X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FMOP%2FClass.pm;h=8678844af9f6aec808a759a64787ee0fb5e70d87;hb=53edec17bae8aa34a398b0bd50dcd7e78e03b733;hp=ccfc2cfcbb77832ee5d3bb3e136adbbc3bb221f9;hpb=6b5ac420e48ce3b29d9fe53094954821508b2925;p=gitmo%2FClass-MOP.git diff --git a/lib/Class/MOP/Class.pm b/lib/Class/MOP/Class.pm index ccfc2cf..8678844 100644 --- a/lib/Class/MOP/Class.pm +++ b/lib/Class/MOP/Class.pm @@ -4,14 +4,18 @@ package Class::MOP::Class; use strict; use warnings; -use Class::MOP::Immutable; use Class::MOP::Instance; use Class::MOP::Method::Wrapped; +use Class::MOP::Method::Accessor; +use Class::MOP::Method::Constructor; use Carp 'confess'; -use Scalar::Util 'blessed', 'weaken'; +use Scalar::Util 'blessed', 'reftype', 'weaken'; +use Sub::Name 'subname'; +use Devel::GlobalDestruction 'in_global_destruction'; +use Try::Tiny; -our $VERSION = '0.71_02'; +our $VERSION = '0.95'; $VERSION = eval $VERSION; our $AUTHORITY = 'cpan:STEVAN'; @@ -31,20 +35,20 @@ sub initialize { $package_name = $options{package}; } - (defined $package_name && $package_name && !ref($package_name)) + ($package_name && !ref($package_name)) || confess "You must pass a package name and it cannot be blessed"; return Class::MOP::get_metaclass_by_name($package_name) - || $class->construct_class_instance(package => $package_name, @_); + || $class->_construct_class_instance(package => $package_name, @_); } # NOTE: (meta-circularity) -# this is a special form of &construct_instance +# this is a special form of _construct_instance # (see below), which is used to construct class # meta-object instances for any Class::MOP::* # class. All other classes will use the more # normal &construct_instance. -sub construct_class_instance { +sub _construct_class_instance { my $class = shift; my $options = @_ == 1 ? $_[0] : {@_}; my $package_name = $options->{package}; @@ -66,26 +70,25 @@ sub construct_class_instance { # get the name of the class appropriately $class = (ref($class) ? ($class->is_immutable - ? $class->get_mutable_metaclass_name() + ? $class->_get_mutable_metaclass_name() : ref($class)) : $class); # now create the metaclass my $meta; if ($class eq 'Class::MOP::Class') { - no strict 'refs'; - $meta = $class->_new($options) + $meta = $class->_new($options); } else { # NOTE: # it is safe to use meta here because # class will always be a subclass of # Class::MOP::Class, which defines meta - $meta = $class->meta->construct_instance($options) + $meta = $class->meta->_construct_instance($options) } # and check the metaclass compatibility - $meta->check_metaclass_compatibility(); + $meta->_check_metaclass_compatibility(); Class::MOP::store_metaclass_by_name($package_name, $meta); @@ -99,11 +102,15 @@ sub construct_class_instance { sub _new { my $class = shift; + + return Class::MOP::Class->initialize($class)->new_object(@_) + if $class ne __PACKAGE__; + my $options = @_ == 1 ? $_[0] : {@_}; - bless { + return bless { # inherited from Class::MOP::Package - 'package' => $options->{package}, + 'package' => $options->{package}, # NOTE: # since the following attributes will @@ -113,18 +120,36 @@ sub _new { # listed here for reference, because they # should not actually have a value associated # with the slot. - 'namespace' => \undef, + 'namespace' => \undef, + 'methods' => {}, + # inherited from Class::MOP::Module - 'version' => \undef, - 'authority' => \undef, - # defined in Class::MOP::Class - 'superclasses' => \undef, + 'version' => \undef, + 'authority' => \undef, - 'methods' => {}, - 'attributes' => {}, - 'attribute_metaclass' => $options->{'attribute_metaclass'} || 'Class::MOP::Attribute', - 'method_metaclass' => $options->{'method_metaclass'} || 'Class::MOP::Method', - 'instance_metaclass' => $options->{'instance_metaclass'} || 'Class::MOP::Instance', + # defined in Class::MOP::Class + 'superclasses' => \undef, + + 'attributes' => {}, + 'attribute_metaclass' => + ( $options->{'attribute_metaclass'} || 'Class::MOP::Attribute' ), + 'method_metaclass' => + ( $options->{'method_metaclass'} || 'Class::MOP::Method' ), + 'wrapped_method_metaclass' => ( + $options->{'wrapped_method_metaclass'} + || 'Class::MOP::Method::Wrapped' + ), + 'instance_metaclass' => + ( $options->{'instance_metaclass'} || 'Class::MOP::Instance' ), + 'immutable_trait' => ( + $options->{'immutable_trait'} + || 'Class::MOP::Class::Immutable::Trait' + ), + 'constructor_name' => ( $options->{constructor_name} || 'new' ), + 'constructor_class' => ( + $options->{constructor_class} || 'Class::MOP::Method::Constructor' + ), + 'destructor_class' => $options->{destructor_class}, }, $class; } @@ -140,7 +165,7 @@ sub update_package_cache_flag { $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name); } -sub check_metaclass_compatibility { +sub _check_metaclass_compatibility { my $self = shift; # this is always okay ... @@ -150,37 +175,33 @@ sub check_metaclass_compatibility { my @class_list = $self->linearized_isa; shift @class_list; # shift off $self->name - foreach my $class_name (@class_list) { - my $meta = Class::MOP::get_metaclass_by_name($class_name) || next; + foreach my $superclass_name (@class_list) { + my $super_meta = Class::MOP::get_metaclass_by_name($superclass_name) || next; # NOTE: # we need to deal with the possibility # of class immutability here, and then # get the name of the class appropriately - my $meta_type = ($meta->is_immutable - ? $meta->get_mutable_metaclass_name() - : ref($meta)); - - ($self->isa($meta_type)) - || confess $self->name . "->meta => (" . (ref($self)) . ")" . - " is not compatible with the " . - $class_name . "->meta => (" . ($meta_type) . ")"; + my $super_meta_type + = $super_meta->is_immutable + ? $super_meta->_get_mutable_metaclass_name() + : ref($super_meta); + + ($self->isa($super_meta_type)) + || confess "The metaclass of " . $self->name . " (" + . (ref($self)) . ")" . " is not compatible with the " . + "metaclass of its superclass, ".$superclass_name . " (" + . ($super_meta_type) . ")"; # NOTE: # we also need to check that instance metaclasses # are compatibile in the same the class. - ($self->instance_metaclass->isa($meta->instance_metaclass)) - || confess $self->name . "->meta->instance_metaclass => (" . ($self->instance_metaclass) . ")" . + ($self->instance_metaclass->isa($super_meta->instance_metaclass)) + || confess "The instance metaclass for " . $self->name . " (" . ($self->instance_metaclass) . ")" . " is not compatible with the " . - $class_name . "->meta->instance_metaclass => (" . ($meta->instance_metaclass) . ")"; + "instance metaclass of its superclass, " . $superclass_name . " (" . ($super_meta->instance_metaclass) . ")"; } } -# backwards compat for stevan's inability to spell ;) -sub check_metaclass_compatability { - my $self = shift; - $self->check_metaclass_compatibility(@_); -} - ## ANON classes { @@ -200,7 +221,7 @@ sub check_metaclass_compatability { sub is_anon_class { my $self = shift; no warnings 'uninitialized'; - $self->name =~ /^$ANON_CLASS_PREFIX/; + $self->name =~ /^$ANON_CLASS_PREFIX/o; } sub create_anon_class { @@ -218,24 +239,26 @@ sub check_metaclass_compatability { sub DESTROY { my $self = shift; - return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated + return if in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated no warnings 'uninitialized'; - return unless $self->name =~ /^$ANON_CLASS_PREFIX/; + my $name = $self->name; + return unless $name =~ /^$ANON_CLASS_PREFIX/o; # Moose does a weird thing where it replaces the metaclass for # class when fixing metaclass incompatibility. In that case, # we don't want to clean out the namespace now. We can detect # that because Moose will explicitly update the singleton # cache in Class::MOP. - my $current_meta = Class::MOP::get_metaclass_by_name($self->name); + my $current_meta = Class::MOP::get_metaclass_by_name($name); return if $current_meta ne $self; - my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/); + my ($serial_id) = ($name =~ /^$ANON_CLASS_PREFIX(\d+)/o); no strict 'refs'; - foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) { - delete ${$ANON_CLASS_PREFIX . $serial_id}{$key}; - } - delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'}; + @{$name . '::ISA'} = (); + %{$name . '::'} = (); + delete ${$ANON_CLASS_PREFIX}{$serial_id . '::'}; + + Class::MOP::remove_metaclass_by_name($name); } } @@ -262,8 +285,6 @@ sub create { || confess "You must pass a HASH ref of methods" if exists $options{methods}; - $class->SUPER::create(%options); - my (%initialize_options) = @args; delete @initialize_options{qw( package @@ -275,6 +296,8 @@ sub create { )}; my $meta = $class->initialize( $package_name => %initialize_options ); + $meta->_instantiate_module( $options{version}, $options{authority} ); + # FIXME totally lame $meta->add_method('meta' => sub { $class->initialize(ref($_[0]) || $_[0]); @@ -306,61 +329,13 @@ sub create { # all these attribute readers will be bootstrapped # away in the Class::MOP bootstrap section -sub get_attribute_map { $_[0]->{'attributes'} } -sub attribute_metaclass { $_[0]->{'attribute_metaclass'} } -sub method_metaclass { $_[0]->{'method_metaclass'} } -sub instance_metaclass { $_[0]->{'instance_metaclass'} } - -sub get_method_map { - my $self = shift; - - my $class_name = $self->name; - - my $current = Class::MOP::check_package_cache_flag($class_name); - - if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) { - return $self->{'methods'} ||= {}; - } - - $self->{_package_cache_flag} = $current; - - my $map = $self->{'methods'} ||= {}; - - my $method_metaclass = $self->method_metaclass; - - my $all_code = $self->get_all_package_symbols('CODE'); - - foreach my $symbol (keys %{ $all_code }) { - my $code = $all_code->{$symbol}; - - next if exists $map->{$symbol} && - defined $map->{$symbol} && - $map->{$symbol}->body == $code; - - my ($pkg, $name) = Class::MOP::get_code_info($code); - - # NOTE: - # in 5.10 constant.pm the constants show up - # as being in the right package, but in pre-5.10 - # they show up as constant::__ANON__ so we - # make an exception here to be sure that things - # work as expected in both. - # - SL - unless ($pkg eq 'constant' && $name eq '__ANON__') { - next if ($pkg || '') ne $class_name || - (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name); - } - - $map->{$symbol} = $method_metaclass->wrap( - $code, - associated_metaclass => $self, - package_name => $class_name, - name => $symbol, - ); - } - - return $map; -} +sub _attribute_map { $_[0]->{'attributes'} } +sub attribute_metaclass { $_[0]->{'attribute_metaclass'} } +sub instance_metaclass { $_[0]->{'instance_metaclass'} } +sub immutable_trait { $_[0]->{'immutable_trait'} } +sub constructor_class { $_[0]->{'constructor_class'} } +sub constructor_name { $_[0]->{'constructor_name'} } +sub destructor_class { $_[0]->{'destructor_class'} } # Instance Construction & Cloning @@ -372,23 +347,27 @@ sub new_object { # Class::MOP::Class singletons here, so we # delegate this to &construct_class_instance # which will deal with the singletons - return $class->construct_class_instance(@_) + return $class->_construct_class_instance(@_) if $class->name->isa('Class::MOP::Class'); - return $class->construct_instance(@_); + return $class->_construct_instance(@_); } -sub construct_instance { +sub _construct_instance { my $class = shift; my $params = @_ == 1 ? $_[0] : {@_}; my $meta_instance = $class->get_meta_instance(); - my $instance = $meta_instance->create_instance(); - foreach my $attr ($class->compute_all_applicable_attributes()) { + # FIXME: + # the code below is almost certainly incorrect + # but this is foreign inheritance, so we might + # have to kludge it in the end. + my $instance = $params->{__INSTANCE__} || $meta_instance->create_instance(); + foreach my $attr ($class->get_all_attributes()) { $attr->initialize_instance_slot($meta_instance, $instance, $params); } # NOTE: # this will only work for a HASH instance type if ($class->is_anon_class) { - (Scalar::Util::reftype($instance) eq 'HASH') + (reftype($instance) eq 'HASH') || confess "Currently only HASH based instances are supported with instance of anon-classes"; # NOTE: # At some point we should make this official @@ -403,15 +382,15 @@ sub construct_instance { sub get_meta_instance { my $self = shift; - $self->{'_meta_instance'} ||= $self->create_meta_instance(); + $self->{'_meta_instance'} ||= $self->_create_meta_instance(); } -sub create_meta_instance { +sub _create_meta_instance { my $self = shift; my $instance = $self->instance_metaclass->new( associated_metaclass => $self, - attributes => [ $self->compute_all_applicable_attributes() ], + attributes => [ $self->get_all_attributes() ], ); $self->add_meta_instance_dependencies() @@ -431,16 +410,16 @@ sub clone_object { # Class::MOP::Class singletons here, they # should not be cloned. return $instance if $instance->isa('Class::MOP::Class'); - $class->clone_instance($instance, @_); + $class->_clone_instance($instance, @_); } -sub clone_instance { +sub _clone_instance { my ($class, $instance, %params) = @_; (blessed($instance)) || confess "You can only clone instances, ($instance) is not a blessed instance"; my $meta_instance = $class->get_meta_instance(); my $clone = $meta_instance->clone_instance($instance); - foreach my $attr ($class->compute_all_applicable_attributes()) { + foreach my $attr ($class->get_all_attributes()) { if ( defined( my $init_arg = $attr->init_arg ) ) { if (exists $params{$init_arg}) { $attr->set_value($clone, $params{$init_arg}); @@ -453,25 +432,22 @@ sub clone_instance { sub rebless_instance { my ($self, $instance, %params) = @_; - my $old_metaclass; - if ($instance->can('meta')) { - ($instance->meta->isa('Class::MOP::Class')) - || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class'; - $old_metaclass = $instance->meta; - } - else { - $old_metaclass = $self->initialize(ref($instance)); - } + my $old_metaclass = Class::MOP::class_of($instance); - my $meta_instance = $self->get_meta_instance(); + my $old_class = $old_metaclass ? $old_metaclass->name : blessed($instance); + $self->name->isa($old_class) + || confess "You may rebless only into a subclass of ($old_class), of which (". $self->name .") isn't."; + + $old_metaclass->rebless_instance_away($instance, $self, %params) + if $old_metaclass; - $self->name->isa($old_metaclass->name) - || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't."; + my $meta_instance = $self->get_meta_instance(); # rebless! - $meta_instance->rebless_instance_structure($instance, $self); + # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8 + $meta_instance->rebless_instance_structure($_[1], $self); - foreach my $attr ( $self->compute_all_applicable_attributes ) { + foreach my $attr ( $self->get_all_attributes ) { if ( $attr->has_value($instance) ) { if ( defined( my $init_arg = $attr->init_arg ) ) { $params{$init_arg} = $attr->get_value($instance) @@ -483,13 +459,17 @@ sub rebless_instance { } } - foreach my $attr ($self->compute_all_applicable_attributes) { + foreach my $attr ($self->get_all_attributes) { $attr->initialize_instance_slot($meta_instance, $instance, \%params); } $instance; } +sub rebless_instance_away { + # this intentionally does nothing, it is just a hook +} + # Inheritance sub superclasses { @@ -513,62 +493,35 @@ sub superclasses { # not potentially creating an issues # we don't know about - $self->check_metaclass_compatibility(); - $self->update_meta_instance_dependencies(); + $self->_check_metaclass_compatibility(); + $self->_superclasses_updated(); } @{$self->get_package_symbol($var_spec)}; } -sub subclasses { +sub _superclasses_updated { my $self = shift; + $self->update_meta_instance_dependencies(); +} +sub subclasses { + my $self = shift; my $super_class = $self->name; - if ( Class::MOP::HAVE_ISAREV() ) { - return @{ $super_class->mro::get_isarev() }; - } else { - my @derived_classes; - - my $find_derived_classes; - $find_derived_classes = sub { - my ($outer_class) = @_; - - my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} }; - - SYMBOL: - for my $symbol ( keys %$symbol_table_hashref ) { - next SYMBOL if $symbol !~ /\A (\w+):: \z/x; - my $inner_class = $1; - - next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER' - - my $class = - $outer_class - ? "${outer_class}::$inner_class" - : $inner_class; - - if ( $class->isa($super_class) and $class ne $super_class ) { - push @derived_classes, $class; - } - - next SYMBOL if $class eq 'main'; # skip 'main::*' - - $find_derived_classes->($class); - } - }; - - my $root_class = q{}; - $find_derived_classes->($root_class); - - undef $find_derived_classes; + return @{ $super_class->mro::get_isarev() }; +} - @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes; +sub direct_subclasses { + my $self = shift; + my $super_class = $self->name; - return @derived_classes; - } + return grep { + grep { + $_ eq $super_class + } Class::MOP::Class->initialize($_)->superclasses + } $self->subclasses; } - sub linearized_isa { return @{ mro::get_linear_isa( (shift)->name ) }; } @@ -609,55 +562,10 @@ sub class_precedence_list { ## Methods -sub wrap_method_body { - my ( $self, %args ) = @_; - - ('CODE' eq ref $args{body}) - || confess "Your code block must be a CODE reference"; - - $self->method_metaclass->wrap( - package_name => $self->name, - %args, - ); -} - -sub add_method { - my ($self, $method_name, $method) = @_; - (defined $method_name && $method_name) - || confess "You must define a method name"; - - my $body; - if (blessed($method)) { - $body = $method->body; - if ($method->package_name ne $self->name) { - $method = $method->clone( - package_name => $self->name, - name => $method_name - ) if $method->can('clone'); - } - } - else { - $body = $method; - $method = $self->wrap_method_body( body => $body, name => $method_name ); - } - - $method->attach_to_class($self); - - # This used to call get_method_map, which meant we would build all - # the method objects for the class just because we added one - # method. This is hackier, but quicker too. - $self->{methods}{$method_name} = $method; - - my $full_method_name = ($self->name . '::' . $method_name); - $self->add_package_symbol( - { sigil => '&', type => 'CODE', name => $method_name }, - Class::MOP::subname($full_method_name => $body) - ); -} - { my $fetch_and_prepare_method = sub { my ($self, $method_name) = @_; + my $wrapped_metaclass = $self->wrapped_method_metaclass; # fetch it locally my $method = $self->get_method($method_name); # if we dont have local ... @@ -666,16 +574,21 @@ sub add_method { $method = $self->find_next_method_by_name($method_name); # die if it does not exist (defined $method) - || confess "The method '$method_name' is not found in the inheritance hierarchy for class " . $self->name; + || confess "The method '$method_name' was not found in the inheritance hierarchy for " . $self->name; # and now make sure to wrap it # even if it is already wrapped # because we need a new sub ref - $method = Class::MOP::Method::Wrapped->wrap($method); + $method = $wrapped_metaclass->wrap($method, + package_name => $self->name, + name => $method_name, + ); } else { # now make sure we wrap it properly - $method = Class::MOP::Method::Wrapped->wrap($method) - unless $method->isa('Class::MOP::Method::Wrapped'); + $method = $wrapped_metaclass->wrap($method, + package_name => $self->name, + name => $method_name, + ) unless $method->isa($wrapped_metaclass); } $self->add_method($method_name => $method); return $method; @@ -683,31 +596,31 @@ sub add_method { sub add_before_method_modifier { my ($self, $method_name, $method_modifier) = @_; - (defined $method_name && $method_name) + (defined $method_name && length $method_name) || confess "You must pass in a method name"; my $method = $fetch_and_prepare_method->($self, $method_name); $method->add_before_modifier( - Class::MOP::subname(':before' => $method_modifier) + subname(':before' => $method_modifier) ); } sub add_after_method_modifier { my ($self, $method_name, $method_modifier) = @_; - (defined $method_name && $method_name) + (defined $method_name && length $method_name) || confess "You must pass in a method name"; my $method = $fetch_and_prepare_method->($self, $method_name); $method->add_after_modifier( - Class::MOP::subname(':after' => $method_modifier) + subname(':after' => $method_modifier) ); } sub add_around_method_modifier { my ($self, $method_name, $method_modifier) = @_; - (defined $method_name && $method_name) + (defined $method_name && length $method_name) || confess "You must pass in a method name"; my $method = $fetch_and_prepare_method->($self, $method_name); $method->add_around_modifier( - Class::MOP::subname(':around' => $method_modifier) + subname(':around' => $method_modifier) ); } @@ -725,90 +638,40 @@ sub add_method { # to, and so don't need the fully qualified name. } -sub alias_method { - my $self = shift; - - $self->add_method(@_); -} - -sub has_method { - my ($self, $method_name) = @_; - (defined $method_name && $method_name) - || confess "You must define a method name"; - - exists $self->{methods}{$method_name} || exists $self->get_method_map->{$method_name}; -} - -sub get_method { - my ($self, $method_name) = @_; - (defined $method_name && $method_name) - || confess "You must define a method name"; - - # NOTE: - # I don't really need this here, because - # if the method_map is missing a key it - # will just return undef for me now - # return unless $self->has_method($method_name); - - return $self->{methods}{$method_name} || $self->get_method_map->{$method_name}; -} - -sub remove_method { - my ($self, $method_name) = @_; - (defined $method_name && $method_name) - || confess "You must define a method name"; - - my $removed_method = delete $self->get_method_map->{$method_name}; - - $self->remove_package_symbol( - { sigil => '&', type => 'CODE', name => $method_name } - ); - - $removed_method->detach_from_class if $removed_method; - - $self->update_package_cache_flag; # still valid, since we just removed the method from the map - - return $removed_method; -} - -sub get_method_list { - my $self = shift; - keys %{$self->get_method_map}; -} - sub find_method_by_name { my ($self, $method_name) = @_; - (defined $method_name && $method_name) + (defined $method_name && length $method_name) || confess "You must define a method name to find"; foreach my $class ($self->linearized_isa) { - # fetch the meta-class ... - my $meta = $self->initialize($class); - return $meta->get_method($method_name) - if $meta->has_method($method_name); + my $method = $self->initialize($class)->get_method($method_name); + return $method if defined $method; } return; } sub get_all_methods { my $self = shift; - my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa; + + my %methods; + for my $class ( reverse $self->linearized_isa ) { + my $meta = $self->initialize($class); + + $methods{$_} = $meta->get_method($_) + for $meta->get_method_list; + } + return values %methods; } -# compatibility -sub compute_all_applicable_methods { - return map { - { - name => $_->name, - class => $_->package_name, - code => $_, # sigh, overloading - }, - } shift->get_all_methods(@_); +sub get_all_method_names { + my $self = shift; + my %uniq; + return grep { !$uniq{$_}++ } map { $self->initialize($_)->get_method_list } $self->linearized_isa; } sub find_all_methods_by_name { my ($self, $method_name) = @_; - (defined $method_name && $method_name) + (defined $method_name && length $method_name) || confess "You must define a method name to find"; my @methods; foreach my $class ($self->linearized_isa) { @@ -825,15 +688,13 @@ sub find_all_methods_by_name { sub find_next_method_by_name { my ($self, $method_name) = @_; - (defined $method_name && $method_name) + (defined $method_name && length $method_name) || confess "You must define a method name to find"; my @cpl = $self->linearized_isa; shift @cpl; # discard ourselves foreach my $class (@cpl) { - # fetch the meta-class ... - my $meta = $self->initialize($class); - return $meta->get_method($method_name) - if $meta->has_method($method_name); + my $method = $self->initialize($class)->get_method($method_name); + return $method if defined $method; } return; } @@ -854,25 +715,35 @@ sub add_attribute { # about the class which it is attached to $attribute->attach_to_class($self); + my $attr_name = $attribute->name; + # then we remove attributes of a conflicting # name here so that we can properly detach # the old attr object, and remove any # accessors it would have generated - if ( $self->has_attribute($attribute->name) ) { - $self->remove_attribute($attribute->name); + if ( $self->has_attribute($attr_name) ) { + $self->remove_attribute($attr_name); } else { $self->invalidate_meta_instances(); } + + # get our count of previously inserted attributes and + # increment by one so this attribute knows its order + my $order = (scalar keys %{$self->_attribute_map}); + $attribute->_set_insertion_order($order); # then onto installing the new accessors - $self->get_attribute_map->{$attribute->name} = $attribute; + $self->_attribute_map->{$attr_name} = $attribute; # invalidate package flag here - my $e = do { local $@; eval { $attribute->install_accessors() }; $@ }; - if ( $e ) { - $self->remove_attribute($attribute->name); - die $e; + try { + local $SIG{__DIE__}; + $attribute->install_accessors(); } + catch { + $self->remove_attribute($attr_name); + die $_; + }; return $attribute; } @@ -888,9 +759,9 @@ sub update_meta_instance_dependencies { sub add_meta_instance_dependencies { my $self = shift; - $self->remove_meta_instance_depdendencies; + $self->remove_meta_instance_dependencies; - my @attrs = $self->compute_all_applicable_attributes(); + my @attrs = $self->get_all_attributes(); my %seen; my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs; @@ -902,7 +773,7 @@ sub add_meta_instance_dependencies { $self->{meta_instance_dependencies} = \@classes; } -sub remove_meta_instance_depdendencies { +sub remove_meta_instance_dependencies { my $self = shift; if ( my $classes = delete $self->{meta_instance_dependencies} ) { @@ -940,16 +811,16 @@ sub invalidate_meta_instance { sub has_attribute { my ($self, $attribute_name) = @_; - (defined $attribute_name && $attribute_name) + (defined $attribute_name) || confess "You must define an attribute name"; - exists $self->get_attribute_map->{$attribute_name}; + exists $self->_attribute_map->{$attribute_name}; } sub get_attribute { my ($self, $attribute_name) = @_; - (defined $attribute_name && $attribute_name) + (defined $attribute_name) || confess "You must define an attribute name"; - return $self->get_attribute_map->{$attribute_name} + return $self->_attribute_map->{$attribute_name} # NOTE: # this will return undef anyway, so no need ... # if $self->has_attribute($attribute_name); @@ -958,11 +829,11 @@ sub get_attribute { sub remove_attribute { my ($self, $attribute_name) = @_; - (defined $attribute_name && $attribute_name) + (defined $attribute_name) || confess "You must define an attribute name"; - my $removed_attribute = $self->get_attribute_map->{$attribute_name}; + my $removed_attribute = $self->_attribute_map->{$attribute_name}; return unless defined $removed_attribute; - delete $self->get_attribute_map->{$attribute_name}; + delete $self->_attribute_map->{$attribute_name}; $self->invalidate_meta_instances(); $removed_attribute->remove_accessors(); $removed_attribute->detach_from_class(); @@ -971,16 +842,12 @@ sub remove_attribute { sub get_attribute_list { my $self = shift; - keys %{$self->get_attribute_map}; + keys %{$self->_attribute_map}; } sub get_all_attributes { - shift->compute_all_applicable_attributes(@_); -} - -sub compute_all_applicable_attributes { my $self = shift; - my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa; + my %attrs = map { %{ $self->initialize($_)->_attribute_map } } reverse $self->linearized_isa; return values %attrs; } @@ -1003,12 +870,9 @@ sub is_pristine { return if $self->get_attribute_list; # or any non-declared methods - if ( my @methods = values %{ $self->get_method_map } ) { - my $metaclass = $self->method_metaclass; - foreach my $method ( @methods ) { - return if $method->isa("Class::MOP::Method::Generated"); - # FIXME do we need to enforce this too? return unless $method->isa($metaclass); - } + for my $method ( map { $self->get_method($_) } $self->get_method_list ) { + return if $method->isa("Class::MOP::Method::Generated"); + # FIXME do we need to enforce this too? return unless $method->isa( $self->method_metaclass ); } return 1; @@ -1019,118 +883,234 @@ sub is_pristine { sub is_mutable { 1 } sub is_immutable { 0 } -# NOTE: -# Why I changed this (groditi) -# - One Metaclass may have many Classes through many Metaclass instances -# - One Metaclass should only have one Immutable Transformer instance -# - Each Class may have different Immutabilizing options -# - Therefore each Metaclass instance may have different Immutabilizing options -# - We need to store one Immutable Transformer instance per Metaclass -# - We need to store one set of Immutable Transformer options per Class -# - Upon make_mutable we may delete the Immutabilizing options -# - We could clean the immutable Transformer instance when there is no more -# immutable Classes of that type, but we can also keep it in case -# another class with this same Metaclass becomes immutable. It is a case -# of trading of storing an instance to avoid unnecessary instantiations of -# Immutable Transformers. You may view this as a memory leak, however -# Because we have few Metaclasses, in practice it seems acceptable -# - To allow Immutable Transformers instances to be cleaned up we could weaken -# the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM +sub immutable_options { %{ $_[0]{__immutable}{options} || {} } } + +sub _immutable_options { + my ( $self, @args ) = @_; + + return ( + inline_accessors => 1, + inline_constructor => 1, + inline_destructor => 0, + debug => 0, + immutable_trait => $self->immutable_trait, + constructor_name => $self->constructor_name, + constructor_class => $self->constructor_class, + destructor_class => $self->destructor_class, + @args, + ); +} -{ +sub make_immutable { + my ( $self, @args ) = @_; + + if ( $self->is_mutable ) { + $self->_initialize_immutable( $self->_immutable_options(@args) ); + $self->_rebless_as_immutable(@args); + return $self; + } + else { + return; + } +} - my %IMMUTABLE_TRANSFORMERS; - my %IMMUTABLE_OPTIONS; +sub make_mutable { + my $self = shift; - sub get_immutable_options { - my $self = shift; - return if $self->is_mutable; - confess "unable to find immutabilizing options" - unless exists $IMMUTABLE_OPTIONS{$self->name}; - my %options = %{$IMMUTABLE_OPTIONS{$self->name}}; - delete $options{IMMUTABLE_TRANSFORMER}; - return \%options; + if ( $self->is_immutable ) { + my @args = $self->immutable_options; + $self->_rebless_as_mutable(); + $self->_remove_inlined_code(@args); + delete $self->{__immutable}; + return $self; + } + else { + return; } +} - sub get_immutable_transformer { - my $self = shift; - if( $self->is_mutable ){ - my $class = ref $self || $self; - return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer; - } - confess "unable to find transformer for immutable class" - unless exists $IMMUTABLE_OPTIONS{$self->name}; - return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER}; +sub _rebless_as_immutable { + my ( $self, @args ) = @_; + + $self->{__immutable}{original_class} = ref $self; + + bless $self => $self->_immutable_metaclass(@args); +} + +sub _immutable_metaclass { + my ( $self, %args ) = @_; + + if ( my $class = $args{immutable_metaclass} ) { + return $class; } - sub make_immutable { - my $self = shift; - my %options = @_; + my $trait = $args{immutable_trait} = $self->immutable_trait + || confess "no immutable trait specified for $self"; - my $transformer = $self->get_immutable_transformer; - $transformer->make_metaclass_immutable($self, \%options); - $IMMUTABLE_OPTIONS{$self->name} = - { %options, IMMUTABLE_TRANSFORMER => $transformer }; + my $meta = $self->meta; + my $meta_attr = $meta->find_attribute_by_name("immutable_trait"); - if( exists $options{debug} && $options{debug} ){ - print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS; - print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS; - } + my $class_name; - 1; + if ( $meta_attr and $trait eq $meta_attr->default ) { + # if the trait is the same as the default we try and pick a + # predictable name for the immutable metaclass + $class_name = 'Class::MOP::Class::Immutable::' . ref($self); + } + else { + $class_name = join '::', 'Class::MOP::Class::Immutable::CustomTrait', + $trait, 'ForMetaClass', ref($self); } - sub make_mutable{ - my $self = shift; - return if $self->is_mutable; - my $options = delete $IMMUTABLE_OPTIONS{$self->name}; - confess "unable to find immutabilizing options" unless ref $options; - my $transformer = delete $options->{IMMUTABLE_TRANSFORMER}; - $transformer->make_metaclass_mutable($self, $options); - 1; + return $class_name + if Class::MOP::is_class_loaded($class_name); + + # If the metaclass is a subclass of CMOP::Class which has had + # metaclass roles applied (via Moose), then we want to make sure + # that we preserve that anonymous class (see Fey::ORM for an + # example of where this matters). + my $meta_name + = $meta->is_immutable + ? $meta->_get_mutable_metaclass_name + : ref $meta; + + my $immutable_meta = $meta_name->create( + $class_name, + superclasses => [ ref $self ], + ); + + Class::MOP::load_class($trait); + for my $meth ( Class::MOP::Class->initialize($trait)->get_all_methods ) { + my $meth_name = $meth->name; + + if ( $immutable_meta->find_method_by_name( $meth_name ) ) { + $immutable_meta->add_around_method_modifier( $meth_name, $meth->body ); + } + else { + $immutable_meta->add_method( $meth_name, $meth->clone ); + } } + + $immutable_meta->make_immutable( + inline_constructor => 0, + inline_accessors => 0, + ); + + return $class_name; } -sub create_immutable_transformer { +sub _remove_inlined_code { my $self = shift; - my $class = Class::MOP::Immutable->new($self, { - read_only => [qw/superclasses/], - cannot_call => [qw/ - add_method - alias_method - remove_method - add_attribute - remove_attribute - remove_package_symbol - /], - memoize => { - class_precedence_list => 'ARRAY', - linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need? - get_all_methods => 'ARRAY', - #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future - compute_all_applicable_attributes => 'ARRAY', - get_meta_instance => 'SCALAR', - get_method_map => 'SCALAR', - }, - # NOTE: - # this is ugly, but so are typeglobs, - # so whattayahgonnadoboutit - # - SL - wrapped => { - add_package_symbol => sub { - my $original = shift; - confess "Cannot add package symbols to an immutable metaclass" - unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol'; - - # This is a workaround for a bug in 5.8.1 which thinks that - # goto $original->body - # is trying to go to a label - my $body = $original->body; - goto $body; - }, - }, - }); - return $class; + + $self->remove_method( $_->name ) for $self->_inlined_methods; + + delete $self->{__immutable}{inlined_methods}; +} + +sub _inlined_methods { @{ $_[0]{__immutable}{inlined_methods} || [] } } + +sub _add_inlined_method { + my ( $self, $method ) = @_; + + push @{ $self->{__immutable}{inlined_methods} ||= [] }, $method; +} + +sub _initialize_immutable { + my ( $self, %args ) = @_; + + $self->{__immutable}{options} = \%args; + $self->_install_inlined_code(%args); +} + +sub _install_inlined_code { + my ( $self, %args ) = @_; + + # FIXME + $self->_inline_accessors(%args) if $args{inline_accessors}; + $self->_inline_constructor(%args) if $args{inline_constructor}; + $self->_inline_destructor(%args) if $args{inline_destructor}; +} + +sub _rebless_as_mutable { + my $self = shift; + + bless $self, $self->_get_mutable_metaclass_name; + + return $self; +} + +sub _inline_accessors { + my $self = shift; + + foreach my $attr_name ( $self->get_attribute_list ) { + $self->get_attribute($attr_name)->install_accessors(1); + } +} + +sub _inline_constructor { + my ( $self, %args ) = @_; + + my $name = $args{constructor_name}; + + if ( $self->has_method($name) && !$args{replace_constructor} ) { + my $class = $self->name; + warn "Not inlining a constructor for $class since it defines" + . " its own constructor.\n" + . "If you are certain you don't need to inline your" + . " constructor, specify inline_constructor => 0 in your" + . " call to $class->meta->make_immutable\n"; + return; + } + + my $constructor_class = $args{constructor_class}; + + Class::MOP::load_class($constructor_class); + + my $constructor = $constructor_class->new( + options => \%args, + metaclass => $self, + is_inline => 1, + package_name => $self->name, + name => $name, + ); + + if ( $args{replace_constructor} or $constructor->can_be_inlined ) { + $self->add_method( $name => $constructor ); + $self->_add_inlined_method($constructor); + } +} + +sub _inline_destructor { + my ( $self, %args ) = @_; + + ( exists $args{destructor_class} && defined $args{destructor_class} ) + || confess "The 'inline_destructor' option is present, but " + . "no destructor class was specified"; + + if ( $self->has_method('DESTROY') && ! $args{replace_destructor} ) { + my $class = $self->name; + warn "Not inlining a destructor for $class since it defines" + . " its own destructor.