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, @_);
40 # NOTE: (meta-circularity)
41 # this is a special form of &construct_instance
42 # (see below), which is used to construct class
43 # meta-object instances for any Class::MOP::*
44 # class. All other classes will use the more
45 # normal &construct_instance.
46 sub construct_class_instance {
48 my $options = @_ == 1 ? $_[0] : {@_};
49 my $package_name = $options->{package};
50 (defined $package_name && $package_name)
51 || confess "You must pass a package name";
53 # return the metaclass if we have it cached,
54 # and it is still defined (it has not been
55 # reaped by DESTROY yet, which can happen
56 # annoyingly enough during global destruction)
58 if (defined(my $meta = Class::MOP::get_metaclass_by_name($package_name))) {
63 # we need to deal with the possibility
64 # of class immutability here, and then
65 # get the name of the class appropriately
67 ? ($class->is_immutable
68 ? $class->get_mutable_metaclass_name()
72 # now create the metaclass
74 if ($class eq 'Class::MOP::Class') {
76 $meta = $class->_new($options)
80 # it is safe to use meta here because
81 # class will always be a subclass of
82 # Class::MOP::Class, which defines meta
83 $meta = $class->meta->construct_instance($options)
86 # and check the metaclass compatibility
87 $meta->check_metaclass_compatability();
89 Class::MOP::store_metaclass_by_name($package_name, $meta);
92 # we need to weaken any anon classes
93 # so that they can call DESTROY properly
94 Class::MOP::weaken_metaclass($package_name) if $meta->is_anon_class;
101 my $options = @_ == 1 ? $_[0] : {@_};
104 # inherited from Class::MOP::Package
105 'package' => $options->{package},
108 # since the following attributes will
109 # actually be loaded from the symbol
110 # table, and actually bypass the instance
111 # entirely, we can just leave these things
112 # listed here for reference, because they
113 # should not actually have a value associated
115 'namespace' => \undef,
116 # inherited from Class::MOP::Module
118 'authority' => \undef,
119 # defined in Class::MOP::Class
120 'superclasses' => \undef,
124 'attribute_metaclass' => $options->{'attribute_metaclass'} || 'Class::MOP::Attribute',
125 'method_metaclass' => $options->{'method_metaclass'} || 'Class::MOP::Method',
126 'instance_metaclass' => $options->{'instance_metaclass'} || 'Class::MOP::Instance',
130 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
131 sub update_package_cache_flag {
134 # we can manually update the cache number
135 # since we are actually adding the method
136 # to our cache as well. This avoids us
137 # having to regenerate the method_map.
139 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
142 sub check_metaclass_compatability {
145 # this is always okay ...
146 return if ref($self) eq 'Class::MOP::Class' &&
147 $self->instance_metaclass eq 'Class::MOP::Instance';
149 my @class_list = $self->linearized_isa;
150 shift @class_list; # shift off $self->name
152 foreach my $class_name (@class_list) {
153 my $meta = Class::MOP::get_metaclass_by_name($class_name) || next;
156 # we need to deal with the possibility
157 # of class immutability here, and then
158 # get the name of the class appropriately
159 my $meta_type = ($meta->is_immutable
160 ? $meta->get_mutable_metaclass_name()
163 ($self->isa($meta_type))
164 || confess $self->name . "->meta => (" . (ref($self)) . ")" .
165 " is not compatible with the " .
166 $class_name . "->meta => (" . ($meta_type) . ")";
168 # we also need to check that instance metaclasses
169 # are compatabile in the same the class.
170 ($self->instance_metaclass->isa($meta->instance_metaclass))
171 || confess $self->name . "->meta => (" . ($self->instance_metaclass) . ")" .
172 " is not compatible with the " .
173 $class_name . "->meta => (" . ($meta->instance_metaclass) . ")";
181 # this should be sufficient, if you have a
182 # use case where it is not, write a test and
184 my $ANON_CLASS_SERIAL = 0;
187 # we need a sufficiently annoying prefix
188 # this should suffice for now, this is
189 # used in a couple of places below, so
190 # need to put it up here for now.
191 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
195 no warnings 'uninitialized';
196 $self->name =~ /^$ANON_CLASS_PREFIX/;
199 sub create_anon_class {
200 my ($class, %options) = @_;
201 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
202 return $class->create($package_name, %options);
206 # this will only get called for
207 # anon-classes, all other calls
208 # are assumed to occur during
209 # global destruction and so don't
210 # really need to be handled explicitly
214 return if Class::MOP::in_global_destruction; # it'll happen soon anyway and this just makes things more complicated
216 no warnings 'uninitialized';
217 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
218 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
220 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
221 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
223 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
228 # creating classes with MOP ...
231 my ( $class, @args ) = @_;
233 unshift @args, 'package' if @args % 2 == 1;
235 my (%options) = @args;
236 my $package_name = $options{package};
238 (defined $package_name && $package_name)
239 || confess "You must pass a package name";
241 (ref $options{superclasses} eq 'ARRAY')
242 || confess "You must pass an ARRAY ref of superclasses"
243 if exists $options{superclasses};
245 (ref $options{attributes} eq 'ARRAY')
246 || confess "You must pass an ARRAY ref of attributes"
247 if exists $options{attributes};
249 (ref $options{methods} eq 'HASH')
250 || confess "You must pass an HASH ref of methods"
251 if exists $options{methods};
253 my $code = "package $package_name;";
254 $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';"
255 if exists $options{version};
256 $code .= "\$$package_name\:\:AUTHORITY = '" . $options{authority} . "';"
257 if exists $options{authority};
260 confess "creation of $package_name failed : $@" if $@;
262 my $meta = $class->initialize($package_name);
265 $meta->add_method('meta' => sub {
266 $class->initialize(ref($_[0]) || $_[0]);
269 $meta->superclasses(@{$options{superclasses}})
270 if exists $options{superclasses};
272 # process attributes first, so that they can
273 # install accessors, but locally defined methods
274 # can then overwrite them. It is maybe a little odd, but
275 # I think this should be the order of things.
