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', 'weaken';
use Sub::Name 'subname';
use B 'svref_2object';
-our $VERSION = '0.15';
+our $VERSION = '0.24';
+our $AUTHORITY = 'cpan:STEVAN';
use base 'Class::MOP::Module';
-use Class::MOP::Instance;
-
-# Self-introspection
+# Self-introspection
sub meta { Class::MOP::Class->initialize(blessed($_[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;
-
- # 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;
- 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";
+ if (defined(my $meta = Class::MOP::get_metaclass_by_name($package_name))) {
+ return $meta;
}
-
- 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, @_);
- }
-
+ $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";
# NOTE:
- # we need a sufficiently annoying prefix
- # this should suffice for now
- my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
-
- {
+ # 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)
+
+ if (defined(my $meta = Class::MOP::get_metaclass_by_name($package_name))) {
+ return $meta;
+ }
+
+ # 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 eq 'Class::MOP::Class') {
+ no strict 'refs';
+ $meta = bless {
+ # inherited from Class::MOP::Package
+ '$!package' => $package_name,
+
+ # NOTE:
+ # since the following attributes will
+ # actually be loaded from the symbol
+ # table, and actually bypass the instance
+ # entirely, we can just leave these things
+ # listed here for reference, because they
+ # should not actually have a value associated
+ # with the slot.
+ '%!namespace' => \undef,
+ # inherited from Class::MOP::Module
+ '$!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:
- # 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: (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";
+ # 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)
+ }
+
+ # 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->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;
+
# 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};
- $class = blessed($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' => $options{':method_metaclass'} || 'Class::MOP::Method',
- '$: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)
- }
- # and check the metaclass compatibility
- $meta->check_metaclass_compatability();
- $METAS{$package_name} = $meta;
+ # 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 need to weaken any anon classes
- # so that they can call DESTROY properly
- weaken($METAS{$package_name})
- if $package_name =~ /^$ANON_CLASS_PREFIX/;
- $meta;
- }
-
+ # we also need to check that instance metaclasses
+ # are compatabile in the same the class.
+ ($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 will only get called for
- # anon-classes, all other calls
- # are assumed to occur during
+ # 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;
+ }
+
+ sub create_anon_class {
+ my ($class, %options) = @_;
+ my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
+ return $class->create($package_name, %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;
+ no warnings 'uninitialized';
return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
- no strict 'refs';
+ 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 . '::'};
+ delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
}
-
- 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 = $METAS{$class_name} || next;
- ($self->isa(blessed($meta)))
- || confess $self->name . "->meta => (" . (blessed($self)) . ")" .
- " is not compatible with the " .
- $class_name . "->meta => (" . (blessed($meta)) . ")";
- # NOTE:
- # 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) . ")";
- }
- }
}
+# 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 $@;
+ confess "creation of $package_name failed : $@" if $@;
+
my $meta = $class->initialize($package_name);
-
- $meta->add_method('meta' => sub {
+
+ $meta->add_method('meta' => sub {
$class->initialize(blessed($_[0]) || $_[0]);
});
-
+
$meta->superclasses(@{$options{superclasses}})
if exists $options{superclasses};
# NOTE:
- # process attributes first, so that they can
+ # process attributes first, so that they can
# install accessors, but locally defined methods
# can then overwrite them. It is maybe a little odd, but
# I think this should be the order of things.
foreach my $attr (@{$options{attributes}}) {
$meta->add_attribute($attr);
}
- }
+ }
if (exists $options{methods}) {
foreach my $method_name (keys %{$options{methods}}) {
$meta->add_method($method_name, $options{methods}->{$method_name});
}
- }
+ }
return $meta;
}
## Attribute readers
# NOTE:
-# all these attribute readers will be bootstrapped
+# 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'} }
+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
sub new_object {
my $class = shift;
# NOTE:
- # we need to protect the integrity of the
+ # we need to protect the integrity of the
# Class::MOP::Class singletons here, so we
# delegate this to &construct_class_instance
# which will deal with the singletons
foreach my $attr ($class->compute_all_applicable_attributes()) {
$attr->initialize_instance_slot($meta_instance, $instance, \%params);
}
+ # NOTE:
+ # this will only work for a HASH instance type
+ if ($class->is_anon_class) {
+ (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
+ # as a reserved slot name, but right now I am
+ # going to keep it here.