\n"; + return; + } + + my $destructor_class = $args{destructor_class}; + + Class::MOP::load_class($destructor_class); + + return unless $destructor_class->is_needed($self); + + my $destructor = $destructor_class->new( + options => \%args, + metaclass => $self, + package_name => $self->name, + name => 'DESTROY' + ); + + if ( $args{replace_destructor} or $destructor->can_be_inlined ) { + $self->add_method( 'DESTROY' => $destructor ); + $self->_add_inlined_method($destructor); + } } 1; @@ -1151,7 +1131,7 @@ Class::MOP::Class - Class Meta Object # use this for introspection ... # add a method to Foo ... - Foo->meta->add_method('bar' => sub { ... }) + Foo->meta->add_method( 'bar' => sub {...} ) # get a list of all the classes searched # the method dispatcher in the correct order @@ -1162,264 +1142,203 @@ Class::MOP::Class - Class Meta Object # or use this to actually create classes ... - Class::MOP::Class->create('Bar' => ( - version => '0.01', - superclasses => [ 'Foo' ], - attributes => [ - Class::MOP:::Attribute->new('$bar'), - Class::MOP:::Attribute->new('$baz'), - ], - methods => { - calculate_bar => sub { ... }, - construct_baz => sub { ... } - } - )); + Class::MOP::Class->create( + 'Bar' => ( + version => '0.01', + superclasses => ['Foo'], + attributes => [ + Class::MOP::Attribute->new('$bar'), + Class::MOP::Attribute->new('$baz'), + ], + methods => { + calculate_bar => sub {...}, + construct_baz => sub {...} + } + ) + ); =head1 DESCRIPTION -This is the largest and currently most complex part of the Perl 5 -meta-object protocol. It controls the introspection and -manipulation of Perl 5 classes (and it can create them too). The -best way to understand what this module can do, is to read the -documentation for each of it's methods. +The Class Protocol is the largest and most complex part of the +Class::MOP meta-object protocol. It controls the introspection and +manipulation of Perl 5 classes, and it can create them as well. The +best way to understand what this module can do is to read the +documentation for each of its methods. -=head1 METHODS +=head1 INHERITANCE -=head2 Self Introspection +C is a subclass of L. -=over 4 - -=item B - -This will return a B instance which is related -to this class. Thereby allowing B to actually -introspect itself. - -As with B, B will actually -bootstrap this module by installing a number of attribute meta-objects -into it's metaclass. This will allow this class to reap all the benifits -of the MOP when subclassing it. - -=back +=head1 METHODS =head2 Class construction -These methods will handle creating B objects, -which can be used to both create new classes, and analyze -pre-existing classes. +These methods all create new C objects. These +objects can represent existing classes or they can be used to create +new classes from scratch. -This module will internally store references to all the instances -you create with these methods, so that they do not need to be -created any more than nessecary. Basically, they are singletons. +The metaclass object for a given class is a singleton. If you attempt +to create a metaclass for the same class twice, you will just get the +existing object. =over 4 -=item B ?$version, - authority =E ?$authority, - superclasses =E ?@superclasses, - methods =E ?%methods, - attributes =E ?%attributes)> - -This returns a B object, bringing the specified -C<$package_name> into existence and adding any of the C<$version>, -C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to -it. - -=item B ?@superclasses, - methods =E ?%methods, - attributes =E ?%attributes)> +=item B<< Class::MOP::Class->create($package_name, %options) >> -This will create an anonymous class, it works much like C but -it does not need a C<$package_name>. Instead it will create a suitably -unique package name for you to stash things into. +This method creates a new C object with the given +package name. It accepts a number of options: -On very important distinction is that anon classes are destroyed once -the metaclass they are attached to goes out of scope. In the DESTROY -method, the created package will be removed from the symbol table. +=over 8 -It is also worth noting that any instances created with an anon-class -will keep a special reference to the anon-meta which will prevent the -anon-class from going out of scope until all instances of it have also -been destroyed. This however only works for HASH based instance types, -as we use a special reserved slot (C<__MOP__>) to store this. +=item * version -=item B +An optional version number for the newly created package. -This initializes and returns returns a B object -for a given a C<$package_name>. +=item * authority -=item B +An optional authority for the newly created package. -This will construct an instance of B, it is -here so that we can actually "tie the knot" for B -to use C once all the bootstrapping is done. This -method is used internally by C and should never be called -from outside of that method really. +=item * superclasses -=item B +An optional array reference of superclass names. -This method is called as the very last thing in the -C method. This will check that the -metaclass you are creating is compatible with the metaclasses of all -your ancestors. For more inforamtion about metaclass compatibility -see the C section in L. +=item * methods -=item B +An optional hash reference of methods for the class. The keys of the +hash reference are method names and values are subroutine references. -This will reset the package cache flag for this particular metaclass -it is basically the value of the C -function. This is very rarely needed from outside of C -but in some cases you might want to use it, so it is here. +=item * attributes -=item B +An optional array reference of L objects. -Clears the package cache flag to announce to the internals that we need -to rebuild the method map. - -=item B - -Registers this class as dependent on its superclasses. - -Only superclasses from which this class inherits attributes will be added. - -=item B +=back -Unregisters this class from its superclasses. +=item B<< Class::MOP::Class->create_anon_class(%options) >> -=item B +This method works just like C<< Class::MOP::Class->create >> but it +creates an "anonymous" class. In fact, the class does have a name, but +that name is a unique name generated internally by this module. -Reregisters if necessary. +It accepts the same C, C, and C +parameters that C accepts. -=item B $metaclass +Anonymous classes are destroyed once the metaclass they are attached +to goes out of scope, and will be removed from Perl's internal symbol +table. -Registers the class as having a meta instance dependent on this class. +All instances of an anonymous class keep a special reference to the +metaclass object, which prevents the metaclass from going out of scope +while any instances exist. -=item B $metaclass +This only works if the instance is based on a hash reference, however. -Remove the class from the list of dependent classes. +=item B<< Class::MOP::Class->initialize($package_name, %options) >> -=item B +This method will initialize a C object for the +named package. Unlike C, this method I create a new +class. -Clears the cached meta instance for this metaclass and all of the registered -classes with dependent meta instances. +The purpose of this method is to retrieve a C +object for introspecting an existing class. -Called by C and C to recalculate the attribute -slots. +If an existing C object exists for the named +package, it will be returned, and any options provided will be +ignored! -=item B +If the object does not yet exist, it will be created. -Used by C. +The valid options that can be passed to this method are +C, C, +C, and C. These are all +optional, and default to the appropriate class in the C +distribution. =back =head2 Object instance construction and cloning -These methods are B, it is up to you whether you want -to use them or not. +These methods are all related to creating and/or cloning object +instances. =over 4 -=item B - -Returns the class name of the instance metaclass, see L -for more information on the instance metaclasses. - -=item B - -Returns an instance of L to be used in the construction -of a new instance of the class. - -=item B +=item B<< $metaclass->clone_object($instance, %params) >> -Called by C if necessary. +This method clones an existing object instance. Any parameters you +provide are will override existing attribute values in the object. -=item B +This is a convenience method for cloning an object instance, then +blessing it into the appropriate package. -This is a convience method for creating a new object of the class, and -blessing it into the