer;
1055 $transformer->make_metaclass_immutable($self, \%options);
1056 $IMMUTABLE_OPTIONS{$self->name} =
1057 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1059 if( exists $options{debug} && $options{debug} ){
1060 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1061 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1069 return if $self->is_mutable;
1070 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1071 confess "unable to find immutabilizing options" unless ref $options;
1072 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1073 $transformer->make_metaclass_mutable($self, $options);
1078 sub create_immutable_transformer {
1080 my $class = Class::MOP::Immutable->new($self, {
1081 read_only => [qw/superclasses/],
1088 remove_package_symbol
1091 class_precedence_list => 'ARRAY',
1092 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
1093 get_all_methods => 'ARRAY',
1094 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
1095 compute_all_applicable_attributes => 'ARRAY',
1096 get_meta_instance => 'SCALAR',
1097 get_method_map => 'SCALAR',
1100 # this is ugly, but so are typeglobs,
1101 # so whattayahgonnadoboutit
1104 add_package_symbol => sub {
1105 my $original = shift;
1106 confess "Cannot add package symbols to an immutable metaclass"
1107 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1109 # This is a workaround for a bug in 5.8.1 which thinks that
1110 # goto $original->body
1111 # is trying to go to a label
1112 my $body = $original->body;
1128 Class::MOP::Class - Class Meta Object
1132 # assuming that class Foo
1133 # has been defined, you can
1135 # use this for introspection ...
1137 # add a method to Foo ...
1138 Foo->meta->add_method('bar' => sub { ... })
1140 # get a list of all the classes searched
1141 # the method dispatcher in the correct order
1142 Foo->meta->class_precedence_list()
1144 # remove a method from Foo
1145 Foo->meta->remove_method('bar');
1147 # or use this to actually create classes ...
1149 Class::MOP::Class->create('Bar' => (
1151 superclasses => [ 'Foo' ],
1153 Class::MOP:::Attribute->new('$bar'),
1154 Class::MOP:::Attribute->new('$baz'),
1157 calculate_bar => sub { ... },
1158 construct_baz => sub { ... }
1164 This is the largest and currently most complex part of the Perl 5
1165 meta-object protocol. It controls the introspection and
1166 manipulation of Perl 5 classes (and it can create them too). The
1167 best way to understand what this module can do, is to read the
1168 documentation for each of it's methods.
1172 =head2 Self Introspection
1178 This will return a B<Class::MOP::Class> instance which is related
1179 to this class. Thereby allowing B<Class::MOP::Class> to actually
1182 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1183 bootstrap this module by installing a number of attribute meta-objects
1184 into it's metaclass. This will allow this class to reap all the benifits
1185 of the MOP when subclassing it.
1189 =head2 Class construction
1191 These methods will handle creating B<Class::MOP::Class> objects,
1192 which can be used to both create new classes, and analyze
1193 pre-existing classes.
1195 This module will internally store references to all the instances
1196 you create with these methods, so that they do not need to be
1197 created any more than nessecary. Basically, they are singletons.
1201 =item B<create ($package_name,
1202 version =E<gt> ?$version,
1203 authority =E<gt> ?$authority,
1204 superclasses =E<gt> ?@superclasses,
1205 methods =E<gt> ?%methods,
1206 attributes =E<gt> ?%attributes)>
1208 This returns a B<Class::MOP::Class> object, bringing the specified
1209 C<$package_name> into existence and adding any of the C<$version>,
1210 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1213 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1214 methods =E<gt> ?%methods,
1215 attributes =E<gt> ?%attributes)>
1217 This will create an anonymous class, it works much like C<create> but
1218 it does not need a C<$package_name>. Instead it will create a suitably
1219 unique package name for you to stash things into.
1221 On very important distinction is that anon classes are destroyed once
1222 the metaclass they are attached to goes out of scope. In the DESTROY
1223 method, the created package will be removed from the symbol table.
1225 It is also worth noting that any instances created with an anon-class
1226 will keep a special reference to the anon-meta which will prevent the
1227 anon-class from going out of scope until all instances of it have also
1228 been destroyed. This however only works for HASH based instance types,
1229 as we use a special reserved slot (C<__MOP__>) to store this.