276 if (exists $options{attributes}) {
277 foreach my $attr (@{$options{attributes}}) {
278 $meta->add_attribute($attr);
281 if (exists $options{methods}) {
282 foreach my $method_name (keys %{$options{methods}}) {
283 $meta->add_method($method_name, $options{methods}->{$method_name});
292 # all these attribute readers will be bootstrapped
293 # away in the Class::MOP bootstrap section
295 sub get_attribute_map { $_[0]->{'attributes'} }
296 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
297 sub method_metaclass { $_[0]->{'method_metaclass'} }
298 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
301 # this is a prime canidate for conversion to XS
305 my $current = Class::MOP::check_package_cache_flag($self->name);
307 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
308 return $self->{'methods'} ||= {};
311 $self->{_package_cache_flag} = $current;
313 my $map = $self->{'methods'} ||= {};
315 my $class_name = $self->name;
316 my $method_metaclass = $self->method_metaclass;
318 my %all_code = $self->get_all_package_symbols('CODE');
320 foreach my $symbol (keys %all_code) {
321 my $code = $all_code{$symbol};
323 next if exists $map->{$symbol} &&
324 defined $map->{$symbol} &&
325 $map->{$symbol}->body == $code;
327 my ($pkg, $name) = Class::MOP::get_code_info($code);
330 # in 5.10 constant.pm the constants show up
331 # as being in the right package, but in pre-5.10
332 # they show up as constant::__ANON__ so we
333 # make an exception here to be sure that things
334 # work as expected in both.
336 unless ($pkg eq 'constant' && $name eq '__ANON__') {
337 next if ($pkg || '') ne $class_name ||
338 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
341 $map->{$symbol} = $method_metaclass->wrap(
343 associated_metaclass => $self,
344 package_name => $class_name,
352 # Instance Construction & Cloning
358 # we need to protect the integrity of the
359 # Class::MOP::Class singletons here, so we
360 # delegate this to &construct_class_instance
361 # which will deal with the singletons
362 return $class->construct_class_instance(@_)
363 if $class->name->isa('Class::MOP::Class');
364 return $class->construct_instance(@_);
367 sub construct_instance {
369 my $params = @_ == 1 ? $_[0] : {@_};
370 my $meta_instance = $class->get_meta_instance();
371 my $instance = $meta_instance->create_instance();
372 foreach my $attr ($class->compute_all_applicable_attributes()) {
373 $attr->initialize_instance_slot($meta_instance, $instance, $params);
376 # this will only work for a HASH instance type
377 if ($class->is_anon_class) {
378 (Scalar::Util::reftype($instance) eq 'HASH')
379 || confess "Currently only HASH based instances are supported with instance of anon-classes";
381 # At some point we should make this official
382 # as a reserved slot name, but right now I am
383 # going to keep it here.
384 # my $RESERVED_MOP_SLOT = '__MOP__';
385 $instance->{'__MOP__'} = $class;
391 sub get_meta_instance {
393 $self->{'_meta_instance'} ||= $self->create_meta_instance();
396 sub create_meta_instance {
399 my $instance = $self->instance_metaclass->new(
400 associated_metaclass => $self,
401 attributes => [ $self->compute_all_applicable_attributes() ],
404 $self->add_meta_instance_dependencies()
405 if $instance->is_dependent_on_superclasses();
412 my $instance = shift;
413 (blessed($instance) && $instance->isa($class->name))
414 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
417 # we need to protect the integrity of the
418 # Class::MOP::Class singletons here, they
419 # should not be cloned.
420 return $instance if $instance->isa('Class::MOP::Class');
421 $class->clone_instance($instance, @_);
425 my ($class, $instance, %params) = @_;
427 || confess "You can only clone instances, ($instance) is not a blessed instance";
428 my $meta_instance = $class->get_meta_instance();
429 my $clone = $meta_instance->clone_instance($instance);
430 foreach my $attr ($class->compute_all_applicable_attributes()) {
431 if ( defined( my $init_arg = $attr->init_arg ) ) {
432 if (exists $params{$init_arg}) {
433 $attr->set_value($clone, $params{$init_arg});
440 sub rebless_instance {
441 my ($self, $instance, %params) = @_;
444 if ($instance->can('meta')) {
445 ($instance->meta->isa('Class::MOP::Class'))
446 || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
447 $old_metaclass = $instance->meta;
450 $old_metaclass = $self->initialize(ref($instance));
453 my $meta_instance = $self->get_meta_instance();
455 $self->name->isa($old_metaclass->name)
456 || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
459 $meta_instance->rebless_instance_structure($instance, $self);
461 foreach my $attr ( $self->compute_all_applicable_attributes ) {
462 if ( $attr->has_value($instance) ) {
463 if ( defined( my $init_arg = $attr->init_arg ) ) {
464 $params{$init_arg} = $attr->get_value($instance)
465 unless exists $params{$init_arg};
468 $attr->set_value($instance, $attr->get_value($instance));
473 foreach my $attr ($self->compute_all_applicable_attributes) {
474 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
484 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
487 @{$self->get_package_symbol($var_spec)} = @supers;
489 # we need to check the metaclass
490 # compatibility here so that we can
491 # be sure that the superclass is
492 # not potentially creating an issues
493 # we don't know about
494 $self->check_metaclass_compatability();
495 $self->update_meta_instance_dependencies();
497 @{$self->get_package_symbol($var_spec)};
503 my $super_class = $self->name;
505 if ( Class::MOP::HAVE_ISAREV() ) {
506 return @{ $super_class->mro::get_isarev() };
510 my $find_derived_classes;
511 $find_derived_classes = sub {
512 my ($outer_class) = @_;
514 my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
517 for my $symbol ( keys %$symbol_table_hashref ) {
518 next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
519 my $inner_class = $1;
521 next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
525 ? "${outer_class}::$inner_class"
528 if ( $class->isa($super_class) and $class ne $super_class ) {
529 push @derived_classes, $class;
532 next SYMBOL if $class eq 'main'; # skip 'main::*'
534 $find_derived_classes->($class);
538 my $root_class = q{};
539 $find_derived_classes->($root_class);
541 undef $find_derived_classes;
543 @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
545 return @derived_classes;
551 return @{ mro::get_linear_isa( (shift)->name ) };
554 sub class_precedence_list {
556 my $name = $self->name;
558 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
560 # We need to check for circular inheritance here
561 # if we are are not on 5.10, cause 5.8 detects it
562 # late. This will do nothing if all is well, and
563 # blow up otherwise. Yes, it's an ugly hack, better
564 # suggestions are welcome.