+ # my $RESERVED_MOP_SLOT = '__MOP__';
+ $instance->{'__MOP__'} = $class;
+ }
return $instance;
}
sub get_meta_instance {
my $class = shift;
return $class->instance_metaclass->new(
- $class,
+ $class,
$class->compute_all_applicable_attributes()
);
}
sub clone_object {
my $class = shift;
- my $instance = shift;
+ my $instance = shift;
(blessed($instance) && $instance->isa($class->name))
|| confess "You must pass an instance ($instance) of the metaclass (" . $class->name . ")";
# NOTE:
- # we need to protect the integrity of the
- # Class::MOP::Class singletons here, they
+ # we need to protect the integrity of the
+ # Class::MOP::Class singletons here, they
# should not be cloned.
- return $instance if $instance->isa('Class::MOP::Class');
+ return $instance if $instance->isa('Class::MOP::Class');
$class->clone_instance($instance, @_);
}
(blessed($instance))
|| confess "You can only clone instances, \$self is not a blessed instance";
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});
+ my $clone = $meta_instance->clone_instance($instance);
+ foreach my $attr ($class->compute_all_applicable_attributes()) {
+ if (exists $params{$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')};
+ return $clone;
}
# 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 need to check the metaclass
+ # compatibility 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'};
+ @{$self->get_package_symbol('@ISA')};
+}
+
+sub linearized_isa {
+ my %seen;
+ grep { !($seen{$_}++) } (shift)->class_precedence_list
}
sub class_precedence_list {
my $self = shift;
# NOTE:
- # We need to check for ciruclar inheirtance here.
+ # We need to check for circular inheritance here.
# This will do nothing if all is well, and blow
- # up otherwise. Yes, it's an ugly hack, better
+ # up otherwise. Yes, it's an ugly hack, better
# suggestions are welcome.
{ ($self->name || return)->isa('This is a test for circular inheritance') }
- # ... and now back to our regularly scheduled program
+
(
- $self->name,
- map {
+ $self->name,
+ map {
$self->initialize($_)->class_precedence_list()
} $self->superclasses()
- );
+ );
}
## Methods
my ($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);
}
{
$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
+ || confess "The method '$method_name' is not found in the inheritance 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
+ # 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);
+ 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";
+ || 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";
+ || 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:
+ # 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
+ # 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
+ # 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.
}
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) || ''))
+
+ my $body = (blessed($method) ? $method->body : $method);
+ ('CODE' eq (reftype($body) || ''))
|| 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} = $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);
+ || confess "You must define a method name";
+
+ return 0 unless exists $self->get_method_map->{$method_name};
return 1;
}
(defined $method_name && $method_name)
|| confess "You must define a method name";
- return unless $self->has_method($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);
- no strict 'refs';
- return \&{$self->name . '::' . $method_name};
+ return $self->get_method_map->{$method_name};
}
sub remove_method {
my ($self, $method_name) = @_;
(defined $method_name && $method_name)
|| confess "You must define a method name";
-
- my $removed_method = $self->get_method($method_name);
-
- no strict 'refs';
- delete ${$self->name . '::'}{$method_name}
- if defined $removed_method;
-
+
+ my $removed_method = $self->get_method($method_name);
+
+ 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 { $self->has_method($_) } keys %{$self->name . '::'};
+ keys %{$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";
+ 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);
+ }
+ return;
}
sub compute_all_applicable_methods {
my $self = shift;
- my @methods;
- # 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, %seen_method);
- foreach my $class ($self->class_precedence_list()) {
- next if $seen_class{$class};
- $seen_class{$class}++;
+ my (@methods, %seen_method);
+ foreach my $class ($self->linearized_isa) {
# fetch the meta-class ...
my $meta = $self->initialize($class);
- foreach my $method_name ($meta->get_method_list()) {
+ foreach my $method_name ($meta->get_method_list()) {
next if exists $seen_method{$method_name};
$seen_method{$method_name}++;
push @methods => {
- name => $method_name,
+ name => $method_name,
class => $class,
code => $meta->get_method($method_name)
};
sub find_all_methods_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";
my @methods;
- # 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}++;
+ foreach my $class ($self->linearized_isa) {
# fetch the meta-class ...
my $meta = $self->initialize($class);
push @methods => {
- name => $method_name,
+ name => $method_name,
class => $class,
code => $meta->get_method($method_name)
} if $meta->has_method($method_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";
- # 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();
+ || confess "You must define a method name to find";
+ my @cpl = $self->linearized_isa;
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)
+ return $meta->get_method($method_name)
if $meta->has_method($method_name);
}
return;
my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
# make sure it is derived from the correct type though
($attribute->isa('Class::MOP::Attribute'))
- || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
+ || 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);
+
+ # 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} = $attribute;
-
- # FIXME
- # in theory we have to tell everyone the slot structure may have changed
}
sub has_attribute {
my ($self, $attribute_name) = @_;
(defined $attribute_name && $attribute_name)
|| confess "You must define an attribute name";
- exists $self->get_attribute_map->{$attribute_name} ? 1 : 0;
-}
+ exists $self->get_attribute_map->{$attribute_name} ? 1 : 0;
+}
sub get_attribute {
my ($self, $attribute_name) = @_;
(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;
-}
+ return $self->get_attribute_map->{$attribute_name}
+ # NOTE:
+ # this will return undef anyway, so no need ...