1231 =item B<initialize ($package_name, %options)>
1233 This initializes and returns returns a B<Class::MOP::Class> object
1234 for a given a C<$package_name>.
1236 =item B<construct_class_instance (%options)>
1238 This will construct an instance of B<Class::MOP::Class>, it is
1239 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1240 to use C<construct_instance> once all the bootstrapping is done. This
1241 method is used internally by C<initialize> and should never be called
1242 from outside of that method really.
1244 =item B<check_metaclass_compatability>
1246 This method is called as the very last thing in the
1247 C<construct_class_instance> method. This will check that the
1248 metaclass you are creating is compatible with the metaclasses of all
1249 your ancestors. For more inforamtion about metaclass compatibility
1250 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1252 =item B<update_package_cache_flag>
1254 This will reset the package cache flag for this particular metaclass
1255 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1256 function. This is very rarely needed from outside of C<Class::MOP::Class>
1257 but in some cases you might want to use it, so it is here.
1259 =item B<reset_package_cache_flag>
1261 Clears the package cache flag to announce to the internals that we need
1262 to rebuild the method map.
1264 =item B<add_meta_instance_dependencies>
1266 Registers this class as dependent on its superclasses.
1268 Only superclasses from which this class inherits attributes will be added.
1270 =item B<remove_meta_instance_depdendencies>
1272 Unregisters this class from its superclasses.
1274 =item B<update_meta_instance_dependencies>
1276 Reregisters if necessary.
1278 =item B<add_dependent_meta_instance> $metaclass
1280 Registers the class as having a meta instance dependent on this class.
1282 =item B<remove_dependent_meta_instance> $metaclass
1284 Remove the class from the list of dependent classes.
1286 =item B<invalidate_meta_instances>
1288 Clears the cached meta instance for this metaclass and all of the registered
1289 classes with dependent meta instances.
1291 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1294 =item B<invalidate_meta_instance>
1296 Used by C<invalidate_meta_instances>.
1300 =head2 Object instance construction and cloning
1302 These methods are B<entirely optional>, it is up to you whether you want
1307 =item B<instance_metaclass>
1309 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1310 for more information on the instance metaclasses.
1312 =item B<get_meta_instance>
1314 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1315 of a new instance of the class.
1317 =item B<create_meta_instance>
1319 Called by C<get_meta_instance> if necessary.
1321 =item B<new_object (%params)>
1323 This is a convience method for creating a new object of the class, and
1324 blessing it into the appropriate package as well. Ideally your class
1325 would call a C<new> this method like so:
1328 my ($class, %param) = @_;
1329 $class->meta->new_object(%params);
1332 =item B<construct_instance (%params)>
1334 This method is used to construct an instance structure suitable for
1335 C<bless>-ing into your package of choice. It works in conjunction
1336 with the Attribute protocol to collect all applicable attributes.
1338 This will construct and instance using a HASH ref as storage
1339 (currently only HASH references are supported). This will collect all
1340 the applicable attributes and layout out the fields in the HASH ref,
1341 it will then initialize them using either use the corresponding key
1342 in C<%params> or any default value or initializer found in the
1343 attribute meta-object.
1345 =item B<clone_object ($instance, %params)>
1347 This is a convience method for cloning an object instance, then
1348 blessing it into the appropriate package. This method will call
1349 C<clone_instance>, which performs a shallow copy of the object,
1350 see that methods documentation for more details. Ideally your
1351 class would call a C<clone> this method like so:
1353 sub MyClass::clone {
1354 my ($self, %param) = @_;
1355 $self->meta->clone_object($self, %params);
1358 =item B<clone_instance($instance, %params)>
1360 This method is a compliment of C<construct_instance> (which means if
1361 you override C<construct_instance>, you need to override this one too),
1362 and clones the instance shallowly.
1364 The cloned structure returned is (like with C<construct_instance>) an
1365 unC<bless>ed HASH reference, it is your responsibility to then bless
1366 this cloned structure into the right class (which C<clone_object> will
1369 As of 0.11, this method will clone the C<$instance> structure shallowly,
1370 as opposed to the deep cloning implemented in prior versions. After much
1371 thought, research and discussion, I have decided that anything but basic
1372 shallow cloning is outside the scope of the meta-object protocol. I
1373 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1374 is too I<context-specific> to be part of the MOP.
