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 our $AUTHORITY = 'cpan:STEVAN';
17 use base 'Class::MOP::Module';
27 $package_name = shift;
30 $package_name = $options{package};
33 (defined $package_name && $package_name && !ref($package_name))
34 || confess "You must pass a package name and it cannot be blessed";
36 return Class::MOP::get_metaclass_by_name($package_name)
37 || $class->construct_class_instance(package => $package_name, @_);
42 my $package_name = shift;
43 (defined $package_name && $package_name && !blessed($package_name))
44 || confess "You must pass a package name and it cannot be blessed";
45 Class::MOP::remove_metaclass_by_name($package_name);
46 $class->construct_class_instance('package' => $package_name, @_);
49 # NOTE: (meta-circularity)
50 # this is a special form of &construct_instance
51 # (see below), which is used to construct class
52 # meta-object instances for any Class::MOP::*
53 # class. All other classes will use the more
54 # normal &construct_instance.
55 sub construct_class_instance {
58 my $package_name = $options{'package'};
59 (defined $package_name && $package_name)
60 || confess "You must pass a package name";
62 # return the metaclass if we have it cached,
63 # and it is still defined (it has not been
64 # reaped by DESTROY yet, which can happen
65 # annoyingly enough during global destruction)
67 if (defined(my $meta = Class::MOP::get_metaclass_by_name($package_name))) {
72 # we need to deal with the possibility
73 # of class immutability here, and then
74 # get the name of the class appropriately
75 $class = (blessed($class)
76 ? ($class->is_immutable
77 ? $class->get_mutable_metaclass_name()
81 # now create the metaclass
83 if ($class eq 'Class::MOP::Class') {
86 # inherited from Class::MOP::Package
87 'package' => $package_name,
90 # since the following attributes will
91 # actually be loaded from the symbol
92 # table, and actually bypass the instance
93 # entirely, we can just leave these things
94 # listed here for reference, because they
95 # should not actually have a value associated
97 'namespace' => \undef,
98 # inherited from Class::MOP::Module
100 'authority' => \undef,
101 # defined in Class::MOP::Class
102 'superclasses' => \undef,
106 'attribute_metaclass' => $options{'attribute_metaclass'} || 'Class::MOP::Attribute',
107 'method_metaclass' => $options{'method_metaclass'} || 'Class::MOP::Method',
108 'instance_metaclass' => $options{'instance_metaclass'} || 'Class::MOP::Instance',
110 ## uber-private variables
112 # this starts out as undef so that
113 # we can tell the first time the
114 # methods are fetched
116 '_package_cache_flag' => undef,
117 '_meta_instance' => undef,
122 # it is safe to use meta here because
123 # class will always be a subclass of
124 # Class::MOP::Class, which defines meta
125 $meta = $class->meta->construct_instance(%options)
128 # and check the metaclass compatibility
129 $meta->check_metaclass_compatability();
131 Class::MOP::store_metaclass_by_name($package_name, $meta);
134 # we need to weaken any anon classes
135 # so that they can call DESTROY properly
136 Class::MOP::weaken_metaclass($package_name) if $meta->is_anon_class;
141 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
142 sub update_package_cache_flag {
145 # we can manually update the cache number
146 # since we are actually adding the method
147 # to our cache as well. This avoids us
148 # having to regenerate the method_map.
150 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
153 sub check_metaclass_compatability {
156 # this is always okay ...
157 return if blessed($self) eq 'Class::MOP::Class' &&
158 $self->instance_metaclass eq 'Class::MOP::Instance';
160 my @class_list = $self->linearized_isa;
161 shift @class_list; # shift off $self->name
163 foreach my $class_name (@class_list) {
164 my $meta = Class::MOP::get_metaclass_by_name($class_name) || next;
167 # we need to deal with the possibility
168 # of class immutability here, and then
169 # get the name of the class appropriately
170 my $meta_type = ($meta->is_immutable
171 ? $meta->get_mutable_metaclass_name()
174 ($self->isa($meta_type))
175 || confess $self->name . "->meta => (" . (blessed($self)) . ")" .
176 " is not compatible with the " .
177 $class_name . "->meta => (" . ($meta_type) . ")";
179 # we also need to check that instance metaclasses
180 # are compatabile in the same the class.
181 ($self->instance_metaclass->isa($meta->instance_metaclass))
182 || confess $self->name . "->meta => (" . ($self->instance_metaclass) . ")" .
183 " is not compatible with the " .
184 $class_name . "->meta => (" . ($meta->instance_metaclass) . ")";
192 # this should be sufficient, if you have a
193 # use case where it is not, write a test and
195 my $ANON_CLASS_SERIAL = 0;
198 # we need a sufficiently annoying prefix
199 # this should suffice for now, this is
200 # used in a couple of places below, so
201 # need to put it up here for now.
202 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
206 no warnings 'uninitialized';
207 $self->name =~ /^$ANON_CLASS_PREFIX/ ? 1 : 0;
210 sub create_anon_class {
211 my ($class, %options) = @_;
212 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
213 return $class->create($package_name, %options);
219 require Devel::GlobalDestruction;
220 Devel::GlobalDestruction->import("in_global_destruction");
222 } or *in_global_destruction = sub () { '' };
226 # this will only get called for
227 # anon-classes, all other calls
228 # are assumed to occur during
229 # global destruction and so don't
230 # really need to be handled explicitly
234 return if in_global_destruction; # it'll happen soon anyway and this just makes things more complicated
236 no warnings 'uninitialized';
237 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
238 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
240 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
241 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
243 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
248 # creating classes with MOP ...
