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 get_all_methods {
798 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
799 return values %methods;
803 sub compute_all_applicable_methods {
807 class => $_->package_name,
808 code => $_, # sigh, overloading
810 } shift->get_all_methods(@_);
813 sub find_all_methods_by_name {
814 my ($self, $method_name) = @_;
815 (defined $method_name && $method_name)
816 || confess "You must define a method name to find";
818 foreach my $class ($self->linearized_isa) {
819 # fetch the meta-class ...
820 my $meta = $self->initialize($class);
822 name => $method_name,
824 code => $meta->get_method($method_name)
825 } if $meta->has_method($method_name);
830 sub find_next_method_by_name {
831 my ($self, $method_name) = @_;
832 (defined $method_name && $method_name)
833 || confess "You must define a method name to find";
834 my @cpl = $self->linearized_isa;
835 shift @cpl; # discard ourselves
836 foreach my $class (@cpl) {
837 # fetch the meta-class ...
838 my $meta = $self->initialize($class);
839 return $meta->get_method($method_name)
840 if $meta->has_method($method_name);
849 # either we have an attribute object already
850 # or we need to create one from the args provided
851 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
852 # make sure it is derived from the correct type though
853 ($attribute->isa('Class::MOP::Attribute'))
854 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
856 # first we attach our new attribute
857 # because it might need certain information
858 # about the class which it is attached to
859 $attribute->attach_to_class($self);
861 # then we remove attributes of a conflicting
862 # name here so that we can properly detach
863 # the old attr object, and remove any
864 # accessors it would have generated
865 if ( $self->has_attribute($attribute->name) ) {
866 $self->remove_attribute($attribute->name);
868 $self->invalidate_meta_instances();
871 # then onto installing the new accessors
872 $self->get_attribute_map->{$attribute->name} = $attribute;
874 # invalidate package flag here
875 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
877 $self->remove_attribute($attribute->name);
884 sub update_meta_instance_dependencies {
887 if ( $self->{meta_instance_dependencies} ) {
888 return $self->add_meta_instance_dependencies;
892 sub add_meta_instance_dependencies {
895 $self->remove_meta_instance_depdendencies;
897 my @attrs = $self->compute_all_applicable_attributes();
900 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
902 foreach my $class ( @classes ) {
903 $class->add_dependent_meta_instance($self);
906 $self->{meta_instance_dependencies} = \@classes;
909 sub remove_meta_instance_depdendencies {
912 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
913 foreach my $class ( @$classes ) {
914 $class->remove_dependent_meta_instance($self);
924 sub add_dependent_meta_instance {
925 my ( $self, $metaclass ) = @_;
926 push @{ $self->{dependent_meta_instances} }, $metaclass;
929 sub remove_dependent_meta_instance {
930 my ( $self, $metaclass ) = @_;
931 my $name = $metaclass->name;
932 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
935 sub invalidate_meta_instances {
937 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
940 sub invalidate_meta_instance {
942 undef $self->{_meta_instance};
946 my ($self, $attribute_name) = @_;
947 (defined $attribute_name && $attribute_name)
948 || confess "You must define an attribute name";
949 exists $self->get_attribute_map->{$attribute_name} ? 1 : 0;
953 my ($self, $attribute_name) = @_;
954 (defined $attribute_name && $attribute_name)
955 || confess "You must define an attribute name";
956 return $self->get_attribute_map->{$attribute_name}
958 # this will return undef anyway, so no need ...
959 # if $self->has_attribute($attribute_name);
963 sub remove_attribute {
964 my ($self, $attribute_name) = @_;
965 (defined $attribute_name && $attribute_name)
966 || confess "You must define an attribute name";
967 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
968 return unless defined $removed_attribute;
969 delete $self->get_attribute_map->{$attribute_name};
970 $self->invalidate_meta_instances();
971 $removed_attribute->remove_accessors();
972 $removed_attribute->detach_from_class();
973 return $removed_attribute;
976 sub get_attribute_list {
978 keys %{$self->get_attribute_map};
981 sub get_all_attributes {
982 shift->compute_all_applicable_attributes(@_);
985 sub compute_all_applicable_attributes {
987 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
988 return values %attrs;
991 sub find_attribute_by_name {
992 my ($self, $attr_name) = @_;
993 foreach my $class ($self->linearized_isa) {
994 # fetch the meta-class ...