566 ($name || return)->isa('This is a test for circular inheritance')
569 # if our mro is c3, we can
570 # just grab the linear_isa
571 if (mro::get_mro($name) eq 'c3') {
572 return @{ mro::get_linear_isa($name) }
576 # we can't grab the linear_isa for dfs
577 # since it has all the duplicates
582 $self->initialize($_)->class_precedence_list()
583 } $self->superclasses()
591 my ($self, $method_name, $method) = @_;
592 (defined $method_name && $method_name)
593 || confess "You must define a method name";
596 if (blessed($method)) {
597 $body = $method->body;
598 if ($method->package_name ne $self->name &&
599 $method->name ne $method_name) {
600 warn "Hello there, got something for you."
601 . " Method says " . $method->package_name . " " . $method->name
602 . " Class says " . $self->name . " " . $method_name;
603 $method = $method->clone(
604 package_name => $self->name,
606 ) if $method->can('clone');
611 ('CODE' eq ref($body))
612 || confess "Your code block must be a CODE reference";
613 $method = $self->method_metaclass->wrap(
615 package_name => $self->name,
621 $method->attach_to_class($self);
623 $self->get_method_map->{$method_name} = $method;
625 my $full_method_name = ($self->name . '::' . $method_name);
626 $self->add_package_symbol(
627 { sigil => '&', type => 'CODE', name => $method_name },
628 Class::MOP::subname($full_method_name => $body)
631 $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
635 my $fetch_and_prepare_method = sub {
636 my ($self, $method_name) = @_;
638 my $method = $self->get_method($method_name);
639 # if we dont have local ...
641 # try to find the next method
642 $method = $self->find_next_method_by_name($method_name);
643 # die if it does not exist
645 || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name;
646 # and now make sure to wrap it
647 # even if it is already wrapped
648 # because we need a new sub ref
649 $method = Class::MOP::Method::Wrapped->wrap($method);
652 # now make sure we wrap it properly
653 $method = Class::MOP::Method::Wrapped->wrap($method)
654 unless $method->isa('Class::MOP::Method::Wrapped');
656 $self->add_method($method_name => $method);
660 sub add_before_method_modifier {
661 my ($self, $method_name, $method_modifier) = @_;
662 (defined $method_name && $method_name)
663 || confess "You must pass in a method name";
664 my $method = $fetch_and_prepare_method->($self, $method_name);
665 $method->add_before_modifier(
666 Class::MOP::subname(':before' => $method_modifier)
670 sub add_after_method_modifier {
671 my ($self, $method_name, $method_modifier) = @_;
672 (defined $method_name && $method_name)
673 || confess "You must pass in a method name";
674 my $method = $fetch_and_prepare_method->($self, $method_name);
675 $method->add_after_modifier(
676 Class::MOP::subname(':after' => $method_modifier)
680 sub add_around_method_modifier {
681 my ($self, $method_name, $method_modifier) = @_;
682 (defined $method_name && $method_name)
683 || confess "You must pass in a method name";
684 my $method = $fetch_and_prepare_method->($self, $method_name);
685 $method->add_around_modifier(
686 Class::MOP::subname(':around' => $method_modifier)
691 # the methods above used to be named like this:
692 # ${pkg}::${method}:(before|after|around)
693 # but this proved problematic when using one modifier
694 # to wrap multiple methods (something which is likely
695 # to happen pretty regularly IMO). So instead of naming
696 # it like this, I have chosen to just name them purely
697 # with their modifier names, like so:
698 # :(before|after|around)
699 # The fact is that in a stack trace, it will be fairly
700 # evident from the context what method they are attached
701 # to, and so don't need the fully qualified name.
705 my ($self, $method_name, $method) = @_;
706 (defined $method_name && $method_name)
707 || confess "You must define a method name";
709 my $body = (blessed($method) ? $method->body : $method);
710 ('CODE' eq ref($body))
711 || confess "Your code block must be a CODE reference";
713 $self->add_package_symbol(
714 { sigil => '&', type => 'CODE', name => $method_name } => $body
719 my ($self, $method_name) = @_;
720 (defined $method_name && $method_name)
721 || confess "You must define a method name";
723 exists $self->get_method_map->{$method_name};
727 my ($self, $method_name) = @_;
728 (defined $method_name && $method_name)
729 || confess "You must define a method name";
732 # I don't really need this here, because
733 # if the method_map is missing a key it
734 # will just return undef for me now
735 # return unless $self->has_method($method_name);
737 return $self->get_method_map->{$method_name};
741 my ($self, $method_name) = @_;
742 (defined $method_name && $method_name)
743 || confess "You must define a method name";
745 my $removed_method = delete $self->get_method_map->{$method_name};
747 $self->remove_package_symbol(
748 { sigil => '&', type => 'CODE', name => $method_name }
751 $removed_method->detach_from_class if $removed_method;
753 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
755 return $removed_method;
758 sub get_method_list {
760 keys %{$self->get_method_map};
763 sub find_method_by_name {
764 my ($self, $method_name) = @_;
765 (defined $method_name && $method_name)
766 || confess "You must define a method name to find";
767 foreach my $class ($self->linearized_isa) {
768 # fetch the meta-class ...