251 my ( $class, @args ) = @_;
253 unshift @args, 'package' if @args % 2 == 1;
255 my (%options) = @args;
256 my $package_name = $options{package};
258 (defined $package_name && $package_name)
259 || confess "You must pass a package name";
261 (ref $options{superclasses} eq 'ARRAY')
262 || confess "You must pass an ARRAY ref of superclasses"
263 if exists $options{superclasses};
265 (ref $options{attributes} eq 'ARRAY')
266 || confess "You must pass an ARRAY ref of attributes"
267 if exists $options{attributes};
269 (ref $options{methods} eq 'HASH')
270 || confess "You must pass an HASH ref of methods"
271 if exists $options{methods};
273 my $code = "package $package_name;";
274 $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';"
275 if exists $options{version};
276 $code .= "\$$package_name\:\:AUTHORITY = '" . $options{authority} . "';"
277 if exists $options{authority};
280 confess "creation of $package_name failed : $@" if $@;
282 my $meta = $class->initialize($package_name);
285 $meta->add_method('meta' => sub {
286 $class->initialize(blessed($_[0]) || $_[0]);
289 $meta->superclasses(@{$options{superclasses}})
290 if exists $options{superclasses};
292 # process attributes first, so that they can
293 # install accessors, but locally defined methods
294 # can then overwrite them. It is maybe a little odd, but
295 # I think this should be the order of things.
296 if (exists $options{attributes}) {
297 foreach my $attr (@{$options{attributes}}) {
298 $meta->add_attribute($attr);
301 if (exists $options{methods}) {
302 foreach my $method_name (keys %{$options{methods}}) {
303 $meta->add_method($method_name, $options{methods}->{$method_name});
312 # all these attribute readers will be bootstrapped
313 # away in the Class::MOP bootstrap section
315 sub get_attribute_map { $_[0]->{'attributes'} }
316 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
317 sub method_metaclass { $_[0]->{'method_metaclass'} }
318 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
321 # this is a prime canidate for conversion to XS
325 my $current = Class::MOP::check_package_cache_flag($self->name);
327 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
328 return $self->{'methods'};
331 $self->{_package_cache_flag} = $current;
333 my $map = $self->{'methods'};
335 my $class_name = $self->name;
336 my $method_metaclass = $self->method_metaclass;
338 my %all_code = $self->get_all_package_symbols('CODE');
340 foreach my $symbol (keys %all_code) {
341 my $code = $all_code{$symbol};
343 next if exists $map->{$symbol} &&
344 defined $map->{$symbol} &&
345 $map->{$symbol}->body == $code;
347 my ($pkg, $name) = Class::MOP::get_code_info($code);
350 # in 5.10 constant.pm the constants show up
351 # as being in the right package, but in pre-5.10
352 # they show up as constant::__ANON__ so we
353 # make an exception here to be sure that things
354 # work as expected in both.
356 unless ($pkg eq 'constant' && $name eq '__ANON__') {
357 next if ($pkg || '') ne $class_name ||
358 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
361 $map->{$symbol} = $method_metaclass->wrap(
363 associated_metaclass => $self,
364 package_name => $class_name,
372 # Instance Construction & Cloning
378 # we need to protect the integrity of the
379 # Class::MOP::Class singletons here, so we
380 # delegate this to &construct_class_instance
381 # which will deal with the singletons
382 return $class->construct_class_instance(@_)
383 if $class->name->isa('Class::MOP::Class');
384 return $class->construct_instance(@_);
387 sub construct_instance {
388 my ($class, %params) = @_;
389 my $meta_instance = $class->get_meta_instance();
390 my $instance = $meta_instance->create_instance();
391 foreach my $attr ($class->compute_all_applicable_attributes()) {
392 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
395 # this will only work for a HASH instance type
396 if ($class->is_anon_class) {
397 (Scalar::Util::reftype($instance) eq 'HASH')
398 || confess "Currently only HASH based instances are supported with instance of anon-classes";
400 # At some point we should make this official
401 # as a reserved slot name, but right now I am
402 # going to keep it here.
403 # my $RESERVED_MOP_SLOT = '__MOP__';
404 $instance->{'__MOP__'} = $class;
410 sub get_meta_instance {
412 $self->{'_meta_instance'} ||= $self->create_meta_instance();
415 sub create_meta_instance {
418 my $instance = $self->instance_metaclass->new(
419 associated_metaclass => $self,
420 attributes => [ $self->compute_all_applicable_attributes() ],
423 $self->add_meta_instance_dependencies()
424 if $instance->is_dependent_on_superclasses();
431 my $instance = shift;
432 (blessed($instance) && $instance->isa($class->name))
433 || confess "You must pass an instance of the metaclass (" . $class->name . "), not ($instance)";
436 # we need to protect the integrity of the
437 # Class::MOP::Class singletons here, they
438 # should not be cloned.