appropriate package as well. Ideally your class -would call a C this method like so: +You could implement a clone method in your class, using this method: - sub MyClass::new { - my ($class, %param) = @_; - $class->meta->new_object(%params); + sub clone { + my ($self, %params) = @_; + $self->meta->clone_object($self, %params); } -=item B - -This method is used to construct an instance structure suitable for -C-ing into your package of choice. It works in conjunction -with the Attribute protocol to collect all applicable attributes. - -This will construct and instance using a HASH ref as storage -(currently only HASH references are supported). This will collect all -the applicable attributes and layout out the fields in the HASH ref, -it will then initialize them using either use the corresponding key -in C<%params> or any default value or initializer found in the -attribute meta-object. +=item B<< $metaclass->rebless_instance($instance, %params) >> -=item B +This method changes the class of C<$instance> to the metaclass's class. -This is a convience method for cloning an object instance, then -blessing it into the appropriate package. This method will call -C, which performs a shallow copy of the object, -see that methods documentation for more details. Ideally your -class would call a C this method like so: +You can only rebless an instance into a subclass of its current +class. If you pass any additional parameters, these will be treated +like constructor parameters and used to initialize the object's +attributes. Any existing attributes that are already set will be +overwritten. - sub MyClass::clone { - my ($self, %param) = @_; - $self->meta->clone_object($self, %params); - } +Before reblessing the instance, this method will call +C on the instance's current metaclass. This method +will be passed the instance, the new metaclass, and any parameters +specified to C. By default, C +does nothing; it is merely a hook. -=item B +=item B<< $metaclass->new_object(%params) >> -This method is a compliment of C (which means if -you override C, you need to override this one too), -and clones the instance shallowly. +This method is used to create a new object of the metaclass's +class. Any parameters you provide are used to initialize the +instance's attributes. A special C<__INSTANCE__> key can be passed to +provide an already generated instance, rather than having Class::MOP +generate it for you. This is mostly useful for using Class::MOP with +foreign classes which generate instances using their own constructors. -The cloned structure returned is (like with C) an -unCed HASH reference, it is your responsibility to then bless -this cloned structure into the right class (which C will -do for you). +=item B<< $metaclass->instance_metaclass >> -As of 0.11, this method will clone the C<$instance> structure shallowly, -as opposed to the deep cloning implemented in prior versions. After much -thought, research and discussion, I have decided that anything but basic -shallow cloning is outside the scope of the meta-object protocol. I -think Yuval "nothingmuch" Kogman put it best when he said that cloning -is too I to be part of the MOP. +Returns the class name of the instance metaclass. See +L for more information on the instance +metaclass. -=item B +=item B<< $metaclass->get_meta_instance >> -This will change the class of C<$instance> to the class of the invoking -C. You may only rebless the instance to a subclass of -itself. You may pass in optional C<%params> which are like constructor -params and will override anything already defined in the instance. +Returns an instance of the C to be used in the +construction of a new instance of the class. =back -=head2 Informational +=head2 Informational predicates -These are a few predicate methods for asking information about the class. +These are a few predicate methods for asking information about the +class itself. =over 4 -=item B +=item B<< $metaclass->is_anon_class >> -This returns true if the class is a C created anon class. +This returns true if the class was created by calling C<< +Class::MOP::Class->create_anon_class >>. -=item B +=item B<< $metaclass->is_mutable >> This returns true if the class is still mutable. -=item B +=item B<< $metaclass->is_immutable >> This returns true if the class has been made immutable. -=item B +=item B<< $metaclass->is_pristine >> -Checks whether the class has any data that will be lost if C is -called. +A class is I pristine if it has non-inherited attributes or if it +has any generated methods. =back @@ -1427,374 +1346,365 @@ called. =over 4 -=item B +=item B<< $metaclass->superclasses(@superclasses) >> -This is a read-write attribute which represents the superclass -relationships of the class the B instance is -associated with. Basically, it can get and set the C<@ISA> for you. +This is a read-write accessor which represents the superclass +relationships of the metaclass's class. -=item B +This is basically sugar around getting and setting C<@ISA>. -This computes the a list of all the class's ancestors in the same order -in which method dispatch will be done. This is similair to what -B does, but we don't remove duplicate names. +=item B<< $metaclass->class_precedence_list >> -=item B +This returns a list of all of the class's ancestor classes. The +classes are returned in method dispatch order. -This returns a list based on C but with all +=item B<< $metaclass->linearized_isa >> + +This returns a list based on C but with all duplicates removed. -=item B +=item B<< $metaclass->subclasses >> + +This returns a list of all subclasses for this class, even indirect +subclasses. + +=item B<< $metaclass->direct_subclasses >> -This returns a list of subclasses for this class. +This returns a list of immediate subclasses for this class, which does not +include indirect subclasses. =back -=head2 Methods +=head2 Method introspection + +See L for +methods that operate only on the current class. Class::MOP::Class adds +introspection capabilities that take inheritance into account. =over 4 -=item B +=item B<< $metaclass->get_all_methods >> -Returns a HASH ref of name to CODE reference mapping for this class. +This will traverse the inheritance hierarchy and return a list of all +the L objects for this class and its parents. -=item B +=item B<< $metaclass->find_method_by_name($method_name) >> -Returns the class name of the method metaclass, see L -for more information on the method metaclasses. +This will return a L for the specified +C<$method_name>. If the class does not have the specified method, it +returns C -=item B +Unlike C, this method I look for the named method in +superclasses. -Wrap a code ref (C<$attrs{body>) with C. +=item B<< $metaclass->get_all_method_names >> -=item B +This will return a list of method I for all of this class's +methods, including inherited methods. -This will take a C<$method_name> and CODE reference or meta method -objectand install it into the class's package. +=item B<< $metaclass->find_all_methods_by_name($method_name) >> -You are strongly encouraged to pass a meta method object instead of a -code reference. If you do so, that object gets stored as part of the -class's method map, providing more useful information about the method -for introspection. +This method looks for the named method in the class and all of its +parents. It returns every matching method it finds in the inheritance +tree, so it returns a list of methods. -When you provide a method object, this method will clone that object -if the object's package name does not match the class name. This lets -us track the original source of any methods added from other classes -(notably Moose roles). +Each method is returned as a hash reference with three keys. The keys +are C, C, and C. The C key has a +L object as its value. -B: -This does absolutely nothing special to C<$method> -other than use B to make sure it is tagged with the -correct name, and therefore show up correctly in stack traces and -such. +The list of methods is distinct. -=item B +=item B<< $metaclass->find_next_method_by_name($method_name) >> -This just provides a simple way to check if the class implements -a specific C<$method_name>. It will I however, attempt to check -if the class inherits the method (use C for that). +This method returns the first method in any superclass matching the +given name. It is effectively the method that C +would dispatch to. -This will correctly handle functions defined outside of the package -that use a fully qualified name (C). +=back -This will correctly handle functions renamed with B and -installed using the symbol tables. However, if you are naming the -subroutine outside of the package scope, you must use the fully -qualified name, including the package name, for C to -correctly identify it. +=head2 Attribute introspection and creation -This will attempt to correctly ignore functions imported from other -packages using B. It breaks down if the function imported -is an C<__ANON__> sub (such as with C), which very well -may be a valid method being applied to the class. +Because Perl 5 does not have a core concept of attributes in classes, +we can only return information about attributes