769 my $meta = $self->initialize($class);
770 return $meta->get_method($method_name)
771 if $meta->has_method($method_name);
776 sub get_all_methods {
778 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
779 return values %methods;
783 sub compute_all_applicable_methods {
787 class => $_->package_name,
788 code => $_, # sigh, overloading
790 } shift->get_all_methods(@_);
793 sub find_all_methods_by_name {
794 my ($self, $method_name) = @_;
795 (defined $method_name && $method_name)
796 || confess "You must define a method name to find";
798 foreach my $class ($self->linearized_isa) {
799 # fetch the meta-class ...
800 my $meta = $self->initialize($class);
802 name => $method_name,
804 code => $meta->get_method($method_name)
805 } if $meta->has_method($method_name);
810 sub find_next_method_by_name {
811 my ($self, $method_name) = @_;
812 (defined $method_name && $method_name)
813 || confess "You must define a method name to find";
814 my @cpl = $self->linearized_isa;
815 shift @cpl; # discard ourselves
816 foreach my $class (@cpl) {
817 # fetch the meta-class ...
818 my $meta = $self->initialize($class);
819 return $meta->get_method($method_name)
820 if $meta->has_method($method_name);
829 # either we have an attribute object already
830 # or we need to create one from the args provided
831 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
832 # make sure it is derived from the correct type though
833 ($attribute->isa('Class::MOP::Attribute'))
834 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
836 # first we attach our new attribute
837 # because it might need certain information
838 # about the class which it is attached to
839 $attribute->attach_to_class($self);
841 # then we remove attributes of a conflicting
842 # name here so that we can properly detach
843 # the old attr object, and remove any
844 # accessors it would have generated
845 if ( $self->has_attribute($attribute->name) ) {
846 $self->remove_attribute($attribute->name);
848 $self->invalidate_meta_instances();
851 # then onto installing the new accessors
852 $self->get_attribute_map->{$attribute->name} = $attribute;
854 # invalidate package flag here
855 my $e = do { local $@; eval { $attribute->install_accessors() }; $@ };
857 $self->remove_attribute($attribute->name);
864 sub update_meta_instance_dependencies {
867 if ( $self->{meta_instance_dependencies} ) {
868 return $self->add_meta_instance_dependencies;
872 sub add_meta_instance_dependencies {
875 $self->remove_meta_instance_depdendencies;
877 my @attrs = $self->compute_all_applicable_attributes();
880 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
882 foreach my $class ( @classes ) {
883 $class->add_dependent_meta_instance($self);
886 $self->{meta_instance_dependencies} = \@classes;
889 sub remove_meta_instance_depdendencies {
892 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
893 foreach my $class ( @$classes ) {
894 $class->remove_dependent_meta_instance($self);
904 sub add_dependent_meta_instance {
905 my ( $self, $metaclass ) = @_;
906 push @{ $self->{dependent_meta_instances} }, $metaclass;
909 sub remove_dependent_meta_instance {
910 my ( $self, $metaclass ) = @_;
911 my $name = $metaclass->name;
912 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
915 sub invalidate_meta_instances {
917 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
920 sub invalidate_meta_instance {
922 undef $self->{_meta_instance};
926 my ($self, $attribute_name) = @_;
927 (defined $attribute_name && $attribute_name)
928 || confess "You must define an attribute name";
929 exists $self->get_attribute_map->{$attribute_name};
933 my ($self, $attribute_name) = @_;
934 (defined $attribute_name && $attribute_name)
935 || confess "You must define an attribute name";
936 return $self->get_attribute_map->{$attribute_name}
938 # this will return undef anyway, so no need ...
939 # if $self->has_attribute($attribute_name);
943 sub remove_attribute {
944 my ($self, $attribute_name) = @_;
945 (defined $attribute_name && $attribute_name)
946 || confess "You must define an attribute name";
947 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
948 return unless defined $removed_attribute;
949 delete $self->get_attribute_map->{$attribute_name};
950 $self->invalidate_meta_instances();
951 $removed_attribute->remove_accessors();
952 $removed_attribute->detach_from_class();
953 return $removed_attribute;
956 sub get_attribute_list {
958 keys %{$self->get_attribute_map};
961 sub get_all_attributes {
962 shift->compute_all_applicable_attributes(@_);
965 sub compute_all_applicable_attributes {
967 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
968 return values %attrs;
971 sub find_attribute_by_name {
972 my ($self, $attr_name) = @_;
973 foreach my $class ($self->linearized_isa) {
974 # fetch the meta-class ...
