X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FMOP%2FClass.pm;h=bde5f52804739b5dac966ca1d9baf85088f148a0;hb=2367814a108bbb85efbf76b57fc58bf464d68455;hp=474783b79c1d3b6f6b3559024f0b8d614186bc3e;hpb=96ceced87583646c1396bba4fdfa92d0b6c37058;p=gitmo%2FClass-MOP.git diff --git a/lib/Class/MOP/Class.pm b/lib/Class/MOP/Class.pm index 474783b..bde5f52 100644 --- a/lib/Class/MOP/Class.pm +++ b/lib/Class/MOP/Class.pm @@ -4,102 +4,235 @@ package Class::MOP::Class; use strict; use warnings; +use Class::MOP::Immutable; +use Class::MOP::Instance; +use Class::MOP::Method::Wrapped; + use Carp 'confess'; -use Scalar::Util 'blessed', 'reftype'; +use Scalar::Util 'blessed', 'reftype', 'weaken'; use Sub::Name 'subname'; use B 'svref_2object'; -our $VERSION = '0.06'; +our $VERSION = '0.21'; +our $AUTHORITY = 'cpan:STEVAN'; + +use base 'Class::MOP::Module'; # Self-introspection sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) } # Creation - -{ - # Metaclasses are singletons, so we cache them here. - # there is no need to worry about destruction though - # because they should die only when the program dies. - # After all, do package definitions even get reaped? - my %METAS; - sub initialize { - my $class = shift; - my $package_name = shift; - (defined $package_name && $package_name && !blessed($package_name)) - || confess "You must pass a package name and it cannot be blessed"; - $class->construct_class_instance(':package' => $package_name, @_); - } +sub initialize { + my $class = shift; + my $package_name = shift; + (defined $package_name && $package_name && !blessed($package_name)) + || confess "You must pass a package name and it cannot be blessed"; + $class->construct_class_instance('package' => $package_name, @_); +} + +sub reinitialize { + my $class = shift; + my $package_name = shift; + (defined $package_name && $package_name && !blessed($package_name)) + || confess "You must pass a package name and it cannot be blessed"; + Class::MOP::remove_metaclass_by_name($package_name); + $class->construct_class_instance('package' => $package_name, @_); +} - # NOTE: (meta-circularity) - # 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 { - my $class = shift; - my %options = @_; - my $package_name = $options{':package'}; - (defined $package_name && $package_name) - || confess "You must pass a package name"; - return $METAS{$package_name} if exists $METAS{$package_name}; - $class = blessed($class) || $class; - # now create the metaclass - my $meta; - if ($class =~ /^Class::MOP::/) { - $meta = bless { - '$:package' => $package_name, - '%:attributes' => {}, - '$:attribute_metaclass' => $options{':attribute_metaclass'} || 'Class::MOP::Attribute', - '$:method_metaclass' => $options{':method_metaclass'} || 'Class::MOP::Method', - } => $class; - } - else { +# NOTE: (meta-circularity) +# 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 { + my $class = shift; + my %options = @_; + my $package_name = $options{'package'}; + (defined $package_name && $package_name) + || confess "You must pass a package name"; + # NOTE: + # return the metaclass if we have it cached, + # and it is still defined (it has not been + # reaped by DESTROY yet, which can happen + # annoyingly enough during global destruction) + return Class::MOP::get_metaclass_by_name($package_name) + if Class::MOP::does_metaclass_exist($package_name); + + # NOTE: + # we need to deal with the possibility + # of class immutability here, and then + # get the name of the class appropriately + $class = (blessed($class) + ? ($class->is_immutable + ? $class->get_mutable_metaclass_name() + : blessed($class)) + : $class); + + # now create the metaclass + my $meta; + if ($class =~ /^Class::MOP::Class$/) { + no strict 'refs'; + $meta = bless { + # inherited from Class::MOP::Package + '$!package' => $package_name, + # NOTE: - # it is safe to use meta here because - # class will always be a subclass of - # Class::MOP::Class, which defines meta - $meta = bless $class->meta->construct_instance(%options) => $class - } - # and check the metaclass compatibility - $meta->check_metaclass_compatability(); - $METAS{$package_name} = $meta; + # since the following attributes will + # actually be loaded from the symbol + # table, and actually bypass the instance + # entirely, we can just leave these things + # listed here for reference, because they + # should not actually have a value associated + # with the slot. + '%!namespace' => \undef, + # inherited from Class::MOP::Module + '$!version' => \undef, + '$!authority' => \undef, + # defined in Class::MOP::Class + '@!superclasses' => \undef, + + '%!methods' => {}, + '%!attributes' => {}, + '$!attribute_metaclass' => $options{'attribute_metaclass'} || 'Class::MOP::Attribute', + '$!method_metaclass' => $options{'method_metaclass'} || 'Class::MOP::Method', + '$!instance_metaclass' => $options{'instance_metaclass'} || 'Class::MOP::Instance', + } => $class; + } + 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) } - sub check_metaclass_compatability { - my $self = shift; + # and check the metaclass compatibility + $meta->check_metaclass_compatability(); + + Class::MOP::store_metaclass_by_name($package_name, $meta); + + # NOTE: + # we need to weaken any anon classes + # so that they can call DESTROY properly + Class::MOP::weaken_metaclass($package_name) if $meta->is_anon_class; + + $meta; +} + +sub check_metaclass_compatability { + my $self = shift; + + # this is always okay ... + return if blessed($self) eq 'Class::MOP::Class' && + $self->instance_metaclass eq 'Class::MOP::Instance'; + + my @class_list = $self->class_precedence_list; + shift @class_list; # shift off $self->name + + foreach my $class_name (@class_list) { + my $meta = Class::MOP::get_metaclass_by_name($class_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 + ? $meta->get_mutable_metaclass_name() + : blessed($meta)); + + ($self->isa($meta_type)) + || confess $self->name . "->meta => (" . (blessed($self)) . ")" . + " is not compatible with the " . + $class_name . "->meta => (" . ($meta_type) . ")"; + # NOTE: + # we also need to check that instance metaclasses + # are compatabile in the same the class. + ($self->instance_metaclass->isa($meta->instance_metaclass)) + || confess $self->name . "->meta => (" . ($self->instance_metaclass) . ")" . + " is not compatible with the " . + $class_name . "->meta => (" . ($meta->instance_metaclass) . ")"; + } +} + +## ANON classes - # this is always okay ... - return if blessed($self) eq 'Class::MOP::Class'; +{ + # NOTE: + # this should be sufficient, if you have a + # use case where it is not, write a test and + # I will change it. + my $ANON_CLASS_SERIAL = 0; + + # NOTE: + # we need a sufficiently annoying prefix + # this should suffice for now, this is + # used in a couple of places below, so + # need to put it up here for now. + my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::'; + + sub is_anon_class { + my $self = shift; + no warnings 'uninitialized'; + $self->name =~ /^$ANON_CLASS_PREFIX/ ? 1 : 0; + } - my @class_list = $self->class_precedence_list; - shift @class_list; # shift off $self->name + sub create_anon_class { + my ($class, %options) = @_; + my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL; + return $class->create($package_name, %options); + } - foreach my $class_name (@class_list) { - my $meta = $METAS{$class_name} || next; - ($self->isa(blessed($meta))) - || confess $self->name . "->meta => (" . (blessed($self)) . ")" . - " is not compatible with the " . - $class_name . "->meta => (" . (blessed($meta)) . ")"; - } + # NOTE: + # this will only get called for + # anon-classes, all other calls + # are assumed to occur during + # global destruction and so don't + # really need to be handled explicitly + sub DESTROY { + my $self = shift; + no warnings 'uninitialized'; + return unless $self->name =~ /^$ANON_CLASS_PREFIX/; + my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/); + 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 . '::'}; } + } +# creating classes with MOP ... + sub create { - my ($class, $package_name, $package_version, %options) = @_; + my $class = shift; + my $package_name = shift; + (defined $package_name && $package_name) || confess "You must pass a package name"; + + (scalar @_ % 2 == 0) + || confess "You much pass all parameters as name => value pairs " . + "(I found an uneven number of params in \@_)"; + + my (%options) = @_; + my $code = "package $package_name;"; - $code .