1376 =item B<rebless_instance($instance, ?%params)>
1378 This will change the class of C<$instance> to the class of the invoking
1379 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1380 itself. You may pass in optional C<%params> which are like constructor
1381 params and will override anything already defined in the instance.
1385 =head2 Informational
1387 These are a few predicate methods for asking information about the class.
1391 =item B<is_anon_class>
1393 This returns true if the class is a C<Class::MOP::Class> created anon class.
1397 This returns true if the class is still mutable.
1399 =item B<is_immutable>
1401 This returns true if the class has been made immutable.
1403 =item B<is_pristine>
1405 Checks whether the class has any data that will be lost if C<reinitialize> is
1410 =head2 Inheritance Relationships
1414 =item B<superclasses (?@superclasses)>
1416 This is a read-write attribute which represents the superclass
1417 relationships of the class the B<Class::MOP::Class> instance is
1418 associated with. Basically, it can get and set the C<@ISA> for you.
1420 =item B<class_precedence_list>
1422 This computes the a list of all the class's ancestors in the same order
1423 in which method dispatch will be done. This is similair to what
1424 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1426 =item B<linearized_isa>
1428 This returns a list based on C<class_precedence_list> but with all
1433 This returns a list of subclasses for this class.
1441 =item B<get_method_map>
1443 Returns a HASH ref of name to CODE reference mapping for this class.
1445 =item B<method_metaclass>
1447 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1448 for more information on the method metaclasses.
1450 =item B<wrap_method_body(%attrs)>
1452 Wrap a code ref (C<$attrs{body>) with C<method_metaclass>.
1454 =item B<add_method ($method_name, $method, %attrs)>
1456 This will take a C<$method_name> and CODE reference or meta method
1457 objectand install it into the class's package.
1459 You are strongly encouraged to pass a meta method object instead of a
1460 code reference. If you do so, that object gets stored as part of the
1461 class's method map, providing more useful information about the method
1465 This does absolutely nothing special to C<$method>
1466 other than use B<Sub::Name> to make sure it is tagged with the
1467 correct name, and therefore show up correctly in stack traces and
1470 =item B<has_method ($method_name)>
1472 This just provides a simple way to check if the class implements
1473 a specific C<$method_name>. It will I<not> however, attempt to check
1474 if the class inherits the method (use C<UNIVERSAL::can> for that).
1476 This will correctly handle functions defined outside of the package
1477 that use a fully qualified name (C<sub Package::name { ... }>).
1479 This will correctly handle functions renamed with B<Sub::Name> and
1480 installed using the symbol tables. However, if you are naming the
1481 subroutine outside of the package scope, you must use the fully
1482 qualified name, including the package name, for C<has_method> to
1483 correctly identify it.
1485 This will attempt to correctly ignore functions imported from other
1486 packages using B<Exporter>. It breaks down if the function imported
1487 is an C<__ANON__> sub (such as with C<use constant>), which very well
1488 may be a valid method being applied to the class.
1490 In short, this method cannot always be trusted to determine if the
1491 C<$method_name> is actually a method. However, it will DWIM about
1492 90% of the time, so it's a small trade off I think.
1494 =item B<get_method ($method_name)>
1496 This will return a Class::MOP::Method instance related to the specified
1497 C<$method_name>, or return undef if that method does not exist.
1499 The Class::MOP::Method is codifiable, so you can use it like a normal
1500 CODE reference, see L<Class::MOP::Method> for more information.
1502 =item B<find_method_by_name ($method_name)>
1504 This will return a CODE reference of the specified C<$method_name>,
1505 or return undef if that method does not exist.
1507 Unlike C<get_method> this will also look in the superclasses.
1509 =item B<remove_method ($method_name)>
1511 This will attempt to remove a given C<$method_name> from the class.
1512 It will return the CODE reference that it has removed, and will
1513 attempt to use B<Sub::Name> to clear the methods associated name.
1515 =item B<get_method_list>
1517 This will return a list of method names for all I<locally> defined
1518 methods. It does B<not> provide a list of all applicable methods,
1519 including any inherited ones. If you want a list of all applicable
1520 methods, use the C<compute_all_applicable_methods> method.
1522 =item B<get_all_methods>
1524 This will traverse the inheritance heirachy and return a list of all
1525 the applicable L<Class::MOP::Method> objects for this class.