975 my $meta = $self->initialize($class);
976 return $meta->get_attribute($attr_name)
977 if $meta->has_attribute($attr_name);
982 # check if we can reinitialize
986 # if any local attr is defined
987 return if $self->get_attribute_list;
989 # or any non-declared methods
990 if ( my @methods = values %{ $self->get_method_map } ) {
991 my $metaclass = $self->method_metaclass;
992 foreach my $method ( @methods ) {
993 return if $method->isa("Class::MOP::Method::Generated");
994 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1003 sub is_mutable { 1 }
1004 sub is_immutable { 0 }
1007 # Why I changed this (groditi)
1008 # - One Metaclass may have many Classes through many Metaclass instances
1009 # - One Metaclass should only have one Immutable Transformer instance
1010 # - Each Class may have different Immutabilizing options
1011 # - Therefore each Metaclass instance may have different Immutabilizing options
1012 # - We need to store one Immutable Transformer instance per Metaclass
1013 # - We need to store one set of Immutable Transformer options per Class
1014 # - Upon make_mutable we may delete the Immutabilizing options
1015 # - We could clean the immutable Transformer instance when there is no more
1016 # immutable Classes of that type, but we can also keep it in case
1017 # another class with this same Metaclass becomes immutable. It is a case
1018 # of trading of storing an instance to avoid unnecessary instantiations of
1019 # Immutable Transformers. You may view this as a memory leak, however
1020 # Because we have few Metaclasses, in practice it seems acceptable
1021 # - To allow Immutable Transformers instances to be cleaned up we could weaken
1022 # the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
1026 my %IMMUTABLE_TRANSFORMERS;
1027 my %IMMUTABLE_OPTIONS;
1029 sub get_immutable_options {
1031 return if $self->is_mutable;
1032 confess "unable to find immutabilizing options"
1033 unless exists $IMMUTABLE_OPTIONS{$self->name};
1034 my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
1035 delete $options{IMMUTABLE_TRANSFORMER};
1039 sub get_immutable_transformer {
1041 if( $self->is_mutable ){
1042 my $class = ref $self || $self;
1043 return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
1045 confess "unable to find transformer for immutable class"
1046 unless exists $IMMUTABLE_OPTIONS{$self->name};
1047 return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
1050 sub make_immutable {
1054 my $transformer = $self->get_immutable_transformer;
1055 $transformer->make_metaclass_immutable($self, \%options);
1056 $IMMUTABLE_OPTIONS{$self->name} =
1057 { %options, IMMUTABLE_TRANSFORMER => $transformer };
1059 if( exists $options{debug} && $options{debug} ){
1060 print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
1061 print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
1069 return if $self->is_mutable;
1070 my $options = delete $IMMUTABLE_OPTIONS{$self->name};
1071 confess "unable to find immutabilizing options" unless ref $options;
1072 my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
1073 $transformer->make_metaclass_mutable($self, $options);
1078 sub create_immutable_transformer {
1080 my $class = Class::MOP::Immutable->new($self, {
1081 read_only => [qw/superclasses/],
1088 remove_package_symbol
1091 class_precedence_list => 'ARRAY',
1092 linearized_isa => 'ARRAY',
1093 compute_all_applicable_attributes => 'ARRAY',
1094 get_meta_instance => 'SCALAR',
1095 get_method_map => 'SCALAR',
1098 # this is ugly, but so are typeglobs,
1099 # so whattayahgonnadoboutit
1102 add_package_symbol => sub {
1103 my $original = shift;
1104 confess "Cannot add package symbols to an immutable metaclass"
1105 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
1106 goto $original->body;
1121 Class::MOP::Class - Class Meta Object
1125 # assuming that class Foo
1126 # has been defined, you can
1128 # use this for introspection ...
1130 # add a method to Foo ...
1131 Foo->meta->add_method('bar' => sub { ... })
1133 # get a list of all the classes searched
1134 # the method dispatcher in the correct order
1135 Foo->meta->class_precedence_list()
1137 # remove a method from Foo
1138 Foo->meta->remove_method('bar');
1140 # or use this to actually create classes ...
1142 Class::MOP::Class->create('Bar' => (
1144 superclasses => [ 'Foo' ],
1146 Class::MOP:::Attribute->new('$bar'),
1147 Class::MOP:::Attribute->new('$baz'),
1150 calculate_bar => sub { ... },
1151 construct_baz => sub { ... }
1157 This is the largest and currently most complex part of the Perl 5
1158 meta-object protocol. It controls the introspection and
1159 manipulation of Perl 5 classes (and it can create them too). The
1160 best way to understand what this module can do, is to read the
1161 documentation for each of it's methods.
1165 =head2 Self Introspection
1171 This will return a B<Class::MOP::Class> instance which is related
1172 to this class. Thereby allowing B<Class::MOP::Class> to actually
1175 As with B<Class::MOP::Attribute>, B<Class::MOP> will actually
1176 bootstrap this module by installing a number of attribute meta-objects
1177 into it's metaclass. This will allow this class to reap all the benifits
1178 of the MOP when subclassing it.
1182 =head2 Class construction
1184 These methods will handle creating B<Class::MOP::Class> objects,
1185 which can be used to both create new classes, and analyze
1186 pre-existing classes.
1188 This module will internally store references to all the instances
1189 you create with these methods, so that they do not need to be
1190 created any more than nessecary. Basically, they are singletons.
1194 =item B<create ($package_name,
1195 version =E<gt> ?$version,
1196 authority =E<gt> ?$authority,
1197 superclasses =E<gt> ?@superclasses,
1198 methods =E<gt> ?%methods,
1199 attributes =E<gt> ?%attributes)>
1201 This returns a B<Class::MOP::Class> object, bringing the specified
1202 C<$package_name> into existence and adding any of the C<$version>,
1203 C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
1206 =item B<create_anon_class (superclasses =E<gt> ?@superclasses,
1207 methods =E<gt> ?%methods,
1208 attributes =E<gt> ?%attributes)>
1210 This will create an anonymous class, it works much like C<create> but
1211 it does not need a C<$package_name>. Instead it will create a suitably
1212 unique package name for you to stash things into.
1214 On very important distinction is that anon classes are destroyed once
1215 the metaclass they are attached to goes out of scope. In the DESTROY
1216 method, the created package will be removed from the symbol table.
1218 It is also worth noting that any instances created with an anon-class
1219 will keep a special reference to the anon-meta which will prevent the
1220 anon-class from going out of scope until all instances of it have also
1221 been destroyed. This however only works for HASH based instance types,
1222 as we use a special reserved slot (C<__MOP__>) to store this.
1224 =item B<initialize ($package_name, %options)>
1226 This initializes and returns returns a B<Class::MOP::Class> object
1227 for a given a C<$package_name>.