439 return $instance if $instance->isa('Class::MOP::Class');
440 $class->clone_instance($instance, @_);
444 my ($class, $instance, %params) = @_;
446 || confess "You can only clone instances, ($instance) is not a blessed instance";
447 my $meta_instance = $class->get_meta_instance();
448 my $clone = $meta_instance->clone_instance($instance);
449 foreach my $attr ($class->compute_all_applicable_attributes()) {
450 if ( defined( my $init_arg = $attr->init_arg ) ) {
451 if (exists $params{$init_arg}) {
452 $attr->set_value($clone, $params{$init_arg});
459 sub rebless_instance {
460 my ($self, $instance, %params) = @_;
463 if ($instance->can('meta')) {
464 ($instance->meta->isa('Class::MOP::Class'))
465 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
466 $old_metaclass = $instance->meta;
469 $old_metaclass = $self->initialize(blessed($instance));
472 my $meta_instance = $self->get_meta_instance();
474 $self->name->isa($old_metaclass->name)
475 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
478 $meta_instance->rebless_instance_structure($instance, $self);
480 foreach my $attr ( $self->compute_all_applicable_attributes ) {
481 if ( $attr->has_value($instance) ) {
482 if ( defined( my $init_arg = $attr->init_arg ) ) {
483 $params{$init_arg} = $attr->get_value($instance)
484 unless exists $params{$init_arg};
487 $attr->set_value($instance, $attr->get_value($instance));
492 foreach my $attr ($self->compute_all_applicable_attributes) {
493 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
503 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
506 @{$self->get_package_symbol($var_spec)} = @supers;
508 # we need to check the metaclass
509 # compatibility here so that we can
510 # be sure that the superclass is
511 # not potentially creating an issues
512 # we don't know about
513 $self->check_metaclass_compatability();
514 $self->update_meta_instance_dependencies();
516 @{$self->get_package_symbol($var_spec)};
522 my $super_class = $self->name;
524 if ( Class::MOP::HAVE_ISAREV() ) {
525 return @{ $super_class->mro::get_isarev() };
529 my $find_derived_classes;
530 $find_derived_classes = sub {
531 my ($outer_class) = @_;
533 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
536 for my $symbol ( keys %$symbol_table_hashref ) {
537 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
538 my $inner_class = $1;
540 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
544 ? "${outer_class}::$inner_class"
547 if ( $class->isa($super_class) and $class ne $super_class ) {
548 push @derived_classes, $class;
551 next SYMBOL if $class eq 'main'; # skip 'main::*'
553 $find_derived_classes->($class);
557 my $root_class = q{};
558 $find_derived_classes->($root_class);
560 undef $find_derived_classes;
562 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
564 return @derived_classes;
570 return @{ mro::get_linear_isa( (shift)->name ) };
573 sub class_precedence_list {
575 my $name = $self->name;
577 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
579 # We need to check for circular inheritance here
580 # if we are are not on 5.10, cause 5.8 detects it
581 # late. This will do nothing if all is well, and
582 # blow up otherwise. Yes, it's an ugly hack, better
583 # suggestions are welcome.
585 ($name || return)->isa('This is a test for circular inheritance')
588 # if our mro is c3, we can
589 # just grab the linear_isa
590 if (mro::get_mro($name) eq 'c3') {
591 return @{ mro::get_linear_isa($name) }
595 # we can't grab the linear_isa for dfs
596 # since it has all the duplicates
601 $self->initialize($_)->class_precedence_list()
602 } $self->superclasses()
610 my ($self, $method_name, $method) = @_;
611 (defined $method_name && $method_name)
612 || confess "You must define a method name";
615 if (blessed($method)) {
616 $body = $method->body;
617 if ($method->package_name ne $self->name &&
618 $method->name ne $method_name) {
619 warn "Hello there, got something for you."
620 . " Method says " . $method->package_name . " " . $method->name
621 . " Class says " . $self->name . " " . $method_name;
622 $method = $method->clone(
623 package_name => $self->name,
625 ) if $method->can('clone');
630 ('CODE' eq ref($body))
631 || confess "Your code block must be a CODE reference";
632 $method = $self->method_metaclass->wrap(
634 package_name => $self->name,
640 $method->attach_to_class($self);
642 $self->get_method_map->{$method_name} = $method;
644 my $full_method_name = ($self->name . '::' . $method_name);
645 $self->add_package_symbol(
646 { sigil => '&', type => 'CODE', name => $method_name },
647 Class::MOP::subname($full_method_name => $body)
650 $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
654 my $fetch_and_prepare_method = sub {
655 my ($self, $method_name) = @_;
657 my $method = $self->get_method($method_name);
658 # if we dont have local ...
660 # try to find the next method
661 $method = $self->find_next_method_by_name($method_name);
662 # die if it does not exist
664 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
665 # and now make sure to wrap it
666 # even if it is already wrapped
667 # because we need a new sub ref
668 $method = Class::MOP::Method::Wrapped->wrap($method);
671 # now make sure we wrap it properly
672 $method = Class::MOP::Method::Wrapped->wrap($method)
673 unless $method->isa('Class::MOP::Method::Wrapped');
675 $self->add_method($method_name => $method);
679 sub add_before_method_modifier {
680 my ($self, $method_name, $method_modifier) = @_;
681 (defined $method_name && $method_name)
682 || confess "You must pass in a method name";
683 my $method = $fetch_and_prepare_method->($self, $method_name);
684 $method->add_before_modifier(
685 Class::MOP::subname(':before' => $method_modifier)
689 sub add_after_method_modifier {
690 my ($self, $method_name, $method_modifier) = @_;
691 (defined $method_name && $method_name)
692 || confess "You must pass in a method name";
693 my $method = $fetch_and_prepare_method->($self, $method_name);
694 $method->add_after_modifier(
695 Class::MOP::subname(':after' => $method_modifier)
699 sub add_around_method_modifier {
700 my ($self, $method_name, $method_modifier) = @_;
701 (defined $method_name && $method_name)
702 || confess "You must pass in a method name";
703 my $method = $fetch_and_prepare_method->($self, $method_name);
704 $method->add_around_modifier(
705 Class::MOP::subname(':around' => $method_modifier)
710 # the methods above used to be named like this:
711 # ${pkg}::${method}:(before|after|around)
712 # but this proved problematic when using one modifier
713 # to wrap multiple methods (something which is likely
714 # to happen pretty regularly IMO). So instead of naming
715 # it like this, I have chosen to just name them purely
716 # with their modifier names, like so:
717 # :(before|after|around)
718 # The fact is that in a stack trace, it will be fairly
719 # evident from the context what method they are attached
720 # to, and so don't need the fully qualified name.