which have been added +via this class's methods. We cannot discover information about +attributes which are defined in terms of "regular" Perl 5 methods. -In short, this method cannot always be trusted to determine if the -C<$method_name> is actually a method. However, it will DWIM about -90% of the time, so it's a small trade off I think. +=over 4 -=item B +=item B<< $metaclass->get_attribute($attribute_name) >> -This will return a Class::MOP::Method instance related to the specified -C<$method_name>, or return undef if that method does not exist. +This will return a L for the specified +C<$attribute_name>. If the class does not have the specified +attribute, it returns C. -The Class::MOP::Method is codifiable, so you can use it like a normal -CODE reference, see L for more information. +NOTE that get_attribute does not search superclasses, for that you +need to use C. -=item B +=item B<< $metaclass->has_attribute($attribute_name) >> -This will return a CODE reference of the specified C<$method_name>, -or return undef if that method does not exist. +Returns a boolean indicating whether or not the class defines the +named attribute. It does not include attributes inherited from parent +classes. -Unlike C this will also look in the superclasses. +=item B<< $metaclass->get_attribute_list >> -=item B +This will return a list of attributes I for all attributes +defined in this class. -This will attempt to remove a given C<$method_name> from the class. -It will return the CODE reference that it has removed, and will -attempt to use B to clear the methods associated name. +=item B<< $metaclass->get_all_attributes >> -=item B +This will traverse the inheritance hierarchy and return a list of all +the L objects for this class and its parents. -This will return a list of method names for all I defined -methods. It does B provide a list of all applicable methods, -including any inherited ones. If you want a list of all applicable -methods, use the C method. +=item B<< $metaclass->find_attribute_by_name($attribute_name) >> -=item B +This will return a L for the specified +C<$attribute_name>. If the class does not have the specified +attribute, it returns C. -This will traverse the inheritance heirachy and return a list of all -the applicable L objects for this class. +Unlike C, this attribute I look for the named +attribute in superclasses. -=item B +=item B<< $metaclass->add_attribute(...) >> -Deprecated. +This method accepts either an existing L +object or parameters suitable for passing to that class's C +method. -This method returns a list of hashes describing the all the methods of the -class. +The attribute provided will be added to the class. -Use L, which is easier/better/faster. This method predates -L. +Any accessor methods defined by the attribute will be added to the +class when the attribute is added. -=item B +If an attribute of the same name already exists, the old attribute +will be removed first. -This will traverse the inheritence hierarchy and locate all methods -with a given C<$method_name>. Similar to -C it returns a list of HASH references -with the following information; method name (which will always be the -same as C<$method_name>), the name of the class in which the method -lives and a CODE reference for the actual method. +=item B<< $metaclass->remove_attribute($attribute_name) >> -The list of methods produced is a distinct list, meaning there are no -duplicates in it. This is especially useful for things like object -initialization and destruction where you only want the method called -once, and in the correct order. +This will remove the named attribute from the class, and +L object. -=item B +Removing an attribute also removes any accessor methods defined by the +attribute. -This will return the first method to match a given C<$method_name> in -the superclasses, this is basically equivalent to calling -C, but it can be dispatched at runtime. +However, note that removing an attribute will only affect I +object instances created for this class, not existing instances. -=item B +=item B<< $metaclass->attribute_metaclass >> -B: This method is now deprecated. Just use C -instead. +Returns the class name of the attribute metaclass for this class. By +default, this is L. =back -=head2 Method Modifiers +=head2 Class Immutability -Method modifiers are a concept borrowed from CLOS, in which a method -can be wrapped with I, I and I method modifiers -that will be called everytime the method is called. +Making a class immutable "freezes" the class definition. You can no +longer call methods which alter the class, such as adding or removing +methods or attributes. -=head3 How method modifiers work? +Making a class immutable lets us optimize the class by inlining some +methods, and also allows us to optimize some methods on the metaclass +object itself. -Method modifiers work by wrapping the original method and then replacing -it in the classes symbol table. The wrappers will handle calling all the -modifiers in the appropariate orders and preserving the calling context -for the original method. - -Each method modifier serves a particular purpose, which may not be -obvious to users of other method wrapping modules. To start with, the -return values of I and I modifiers are ignored. This is -because thier purpose is B to filter the input and output of the -primary method (this is done with an I modifier). This may seem -like an odd restriction to some, but doing this allows for simple code -to be added at the begining or end of a method call without jeapordizing -the normal functioning of the primary method or placing any extra -responsibility on the code of the modifier. Of course if you have more -complex needs, then use the I modifier, which uses a variation -of continutation passing style to allow for a high degree of flexibility. - -Before and around modifiers are called in last-defined-first-called order, -while after modifiers are called in first-defined-first-called order. So -the call tree might looks something like this: +After immutabilization, the metaclass object will cache most informational +methods that returns information about methods or attributes. Methods which +would alter the class, such as C and C, will +throw an error on an immutable metaclass object. - before 2 - before 1 - around 2 - around 1 - primary - after 1 - after 2 +The immutabilization system in L takes much greater advantage +of the inlining features than Class::MOP itself does. -To see examples of using method modifiers, see the following examples -included in the distribution; F, F, -F and F. There is also a -classic CLOS usage example in the test F<017_add_method_modifier.t>. +=over 4 -=head3 What is the performance impact? +=item B<< $metaclass->make_immutable(%options) >> -Of course there is a performance cost associated with method modifiers, -but we have made every effort to make that cost be directly proportional -to the amount of modifier features you utilize. +This method will create an immutable transformer and use it to make +the class and its metaclass object immutable. -The wrapping method does it's best to B do as much work as it -absolutely needs to. In order to do this we have moved some of the -performance costs to set-up time, where they are easier to amortize. +This method accepts the following options: -All this said, my benchmarks have indicated the following: +=over 8 - simple wrapper with no modifiers 100% slower - simple wrapper with simple before modifier 400% slower - simple wrapper with simple after modifier 450% slower - simple wrapper with simple around modifier 500-550% slower - simple wrapper with all 3 modifiers 1100% slower +=item * inline_accessors -These numbers may seem daunting, but you must remember, every feature -comes with some cost. To put things in perspective, just doing a simple -C which does nothing but extract the name of the method called -and return it costs about 400% over a normal method call. +=item * inline_constructor -=over 4 +=item * inline_destructor -=item B +These are all booleans indicating whether the specified method(s) +should be inlined. -This will wrap the method at C<$method_name> and the supplied C<$code> -will be passed the C<@_> arguments, and called before the original -method is called. As specified above, the return value of the I -method modifiers is ignored, and it's ability to modify C<@_> is -fairly limited. If you need to do either of these things, use an -C method modifier. +By default, accessors and the constructor are inlined, but not the +destructor. -=item B +=item * immutable_trait -This will wrap the method at C<$method_name> so that the original -method will be called, it's return values stashed, and then the -supplied C<$code> will be passed the C<@_> arguments, and called. -As specified above, the return value of the I method -modifiers is ignored, and it cannot modify the return values of -the original method. If you need to do either of these things, use an -C method modifier. +The name of a class which will be used as a parent class for the +metaclass object being made immutable. This "trait" implements the +post-immutability functionality of the metaclass (but not the +transformation itself). -=item B +This defaults to L. -This will wrap the method at C<$method_name> so that C<$code> -will be called and passed the original method as an extra argument -at the begining of the C<@_> argument list. This is a variation of -continuation passing style, where the function prepended to C<@_> -can be considered a continuation. It is up to C<$code> if it calls -the original method or not, there is no restriction on what the -C<$code> can or cannot do. +=item * constructor_name -=back +This is the constructor method name. This defaults to "new". -=head2 Attributes +=item * constructor_class -It should be noted that since there is no one consistent way to define -the attributes of a class in Perl 5. These methods can only work with -the information given, and can not easily discover information on -their own. See L for more details. +The name of the method metaclass for constructors. It will be used to +generate the inlined constructor. This defaults to +"Class::MOP::Method::Constructor". -=over 4 +=item * replace_constructor -=item B +This is a boolean indicating whether an existing constructor should be +replaced when inlining a constructor. This defaults to false. -Returns the class name of the attribute metaclass, see L -for more information on the attribute metaclasses. +=item * destructor_class -=item B +The name of the method metaclass for destructors. It will be used to +generate the inlined destructor. This defaults to +"Class::MOP::Method::Denstructor". -This returns a HASH ref of name to attribute meta-object mapping. +=item * replace_destructor -=item B +This is a boolean indicating whether an existing destructor should be +replaced when inlining a destructor. This defaults to false. -This stores the C<$attribute_meta_object> (or creates one from the -C<$attribute_name> and C<%attribute_spec>) in the B -instance associated with the given class. Unlike methods, attributes -within the MOP are stored as meta-information only. They will be used -later to construct instances from (see C above). -More details about the attribute meta-objects can be found in the -L or the L -section. +=back -It should be noted that any accessor, reader/writer or predicate -methods which the C<$attribute_meta_object> has will be installed -into the class at this time. +=item B<< $metaclass->immutable_options >> -B -If an attribute already exists for C<$attribute_name>, the old one -will be removed (as well as removing all it's accessors), and then -the new one added. +Returns a hash of the options used when making the class immutable, including +both defaults and anything supplied by the user in the call to C<< +$metaclass->make_immutable >>. This is useful if you need to temporarily make +a class mutable and then restore immutability as it was before. -=item B +=item B<< $metaclass->make_mutable >> -Checks to see if this class has an attribute by the name of -C<$attribute_name> and returns a boolean. +Calling this method reverse the immutabilization transformation. -=item B +=back -Returns the attribute meta-object associated with C<$attribute_name>, -if none is found, it will return undef. +=head2 Method Modifiers -=item B +Method modifiers are hooks which allow a method to be wrapped with +I, I and I method modifiers. Every time a +method is called, its modifiers are also called. -This will remove the attribute meta-object stored at -C<$attribute_name>, then return the removed attribute meta-object. +A class can modify its own methods, as well as methods defined in +parent classes. -B -Removing an attribute will only affect future instances of -the class, it will not make any attempt to remove the attribute from -any existing instances of the class. +=head3 How method modifiers work? -It should be noted that any accessor, reader/writer or predicate -methods which the attribute meta-object stored at C<$attribute_name> -has will be removed from the class at this time. This B make -these attributes somewhat inaccessable in previously created -instances. But if you are crazy enough to do this at runtime, then -you are crazy enough to deal with something like this :). +Method modifiers work by wrapping the original method and then +replacing it in the class's symbol table. The wrappers will handle +calling all the modifiers in the appropriate order and preserving the +calling context for the original method. -=item B +The return values of C and C modifiers are +ignored. This is because their purpose is B to filter the input +and output of the primary method (this is done with an I +modifier). -This returns a list of attribute names which are defined in the local -class. If you want a list of all applicable attributes for a class, -use the C method. +This may seem like an odd restriction to some, but doing this allows +for simple code to be added at the beginning or end of a method call +without altering the function of the wrapped method or placing any +extra responsibility on the code of the modifier. -=item B +Of course if you have more complex needs, you can use the C +modifier which allows you to change both the parameters passed to the +wrapped method, as well as its return value. -=item B +Before and around modifiers are called in last-defined-first-called +order, while after modifiers are called in first-defined-first-called +order. So the call tree might looks something like this: -This will traverse the inheritance heirachy and return a list of all -the applicable L objects for this class. + before 2 + before 1 + around 2 + around 1 + primary + around 1 + around 2 + after 1 + after 2 -C is an alias for consistency with C. +=head3 What is the performance impact? -=item B +Of course there is a performance cost associated with method +modifiers, but we have made every effort to make that cost directly +proportional to the number of modifier features you use. -This method will traverse the inheritance heirachy and find the -first attribute whose name matches C<$attr_name>, then return it. -It will return undef if nothing is found. +The wrapping method does its best to B do as much work as it +absolutely needs to. In order to do this we have moved some of the +performance costs to set-up time, where they are easier to amortize. -=back +All this said, our benchmarks have indicated the following: -=head2 Class Immutability + simple wrapper with no modifiers 100% slower + simple wrapper with simple before modifier 400% slower + simple wrapper with simple after modifier 450% slower + simple wrapper with simple around modifier 500-550% slower + simple wrapper with all 3 modifiers 1100% slower + +These numbers may seem daunting, but you must remember, every feature +comes with some cost. To put things in perspective, just doing a +simple C which does nothing but extract the name of the +method called and return it costs about 400% over a normal method +call. =over 4 -=item B +=item B<< $metaclass->add_before_method_modifier($method_name, $code) >> + +This wraps the specified method with the supplied subroutine +reference. The modifier will be called as a method itself, and will +receive the same arguments as are passed to the method. + +When the modifier exits, the wrapped method will be called. -This method will invoke a tranforamtion upon the class which will -make it immutable. Details of this transformation can be found in -the L documentation. +The return value of the modifier will be ignored. -=item B +=item B<< $metaclass->add_after_method_modifier($method_name, $code) >> -This method will reverse tranforamtion upon the class which -made it immutable. +This wraps the specified method with the supplied subroutine +reference. The modifier will be called as a method itself, and will +receive the same arguments as are passed to the method. -=item B +When the wrapped methods exits, the modifier will be called. -Return a transformer suitable for making this class immutable or, if this -class is immutable, the transformer used to make it immutable. +The return value of the modifier will be ignored. -=item B +=item B<< $metaclass->add_around_method_modifier($method_name, $code) >> + +This wraps the specified method with the supplied subroutine +reference. + +The first argument passed to the modifier will be a subroutine +reference to the wrapped method. The second argument is the object, +and after that come any arguments passed when the method is called. + +The around modifier can choose to call the original method, as well as +what arguments to pass if it does so. + +The return value of the modifier is what will be seen by the caller. + +=back + +=head2 Introspection + +=over 4 -If the class is immutable, return the options used to make it immutable. +=item B<< Class::MOP::Class->meta >> -=item B +This will return a L instance for this class. -Create a transformer suitable for making this class immutable +It should also be noted that L will actually bootstrap +this module by installing a number of attribute meta-objects into its +metaclass. =back @@ -1804,7 +1714,7 @@ Stevan Little Estevan@iinteractive.comE =head1 COPYRIGHT AND LICENSE -Copyright 2006-2008 by Infinity Interactive, Inc. +Copyright 2006-2009 by Infinity Interactive, Inc. L