1229 =item B<construct_class_instance (%options)>
1231 This will construct an instance of B<Class::MOP::Class>, it is
1232 here so that we can actually "tie the knot" for B<Class::MOP::Class>
1233 to use C<construct_instance> once all the bootstrapping is done. This
1234 method is used internally by C<initialize> and should never be called
1235 from outside of that method really.
1237 =item B<check_metaclass_compatability>
1239 This method is called as the very last thing in the
1240 C<construct_class_instance> method. This will check that the
1241 metaclass you are creating is compatible with the metaclasses of all
1242 your ancestors. For more inforamtion about metaclass compatibility
1243 see the C<About Metaclass compatibility> section in L<Class::MOP>.
1245 =item B<update_package_cache_flag>
1247 This will reset the package cache flag for this particular metaclass
1248 it is basically the value of the C<Class::MOP::get_package_cache_flag>
1249 function. This is very rarely needed from outside of C<Class::MOP::Class>
1250 but in some cases you might want to use it, so it is here.
1252 =item B<reset_package_cache_flag>
1254 Clears the package cache flag to announce to the internals that we need
1255 to rebuild the method map.
1257 =item B<add_meta_instance_dependencies>
1259 Registers this class as dependent on its superclasses.
1261 Only superclasses from which this class inherits attributes will be added.
1263 =item B<remove_meta_instance_depdendencies>
1265 Unregisters this class from its superclasses.
1267 =item B<update_meta_instance_dependencies>
1269 Reregisters if necessary.
1271 =item B<add_dependent_meta_instance> $metaclass
1273 Registers the class as having a meta instance dependent on this class.
1275 =item B<remove_dependent_meta_instance> $metaclass
1277 Remove the class from the list of dependent classes.
1279 =item B<invalidate_meta_instances>
1281 Clears the cached meta instance for this metaclass and all of the registered
1282 classes with dependent meta instances.
1284 Called by C<add_attribute> and C<remove_attribute> to recalculate the attribute
1287 =item B<invalidate_meta_instance>
1289 Used by C<invalidate_meta_instances>.
1293 =head2 Object instance construction and cloning
1295 These methods are B<entirely optional>, it is up to you whether you want
1300 =item B<instance_metaclass>
1302 Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
1303 for more information on the instance metaclasses.
1305 =item B<get_meta_instance>
1307 Returns an instance of L<Class::MOP::Instance> to be used in the construction
1308 of a new instance of the class.
1310 =item B<create_meta_instance>
1312 Called by C<get_meta_instance> if necessary.
1314 =item B<new_object (%params)>
1316 This is a convience method for creating a new object of the class, and
1317 blessing it into the appropriate package as well. Ideally your class
1318 would call a C<new> this method like so:
1321 my ($class, %param) = @_;
1322 $class->meta->new_object(%params);
1325 =item B<construct_instance (%params)>
1327 This method is used to construct an instance structure suitable for
1328 C<bless>-ing into your package of choice. It works in conjunction
1329 with the Attribute protocol to collect all applicable attributes.
1331 This will construct and instance using a HASH ref as storage
1332 (currently only HASH references are supported). This will collect all
1333 the applicable attributes and layout out the fields in the HASH ref,
1334 it will then initialize them using either use the corresponding key
1335 in C<%params> or any default value or initializer found in the
1336 attribute meta-object.
1338 =item B<clone_object ($instance, %params)>
1340 This is a convience method for cloning an object instance, then
1341 blessing it into the appropriate package. This method will call
1342 C<clone_instance>, which performs a shallow copy of the object,
1343 see that methods documentation for more details. Ideally your
1344 class would call a C<clone> this method like so:
1346 sub MyClass::clone {
1347 my ($self, %param) = @_;
1348 $self->meta->clone_object($self, %params);
1351 =item B<clone_instance($instance, %params)>
1353 This method is a compliment of C<construct_instance> (which means if
1354 you override C<construct_instance>, you need to override this one too),
1355 and clones the instance shallowly.
1357 The cloned structure returned is (like with C<construct_instance>) an
1358 unC<bless>ed HASH reference, it is your responsibility to then bless
1359 this cloned structure into the right class (which C<clone_object> will
1362 As of 0.11, this method will clone the C<$instance> structure shallowly,
1363 as opposed to the deep cloning implemented in prior versions. After much
1364 thought, research and discussion, I have decided that anything but basic
1365 shallow cloning is outside the scope of the meta-object protocol. I
1366 think Yuval "nothingmuch" Kogman put it best when he said that cloning
1367 is too I<context-specific> to be part of the MOP.
1369 =item B<rebless_instance($instance, ?%params)>
1371 This will change the class of C<$instance> to the class of the invoking
1372 C<Class::MOP::Class>. You may only rebless the instance to a subclass of
1373 itself. You may pass in optional C<%params> which are like constructor
1374 params and will override anything already defined in the instance.
1378 =head2 Informational
1380 These are a few predicate methods for asking information about the class.
1384 =item B<is_anon_class>
1386 This returns true if the class is a C<Class::MOP::Class> created anon class.
1390 This returns true if the class is still mutable.
1392 =item B<is_immutable>
1394 This returns true if the class has been made immutable.
1396 =item B<is_pristine>
1398 Checks whether the class has any data that will be lost if C<reinitialize> is
1403 =head2 Inheritance Relationships
1407 =item B<superclasses (?@superclasses)>
1409 This is a read-write attribute which represents the superclass
1410 relationships of the class the B<Class::MOP::Class> instance is
1411 associated with. Basically, it can get and set the C<@ISA> for you.
1413 =item B<class_precedence_list>
1415 This computes the a list of all the class's ancestors in the same order
1416 in which method dispatch will be done. This is similair to what
1417 B<Class::ISA::super_path> does, but we don't remove duplicate names.
1419 =item B<linearized_isa>
1421 This returns a list based on C<class_precedence_list> but with all
1426 This returns a list of subclasses for this class.
1434 =item B<get_method_map>
1436 Returns a HASH ref of name to CODE reference mapping for this class.
1438 =item B<method_metaclass>
1440 Returns the class name of the method metaclass, see L<Class::MOP::Method>
1441 for more information on the method metaclasses.
