X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FMOP%2FClass.pm;h=b2cb51d9e665aca776a84672703039d0c4e5ceeb;hb=9d6dce77cd867d92c418eb4fcfd199eaca6efc10;hp=a6514cd6b89305176821d6cd5cbf0d02dc02780b;hpb=19d4b5b84fffff46f1b46f7dae5966fea399d003;p=gitmo%2FClass-MOP.git diff --git a/lib/Class/MOP/Class.pm b/lib/Class/MOP/Class.pm index a6514cd..b2cb51d 100644 --- a/lib/Class/MOP/Class.pm +++ b/lib/Class/MOP/Class.pm @@ -5,17 +5,29 @@ use strict; use warnings; use Carp 'confess'; -use Scalar::Util 'blessed', 'reftype'; +use Scalar::Util 'blessed', 'reftype', 'weaken'; use Sub::Name 'subname'; use B 'svref_2object'; -use Clone (); -our $VERSION = '0.04'; +our $VERSION = '0.17'; + +use base 'Class::MOP::Module'; + +use Class::MOP::Instance; # Self-introspection sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) } +# Class globals ... + +# 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 $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::'; + # Creation { @@ -23,7 +35,13 @@ sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) } # 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; + my %METAS; + + # means of accessing all the metaclasses that have + # been initialized thus far (for mugwumps obj browser) + sub get_all_metaclasses { %METAS } + sub get_all_metaclass_instances { values %METAS } + sub get_all_metaclass_names { keys %METAS } sub initialize { my $class = shift; @@ -33,6 +51,15 @@ sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) } $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"; + $METAS{$package_name} = undef; + $class->construct_class_instance(':package' => $package_name, @_); + } + # NOTE: (meta-circularity) # this is a special form of &construct_instance # (see below), which is used to construct class @@ -45,16 +72,34 @@ sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) } 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}; + # 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 $METAS{$package_name} + if exists $METAS{$package_name} && defined $METAS{$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); + $class = blessed($class) || $class; # now create the metaclass my $meta; - if ($class =~ /^Class::MOP::/) { + if ($class =~ /^Class::MOP::Class$/) { $meta = bless { '$:package' => $package_name, '%:attributes' => {}, '$:attribute_metaclass' => $options{':attribute_metaclass'} || 'Class::MOP::Attribute', - '$:method_metaclass' => $options{':method_metaclass'} || 'Class::MOP::Method', + '$:method_metaclass' => $options{':method_metaclass'} || 'Class::MOP::Method', + '$:instance_metaclass' => $options{':instance_metaclass'} || 'Class::MOP::Instance', } => $class; } else { @@ -62,32 +107,90 @@ sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) } # 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 + $meta = $class->meta->construct_instance(%options) } # and check the metaclass compatibility $meta->check_metaclass_compatability(); $METAS{$package_name} = $meta; - } + # NOTE: + # we need to weaken any anon classes + # so that they can call DESTROY properly + weaken($METAS{$package_name}) + if $package_name =~ /^$ANON_CLASS_PREFIX/; + $meta; + } sub check_metaclass_compatability { my $self = shift; # this is always okay ... - return if blessed($self) eq 'Class::MOP::Class'; + 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 = $METAS{$class_name}; - ($self->isa(blessed($meta))) + my $meta = $METAS{$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 " . - $class_name . "->meta => (" . (blessed($meta)) . ")"; + $class_name . "->meta => (" . ($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 + +{ + # NOTE: + # this should be sufficient, if you have a + # use case where it is not, write a test and + # I will change it. + my $ANON_CLASS_SERIAL = 0; + + sub create_anon_class { + my ($class, %options) = @_; + my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL; + return $class->create($package_name, '0.00', %options); } +} + +# 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; + 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) = @_; (defined $package_name && $package_name) @@ -100,7 +203,7 @@ sub create { 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}}) @@ -129,10 +232,10 @@ 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 instance_metaclass { $_[0]->{'$:instance_metaclass'} } # Instance Construction & Cloning @@ -145,25 +248,27 @@ 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; @@ -174,38 +279,38 @@ 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 $key (keys %params) { + next unless $meta_instance->is_valid_slot($key); + $meta_instance->set_slot_value($clone, $key, $params{$key}); + } return $clone; } -# Informational - -# &name should be here too, but it is above -# because it gets bootstrapped away - -sub version { - my $self = shift; - no strict 'refs'; - ${$self->name . '::VERSION'}; -} - # Inheritance sub superclasses { my $self = shift; - no strict 