+ # if $self->has_attribute($attribute_name);
+ #return;
+}
sub remove_attribute {
my ($self, $attribute_name) = @_;
(defined $attribute_name && $attribute_name)
|| confess "You must define an attribute name";
- my $removed_attribute = $self->get_attribute_map->{$attribute_name};
+ 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();
+ delete $self->get_attribute_map->{$attribute_name};
+ $removed_attribute->remove_accessors();
$removed_attribute->detach_from_class();
return $removed_attribute;
-}
+}
sub get_attribute_list {
my $self = shift;
keys %{$self->get_attribute_map};
-}
+}
sub compute_all_applicable_attributes {
my $self = shift;
- my @attrs;
- # 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, %seen_attr);
- foreach my $class ($self->class_precedence_list()) {
- next if $seen_class{$class};
- $seen_class{$class}++;
+ my (@attrs, %seen_attr);
+ foreach my $class ($self->linearized_isa) {
# fetch the meta-class ...
my $meta = $self->initialize($class);
- foreach my $attr_name ($meta->get_attribute_list()) {
+ foreach my $attr_name ($meta->get_attribute_list()) {
next if exists $seen_attr{$attr_name};
$seen_attr{$attr_name}++;
push @attrs => $meta->get_attribute($attr_name);
}
}
- return @attrs;
+ return @attrs;
}
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}++;
+ foreach my $class ($self->linearized_isa) {
# fetch the meta-class ...
my $meta = $self->initialize($class);
return $meta->get_attribute($attr_name)
return;
}
-# Class attributes
+## Class closing
-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 {
- my $e;
- {
- # NOTE:
- # We HAVE to localize $@ or all
- # hell breaks loose. It is not
- # good, believe me, not good.
- local $@;
- eval $sigil . $self->name . '::' . $name;
- $e = $@ if $@;
- }
- confess "Could not create package variable ($variable) because : $e" if $e;
- }
-}
+sub is_mutable { 1 }
+sub is_immutable { 0 }
-sub has_package_variable {
- my ($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;
-}
+# 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 get_package_variable {
- my ($self, $variable) = @_;
- (defined $variable && $variable =~ /^[\$\@\%]/)
- || confess "variable name does not have a sigil";
- my ($sigil, $name) = ($variable =~ /^(.)(.*)$/);
- my ($ref, $e);
- {
- # NOTE:
- # We HAVE to localize $@ or all
- # hell breaks loose. It is not
- # good, believe me, not good.
- local $@;
- $ref = eval '\\' . $sigil . $self->name . '::' . $name;
- $e = $@ if $@;
- }
- confess "Could not get the package variable ($variable) because : $e" if $e;
- # if we didn't die, then we can return it
- return $ref;
-}
+{
+ my %IMMUTABLE_TRANSFORMERS;
+ my %IMMUTABLE_OPTIONS;
+ sub make_immutable {
+ my $self = shift;
+ my %options = @_;
+ my $class = blessed $self || $self;
-sub remove_package_variable {
- my ($self, $variable) = @_;
- (defined $variable && $variable =~ /^[\$\@\%]/)
- || confess "variable name does not have a sigil";
- my ($sigil, $name) = ($variable =~ /^(.)(.*)$/);
- no strict 'refs';
- delete ${$self->name . '::'}{$name};
-}
+ $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
+ my $transformer = $IMMUTABLE_TRANSFORMERS{$class};
-## Class closing
+ $transformer->make_metaclass_immutable($self, %options);
+ $IMMUTABLE_OPTIONS{$self->name} =
+ { %options, IMMUTABLE_TRANSFORMER => $transformer };
-sub is_mutable { 1 }
-sub is_immutable { 0 }
+ if( exists $options{debug} && $options{debug} ){
+ print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
+ print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
+ }
+ }
-sub make_immutable {
- my ($class) = @_;
- return Class::MOP::Class::Immutable->make_metaclass_immutable($class);
+ 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);
+ }
+}
+
+sub create_immutable_transformer {
+ 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
+ add_package_symbol
+ remove_package_symbol
+ /],
+ memoize => {
+ class_precedence_list => 'ARRAY',
+ linearized_isa => 'ARRAY',
+ compute_all_applicable_attributes => 'ARRAY',
+ get_meta_instance => 'SCALAR',
+ get_method_map => 'SCALAR',
+ }
+ });
+ return $class;
}
1;