1443 =item B<add_method ($method_name, $method)>
1445 This will take a C<$method_name> and CODE reference to that
1446 C<$method> and install it into the class's package.
1449 This does absolutely nothing special to C<$method>
1450 other than use B<Sub::Name> to make sure it is tagged with the
1451 correct name, and therefore show up correctly in stack traces and
1454 =item B<alias_method ($method_name, $method)>
1456 This will take a C<$method_name> and CODE reference to that
1457 C<$method> and alias the method into the class's package.
1460 Unlike C<add_method>, this will B<not> try to name the
1461 C<$method> using B<Sub::Name>, it only aliases the method in
1462 the class's package.
1464 =item B<has_method ($method_name)>
1466 This just provides a simple way to check if the class implements
1467 a specific C<$method_name>. It will I<not> however, attempt to check
1468 if the class inherits the method (use C<UNIVERSAL::can> for that).
1470 This will correctly handle functions defined outside of the package
1471 that use a fully qualified name (C<sub Package::name { ... }>).
1473 This will correctly handle functions renamed with B<Sub::Name> and
1474 installed using the symbol tables. However, if you are naming the
1475 subroutine outside of the package scope, you must use the fully
1476 qualified name, including the package name, for C<has_method> to
1477 correctly identify it.
1479 This will attempt to correctly ignore functions imported from other
1480 packages using B<Exporter>. It breaks down if the function imported
1481 is an C<__ANON__> sub (such as with C<use constant>), which very well
1482 may be a valid method being applied to the class.
1484 In short, this method cannot always be trusted to determine if the
1485 C<$method_name> is actually a method. However, it will DWIM about
1486 90% of the time, so it's a small trade off I think.
1488 =item B<get_method ($method_name)>
1490 This will return a Class::MOP::Method instance related to the specified
1491 C<$method_name>, or return undef if that method does not exist.
1493 The Class::MOP::Method is codifiable, so you can use it like a normal
1494 CODE reference, see L<Class::MOP::Method> for more information.
1496 =item B<find_method_by_name ($method_name)>
1498 This will return a CODE reference of the specified C<$method_name>,
1499 or return undef if that method does not exist.
1501 Unlike C<get_method> this will also look in the superclasses.
1503 =item B<remove_method ($method_name)>
1505 This will attempt to remove a given C<$method_name> from the class.
1506 It will return the CODE reference that it has removed, and will
1507 attempt to use B<Sub::Name> to clear the methods associated name.
1509 =item B<get_method_list>
1511 This will return a list of method names for all I<locally> defined
1512 methods. It does B<not> provide a list of all applicable methods,
1513 including any inherited ones. If you want a list of all applicable
1514 methods, use the C<compute_all_applicable_methods> method.
1516 =item B<get_all_methods>
1518 This will traverse the inheritance heirachy and return a list of all
1519 the applicable L<Class::MOP::Method> objects for this class.
1521 =item B<compute_all_applicable_methods>
1525 This method returns a list of hashes describing the all the methods of the
1528 Use L<get_all_methods>, which is easier/better/faster. This method predates
1529 L<Class::MOP::Method>.
1531 =item B<find_all_methods_by_name ($method_name)>
1533 This will traverse the inheritence hierarchy and locate all methods
1534 with a given C<$method_name>. Similar to
1535 C<compute_all_applicable_methods> it returns a list of HASH references
1536 with the following information; method name (which will always be the
1537 same as C<$method_name>), the name of the class in which the method
1538 lives and a CODE reference for the actual method.
1540 The list of methods produced is a distinct list, meaning there are no
1541 duplicates in it. This is especially useful for things like object
1542 initialization and destruction where you only want the method called
1543 once, and in the correct order.
1545 =item B<find_next_method_by_name ($method_name)>
1547 This will return the first method to match a given C<$method_name> in
1548 the superclasses, this is basically equivalent to calling
1549 C<SUPER::$method_name>, but it can be dispatched at runtime.
1553 =head2 Method Modifiers
1555 Method modifiers are a concept borrowed from CLOS, in which a method
1556 can be wrapped with I<before>, I<after> and I<around> method modifiers
1557 that will be called everytime the method is called.
1559 =head3 How method modifiers work?
1561 Method modifiers work by wrapping the original method and then replacing
1562 it in the classes symbol table. The wrappers will handle calling all the
1563 modifiers in the appropariate orders and preserving the calling context
1564 for the original method.
1566 Each method modifier serves a particular purpose, which may not be
1567 obvious to users of other method wrapping modules. To start with, the
1568 return values of I<before> and I<after> modifiers are ignored. This is
1569 because thier purpose is B<not> to filter the input and output of the
1570 primary method (this is done with an I<around> modifier). This may seem
1571 like an odd restriction to some, but doing this allows for simple code
1572 to be added at the begining or end of a method call without jeapordizing
1573 the normal functioning of the primary method or placing any extra
1574 responsibility on the code of the modifier. Of course if you have more
1575 complex needs, then use the I<around> modifier, which uses a variation
1576 of continutation passing style to allow for a high degree of flexibility.
1578 Before and around modifiers are called in last-defined-first-called order,
1579 while after modifiers are called in first-defined-first-called order. So
1580 the call tree might looks something like this:
1590 To see examples of using method modifiers, see the following examples
1591 included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
1592 F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
1593 classic CLOS usage example in the test F<017_add_method_modifier.t>.
1595 =head3 What is the performance impact?
1597 Of course there is a performance cost associated with method modifiers,
1598 but we have made every effort to make that cost be directly proportional
1599 to the amount of modifier features you utilize.