'refs'; if (@_) { my @supers = @_; - @{$self->name . '::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->name . '::ISA'}; + @{$self->get_package_symbol('@ISA')}; } sub class_precedence_list { @@ -215,8 +320,8 @@ 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 { @@ -232,13 +337,79 @@ sub add_method { (defined $method_name && $method_name) || confess "You must define a method name"; # use reftype here to allow for blessed subs ... - (reftype($method) && reftype($method) eq 'CODE') + ('CODE' eq (reftype($method) || '')) || confess "Your code block must be a CODE reference"; my $full_method_name = ($self->name . '::' . $method_name); - - no strict 'refs'; - no warnings 'redefine'; - *{$full_method_name} = subname $full_method_name => $method; + + # FIXME: + # dont bless subs, its bad mkay + $method = $self->method_metaclass->wrap($method) unless blessed($method); + + $self->add_package_symbol("&${method_name}" => subname $full_method_name => $method); +} + +{ + 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 this class"; + # 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 { @@ -246,35 +417,36 @@ sub alias_method { (defined $method_name && $method_name) || confess "You must define a method name"; # use reftype here to allow for blessed subs ... - (reftype($method) && reftype($method) eq 'CODE') + ('CODE' eq (reftype($method) || '')) || confess "Your code block must be a CODE reference"; - my $full_method_name = ($self->name . '::' . $method_name); + + # FIXME: + # dont bless subs, its bad mkay + $method = $self->method_metaclass->wrap($method) unless blessed($method); - no strict 'refs'; - no warnings 'redefine'; - *{$full_method_name} = $method; + $self->add_package_symbol("&${method_name}" => $method); } -{ - - ## private utility functions for has_method - my $_find_subroutine_package_name = sub { eval { svref_2object($_[0])->GV->STASH->NAME } || '' }; - my $_find_subroutine_name = sub { eval { svref_2object($_[0])->GV->NAME } || '' }; +sub find_method_by_name { + my ($self, $method_name) = @_; + return $self->name->can($method_name); +} - sub has_method { - my ($self, $method_name) = @_; - (defined $method_name && $method_name) - || confess "You must define a method name"; +sub has_method { + my ($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}); - return 0 if $_find_subroutine_package_name->(\&{$sub_name}) ne $self->name && - $_find_subroutine_name->(\&{$sub_name}) ne '__ANON__'; - return 1; - } - + return 0 if !$self->has_package_symbol("&${method_name}"); + my $method = $self->get_package_symbol("&${method_name}"); + return 0 if (svref_2object($method)->GV->STASH->NAME || '') ne $self->name && + (svref_2object($method)->GV->NAME || '') ne '__ANON__'; + + # FIXME: + # dont bless subs, its bad mkay + $self->method_metaclass->wrap($method) unless blessed($method); + + return 1; } sub get_method { @@ -282,10 +454,9 @@ sub get_method { (defined $method_name && $method_name) || confess "You must define a method name"; - no strict 'refs'; - return \&{$self->name . '::' . $method_name} - if $self->has_method($method_name); - return; # <- make sure to return undef + return unless $self->has_method($method_name); + + return $self->get_package_symbol("&${method_name}"); } sub remove_method { @@ -295,8 +466,7 @@ sub remove_method { my $removed_method = $self->get_method($method_name); - no strict 'refs'; - delete ${$self->name . '::'}{$method_name} + $self->remove_package_symbol("&${method_name}") if defined $removed_method; return $removed_method; @@ -304,8 +474,7 @@ sub remove_method { sub get_method_list { my $self = shift; - no strict 'refs'; - grep { $self->has_method($_) } %{$self->name . '::'}; + grep { $self->has_method($_) } $self->list_all_package_symbols; } sub compute_all_applicable_methods { @@ -348,7 +517,7 @@ sub find_all_methods_by_name { next if $seen_class{$class}; $seen_class{$class}++; # fetch the meta-class ... - my $meta = $self->initialize($class);; + my $meta = $self->initialize($class); push @methods => { name => $method_name, class => $class, @@ -356,7 +525,28 @@ sub find_all_methods_by_name { } if $meta->has_method($method_name); } return @methods; +} +sub find_next_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(); + 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; } ## Attributes @@ -370,7 +560,7 @@ sub add_attribute { ($attribute->isa('Class::MOP::Attribute')) || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)"; $attribute->attach_to_class($self); - $attribute->install_accessors(); + $attribute->install_accessors(); $self->get_attribute_map->{$attribute->name} = $attribute; } @@ -397,8 +587,8 @@ 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 $removed_attribute; } @@ -429,55 +619,31 @@ sub compute_all_applicable_attributes { return @attrs; } -# Class attributes - -sub add_package_variable { - my ($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 - 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 - # NOTE: - # this is not ideal, better suggestions are welcome - eval '\\' . $sigil . $self->name . '::' . $name; -} +sub is_mutable { 1 } +sub is_immutable { 0 } -sub remove_package_variable { - my ($self, $variable) = @_; - (defined $variable && $variable =~ /^[\$\@\%]/) - || confess "variable name does not have a sigil"; - my ($sigil, $name) = ($variable =~ /^(.)