=pod
-=head1 NAME
+=head1 NAME
Class::MOP::Class - Class Meta Object
=head1 SYNOPSIS
- # assuming that class Foo
+ # assuming that class Foo
# has been defined, you can
-
+
# use this for introspection ...
-
+
# add a method to Foo ...
Foo->meta->add_method('bar' => sub { ... })
-
- # get a list of all the classes searched
- # the method dispatcher in the correct order
+
+ # get a list of all the classes searched
+ # the method dispatcher in the correct order
Foo->meta->class_precedence_list()
-
+
# remove a method from Foo
Foo->meta->remove_method('bar');
-
+
# or use this to actually create classes ...
-
- Class::MOP::Class->create('Bar' => '0.01' => (
+
+ Class::MOP::Class->create('Bar' => (
+ version => '0.01',
superclasses => [ 'Foo' ],
attributes => [
Class::MOP:::Attribute->new('$bar'),
- Class::MOP:::Attribute->new('$baz'),
+ Class::MOP:::Attribute->new('$baz'),
],
methods => {
calculate_bar => sub { ... },
- construct_baz => 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
+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.
=head1 METHODS
=item B<meta>
-This will return a B<Class::MOP::Class> instance which is related
-to this class. Thereby allowing B<Class::MOP::Class> to actually
+This will return a B<Class::MOP::Class> instance which is related
+to this class. Thereby allowing B<Class::MOP::Class> to actually
introspect itself.
-As with B<Class::MOP::Attribute>, B<Class::MOP> 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.
-
-=item B<get_all_metaclasses>
-
-This will return an hash of all the metaclass instances that have
-been cached by B<Class::MOP::Class> keyed by the package name.
-
-=item B<get_all_metaclass_instances>
-
-This will return an array of all the metaclass instances that have
-been cached by B<Class::MOP::Class>.
-
-=item B<get_all_metaclass_names>
-
-This will return an array of all the metaclass names that have
-been cached by B<Class::MOP::Class>.
+As with B<Class::MOP::Attribute>, B<Class::MOP> 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
=head2 Class construction
-These methods will handle creating B<Class::MOP::Class> objects,
-which can be used to both create new classes, and analyze
-pre-existing classes.
+These methods will handle creating B<Class::MOP::Class> objects,
+which can be used to both create new classes, and analyze
+pre-existing classes.
-This module will internally store references to all the instances
-you create with these methods, so that they do not need to be
+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.
=over 4
-=item B<create ($package_name, ?$package_version,
- superclasses =E<gt> ?@superclasses,
- methods =E<gt> ?%methods,
+=item B<create ($package_name,
+ version =E<gt> ?$version,
+ authority =E<gt> ?$authority,
+ superclasses =E<gt> ?@superclasses,
+ methods =E<gt> ?%methods,
attributes =E<gt> ?%attributes)>
-This returns a B<Class::MOP::Class> object, bringing the specified
-C<$package_name> into existence and adding any of the
-C<$package_version>, C<@superclasses>, C<%methods> and C<%attributes>
-to it.
+This returns a B<Class::MOP::Class> object, bringing the specified
+C<$package_name> into existence and adding any of the C<$version>,
+C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
+it.
-=item B<create_anon_class (superclasses =E<gt> ?@superclasses,
- methods =E<gt> ?%methods,
+=item B<create_anon_class (superclasses =E<gt> ?@superclasses,
+ methods =E<gt> ?%methods,
attributes =E<gt> ?%attributes)>
-This will create an anonymous class, it works much like C<create> but
-it does not need a C<$package_name>. Instead it will create a suitably
+This will create an anonymous class, it works much like C<create> but
+it does not need a C<$package_name>. Instead it will create a suitably
unique package name for you to stash things into.
+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.
+
+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 B<initialize ($package_name, %options)>
-This initializes and returns returns a B<Class::MOP::Class> object
+This initializes and returns returns a B<Class::MOP::Class> object
for a given a C<$package_name>.
=item B<reinitialize ($package_name, %options)>
This removes the old metaclass, and creates a new one in it's place.
-Do B<not> use this unless you really know what you are doing, it could
-very easily make a very large mess of your program.
+Do B<not> use this unless you really know what you are doing, it could
+very easily make a very large mess of your program.