= "\$$package_name\:\:VERSION = '$package_version';" - if defined $package_version; + $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';" + if exists $options{version}; + $code .= "\$$package_name\:\:AUTHORITY = '" . $options{authority} . "';" + if exists $options{authority}; + eval $code; confess "creation of $package_name failed : $@" if $@; + my $meta = $class->initialize($package_name); $meta->add_method('meta' => sub { - Class::MOP::Class->initialize(blessed($_[0]) || $_[0]); + $class->initialize(blessed($_[0]) || $_[0]); }); $meta->superclasses(@{$options{superclasses}}) @@ -128,10 +261,36 @@ sub create { # all these attribute readers will be bootstrapped # away in the Class::MOP bootstrap section -sub name { $_[0]->{'$:package'} } -sub get_attribute_map { $_[0]->{'%:attributes'} } -sub attribute_metaclass { $_[0]->{'$:attribute_metaclass'} } -sub method_metaclass { $_[0]->{'$:method_metaclass'} } +sub get_attribute_map { $_[0]->{'%!attributes'} } +sub attribute_metaclass { $_[0]->{'$!attribute_metaclass'} } +sub method_metaclass { $_[0]->{'$!method_metaclass'} } +sub instance_metaclass { $_[0]->{'$!instance_metaclass'} } + +# FIXME: +# this is a prime canidate for conversion to XS +sub get_method_map { + my $self = shift; + my $map = $self->{'%!methods'}; + + my $class_name = $self->name; + my $method_metaclass = $self->method_metaclass; + + foreach my $symbol ($self->list_all_package_symbols('CODE')) { + my $code = $self->get_package_symbol('&' . $symbol); + + next if exists $map->{$symbol} && + defined $map->{$symbol} && + $map->{$symbol}->body == $code; + + my $gv = svref_2object($code)->GV; + next if ($gv->STASH->NAME || '') ne $class_name && + ($gv->NAME || '') ne '__ANON__'; + + $map->{$symbol} = $method_metaclass->wrap($code); + } + + return $map; +} # Instance Construction & Cloning @@ -144,25 +303,27 @@ sub new_object { # which will deal with the singletons return $class->construct_class_instance(@_) if $class->name->isa('Class::MOP::Class'); - bless $class->construct_instance(@_) => $class->name; + return $class->construct_instance(@_); } sub construct_instance { my ($class, %params) = @_; - my $instance = {}; + my $meta_instance = $class->get_meta_instance(); + my $instance = $meta_instance->create_instance(); foreach my $attr ($class->compute_all_applicable_attributes()) { - my $init_arg = $attr->init_arg(); - # try to fetch the init arg from the %params ... - my $val; - $val = $params{$init_arg} if exists $params{$init_arg}; - # if nothing was in the %params, we can use the - # attribute's default value (if it has one) - $val ||= $attr->default($instance) if $attr->has_default(); - $instance->{$attr->name} = $val; + $attr->initialize_instance_slot($meta_instance, $instance, \%params); } return $instance; } +sub get_meta_instance { + my $class = shift; + return $class->instance_metaclass->new( + $class, + $class->compute_all_applicable_attributes() + ); +} + sub clone_object { my $class = shift; my $instance = shift; @@ -173,36 +334,39 @@ sub clone_object { # Class::MOP::Class singletons here, they # should not be cloned. return $instance if $instance->isa('Class::MOP::Class'); - bless $class->clone_instance($instance, @_) => blessed($instance); + $class->clone_instance($instance, @_); } sub clone_instance { my ($class, $instance, %params) = @_; (blessed($instance)) || confess "You can only clone instances, \$self is not a blessed instance"; - my $clone = { %$instance, %params }; + my $meta_instance = $class->get_meta_instance(); + my $clone = $meta_instance->clone_instance($instance); + foreach my $attr ($class->compute_all_applicable_attributes()) { + if ($params{$attr->init_arg}) { + $meta_instance->set_slot_value($clone, $attr->name, $params{$attr->init_arg}); + } + } return $clone; } -# Informational - -# &name should be here too, but it is above -# because it gets bootstrapped away - -sub version { - my $self = shift; - ${$self->get_package_variable('$VERSION')}; -} - # Inheritance sub superclasses { my $self = shift; if (@_) { my @supers = @_; - @{$self->get_package_variable('@ISA')} = @supers; + @{$self->get_package_symbol('@ISA')} = @supers; + # NOTE: + # we need to check the metaclass + # compatability here so that we can + # be sure that the superclass is + # not potentially creating an issues + # we don't know about + $self->check_metaclass_compatability(); } - @{$self->get_package_variable('@ISA')}; + @{$self->get_package_symbol('@ISA')}; } sub class_precedence_list { @@ -212,8 +376,8 @@ sub class_precedence_list { # This will do nothing if all is well, and blow # up otherwise. Yes, it's an ugly hack, better # suggestions are welcome. - { $self->name->isa('This is a test for circular inheritance') } - # ... and no back to our regularly scheduled program + { ($self->name || return)->isa('This is a test for circular inheritance') } + # ... and now back to our regularly scheduled program ( $self->name, map { @@ -228,106 +392,105 @@ sub add_method { my ($self, $method_name, $method) = @_; (defined $method_name && $method_name) || confess "You must define a method name"; - # use reftype here to allow for blessed subs ... - ('CODE' eq (reftype($method) || '')) - || confess "Your code block must be a CODE reference"; - my $full_method_name = ($self->name . '::' . $method_name); - - $method = $self->method_metaclass->wrap($method) unless blessed($method); - - no strict 'refs'; - no warnings 'redefine'; - *{$full_method_name} = subname $full_method_name => $method; + + my $body; + if (blessed($method)) { + $body = $method->body; + } + else { + $body = $method; + ('CODE' eq (reftype($body) || '')) + || confess "Your code block must be a CODE reference"; + $method = $self->method_metaclass->wrap($body); + } + $self->get_method_map->{$method_name} = $method; + + my $full_method_name = ($self->name . '::' . $method_name); + $self->add_package_symbol("&${method_name}" => subname $full_method_name => $body); } { - my $fetch_and_prepare_method = sub { - my ($self, $method_name) = @_; - # fetch it locally - my $method = $self->get_method($method_name); - # if we dont have local ... - unless ($method) { - # make sure this method even exists ... - ($self->find_next_method_by_name($method_name)) - || confess "The method '$method_name' is not found in the inherience hierarchy for this class"; - # if so, then create a local which just - # calls the next applicable method ... - $self->add_method($method_name => sub { - $self->find_next_method_by_name($method_name)->(@_); - }); - $method = $self->get_method($method_name); - } - - # now make sure we wrap it properly - # (if it isnt already) - unless ($method->isa('Class::MOP::Method::Wrapped')) { - $method = Class::MOP::Method::Wrapped->wrap($method); - $self->add_method($method_name => $method); - } - return $method; - }; - - sub add_before_method_modifier { - my ($self, $method_name, $method_modifier) = @_; - (defined $method_name && $method_name) - || confess "You must pass in a method name"; - my $full_method_modifier_name = ($self->name . '::' . $method_name . ':before'); - my $method = $fetch_and_prepare_method->($self, $method_name); - $method->add_before_modifier(subname $full_method_modifier_name => $method_modifier); - } - - sub add_after_method_modifier { - my ($self, $method_name, $method_modifier) = @_; - (defined $method_name && $method_name) - || confess "You must pass in a method name"; - my $full_method_modifier_name = ($self->name . '::' . $method_name . ':after'); - my $method = $fetch_and_prepare_method->($self, $method_name); - $method->add_after_modifier(subname $full_method_modifier_name => $method_modifier); - } - - sub add_around_method_modifier { - my ($self, $method_name, $method_modifier) = @_; - (defined $method_name && $method_name) - || confess "You must pass in a method name"; - my $full_method_modifier_name = ($self->name . '::' . $method_name . ':around'); - my $method = $fetch_and_prepare_method->($self, $method_name); - $method->add_around_modifier(subname $full_method_modifier_name => $method_modifier); - } + my $fetch_and_prepare_method = sub { + my ($self, $method_name) = @_; + # fetch it locally + my $method = $self->get_method($method_name); + # if we dont have local ... + unless ($method) { + # try to find the next 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 inherience hierarchy for class " . $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); + } + else { + # now make sure we wrap it properly + $method = Class::MOP::Method::Wrapped->wrap($method) + unless $method->isa('Class::MOP::Method::Wrapped'); + } + $self->add_method($method_name => $method); + return $method; + }; + + sub add_before_method_modifier { + my ($self, $method_name, $method_modifier) = @_; + (defined $method_name && $method_name) + || confess "You must pass in a method name"; + my $method = $fetch_and_prepare_method->($self, $method_name); + $method->add_before_modifier(subname ':before' => $method_modifier); + } + sub add_after_method_modifier { + my ($self, $method_name, $method_modifier) = @_; + (defined $method_name && $method_name) + || confess "You must pass in a method name"; + my $method = $fetch_and_prepare_method->($self, $method_name); + $method->add_after_modifier(subname ':after' => $method_modifier); + } + + sub add_around_method_modifier { + my ($self, $method_name, $method_modifier) = @_; + (defined $method_name && $method_name) + || confess "You must pass in a method name"; + my $method = $fetch_and_prepare_method->($self, $method_name); + $method->add_around_modifier(subname ':around' => $method_modifier); + } + + # NOTE: + # the methods above used to be named like this: + # ${pkg}::${method}:(before|after|around) + # but this proved problematic when using one modifier + # to wrap multiple methods (something which is likely + # to happen pretty regularly IMO). So instead of naming + # it like this, I have chosen to just name them purely + # with their modifier names, like so: + # :(before|after|around) + # The fact is that in a stack trace, it will be fairly + # evident from the context what method they are attached + # to, and so don't need the fully qualified name. } sub alias_method { my ($self, $method_name, $method) = @_; (defined $method_name && $method_name) || confess "You must define a method name"; - # use reftype here to allow for blessed subs ... - ('CODE' eq (reftype($method) || '')) - || confess "Your code block must be a CODE reference"; - my $full_method_name = ($self->name . '::' . $method_name); - $method = $self->method_metaclass->wrap($method) unless blessed($method); + my $body = (blessed($method) ? $method->body : $method); + ('CODE' eq (reftype($body) || '')) + || confess "Your code block must be a CODE reference"; - no strict 'refs'; - no warnings 'redefine'; - *{$full_method_name} = $method; + $self->add_package_symbol("&${method_name}" => $body); } sub has_method { my ($self, $method_name) = @_; (defined $method_name && $method_name) || confess "You must define a method name"; - - my $sub_name = ($self->name . '::' . $method_name); - no strict 'refs'; - return 0 if !defined(&{$sub_name}); - my $method = \&{$sub_name}; - return 0 if (svref_2object($method)->GV->STASH->NAME || '') ne $self->name && - (svref_2object($method)->GV->NAME || '') ne '__ANON__'; - - # at this point we are relatively sure - # it is our method, so we bless/wrap it - $self->method_metaclass->wrap($method) unless blessed($method); + return 0 unless exists $self->get_method_map->{$method_name}; return 1; } @@ -335,11 +498,14 @@ sub get_method { my ($self, $method_name) = @_; (defined $method_name && $method_name) || confess "You must define a method name"; - - return unless $self->has_method($method_name); - - no strict 'refs'; - return \&{$self->name . '::' . $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 $self->get_method_map->{$method_name}; } sub remove_method { @@ -349,17 +515,38 @@ sub remove_method { my $removed_method = $self->get_method($method_name); - no strict 'refs'; - delete ${$self->name . '::'}{$method_name} - if defined $removed_method; + do { + $self->remove_package_symbol("&${method_name}"); + delete $self->get_method_map->{$method_name}; + } if defined $removed_method; return $removed_method; } sub get_method_list { my $self = shift; - no strict 'refs'; - grep { $self->has_method($_) } %{$self->name . '::'}; + keys %{$self->get_method_map}; +} + +sub find_method_by_name { + my ($self, $method_name) = @_; + (defined $method_name && $method_name) + || confess "You must define a method name to find"; + # keep a record of what we have seen + # here, this will handle all the + # inheritence issues because we are + # using the &class_precedence_list + my %seen_class; + my @cpl = $self->class_precedence_list(); + foreach my $class (@cpl) { + next if $seen_class{$class}; + $seen_class{$class}++; + # fetch the meta-class ... + my $meta = $self->initialize($class); + return $meta->get_method($method_name) + if $meta->has_method($method_name); + } + return; } sub compute_all_applicable_methods { @@ -415,23 +602,23 @@ sub find_all_methods_by_name { sub find_next_method_by_name { my ($self, $method_name) = @_; (defined $method_name && $method_name) - || confess "You must define a method name to find"; + || confess "You must define a method name to find"; # keep a record of what we have seen # here, this will handle all the # inheritence issues because we are # using the &class_precedence_list my %seen_class; - my @cpl = $self->class_precedence_list(); - shift @cpl; # discard ourselves + my @cpl = $self->class_precedence_list(); + shift @cpl; # discard ourselves foreach my $class (@cpl) { next if $seen_class{$class}; $seen_class{$class}++; # fetch the meta-class ... my $meta = $self->initialize($class); - return $meta->get_method($method_name) - if $meta->has_method($method_name); + return $meta->get_method($method_name) + if $meta->has_method($method_name); } - return; + return; } ## Attributes @@ -444,8 +631,21 @@ sub add_attribute { # make sure it is derived from the correct type though ($attribute->isa('Class::MOP::Attribute')) || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)"; + + # first we attach our new attribute + # because it might need certain information + # about the class which it is attached to $attribute->attach_to_class($self); - $attribute->install_accessors(); + + # 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 + $self->remove_attribute($attribute->name) + if $self->has_attribute($attribute->name); + + # then onto installing the new accessors + $attribute->install_accessors(); $self->get_attribute_map->{$attribute->name} = $attribute; } @@ -461,8 +661,10 @@ sub get_attribute { (defined $attribute_name && $attribute_name) || confess "You must define an attribute name"; return $self->get_attribute_map->{$attribute_name} - if $self->has_attribute($attribute_name); - return; + # NOTE: + # this will return undef anyway, so no need ... + # if $self->has_attribute($attribute_name); + #return; } sub remove_attribute { @@ -472,8 +674,8 @@ sub remove_attribute { my $removed_attribute = $self->get_attribute_map->{$attribute_name}; return unless defined $removed_attribute; delete $self->get_attribute_map->{$attribute_name}; - $removed_attribute->remove_accessors(); - $removed_attribute->detach_from_class(); + $removed_attribute->remove_accessors(); + $removed_attribute->detach_from_class(); return $removed_attribute; } @@ -504,53 +706,61 @@ sub compute_all_applicable_attributes { return @attrs; } -# Class attributes - -sub add_package_variable { - my ($self, $variable, $initial_value) = @_; - (defined $variable && $variable =~ /^[\$\@\%]/) - || confess "variable name does not have a sigil"; - - my ($sigil, $name) = ($variable =~ /^(.)(.