(.*)$/); - no strict 'refs'; - delete ${$self->name . '::'}{$name}; +sub make_immutable { + return Class::MOP::Class::Immutable->make_metaclass_immutable(@_); } 1; @@ -492,6 +658,9 @@ Class::MOP::Class - Class Meta Object =head1 SYNOPSIS + # assuming that class Foo + # has been defined, you can + # use this for introspection ... # add a method to Foo ... @@ -543,6 +712,21 @@ bootstrap this module by installing a number of attribute meta-objects into it's metaclass. This will allow this class to reap all the benifits of the MOP when subclassing it. +=item B + +This will return an hash of all the metaclass instances that have +been cached by B keyed by the package name. + +=item B + +This will return an array of all the metaclass instances that have +been cached by B. + +=item B + +This will return an array of all the metaclass names that have +been cached by B. + =back =head2 Class construction @@ -567,11 +751,25 @@ C<$package_name> into existence and adding any of the C<$package_version>, C<@superclasses>, C<%methods> and C<%attributes> to it. -=item B +=item B ?@superclasses, + methods =E ?%methods, + attributes =E ?%attributes)> + +This will create an anonymous class, it works much like C but +it does not need a C<$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<$package_name>. +=item B + +This removes the old metaclass, and creates a new one in it's place. +Do B use this unless you really know what you are doing, it could +very easily make a very large mess of your program. + =item B This will construct an instance of B, it is @@ -597,6 +795,10 @@ to use them or not. =over 4 +=item B + +=item B + =item B This is a convience method for creating a new object of the class, and @@ -757,6 +959,13 @@ C<$method_name> is actually a method. However, it will DWIM about This will return a CODE reference of the specified C<$method_name>, or return undef if that method does not exist. +=item B + +This will return a CODE reference of the specified C<$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<$method_name> from the class. @@ -792,6 +1001,110 @@ duplicates in it. This is especially useful for things like object initialization and destruction where you only want the method called once, and in the correct order. +=item B + +This will return the first method to match a given C<$method_name> in +the superclasses, this is basically equivalent to calling +C, but it can be dispatched at runtime. + +=back + +=head2 Method Modifiers + +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. + +=head3 How method modifiers work? + +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: + + before 2 + before 1 + around 2 + around 1 + primary + after 1 + after 2 + +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>. + +=head3 What is the performance impact? + +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. + +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. + +All this said, my benchmarks have indicated the following: + + 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 + +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. + +=item B + +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. + +=item B + +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. + =back =head2 Attributes @@ -863,6 +1176,12 @@ HASH reference like C because all that same information is discoverable through the attribute meta-object itself. +=item B + +This method will traverse the inheritance heirachy and find the +first attribute whose name matches C<$attr_name>, then return it. +It will return undef if nothing is found. + =back =head2 Package Variables @@ -874,7 +1193,7 @@ the creation and inspection of package scoped variables. =over 4 -=item B +=item B Given a C<$variable_name>, which must contain a leading sigil, this method will create that variable within the package which houses the @@ -882,26 +1201,40 @@ 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 +=item B This will return a reference to the package variable in C<$variable_name>. -=item B +=item B Returns true (C<1>) if there is a package variable defined for C<$variable_name>, and false (C<0>) otherwise. -=item B +=item B This will attempt to remove the package variable at C<$variable_name>. =back -=head1 AUTHOR +=head2 Class closing + +=over 4 + +=item B + +=item B + +=item B + +=back + +=head1 AUTHORS Stevan Little Estevan@iinteractive.comE +Yuval Kogman Enothingmuch@woobling.comE + =head1 COPYRIGHT AND LICENSE Copyright 2006 by Infinity Interactive, Inc. @@ -911,4 +1244,4 @@ 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