724 my ($self, $method_name, $method) = @_;
725 (defined $method_name && $method_name)
726 || confess "You must define a method name";
728 my $body = (blessed($method) ? $method->body : $method);
729 ('CODE' eq ref($body))
730 || confess "Your code block must be a CODE reference";
732 $self->add_package_symbol(
733 { sigil => '&', type => 'CODE', name => $method_name } => $body
738 my ($self, $method_name) = @_;
739 (defined $method_name && $method_name)
740 || confess "You must define a method name";
742 return 0 unless exists $self->get_method_map->{$method_name};
747 my ($self, $method_name) = @_;
748 (defined $method_name && $method_name)
749 || confess "You must define a method name";
752 # I don't really need this here, because
753 # if the method_map is missing a key it
754 # will just return undef for me now
755 # return unless $self->has_method($method_name);
757 return $self->get_method_map->{$method_name};
761 my ($self, $method_name) = @_;
762 (defined $method_name && $method_name)
763 || confess "You must define a method name";
765 my $removed_method = delete $self->get_method_map->{$method_name};
767 $self->remove_package_symbol(
768 { sigil => '&', type => 'CODE', name => $method_name }
771 $removed_method->detach_from_class if $removed_method;
773 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
775 return $removed_method;
778 sub get_method_list {
780 keys %{$self->get_method_map};
783 sub find_method_by_name {
784 my ($self, $method_name) = @_;
785 (defined $method_name && $method_name)
786 || confess "You must define a method name to find";
787 foreach my $class ($self->linearized_isa) {
788 # fetch the meta-class ...
789 my $meta = $self->initialize($class);
790 return $meta->get_method($method_name)
791 if $meta->has_method($method_name);
796 sub compute_all_applicable_methods {
798 my (@methods, %seen_method);
799 foreach my $class ($self->linearized_isa) {
800 # fetch the meta-class ...
801 my $meta = $self->initialize($class);
802 foreach my $method_name ($meta->get_method_list()) {
803 next if exists $seen_method{$method_name};
804 $seen_method{$method_name}++;
806 name => $method_name,
808 code => $meta->get_method($method_name)
815 sub find_all_methods_by_name {
816 my ($self, $method_name) = @_;
817 (defined $method_name && $method_name)
818 || confess "You must define a method name to find";
820 foreach my $class ($self->linearized_isa) {
821 # fetch the meta-class ...
822 my $meta = $self->initialize($class);
824 name => $method_name,
826 code => $meta->get_method($method_name)
827 } if $meta->has_method($method_name);
832 sub find_next_method_by_name {
833 my ($self, $method_name) = @_;
834 (defined $method_name && $method_name)
835 || confess "You must define a method name to find";
836 my @cpl = $self->linearized_isa;
837 shift @cpl; # discard ourselves
838 foreach my $class (@cpl) {
839 # fetch the meta-class ...
840 my $meta = $self->initialize($class);
841 return $meta->get_method($method_name)
842 if $meta->has_method($method_name);
851 # either we have an attribute object already
852 # or we need to create one from the args provided
853 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
854 # make sure it is derived from the correct type though
855 ($attribute->isa('Class::MOP::Attribute'))
856 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
858 # first we attach our new attribute
859 # because it might need certain information
860 # about the class which it is attached to
861 $attribute->attach_to_class($self);
863 # then we remove attributes of a conflicting
864 # name here so that we can properly detach
865 # the old attr object, and remove any
866 # accessors it would have generated
867 if ( $self->has_attribute($attribute->name) ) {
868 $self->remove_attribute($attribute->name);
870 $self->invalidate_meta_instances();
873 # then onto installing the new accessors
874 $self->get_attribute_map->{$attribute->name} = $attribute;
876 # invalidate package flag here
877 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
879 $self->remove_attribute($attribute->name);
886 sub update_meta_instance_dependencies {
889 if ( $self->{meta_instance_dependencies} ) {
890 return $self->add_meta_instance_dependencies;
894 sub add_meta_instance_dependencies {
897 $self->remove_meta_instance_depdendencies;
899 my @attrs = $self->compute_all_applicable_attributes();
902 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
904 foreach my $class ( @classes ) {
905 $class->add_dependent_meta_instance($self);
908 $self->{meta_instance_dependencies} = \@classes;
911 sub remove_meta_instance_depdendencies {
914 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
915 foreach my $class ( @$classes ) {
916 $class->remove_dependent_meta_instance($self);
926 sub add_dependent_meta_instance {
927 my ( $self, $metaclass ) = @_;
928 push @{ $self->{dependent_meta_instances} }, $metaclass;
931 sub remove_dependent_meta_instance {
932 my ( $self, $metaclass ) = @_;
933 my $name = $metaclass->name;
934 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
937 sub invalidate_meta_instances {
939 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
942 sub invalidate_meta_instance {
944 undef $self->{_meta_instance};
948 my ($self, $attribute_name) = @_;
949 (defined $attribute_name && $attribute_name)
950 || confess "You must define an attribute name";
951 exists $self->get_attribute_map->{$attribute_name} ? 1 : 0;
955 my ($self, $attribute_name) = @_;
956 (defined $attribute_name && $attribute_name)
957 || confess "You must define an attribute name";
958 return $self->get_attribute_map->{$attribute_name}
960 # this will return undef anyway, so no need ...
961 # if $self->has_attribute($attribute_name);
965 sub remove_attribute {
966 my ($self, $attribute_name) = @_;
967 (defined $attribute_name && $attribute_name)
968 || confess "You must define an attribute name";
969 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
970 return unless defined $removed_attribute;
971 delete $self->get_attribute_map->{$attribute_name};
972 $self->invalidate_meta_instances();
973 $removed_attribute->remove_accessors();
974 $removed_attribute->detach_from_class();
975 return $removed_attribute;
978 sub get_attribute_list {
980 keys %{$self->get_attribute_map};
983 sub compute_all_applicable_attributes {
985 my (@attrs, %seen_attr);
986 foreach my $class ($self->linearized_isa) {
987 # fetch the meta-class ...