995 my $meta = $self->initialize($class);
996 return $meta->get_attribute($attr_name)
997 if $meta->has_attribute($attr_name);
1004 sub is_mutable { 1 }
1005 sub is_immutable { 0 }
1008 # Why I changed this (groditi)
1009 # - One Metaclass may have many Classes through many Metaclass instances
1010 # - One Metaclass should only have one Immutable Transformer instance
1011 # - Each Class may have different Immutabilizing options
1012 # - Therefore each Metaclass instance may have different Immutabilizing options
1013 # - We need to store one Immutable Transformer instance per Metaclass
1014 # - We need to store one set of Immutable Transformer options per Class
1015 # - Upon make_mutable we may delete the Immutabilizing options
1016 # - We could clean the immutable Transformer instance when there is no more
1017 # immutable Classes of that type, but we can also keep it in case
1018 # another class with this same Metaclass becomes immutable. It is a case
1019 # of trading of storing an instance to avoid unnecessary instantiations of
1020 # Immutable Transformers. You may view this as a memory leak, however
1021 # Because we have few Metaclasses, in practice it seems acceptable
1022 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1023 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1027 my %IMMUTABLE_TRANSFORMERS;
1028 my %IMMUTABLE_OPTIONS;
1030 sub get_immutable_options {
1032 return if $self->is_mutable;
1033 confess "unable to find immutabilizing options"
1034 unless exists $IMMUTABLE_OPTIONS{$self->name};
1035 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1036 delete $options{IMMUTABLE_TRANSFORMER};
1040 sub get_immutable_transformer {
1042 if( $self->is_mutable ){
1043 my $class = blessed $self || $self;
1044 return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
1046 confess "unable to find transformer for immutable class"
1047 unless exists $IMMUTABLE_OPTIONS{$self->name};
1048 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1051 sub make_immutable {
1055 my $transformer = $self->get_immutable_transformer;
1056 $transformer->make_metaclass_immutable($self, \%options);
1057 $IMMUTABLE_OPTIONS{$self->name} =
1058 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1060 if( exists $options{debug} && $options{debug} ){
1061 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1062 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1070 return if $self->is_mutable;
1071 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1072 confess "unable to find immutabilizing options" unless ref $options;
1073 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1074 $transformer->make_metaclass_mutable($self, $options);
1079 sub create_immutable_transformer {
1081 my $class = Class::MOP::Immutable->new($self, {
1082 read_only => [qw/superclasses/],
1089 remove_package_symbol
1092 class_precedence_list => 'ARRAY',
1093 linearized_isa => 'ARRAY',
1094 compute_all_applicable_attributes => 'ARRAY',
1095 get_meta_instance => 'SCALAR',
1096 get_method_map => 'SCALAR',
1099 # this is ugly, but so are typeglobs,
1100 # so whattayahgonnadoboutit
1103 add_package_symbol => sub {
1104 my $original = shift;
1105 confess "Cannot add package symbols to an immutable metaclass"
1106 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1107 goto $original->body;
1122 Class::MOP::Class - Class Meta Object
1126 # assuming that class Foo
1127 # has been defined, you can
1129 # use this for introspection ...
1131 # add a method to Foo ...
1132 Foo->meta->add_method('bar' => sub { ... })
1134 # get a list of all the classes searched
1135 # the method dispatcher in the correct order
1136 Foo->meta->class_precedence_list()
1138 # remove a method from Foo
1139 Foo->meta->remove_method('bar');
1141 # or use this to actually create classes ...