1527 =item B<compute_all_applicable_methods>
1531 This method returns a list of hashes describing the all the methods of the
1534 Use L<get_all_methods>, which is easier/better/faster. This method predates
1535 L<Class::MOP::Method>.
1537 =item B<find_all_methods_by_name ($method_name)>
1539 This will traverse the inheritence hierarchy and locate all methods
1540 with a given C<$method_name>. Similar to
1541 C<compute_all_applicable_methods> it returns a list of HASH references
1542 with the following information; method name (which will always be the
1543 same as C<$method_name>), the name of the class in which the method
1544 lives and a CODE reference for the actual method.
1546 The list of methods produced is a distinct list, meaning there are no
1547 duplicates in it. This is especially useful for things like object
1548 initialization and destruction where you only want the method called
1549 once, and in the correct order.
1551 =item B<find_next_method_by_name ($method_name)>
1553 This will return the first method to match a given C<$method_name> in
1554 the superclasses, this is basically equivalent to calling
1555 C<SUPER::$method_name>, but it can be dispatched at runtime.
1557 =item B<alias_method ($method_name, $method)>
1559 B<NOTE>: This method is now deprecated. Just use C<add_method>
1564 =head2 Method Modifiers
1566 Method modifiers are a concept borrowed from CLOS, in which a method
1567 can be wrapped with I<before>, I<after> and I<around> method modifiers
1568 that will be called everytime the method is called.
1570 =head3 How method modifiers work?
1572 Method modifiers work by wrapping the original method and then replacing
1573 it in the classes symbol table. The wrappers will handle calling all the
1574 modifiers in the appropariate orders and preserving the calling context
1575 for the original method.
1577 Each method modifier serves a particular purpose, which may not be
1578 obvious to users of other method wrapping modules. To start with, the
1579 return values of I<before> and I<after> modifiers are ignored. This is
1580 because thier purpose is B<not> to filter the input and output of the
1581 primary method (this is done with an I<around> modifier). This may seem
1582 like an odd restriction to some, but doing this allows for simple code
1583 to be added at the begining or end of a method call without jeapordizing
1584 the normal functioning of the primary method or placing any extra
1585 responsibility on the code of the modifier. Of course if you have more
1586 complex needs, then use the I<around> modifier, which uses a variation
1587 of continutation passing style to allow for a high degree of flexibility.
1589 Before and around modifiers are called in last-defined-first-called order,
1590 while after modifiers are called in first-defined-first-called order. So
1591 the call tree might looks something like this:
1601 To see examples of using method modifiers, see the following examples
1602 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1603 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1604 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1606 =head3 What is the performance impact?
1608 Of course there is a performance cost associated with method modifiers,
1609 but we have made every effort to make that cost be directly proportional
1610 to the amount of modifier features you utilize.
1612 The wrapping method does it's best to B<only> do as much work as it
1613 absolutely needs to. In order to do this we have moved some of the
1614 performance costs to set-up time, where they are easier to amortize.
1616 All this said, my benchmarks have indicated the following:
1618 simple wrapper with no modifiers 100% slower
1619 simple wrapper with simple before modifier 400% slower
1620 simple wrapper with simple after modifier 450% slower
1621 simple wrapper with simple around modifier 500-550% slower
1622 simple wrapper with all 3 modifiers 1100% slower
1624 These numbers may seem daunting, but you must remember, every feature
1625 comes with some cost. To put things in perspective, just doing a simple
1626 C<AUTOLOAD> which does nothing but extract the name of the method called
1627 and return it costs about 400% over a normal method call.
1631 =item B<add_before_method_modifier ($method_name, $code)>
1633 This will wrap the method at C<$method_name> and the supplied C<$code>
1634 will be passed the C<@_> arguments, and called before the original
1635 method is called. As specified above, the return value of the I<before>
1636 method modifiers is ignored, and it's ability to modify C<@_> is
1637 fairly limited. If you need to do either of these things, use an
1638 C<around> method modifier.
1640 =item B<add_after_method_modifier ($method_name, $code)>
1642 This will wrap the method at C<$method_name> so that the original
1643 method will be called, it's return values stashed, and then the
1644 supplied C<$code> will be passed the C<@_> arguments, and called.