988 my $meta = $self->initialize($class);
989 foreach my $attr_name ($meta->get_attribute_list()) {
990 next if exists $seen_attr{$attr_name};
991 $seen_attr{$attr_name}++;
992 push @attrs => $meta->get_attribute($attr_name);
998 sub find_attribute_by_name {
999 my ($self, $attr_name) = @_;
1000 foreach my $class ($self->linearized_isa) {
1001 # fetch the meta-class ...
1002 my $meta = $self->initialize($class);
1003 return $meta->get_attribute($attr_name)
1004 if $meta->has_attribute($attr_name);
1011 sub is_mutable { 1 }
1012 sub is_immutable { 0 }
1015 # Why I changed this (groditi)
1016 # - One Metaclass may have many Classes through many Metaclass instances
1017 # - One Metaclass should only have one Immutable Transformer instance
1018 # - Each Class may have different Immutabilizing options
1019 # - Therefore each Metaclass instance may have different Immutabilizing options
1020 # - We need to store one Immutable Transformer instance per Metaclass
1021 # - We need to store one set of Immutable Transformer options per Class
1022 # - Upon make_mutable we may delete the Immutabilizing options
1023 # - We could clean the immutable Transformer instance when there is no more
1024 # immutable Classes of that type, but we can also keep it in case
1025 # another class with this same Metaclass becomes immutable. It is a case
1026 # of trading of storing an instance to avoid unnecessary instantiations of
1027 # Immutable Transformers. You may view this as a memory leak, however
1028 # Because we have few Metaclasses, in practice it seems acceptable
1029 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1030 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1034 my %IMMUTABLE_TRANSFORMERS;
1035 my %IMMUTABLE_OPTIONS;
1037 sub get_immutable_options {
1039 return if $self->is_mutable;
1040 confess "unable to find immutabilizing options"
1041 unless exists $IMMUTABLE_OPTIONS{$self->name};
1042 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1043 delete $options{IMMUTABLE_TRANSFORMER};
1047 sub get_immutable_transformer {
1049 if( $self->is_mutable ){
1050 my $class = blessed $self || $self;
1051 return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
1053 confess "unable to find transformer for immutable class"
1054 unless exists $IMMUTABLE_OPTIONS{$self->name};
1055 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1058 sub make_immutable {
1062 my $transformer = $self->get_immutable_transformer;
1063 $transformer->make_metaclass_immutable($self, \%options);
1064 $IMMUTABLE_OPTIONS{$self->name} =
1065 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1067 if( exists $options{debug} && $options{debug} ){
1068 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1069 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1077 return if $self->is_mutable;
1078 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1079 confess "unable to find immutabilizing options" unless ref $options;
1080 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1081 $transformer->make_metaclass_mutable($self, $options);
1086 sub create_immutable_transformer {
1088 my $class = Class::MOP::Immutable->new($self, {
1089 read_only => [qw/superclasses/],
1096 remove_package_symbol
1099 class_precedence_list => 'ARRAY',
1100 linearized_isa => 'ARRAY',
1101 compute_all_applicable_attributes => 'ARRAY',
1102 get_meta_instance => 'SCALAR',
1103 get_method_map => 'SCALAR',
1106 # this is ugly, but so are typeglobs,
1107 # so whattayahgonnadoboutit
1110 add_package_symbol => sub {
1111 my $original = shift;
1112 confess "Cannot add package symbols to an immutable metaclass"
1113 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1114 goto $original->body;
1129 Class::MOP::Class - Class Meta Object
1133 # assuming that class Foo
1134 # has been defined, you can
1136 # use this for introspection ...
1138 # add a method to Foo ...
1139 Foo->meta->add_method('bar' => sub { ... })
1141 # get a list of all the classes searched
1142 # the method dispatcher in the correct order
1143 Foo->meta->class_precedence_list()
1145 # remove a method from Foo
1146 Foo->meta->remove_method('bar');
1148 # or use this to actually create classes ...
1150 Class::MOP::Class->create('Bar' => (
1152 superclasses => [ 'Foo' ],
1154 Class::MOP:::Attribute->new('$bar'),
1155 Class::MOP:::Attribute->new('$baz'),
1158 calculate_bar => sub { ... },
1159 construct_baz => sub { ... }
1165 This is the largest and currently most complex part of the Perl 5
1166 meta-object protocol. It controls the introspection and
1167 manipulation of Perl 5 classes (and it can create them too). The
1168 best way to understand what this module can do, is to read the
1169 documentation for each of it's methods.
1173 =head2 Self Introspection
1179 This will return a B<Class::MOP::Class> instance which is related
1180 to this class. Thereby allowing B<Class::MOP::Class> to actually
1183 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1184 bootstrap this module by installing a number of attribute meta-objects
1185 into it's metaclass. This will allow this class to reap all the benifits
1186 of the MOP when subclassing it.
1190 =head2 Class construction
1192 These methods will handle creating B<Class::MOP::Class> objects,
1193 which can be used to both create new classes, and analyze
1194 pre-existing classes.
1196 This module will internally store references to all the instances
1197 you create with these methods, so that they do not need to be
1198 created any more than nessecary. Basically, they are singletons.
1202 =item B<create ($package_name,
1203 version =E<gt> ?$version,
1204 authority =E<gt> ?$authority,
1205 superclasses =E<gt> ?@superclasses,
1206 methods =E<gt> ?%methods,
1207 attributes =E<gt> ?%attributes)>
1209 This returns a B<Class::MOP::Class> object, bringing the specified
1210 C<$package_name> into existence and adding any of the C<$version>,
1211 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1214 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1215 methods =E<gt> ?%methods,
1216 attributes =E<gt> ?%attributes)>
1218 This will create an anonymous class, it works much like C<create> but
1219 it does not need a C<$package_name>. Instead it will create a suitably
1220 unique package name for you to stash things into.