1601 The wrapping method does it's best to B<only> do as much work as it
1602 absolutely needs to. In order to do this we have moved some of the
1603 performance costs to set-up time, where they are easier to amortize.
1605 All this said, my benchmarks have indicated the following:
1607 simple wrapper with no modifiers 100% slower
1608 simple wrapper with simple before modifier 400% slower
1609 simple wrapper with simple after modifier 450% slower
1610 simple wrapper with simple around modifier 500-550% slower
1611 simple wrapper with all 3 modifiers 1100% slower
1613 These numbers may seem daunting, but you must remember, every feature
1614 comes with some cost. To put things in perspective, just doing a simple
1615 C<AUTOLOAD> which does nothing but extract the name of the method called
1616 and return it costs about 400% over a normal method call.
1620 =item B<add_before_method_modifier ($method_name, $code)>
1622 This will wrap the method at C<$method_name> and the supplied C<$code>
1623 will be passed the C<@_> arguments, and called before the original
1624 method is called. As specified above, the return value of the I<before>
1625 method modifiers is ignored, and it's ability to modify C<@_> is
1626 fairly limited. If you need to do either of these things, use an
1627 C<around> method modifier.
1629 =item B<add_after_method_modifier ($method_name, $code)>
1631 This will wrap the method at C<$method_name> so that the original
1632 method will be called, it's return values stashed, and then the
1633 supplied C<$code> will be passed the C<@_> arguments, and called.
1634 As specified above, the return value of the I<after> method
1635 modifiers is ignored, and it cannot modify the return values of
1636 the original method. If you need to do either of these things, use an
1637 C<around> method modifier.
1639 =item B<add_around_method_modifier ($method_name, $code)>
1641 This will wrap the method at C<$method_name> so that C<$code>
1642 will be called and passed the original method as an extra argument
1643 at the begining of the C<@_> argument list. This is a variation of
1644 continuation passing style, where the function prepended to C<@_>
1645 can be considered a continuation. It is up to C<$code> if it calls
1646 the original method or not, there is no restriction on what the
1647 C<$code> can or cannot do.
1653 It should be noted that since there is no one consistent way to define
1654 the attributes of a class in Perl 5. These methods can only work with
1655 the information given, and can not easily discover information on
1656 their own. See L<Class::MOP::Attribute> for more details.
1660 =item B<attribute_metaclass>
1662 Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
1663 for more information on the attribute metaclasses.
1665 =item B<get_attribute_map>
1667 This returns a HASH ref of name to attribute meta-object mapping.
1669 =item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
1671 This stores the C<$attribute_meta_object> (or creates one from the
1672 C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
1673 instance associated with the given class. Unlike methods, attributes
1674 within the MOP are stored as meta-information only. They will be used
1675 later to construct instances from (see C<construct_instance> above).
1676 More details about the attribute meta-objects can be found in the
1677 L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
1680 It should be noted that any accessor, reader/writer or predicate
1681 methods which the C<$attribute_meta_object> has will be installed
1682 into the class at this time.
1685 If an attribute already exists for C<$attribute_name>, the old one
1686 will be removed (as well as removing all it's accessors), and then
1689 =item B<has_attribute ($attribute_name)>
1691 Checks to see if this class has an attribute by the name of
1692 C<$attribute_name> and returns a boolean.
1694 =item B<get_attribute ($attribute_name)>
1696 Returns the attribute meta-object associated with C<$attribute_name>,
1697 if none is found, it will return undef.
1699 =item B<remove_attribute ($attribute_name)>
1701 This will remove the attribute meta-object stored at
1702 C<$attribute_name>, then return the removed attribute meta-object.
1705 Removing an attribute will only affect future instances of
1706 the class, it will not make any attempt to remove the attribute from
1707 any existing instances of the class.
1709 It should be noted that any accessor, reader/writer or predicate
1710 methods which the attribute meta-object stored at C<$attribute_name>
1711 has will be removed from the class at this time. This B<will> make
1712 these attributes somewhat inaccessable in previously created
1713 instances. But if you are crazy enough to do this at runtime, then
1714 you are crazy enough to deal with something like this :).
1716 =item B<get_attribute_list>
1718 This returns a list of attribute names which are defined in the local
1719 class. If you want a list of all applicable attributes for a class,
1720 use the C<compute_all_applicable_attributes> method.
1722 =item B<compute_all_applicable_attributes>
1724 =item B<get_all_attributes>
1726 This will traverse the inheritance heirachy and return a list of all
1727 the applicable L<Class::MOP::Attribute> objects for this class.
1729 C<get_all_attributes> is an alias for consistency with C<get_all_methods>.
1731 =item B<find_attribute_by_name ($attr_name)>
1733 This method will traverse the inheritance heirachy and find the
1734 first attribute whose name matches C<$attr_name>, then return it.
1735 It will return undef if nothing is found.
1739 =head2 Class Immutability
1743 =item B<make_immutable (%options)>
1745 This method will invoke a tranforamtion upon the class which will
1746 make it immutable. Details of this transformation can be found in
1747 the L<Class::MOP::Immutable> documentation.
1749 =item B<make_mutable>
1751 This method will reverse tranforamtion upon the class which
1754 =item B<get_immutable_transformer>
1756 Return a transformer suitable for making this class immutable or, if this
1757 class is immutable, the transformer used to make it immutable.
1759 =item B<get_immutable_options>
1761 If the class is immutable, return the options used to make it immutable.
1763 =item B<create_immutable_transformer>
1765 Create a transformer suitable for making this class immutable
1771 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1773 =head1 COPYRIGHT AND LICENSE
1775 Copyright 2006-2008 by Infinity Interactive, Inc.
1777 L<http://www.iinteractive.com>
1779 This library is free software; you can redistribute it and/or modify
1780 it under the same terms as Perl itself.