*)$/); - if (defined $initial_value) { - no strict 'refs'; - *{$self->name . '::' . $name} = $initial_value; - } - else { - eval $sigil . $self->name . '::' . $name; - confess "Could not create package variable ($variable) because : $@" if $@; +sub find_attribute_by_name { + my ($self, $attr_name) = @_; + # keep a record of what we have seen + # here, this will handle all the + # inheritence issues because we are + # using the &class_precedence_list + my %seen_class; + foreach my $class ($self->class_precedence_list()) { + next if $seen_class{$class}; + $seen_class{$class}++; + # fetch the meta-class ... + my $meta = $self->initialize($class); + return $meta->get_attribute($attr_name) + if $meta->has_attribute($attr_name); } + return; } -sub has_package_variable { - my ($self, $variable) = @_; - (defined $variable && $variable =~ /^[\$\@\%]/) - || confess "variable name does not have a sigil"; - my ($sigil, $name) = ($variable =~ /^(.)(.*)$/); - no strict 'refs'; - defined ${$self->name . '::'}{$name} ? 1 : 0; -} +## Class closing -sub get_package_variable { - my ($self, $variable) = @_; - (defined $variable && $variable =~ /^[\$\@\%]/) - || confess "variable name does not have a sigil"; - my ($sigil, $name) = ($variable =~ /^(.)(.*)$/); - no strict 'refs'; - # try to fetch it first,.. see what happens - my $ref = eval '\\' . $sigil . $self->name . '::' . $name; - confess "Could not get the package variable ($variable) because : $@" if $@; - # if we didn't die, then we can return it - return $ref; -} +sub is_mutable { 1 } +sub is_immutable { 0 } -sub remove_package_variable { - my ($self, $variable) = @_; - (defined $variable && $variable =~ /^[\$\@\%]/) - || confess "variable name does not have a sigil"; - my ($sigil, $name) = ($variable =~ /^(.)(.*)$/); - no strict 'refs'; - delete ${$self->name . '::'}{$name}; +{ + # NOTE: + # the immutable version of a + # particular metaclass is + # really class-level data so + # we don't want to regenerate + # it any more than we need to + my $IMMUTABLE_METACLASS; + sub make_immutable { + my ($self) = @_; + + $IMMUTABLE_METACLASS ||= Class::MOP::Immutable->new($self, { + read_only => [qw/superclasses/], + cannot_call => [qw/ + add_method + alias_method + remove_method + add_attribute + remove_attribute + add_package_symbol + remove_package_symbol + /], + memoize => { + class_precedence_list => 'ARRAY', + compute_all_applicable_attributes => 'ARRAY', + get_meta_instance => 'SCALAR', + get_method_map => 'SCALAR', + } + }); + + $IMMUTABLE_METACLASS->make_metaclass_immutable(@_) + } } 1; @@ -565,6 +775,9 @@ Class::MOP::Class - Class Meta Object =head1 SYNOPSIS + # assuming that class Foo + # has been defined, you can + # use this for introspection ... # add a method to Foo ... @@ -579,7 +792,8 @@ Class::MOP::Class - Class Meta Object # or use this to actually create classes ... - Class::MOP::Class->create('Bar' => '0.01' => ( + Class::MOP::Class->create('Bar' => ( + version => '0.01', superclasses => [ 'Foo' ], attributes => [ Class::MOP:::Attribute->new('$bar'), @@ -630,21 +844,37 @@ created any more than nessecary. Basically, they are singletons. =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<$package_name> into existence and adding any of the -C<$package_version>, C<@superclasses>, C<%methods> and C<%attributes> -to it. +C<$package_name> into existence and adding any of the C<$version>, +C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to +it. + +=item B ?@superclasses, + methods =E ?%methods, + attributes =E ?%attributes)> -=item B +This will create an anonymous class, it works much like C but +it does not need a C<$package_name>. Instead it will create a suitably +unique package name for you to stash things into. + +=item B This initializes and returns returns a B object for a given a C<$package_name>. +=item B + +This removes the old metaclass, and creates a new one in it's place. +Do B use this unless you really know what you are doing, it could +very easily make a very large mess of your program. + =item B This will construct an instance of B, it is @@ -670,6 +900,10 @@ to use them or not. =over 4 +=item B + +=item B + =item B This