1222 On very important distinction is that anon classes are destroyed once
1223 the metaclass they are attached to goes out of scope. In the DESTROY
1224 method, the created package will be removed from the symbol table.
1226 It is also worth noting that any instances created with an anon-class
1227 will keep a special reference to the anon-meta which will prevent the
1228 anon-class from going out of scope until all instances of it have also
1229 been destroyed. This however only works for HASH based instance types,
1230 as we use a special reserved slot (C<__MOP__>) to store this.
1232 =item B<initialize ($package_name, %options)>
1234 This initializes and returns returns a B<Class::MOP::Class> object
1235 for a given a C<$package_name>.
1237 =item B<reinitialize ($package_name, %options)>
1239 This removes the old metaclass, and creates a new one in it's place.
1240 Do B<not> use this unless you really know what you are doing, it could
1241 very easily make a very large mess of your program.
1243 =item B<construct_class_instance (%options)>
1245 This will construct an instance of B<Class::MOP::Class>, it is
1246 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1247 to use C<construct_instance> once all the bootstrapping is done. This
1248 method is used internally by C<initialize> and should never be called
1249 from outside of that method really.
1251 =item B<check_metaclass_compatability>
1253 This method is called as the very last thing in the
1254 C<construct_class_instance> method. This will check that the
1255 metaclass you are creating is compatible with the metaclasses of all
1256 your ancestors. For more inforamtion about metaclass compatibility
1257 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1259 =item B<update_package_cache_flag>
1261 This will reset the package cache flag for this particular metaclass
1262 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1263 function. This is very rarely needed from outside of C<Class::MOP::Class>
1264 but in some cases you might want to use it, so it is here.
1266 =item B<reset_package_cache_flag>
1268 Clears the package cache flag to announce to the internals that we need
1269 to rebuild the method map.
1271 =item B<add_meta_instance_dependencies>
1273 Registers this class as dependent on its superclasses.
1275 Only superclasses from which this class inherits attributes will be added.
1277 =item B<remove_meta_instance_depdendencies>
1279 Unregisters this class from its superclasses.
1281 =item B<update_meta_instance_dependencies>
1283 Reregisters if necessary.
1285 =item B<add_dependent_meta_instance> $metaclass
1287 Registers the class as having a meta instance dependent on this class.
1289 =item B<remove_dependent_meta_instance> $metaclass
1291 Remove the class from the list of dependent classes.
1293 =item B<invalidate_meta_instances>
1295 Clears the cached meta instance for this metaclass and all of the registered
1296 classes with dependent meta instances.
1298 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1301 =item B<invalidate_meta_instance>
1303 Used by C<invalidate_meta_instances>.
1307 =head2 Object instance construction and cloning
1309 These methods are B<entirely optional>, it is up to you whether you want
1314 =item B<instance_metaclass>
1316 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1317 for more information on the instance metaclasses.
1319 =item B<get_meta_instance>
1321 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1322 of a new instance of the class.
1324 =item B<create_meta_instance>
1326 Called by C<get_meta_instance> if necessary.
1328 =item B<new_object (%params)>
1330 This is a convience method for creating a new object of the class, and
1331 blessing it into the appropriate package as well. Ideally your class
1332 would call a C<new> this method like so:
1335 my ($class, %param) = @_;
1336 $class->meta->new_object(%params);
1339 =item B<construct_instance (%params)>
1341 This method is used to construct an instance structure suitable for
1342 C<bless>-ing into your package of choice. It works in conjunction
1343 with the Attribute protocol to collect all applicable attributes.
1345 This will construct and instance using a HASH ref as storage
1346 (currently only HASH references are supported). This will collect all
1347 the applicable attributes and layout out the fields in the HASH ref,
1348 it will then initialize them using either use the corresponding key
1349 in C<%params> or any default value or initializer found in the
1350 attribute meta-object.
1352 =item B<clone_object ($instance, %params)>
1354 This is a convience method for cloning an object instance, then
1355 blessing it into the appropriate package. This method will call
1356 C<clone_instance>, which performs a shallow copy of the object,
1357 see that methods documentation for more details. Ideally your
1358 class would call a C<clone> this method like so:
1360 sub MyClass::clone {
1361 my ($self, %param) = @_;
1362 $self->meta->clone_object($self, %params);
1365 =item B<clone_instance($instance, %params)>
1367 This method is a compliment of C<construct_instance> (which means if
1368 you override C<construct_instance>, you need to override this one too),
1369 and clones the instance shallowly.
1371 The cloned structure returned is (like with C<construct_instance>) an
1372 unC<bless>ed HASH reference, it is your responsibility to then bless
1373 this cloned structure into the right class (which C<clone_object> will
1376 As of 0.11, this method will clone the C<$instance> structure shallowly,
1377 as opposed to the deep cloning implemented in prior versions. After much
1378 thought, research and discussion, I have decided that anything but basic
1379 shallow cloning is outside the scope of the meta-object protocol. I
1380 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1381 is too I<context-specific> to be part of the MOP.
1383 =item B<rebless_instance($instance, ?%params)>
1385 This will change the class of C<$instance> to the class of the invoking
1386 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1387 itself. You may pass in optional C<%params> which are like constructor
1388 params and will override anything already defined in the instance.
1392 =head2 Informational
1394 These are a few predicate methods for asking information about the class.
1398 =item B<is_anon_class>
1400 This returns true if the class is a C<Class::MOP::Class> created anon class.
1404 This returns true if the class is still mutable.
1406 =item B<is_immutable>
1408 This returns true if the class has been made immutable.
1412 =head2 Inheritance Relationships
1416 =item B<superclasses (?@superclasses)>
1418 This is a read-write attribute which represents the superclass
1419 relationships of the class the B<Class::MOP::Class> instance is
1420 associated with. Basically, it can get and set the C<@ISA> for you.