=item B<construct_class_instance (%options)>
-This will construct an instance of B<Class::MOP::Class>, it is
-here so that we can actually "tie the knot" for B<Class::MOP::Class>
-to use C<construct_instance> once all the bootstrapping is done. This
+This will construct an instance of B<Class::MOP::Class>, it is
+here so that we can actually "tie the knot" for B<Class::MOP::Class>
+to use C<construct_instance> once all the bootstrapping is done. This
method is used internally by C<initialize> and should never be called
from outside of that method really.
=item B<check_metaclass_compatability>
-This method is called as the very last thing in the
-C<construct_class_instance> 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
+This method is called as the very last thing in the
+C<construct_class_instance> 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<About Metaclass compatibility> section in L<Class::MOP>.
=back
=head2 Object instance construction and cloning
-These methods are B<entirely optional>, it is up to you whether you want
+These methods are B<entirely optional>, it is up to you whether you want
to use them or not.
=over 4
=item B<new_object (%params)>
-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
+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<new> this method like so:
- sub MyClass::new {
+ sub MyClass::new {
my ($class, %param) = @_;
$class->meta->new_object(%params);
}
-Of course the ideal place for this would actually be in C<UNIVERSAL::>
+Of course the ideal place for this would actually be in C<UNIVERSAL::>
but that is considered bad style, so we do not do that.
=item B<construct_instance (%params)>
-This method is used to construct an instace structure suitable for
-C<bless>-ing into your package of choice. It works in conjunction
+This method is used to construct an instace structure suitable for
+C<bless>-ing into your package of choice. It works in conjunction
with the Attribute protocol to collect all applicable attributes.
-This will construct and instance using a HASH ref as storage
-(currently only HASH references are supported). This will collect all
-the applicable attributes and layout out the fields in the HASH ref,
-it will then initialize them using either use the corresponding key
-in C<%params> or any default value or initializer found in the
+This will construct and instance using a HASH ref as storage
+(currently only HASH references are supported). This will collect all
+the applicable attributes and layout out the fields in the HASH ref,
+it will then initialize them using either use the corresponding key
+in C<%params> or any default value or initializer found in the
attribute meta-object.
=item B<clone_object ($instance, %params)>
-This is a convience method for cloning an object instance, then
-blessing it into the appropriate package. This method will call
-C<clone_instance>, which performs a shallow copy of the object,
-see that methods documentation for more details. Ideally your
+This is a convience method for cloning an object instance, then
+blessing it into the appropriate package. This method will call
+C<clone_instance>, which performs a shallow copy of the object,
+see that methods documentation for more details. Ideally your
class would call a C<clone> this method like so:
sub MyClass::clone {
$self->meta->clone_object($self, %params);
}
-Of course the ideal place for this would actually be in C<UNIVERSAL::>
+Of course the ideal place for this would actually be in C<UNIVERSAL::>
but that is considered bad style, so we do not do that.
=item B<clone_instance($instance, %params)>
-This method is a compliment of C<construct_instance> (which means if
-you override C<construct_instance>, you need to override this one too),
+This method is a compliment of C<construct_instance> (which means if
+you override C<construct_instance>, you need to override this one too),
and clones the instance shallowly.
-The cloned structure returned is (like with C<construct_instance>) an
-unC<bless>ed HASH reference, it is your responsibility to then bless
+The cloned structure returned is (like with C<construct_instance>) an
+unC<bless>ed HASH reference, it is your responsibility to then bless
this cloned structure into the right class (which C<clone_object> will
do for you).
-As of 0.11, this method will clone the C<$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
+As of 0.11, this method will clone the C<$instance> structure shallowly,
+as opposed to the deep cloning implemented in prior versions. After much
+thought, research and discussion, I have decided that anything but basic
+shallow cloning is outside the scope of the meta-object protocol. I
+think Yuval "nothingmuch" Kogman put it best when he said that cloning
is too I<context-specific> to be part of the MOP.
=back
-=head2 Informational
+=head2 Informational
+
+These are a few predicate methods for asking information about the class.
=over 4
-=item B<name>
+=item B<is_anon_class>
-This is a read-only attribute which returns the package name for the
-given B<Class::MOP::Class> instance.
+This returns true if the class is a C<Class::MOP::Class> created anon class.
-=item B<version>
+=item B<is_mutable>
-This is a read-only attribute which returns the C<$VERSION> of the
-package for the given B<Class::MOP::Class> instance.
+This returns true if the class is still mutable.
+
+=item B<is_immutable>
+
+This returns true if the class has been made immutable.
=back
=item B<superclasses (?@superclasses)>
-This is a read-write attribute which represents the superclass
+This is a read-write attribute which represents the superclass
relationships of the class the B<Class::MOP::Class> instance is
associated with. Basically, it can get and set the C<@ISA> for you.