is a convience method for creating a new object of the class, and @@ -735,17 +969,15 @@ is too I to be part of the MOP. =head2 Informational -=over 4 +These are a few predicate methods for asking information about the class. -=item B +=over 4 -This is a read-only attribute which returns the package name for the -given B instance. +=item B -=item B +=item B -This is a read-only attribute which returns the C<$VERSION> of the -package for the given B instance. +=item B =back @@ -778,6 +1010,8 @@ what B does, but we don't remove duplicate names. =over 4 +=item B + =item B =item B @@ -827,9 +1061,19 @@ C<$method_name> is actually a method. However, it will DWIM about =item B -This will return a CODE reference of the specified C<$method_name>, +This will return a Class::MOP::Method instance related to the specified +C<$method_name>, or return undef if that method does not exist. + +The Class::MOP::Method is codifiable, so you can use it like a normal +CODE reference, see L for more information. + +=item B + +This will return a CODE reference of the specified C<$method_name>, or return undef if that method does not exist. +Unlike C this will also look in the superclasses. + =item B This will attempt to remove a given C<$method_name> from the class. @@ -984,13 +1228,13 @@ their own. See L for more details. =item B -=item B +=item B -This stores a C<$attribute_meta_object> in the B -instance associated with the given class, and associates it with -the C<$attribute_name>. Unlike methods, attributes within the MOP -are stored as meta-information only. They will be used later to -construct instances from (see C above). +This stores the C<$attribute_meta_object> (or creates one from the +C<$attribute_name> and C<%attribute_spec>) in the B +instance associated with the given class. Unlike methods, attributes +within the MOP are stored as meta-information only. They will be used +later to construct instances from (see C above). More details about the attribute meta-objects can be found in the L or the L section. @@ -999,6 +1243,11 @@ It should be noted that any accessor, reader/writer or predicate methods which the C<$attribute_meta_object> has will be installed into the class at this time. +B +If an attribute already exists for C<$attribute_name>, the old one +will be removed (as well as removing all it's accessors), and then +the new one added. + =item B Checks to see if this class has an attribute by the name of @@ -1040,52 +1289,35 @@ HASH reference like C because all that same information is discoverable through the attribute meta-object itself. -=back - -=head2 Package Variables +=item B -Since Perl's classes are built atop the Perl package system, it is -fairly common to use package scoped variables for things like static -class variables. The following methods are convience methods for -the creation and inspection of package scoped variables. +This method will traverse the inheritance heirachy and find the +first attribute whose name matches C<$attr_name>, then return it. +It will return undef if nothing is found. -=over 4 - -=item B - -Given a C<$variable_name>, which must contain a leading sigil, this -method will create that variable within the package which houses the -class. It also takes an optional C<$initial_value>, which must be a -reference of the same type as the sigil of the C<$variable_name> -implies. - -=item B - -This will return a reference to the package variable in -C<$variable_name>. - -=item B +=back -Returns true (C<1>) if there is a package variable defined for -C<$variable_name>, and false (C<0>) otherwise. +=head2 Class closing -=item B +=over 4 -This will attempt to remove the package variable at C<$variable_name>. +=item B =back -=head1 AUTHOR +=head1 AUTHORS Stevan Little Estevan@iinteractive.comE +Yuval Kogman Enothingmuch@woobling.comE + =head1 COPYRIGHT AND LICENSE -Copyright 2006 by Infinity Interactive, Inc. +Copyright 2006, 2007 by Infinity Interactive, Inc. L This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. -=cut \ No newline at end of file +=cut