1422 =item B<class_precedence_list>
1424 This computes the a list of all the class's ancestors in the same order
1425 in which method dispatch will be done. This is similair to what
1426 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1428 =item B<linearized_isa>
1430 This returns a list based on C<class_precedence_list> but with all
1435 This returns a list of subclasses for this class.
1443 =item B<get_method_map>
1445 Returns a HASH ref of name to CODE reference mapping for this class.
1447 =item B<method_metaclass>
1449 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1450 for more information on the method metaclasses.
1452 =item B<add_method ($method_name, $method)>
1454 This will take a C<$method_name> and CODE reference to that
1455 C<$method> and install it into the class's package.
1458 This does absolutely nothing special to C<$method>
1459 other than use B<Sub::Name> to make sure it is tagged with the
1460 correct name, and therefore show up correctly in stack traces and
1463 =item B<alias_method ($method_name, $method)>
1465 This will take a C<$method_name> and CODE reference to that
1466 C<$method> and alias the method into the class's package.
1469 Unlike C<add_method>, this will B<not> try to name the
1470 C<$method> using B<Sub::Name>, it only aliases the method in
1471 the class's package.
1473 =item B<has_method ($method_name)>
1475 This just provides a simple way to check if the class implements
1476 a specific C<$method_name>. It will I<not> however, attempt to check
1477 if the class inherits the method (use C<UNIVERSAL::can> for that).
1479 This will correctly handle functions defined outside of the package
1480 that use a fully qualified name (C<sub Package::name { ... }>).
1482 This will correctly handle functions renamed with B<Sub::Name> and
1483 installed using the symbol tables. However, if you are naming the
1484 subroutine outside of the package scope, you must use the fully
1485 qualified name, including the package name, for C<has_method> to
1486 correctly identify it.
1488 This will attempt to correctly ignore functions imported from other
1489 packages using B<Exporter>. It breaks down if the function imported
1490 is an C<__ANON__> sub (such as with C<use constant>), which very well
1491 may be a valid method being applied to the class.
1493 In short, this method cannot always be trusted to determine if the
1494 C<$method_name> is actually a method. However, it will DWIM about
1495 90% of the time, so it's a small trade off I think.
1497 =item B<get_method ($method_name)>
1499 This will return a Class::MOP::Method instance related to the specified
1500 C<$method_name>, or return undef if that method does not exist.
1502 The Class::MOP::Method is codifiable, so you can use it like a normal
1503 CODE reference, see L<Class::MOP::Method> for more information.
1505 =item B<find_method_by_name ($method_name)>
1507 This will return a CODE reference of the specified C<$method_name>,
1508 or return undef if that method does not exist.
1510 Unlike C<get_method> this will also look in the superclasses.
1512 =item B<remove_method ($method_name)>
1514 This will attempt to remove a given C<$method_name> from the class.
1515 It will return the CODE reference that it has removed, and will
1516 attempt to use B<Sub::Name> to clear the methods associated name.
1518 =item B<get_method_list>
1520 This will return a list of method names for all I<locally> defined
1521 methods. It does B<not> provide a list of all applicable methods,
1522 including any inherited ones. If you want a list of all applicable
1523 methods, use the C<compute_all_applicable_methods> method.
1525 =item B<compute_all_applicable_methods>
1527 This will return a list of all the methods names this class will
1528 respond to, taking into account inheritance. The list will be a list of
1529 HASH references, each one containing the following information; method
1530 name, the name of the class in which the method lives and a CODE
1531 reference for the actual method.
1533 =item B<find_all_methods_by_name ($method_name)>
1535 This will traverse the inheritence hierarchy and locate all methods
1536 with a given C<$method_name>. Similar to
1537 C<compute_all_applicable_methods> it returns a list of HASH references
1538 with the following information; method name (which will always be the
1539 same as C<$method_name>), the name of the class in which the method
1540 lives and a CODE reference for the actual method.
1542 The list of methods produced is a distinct list, meaning there are no
1543 duplicates in it. This is especially useful for things like object
1544 initialization and destruction where you only want the method called
1545 once, and in the correct order.
1547 =item B<find_next_method_by_name ($method_name)>
1549 This will return the first method to match a given C<$method_name> in
1550 the superclasses, this is basically equivalent to calling
1551 C<SUPER::$method_name>, but it can be dispatched at runtime.
1555 =head2 Method Modifiers
1557 Method modifiers are a concept borrowed from CLOS, in which a method
1558 can be wrapped with I<before>, I<after> and I<around> method modifiers
1559 that will be called everytime the method is called.
1561 =head3 How method modifiers work?
1563 Method modifiers work by wrapping the original method and then replacing
1564 it in the classes symbol table. The wrappers will handle calling all the
1565 modifiers in the appropariate orders and preserving the calling context
1566 for the original method.
1568 Each method modifier serves a particular purpose, which may not be
1569 obvious to users of other method wrapping modules. To start with, the
1570 return values of I<before> and I<after> modifiers are ignored. This is
1571 because thier purpose is B<not> to filter the input and output of the
1572 primary method (this is done with an I<around> modifier). This may seem
1573 like an odd restriction to some, but doing this allows for simple code
1574 to be added at the begining or end of a method call without jeapordizing
1575 the normal functioning of the primary method or placing any extra
1576 responsibility on the code of the modifier. Of course if you have more
1577 complex needs, then use the I<around> modifier, which uses a variation
1578 of continutation passing style to allow for a high degree of flexibility.
1580 Before and around modifiers are called in last-defined-first-called order,
1581 while after modifiers are called in first-defined-first-called order. So
1582 the call tree might looks something like this:
1592 To see examples of using method modifiers, see the following examples
1593 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1594 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1595 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1597 =head3 What is the performance impact?
1599 Of course there is a performance cost associated with method modifiers,
1600 but we have made every effort to make that cost be directly proportional
1601 to the amount of modifier features you utilize.