B<NOTE:>
-Perl will occasionally perform some C<@ISA> and method caching, if
-you decide to change your superclass relationship at runtime (which
-is quite insane and very much not recommened), then you should be
-aware of this and the fact that this module does not make any
+Perl will occasionally perform some C<@ISA> and method caching, if
+you decide to change your superclass relationship at runtime (which
+is quite insane and very much not recommened), then you should be
+aware of this and the fact that this module does not make any
attempt to address this issue.
=item B<class_precedence_list>
-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
+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<Class::ISA::super_path> does, but we don't remove duplicate names.
+=item B<linearized_isa>
+
+This returns a list based on C<class_precedence_list> but with all
+duplicates removed.
+
=back
=head2 Methods
=over 4
+=item B<get_method_map>
+
=item B<method_metaclass>
=item B<add_method ($method_name, $method)>
-This will take a C<$method_name> and CODE reference to that
-C<$method> and install it into the class's package.
+This will take a C<$method_name> and CODE reference to that
+C<$method> and install it into the class's package.
-B<NOTE>:
-This does absolutely nothing special to C<$method>
-other than use B<Sub::Name> to make sure it is tagged with the
-correct name, and therefore show up correctly in stack traces and
+B<NOTE>:
+This does absolutely nothing special to C<$method>
+other than use B<Sub::Name> to make sure it is tagged with the
+correct name, and therefore show up correctly in stack traces and
such.
=item B<alias_method ($method_name, $method)>
-This will take a C<$method_name> and CODE reference to that
-C<$method> and alias the method into the class's package.
+This will take a C<$method_name> and CODE reference to that
+C<$method> and alias the method into the class's package.
-B<NOTE>:
-Unlike C<add_method>, this will B<not> try to name the
-C<$method> using B<Sub::Name>, it only aliases the method in
-the class's package.
+B<NOTE>:
+Unlike C<add_method>, this will B<not> try to name the
+C<$method> using B<Sub::Name>, it only aliases the method in
+the class's package.
=item B<has_method ($method_name)>
-This just provides a simple way to check if the class implements
-a specific C<$method_name>. It will I<not> however, attempt to check
+This just provides a simple way to check if the class implements
+a specific C<$method_name>. It will I<not> however, attempt to check
if the class inherits the method (use C<UNIVERSAL::can> for that).
-This will correctly handle functions defined outside of the package
+This will correctly handle functions defined outside of the package
that use a fully qualified name (C<sub Package::name { ... }>).
-This will correctly handle functions renamed with B<Sub::Name> 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<has_method> to
-correctly identify it.
+This will correctly handle functions renamed with B<Sub::Name> 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<has_method> to
+correctly identify it.
-This will attempt to correctly ignore functions imported from other
-packages using B<Exporter>. It breaks down if the function imported
-is an C<__ANON__> sub (such as with C<use constant>), which very well
-may be a valid method being applied to the class.
+This will attempt to correctly ignore functions imported from other
+packages using B<Exporter>. It breaks down if the function imported
+is an C<__ANON__> sub (such as with C<use constant>), which very well
+may be a valid method being applied to the class.
-In short, this method cannot always be trusted to determine if the
-C<$method_name> is actually a method. However, it will DWIM about
+In short, this method cannot always be trusted to determine if the
+C<$method_name> is actually a method. However, it will DWIM about
90% of the time, so it's a small trade off I think.
=item B<get_method ($method_name)>
-This will return a CODE reference of the specified C<$method_name>,
+This will return a Class::MOP::Method instance related to the specified
+C<$method_name>, or return undef if that method does not exist.
+
+The Class::MOP::Method is codifiable, so you can use it like a normal
+CODE reference, see L<Class::MOP::Method> for more information.
+
+=item B<find_method_by_name ($method_name>
+
+This will return a CODE reference of the specified C<$method_name>,
or return undef if that method does not exist.
+Unlike C<get_method> this will also look in the superclasses.
+
=item B<remove_method ($method_name)>
-This will attempt to remove a given C<$method_name> from the class.
-It will return the CODE reference that it has removed, and will
+This will attempt to remove a given C<$method_name> from the class.
+It will return the CODE reference that it has removed, and will
attempt to use B<Sub::Name> to clear the methods associated name.
=item B<get_method_list>
-This will return a list of method names for all I<locally> defined
-methods. It does B<not> provide a list of all applicable methods,
-including any inherited ones. If you want a list of all applicable
+This will return a list of method names for all I<locally> defined
+methods. It does B<not> provide a list of all applicable methods,
+including any inherited ones. If you want a list of all applicable
methods, use the C<compute_all_applicable_methods> method.