1143 Class::MOP::Class->create('Bar' => (
1145 superclasses => [ 'Foo' ],
1147 Class::MOP:::Attribute->new('$bar'),
1148 Class::MOP:::Attribute->new('$baz'),
1151 calculate_bar => sub { ... },
1152 construct_baz => sub { ... }
1158 This is the largest and currently most complex part of the Perl 5
1159 meta-object protocol. It controls the introspection and
1160 manipulation of Perl 5 classes (and it can create them too). The
1161 best way to understand what this module can do, is to read the
1162 documentation for each of it's methods.
1166 =head2 Self Introspection
1172 This will return a B<Class::MOP::Class> instance which is related
1173 to this class. Thereby allowing B<Class::MOP::Class> to actually
1176 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1177 bootstrap this module by installing a number of attribute meta-objects
1178 into it's metaclass. This will allow this class to reap all the benifits
1179 of the MOP when subclassing it.
1183 =head2 Class construction
1185 These methods will handle creating B<Class::MOP::Class> objects,
1186 which can be used to both create new classes, and analyze
1187 pre-existing classes.
1189 This module will internally store references to all the instances
1190 you create with these methods, so that they do not need to be
1191 created any more than nessecary. Basically, they are singletons.
1195 =item B<create ($package_name,
1196 version =E<gt> ?$version,
1197 authority =E<gt> ?$authority,
1198 superclasses =E<gt> ?@superclasses,
1199 methods =E<gt> ?%methods,
1200 attributes =E<gt> ?%attributes)>
1202 This returns a B<Class::MOP::Class> object, bringing the specified
1203 C<$package_name> into existence and adding any of the C<$version>,
1204 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1207 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1208 methods =E<gt> ?%methods,
1209 attributes =E<gt> ?%attributes)>
1211 This will create an anonymous class, it works much like C<create> but
1212 it does not need a C<$package_name>. Instead it will create a suitably
1213 unique package name for you to stash things into.
1215 On very important distinction is that anon classes are destroyed once
1216 the metaclass they are attached to goes out of scope. In the DESTROY
1217 method, the created package will be removed from the symbol table.
1219 It is also worth noting that any instances created with an anon-class
1220 will keep a special reference to the anon-meta which will prevent the
1221 anon-class from going out of scope until all instances of it have also
1222 been destroyed. This however only works for HASH based instance types,
1223 as we use a special reserved slot (C<__MOP__>) to store this.
1225 =item B<initialize ($package_name, %options)>
1227 This initializes and returns returns a B<Class::MOP::Class> object
1228 for a given a C<$package_name>.
1230 =item B<reinitialize ($package_name, %options)>
1232 This removes the old metaclass, and creates a new one in it's place.
1233 Do B<not> use this unless you really know what you are doing, it could
1234 very easily make a very large mess of your program.
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.
1405 =head2 Inheritance Relationships
1409 =item B<superclasses (?@superclasses)>
1411 This is a read-write attribute which represents the superclass
1412 relationships of the class the B<Class::MOP::Class> instance is
1413 associated with. Basically, it can get and set the C<@ISA> for you.
1415 =item B<class_precedence_list>
1417 This computes the a list of all the class's ancestors in the same order
1418 in which method dispatch will be done. This is similair to what
1419 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1421 =item B<linearized_isa>
1423 This returns a list based on C<class_precedence_list> but with all
1428 This returns a list of subclasses for this class.
1436 =item B<get_method_map>
1438 Returns a HASH ref of name to CODE reference mapping for this class.
1440 =item B<method_metaclass>
1442 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1443 for more information on the method metaclasses.
1445 =item B<add_method ($method_name, $method)>
1447 This will take a C<$method_name> and CODE reference to that
1448 C<$method> and install it into the class's package.
1451 This does absolutely nothing special to C<$method>
1452 other than use B<Sub::Name> to make sure it is tagged with the
1453 correct name, and therefore show up correctly in stack traces and
1456 =item B<alias_method ($method_name, $method)>
1458 This will take a C<$method_name> and CODE reference to that
1459 C<$method> and alias the method into the class's package.
1462 Unlike C<add_method>, this will B<not> try to name the
1463 C<$method> using B<Sub::Name>, it only aliases the method in
1464 the class's package.