1603 The wrapping method does it's best to B<only> do as much work as it
1604 absolutely needs to. In order to do this we have moved some of the
1605 performance costs to set-up time, where they are easier to amortize.
1607 All this said, my benchmarks have indicated the following:
1609 simple wrapper with no modifiers 100% slower
1610 simple wrapper with simple before modifier 400% slower
1611 simple wrapper with simple after modifier 450% slower
1612 simple wrapper with simple around modifier 500-550% slower
1613 simple wrapper with all 3 modifiers 1100% slower
1615 These numbers may seem daunting, but you must remember, every feature
1616 comes with some cost. To put things in perspective, just doing a simple
1617 C<AUTOLOAD> which does nothing but extract the name of the method called
1618 and return it costs about 400% over a normal method call.
1622 =item B<add_before_method_modifier ($method_name, $code)>
1624 This will wrap the method at C<$method_name> and the supplied C<$code>
1625 will be passed the C<@_> arguments, and called before the original
1626 method is called. As specified above, the return value of the I<before>
1627 method modifiers is ignored, and it's ability to modify C<@_> is
1628 fairly limited. If you need to do either of these things, use an
1629 C<around> method modifier.
1631 =item B<add_after_method_modifier ($method_name, $code)>
1633 This will wrap the method at C<$method_name> so that the original
1634 method will be called, it's return values stashed, and then the
1635 supplied C<$code> will be passed the C<@_> arguments, and called.
1636 As specified above, the return value of the I<after> method
1637 modifiers is ignored, and it cannot modify the return values of
1638 the original method. If you need to do either of these things, use an
1639 C<around> method modifier.
1641 =item B<add_around_method_modifier ($method_name, $code)>
1643 This will wrap the method at C<$method_name> so that C<$code>
1644 will be called and passed the original method as an extra argument
1645 at the begining of the C<@_> argument list. This is a variation of
1646 continuation passing style, where the function prepended to C<@_>
1647 can be considered a continuation. It is up to C<$code> if it calls
1648 the original method or not, there is no restriction on what the
1649 C<$code> can or cannot do.
1655 It should be noted that since there is no one consistent way to define
1656 the attributes of a class in Perl 5. These methods can only work with
1657 the information given, and can not easily discover information on
1658 their own. See L<Class::MOP::Attribute> for more details.
1662 =item B<attribute_metaclass>
1664 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1665 for more information on the attribute metaclasses.
1667 =item B<get_attribute_map>
1669 This returns a HASH ref of name to attribute meta-object mapping.
1671 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1673 This stores the C<$attribute_meta_object> (or creates one from the
1674 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1675 instance associated with the given class. Unlike methods, attributes
1676 within the MOP are stored as meta-information only. They will be used
1677 later to construct instances from (see C<construct_instance> above).
1678 More details about the attribute meta-objects can be found in the
1679 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1682 It should be noted that any accessor, reader/writer or predicate
1683 methods which the C<$attribute_meta_object> has will be installed
1684 into the class at this time.
1687 If an attribute already exists for C<$attribute_name>, the old one
1688 will be removed (as well as removing all it's accessors), and then
1691 =item B<has_attribute ($attribute_name)>
1693 Checks to see if this class has an attribute by the name of
1694 C<$attribute_name> and returns a boolean.
1696 =item B<get_attribute ($attribute_name)>
1698 Returns the attribute meta-object associated with C<$attribute_name>,
1699 if none is found, it will return undef.
1701 =item B<remove_attribute ($attribute_name)>
1703 This will remove the attribute meta-object stored at
1704 C<$attribute_name>, then return the removed attribute meta-object.
1707 Removing an attribute will only affect future instances of
1708 the class, it will not make any attempt to remove the attribute from
1709 any existing instances of the class.
1711 It should be noted that any accessor, reader/writer or predicate
1712 methods which the attribute meta-object stored at C<$attribute_name>
1713 has will be removed from the class at this time. This B<will> make
1714 these attributes somewhat inaccessable in previously created
1715 instances. But if you are crazy enough to do this at runtime, then
1716 you are crazy enough to deal with something like this :).
1718 =item B<get_attribute_list>
1720 This returns a list of attribute names which are defined in the local
1721 class. If you want a list of all applicable attributes for a class,
1722 use the C<compute_all_applicable_attributes> method.
1724 =item B<compute_all_applicable_attributes>
1726 This will traverse the inheritance heirachy and return a list of all
1727 the applicable attributes for this class. It does not construct a
1728 HASH reference like C<compute_all_applicable_methods> because all
1729 that same information is discoverable through the attribute
1732 =item B<find_attribute_by_name ($attr_name)>
1734 This method will traverse the inheritance heirachy and find the
1735 first attribute whose name matches C<$attr_name>, then return it.
1736 It will return undef if nothing is found.
1740 =head2 Class Immutability
1744 =item B<make_immutable (%options)>
1746 This method will invoke a tranforamtion upon the class which will
1747 make it immutable. Details of this transformation can be found in
1748 the L<Class::MOP::Immutable> documentation.
1750 =item B<make_mutable>
1752 This method will reverse tranforamtion upon the class which
1755 =item B<get_immutable_transformer>
1757 Return a transformer suitable for making this class immutable or, if this
1758 class is immutable, the transformer used to make it immutable.
1760 =item B<get_immutable_options>
1762 If the class is immutable, return the options used to make it immutable.
1764 =item B<create_immutable_transformer>
1766 Create a transformer suitable for making this class immutable
1772 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1774 =head1 COPYRIGHT AND LICENSE
1776 Copyright 2006-2008 by Infinity Interactive, Inc.
1778 L<http://www.iinteractive.com>
1780 This library is free software; you can redistribute it and/or modify
1781 it under the same terms as Perl itself.