=item B<compute_all_applicable_methods>
-This will return a list of all the methods names this class will
-respond to, taking into account inheritance. The list will be a list of
-HASH references, each one containing the following information; method
-name, the name of the class in which the method lives and a CODE
+This will return a list of all the methods names this class will
+respond to, taking into account inheritance. The list will be a list of
+HASH references, each one containing the following information; method
+name, the name of the class in which the method lives and a CODE
reference for the actual method.
=item B<find_all_methods_by_name ($method_name)>
-This will traverse the inheritence hierarchy and locate all methods
-with a given C<$method_name>. Similar to
-C<compute_all_applicable_methods> it returns a list of HASH references
-with the following information; method name (which will always be the
-same as C<$method_name>), the name of the class in which the method
+This will traverse the inheritence hierarchy and locate all methods
+with a given C<$method_name>. Similar to
+C<compute_all_applicable_methods> it returns a list of HASH references
+with the following information; method name (which will always be the
+same as C<$method_name>), the name of the class in which the method
lives and a CODE reference for the actual method.
-The list of methods produced is a distinct list, meaning there are no
-duplicates in it. This is especially useful for things like object
-initialization and destruction where you only want the method called
+The list of methods produced is a distinct list, meaning there are no
+duplicates in it. This is especially useful for things like object
+initialization and destruction where you only want the method called
once, and in the correct order.
=item B<find_next_method_by_name ($method_name)>
-This will return the first method to match a given C<$method_name> in
-the superclasses, this is basically equivalent to calling
+This will return the first method to match a given C<$method_name> in
+the superclasses, this is basically equivalent to calling
C<SUPER::$method_name>, 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<before>, I<after> and I<around> method modifiers
-that will be called everytime the method is called.
+Method modifiers are a concept borrowed from CLOS, in which a method
+can be wrapped with I<before>, I<after> and I<around> 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<before> and I<after> modifiers are ignored. This is
-because thier purpose is B<not> to filter the input and output of the
-primary method (this is done with an I<around> 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<around> 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
+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<before> and I<after> modifiers are ignored. This is
+because thier purpose is B<not> to filter the input and output of the
+primary method (this is done with an I<around> 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<around> 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
after 1
after 2
-To see examples of using method modifiers, see the following examples
-included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
-F<AttributesWithHistory> and F<C3MethodDispatchOrder>. There is also a
+To see examples of using method modifiers, see the following examples
+included in the distribution; F<InstanceCountingClass>, F<Perl6Attribute>,
+F<AttributesWithHistory> and F<C3MethodDispatchOrder>. 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
+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<only> do as much work as it
-absolutely needs to. In order to do this we have moved some of the
+The wrapping method does it's best to B<only> 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 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
+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<AUTOLOAD> which does nothing but extract the name of the method called
-and return it costs about 400% over a normal method call.
+and return it costs about 400% over a normal method call.
=over 4
=item B<add_before_method_modifier ($method_name, $code)>
-This will wrap the method at C<$method_name> and the supplied C<$code>
-will be passed the C<@_> arguments, and called before the original
-method is called. As specified above, the return value of the I<before>
-method modifiers is ignored, and it's ability to modify C<@_> is
-fairly limited. If you need to do either of these things, use an
+This will wrap the method at C<$method_name> and the supplied C<$code>
+will be passed the C<@_> arguments, and called before the original
+method is called. As specified above, the return value of the I<before>
+method modifiers is ignored, and it's ability to modify C<@_> is
+fairly limited. If you need to do either of these things, use an
C<around> method modifier.
=item B<add_after_method_modifier ($method_name, $code)>
-This will wrap the method at C<$method_name> so that the original
-method will be called, it's return values stashed, and then the
+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<after> 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
+As specified above, the return value of the I<after> 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<around> method modifier.
=item B<add_around_method_modifier ($method_name, $code)>
-This will wrap the method at C<$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
+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
-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
+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<Class::MOP::Attribute> for more details.
=over 4
=item B<get_attribute_map>
-=item B<add_attribute ($attribute_name, $attribute_meta_object)>
+=item B<add_attribute ($attribute_meta_object | $attribute_name, %attribute_spec)>
-This stores a C<$attribute_meta_object> in the B<Class::MOP::Class>
-instance associated with the given class, and associates it with
-the C<$attribute_name>. Unlike methods, attributes within the MOP
-are stored as meta-information only. They will be used later to
-construct instances from (see C<construct_instance> above).