1466 =item B<has_method ($method_name)>
1468 This just provides a simple way to check if the class implements
1469 a specific C<$method_name>. It will I<not> however, attempt to check
1470 if the class inherits the method (use C<UNIVERSAL::can> for that).
1472 This will correctly handle functions defined outside of the package
1473 that use a fully qualified name (C<sub Package::name { ... }>).
1475 This will correctly handle functions renamed with B<Sub::Name> and
1476 installed using the symbol tables. However, if you are naming the
1477 subroutine outside of the package scope, you must use the fully
1478 qualified name, including the package name, for C<has_method> to
1479 correctly identify it.
1481 This will attempt to correctly ignore functions imported from other
1482 packages using B<Exporter>. It breaks down if the function imported
1483 is an C<__ANON__> sub (such as with C<use constant>), which very well
1484 may be a valid method being applied to the class.
1486 In short, this method cannot always be trusted to determine if the
1487 C<$method_name> is actually a method. However, it will DWIM about
1488 90% of the time, so it's a small trade off I think.
1490 =item B<get_method ($method_name)>
1492 This will return a Class::MOP::Method instance related to the specified
1493 C<$method_name>, or return undef if that method does not exist.
1495 The Class::MOP::Method is codifiable, so you can use it like a normal
1496 CODE reference, see L<Class::MOP::Method> for more information.
1498 =item B<find_method_by_name ($method_name)>
1500 This will return a CODE reference of the specified C<$method_name>,
1501 or return undef if that method does not exist.
1503 Unlike C<get_method> this will also look in the superclasses.
1505 =item B<remove_method ($method_name)>
1507 This will attempt to remove a given C<$method_name> from the class.
1508 It will return the CODE reference that it has removed, and will
1509 attempt to use B<Sub::Name> to clear the methods associated name.
1511 =item B<get_method_list>
1513 This will return a list of method names for all I<locally> defined
1514 methods. It does B<not> provide a list of all applicable methods,
1515 including any inherited ones. If you want a list of all applicable
1516 methods, use the C<compute_all_applicable_methods> method.
1518 =item B<get_all_methods>
1520 This will traverse the inheritance heirachy and return a list of all
1521 the applicable L<Class::MOP::Method> objects for this class.
1523 =item B<compute_all_applicable_methods>
1527 This method returns a list of hashes describing the all the methods of the
1530 Use L<get_all_methods>, which is easier/better/faster. This method predates
1531 L<Class::MOP::Method>.
1533 =item B<find_all_methods_by_name ($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 =item B<get_all_attributes>
1728 This will traverse the inheritance heirachy and return a list of all
1729 the applicable L<Class::MOP::Attribute> objects for this class.
1731 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1733 =item B<find_attribute_by_name ($attr_name)>
1735 This method will traverse the inheritance heirachy and find the
1736 first attribute whose name matches C<$attr_name>, then return it.
1737 It will return undef if nothing is found.
1741 =head2 Class Immutability
1745 =item B<make_immutable (%options)>
1747 This method will invoke a tranforamtion upon the class which will
1748 make it immutable. Details of this transformation can be found in
1749 the L<Class::MOP::Immutable> documentation.
1751 =item B<make_mutable>
1753 This method will reverse tranforamtion upon the class which
1756 =item B<get_immutable_transformer>
1758 Return a transformer suitable for making this class immutable or, if this
1759 class is immutable, the transformer used to make it immutable.
1761 =item B<get_immutable_options>
1763 If the class is immutable, return the options used to make it immutable.
1765 =item B<create_immutable_transformer>
1767 Create a transformer suitable for making this class immutable
1773 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1775 =head1 COPYRIGHT AND LICENSE
1777 Copyright 2006-2008 by Infinity Interactive, Inc.
1779 L<http://www.iinteractive.com>
1781 This library is free software; you can redistribute it and/or modify
1782 it under the same terms as Perl itself.