1645 As specified above, the return value of the I<after> method
1646 modifiers is ignored, and it cannot modify the return values of
1647 the original method. If you need to do either of these things, use an
1648 C<around> method modifier.
1650 =item B<add_around_method_modifier ($method_name, $code)>
1652 This will wrap the method at C<$method_name> so that C<$code>
1653 will be called and passed the original method as an extra argument
1654 at the begining of the C<@_> argument list. This is a variation of
1655 continuation passing style, where the function prepended to C<@_>
1656 can be considered a continuation. It is up to C<$code> if it calls
1657 the original method or not, there is no restriction on what the
1658 C<$code> can or cannot do.
1664 It should be noted that since there is no one consistent way to define
1665 the attributes of a class in Perl 5. These methods can only work with
1666 the information given, and can not easily discover information on
1667 their own. See L<Class::MOP::Attribute> for more details.
1671 =item B<attribute_metaclass>
1673 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1674 for more information on the attribute metaclasses.
1676 =item B<get_attribute_map>
1678 This returns a HASH ref of name to attribute meta-object mapping.
1680 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1682 This stores the C<$attribute_meta_object> (or creates one from the
1683 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1684 instance associated with the given class. Unlike methods, attributes
1685 within the MOP are stored as meta-information only. They will be used
1686 later to construct instances from (see C<construct_instance> above).
1687 More details about the attribute meta-objects can be found in the
1688 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1691 It should be noted that any accessor, reader/writer or predicate
1692 methods which the C<$attribute_meta_object> has will be installed
1693 into the class at this time.
1696 If an attribute already exists for C<$attribute_name>, the old one
1697 will be removed (as well as removing all it's accessors), and then
1700 =item B<has_attribute ($attribute_name)>
1702 Checks to see if this class has an attribute by the name of
1703 C<$attribute_name> and returns a boolean.
1705 =item B<get_attribute ($attribute_name)>
1707 Returns the attribute meta-object associated with C<$attribute_name>,
1708 if none is found, it will return undef.
1710 =item B<remove_attribute ($attribute_name)>
1712 This will remove the attribute meta-object stored at
1713 C<$attribute_name>, then return the removed attribute meta-object.
1716 Removing an attribute will only affect future instances of
1717 the class, it will not make any attempt to remove the attribute from
1718 any existing instances of the class.
1720 It should be noted that any accessor, reader/writer or predicate
1721 methods which the attribute meta-object stored at C<$attribute_name>
1722 has will be removed from the class at this time. This B<will> make
1723 these attributes somewhat inaccessable in previously created
1724 instances. But if you are crazy enough to do this at runtime, then
1725 you are crazy enough to deal with something like this :).
1727 =item B<get_attribute_list>
1729 This returns a list of attribute names which are defined in the local
1730 class. If you want a list of all applicable attributes for a class,
1731 use the C<compute_all_applicable_attributes> method.
1733 =item B<compute_all_applicable_attributes>
1735 =item B<get_all_attributes>
1737 This will traverse the inheritance heirachy and return a list of all
1738 the applicable L<Class::MOP::Attribute> objects for this class.
1740 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1742 =item B<find_attribute_by_name ($attr_name)>
1744 This method will traverse the inheritance heirachy and find the
1745 first attribute whose name matches C<$attr_name>, then return it.
1746 It will return undef if nothing is found.
1750 =head2 Class Immutability
1754 =item B<make_immutable (%options)>
1756 This method will invoke a tranforamtion upon the class which will
1757 make it immutable. Details of this transformation can be found in
1758 the L<Class::MOP::Immutable> documentation.
1760 =item B<make_mutable>
1762 This method will reverse tranforamtion upon the class which
1765 =item B<get_immutable_transformer>
1767 Return a transformer suitable for making this class immutable or, if this
1768 class is immutable, the transformer used to make it immutable.
1770 =item B<get_immutable_options>
1772 If the class is immutable, return the options used to make it immutable.
1774 =item B<create_immutable_transformer>
1776 Create a transformer suitable for making this class immutable
1782 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1784 =head1 COPYRIGHT AND LICENSE
1786 Copyright 2006-2008 by Infinity Interactive, Inc.
1788 L<http://www.iinteractive.com>
1790 This library is free software; you can redistribute it and/or modify
1791 it under the same terms as Perl itself.