-More details about the attribute meta-objects can be found in the
+This stores the C<$attribute_meta_object> (or creates one from the
+C<$attribute_name> and C<%attribute_spec>) in the B<Class::MOP::Class>
+instance associated with the given class. Unlike methods, attributes
+within the MOP are stored as meta-information only. They will be used
+later to construct instances from (see C<construct_instance> above).
+More details about the attribute meta-objects can be found in the
L<Class::MOP::Attribute> or the L<Class::MOP/The Attribute protocol>
section.
-It should be noted that any accessor, reader/writer or predicate
-methods which the C<$attribute_meta_object> has will be installed
+It should be noted that any accessor, reader/writer or predicate
+methods which the C<$attribute_meta_object> has will be installed
into the class at this time.
+B<NOTE>
+If an attribute already exists for C<$attribute_name>, the old one
+will be removed (as well as removing all it's accessors), and then
+the new one added.
+
=item B<has_attribute ($attribute_name)>
-Checks to see if this class has an attribute by the name of
+Checks to see if this class has an attribute by the name of
C<$attribute_name> and returns a boolean.
=item B<get_attribute ($attribute_name)>
-Returns the attribute meta-object associated with C<$attribute_name>,
-if none is found, it will return undef.
+Returns the attribute meta-object associated with C<$attribute_name>,
+if none is found, it will return undef.
=item B<remove_attribute ($attribute_name)>
-This will remove the attribute meta-object stored at
-C<$attribute_name>, then return the removed attribute meta-object.
+This will remove the attribute meta-object stored at
+C<$attribute_name>, then return the removed attribute meta-object.
-B<NOTE:>
-Removing an attribute will only affect future instances of
-the class, it will not make any attempt to remove the attribute from
+B<NOTE:>
+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.
-It should be noted that any accessor, reader/writer or predicate
-methods which the attribute meta-object stored at C<$attribute_name>
-has will be removed from the class at this time. This B<will> make
-these attributes somewhat inaccessable in previously created
-instances. But if you are crazy enough to do this at runtime, then
+It should be noted that any accessor, reader/writer or predicate
+methods which the attribute meta-object stored at C<$attribute_name>
+has will be removed from the class at this time. This B<will> 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 :).
=item B<get_attribute_list>
-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,
+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<compute_all_applicable_attributes> method.
=item B<compute_all_applicable_attributes>
-This will traverse the inheritance heirachy and return a list of all
-the applicable attributes for this class. It does not construct a
-HASH reference like C<compute_all_applicable_methods> because all
-that same information is discoverable through the attribute
+This will traverse the inheritance heirachy and return a list of all
+the applicable attributes for this class. It does not construct a
+HASH reference like C<compute_all_applicable_methods> because all
+that same information is discoverable through the attribute
meta-object itself.
=item B<find_attribute_by_name ($attr_name)>
-This method will traverse the inheritance heirachy and find the
-first attribute whose name matches C<$attr_name>, then return it.
+This method will traverse the inheritance heirachy and find the
+first attribute whose name matches C<$attr_name>, then return it.
It will return undef if nothing is found.
=back
-=head2 Package Variables
-
-Since Perl's classes are built atop the Perl package system, it is
-fairly common to use package scoped variables for things like static
-class variables. The following methods are convience methods for
-the creation and inspection of package scoped variables.
+=head2 Class Immutability
=over 4
-=item B<add_package_variable ($variable_name, ?$initial_value)>
+=item B<make_immutable (%options)>
-Given a C<$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.
+This method will invoke a tranforamtion upon the class which will
+make it immutable. Details of this transformation can be found in
+the L<Class::MOP::Immutable> documentation.
-=item B<get_package_variable ($variable_name)>
+=item B<make_mutable>
-This will return a reference to the package variable in
-C<$variable_name>.
+This method will reverse tranforamtion upon the class which
+made it immutable.
-=item B<has_package_variable ($variable_name)>
-
-Returns true (C<1>) if there is a package variable defined for
-C<$variable_name>, and false (C<0>) otherwise.
-
-=item B<remove_package_variable ($variable_name)>
-
-This will attempt to remove the package variable at C<$variable_name>.
-
-=back
-
-=head2 Class closing
-
-=over 4
-
-=item B<is_mutable>
-
-=item B<is_immutable>
+=item B<create_immutable_transformer>
-=item B<make_immutable>
+Create a transformer suitable for making this class immutable
=back
-=head1 AUTHOR
+=head1 AUTHORS
Stevan Little E<lt>stevan@iinteractive.comE<gt>
=head1 COPYRIGHT AND LICENSE
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006, 2007 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+it under the same terms as Perl itself.
=cut