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';
+use Scalar::Util 'blessed', 'weaken';
-our $VERSION = '0.20';
+our $VERSION = '0.65';
our $AUTHORITY = 'cpan:STEVAN';
use base 'Class::MOP::Module';
-# Self-introspection
-
-sub meta { Class::MOP::Class->initialize(blessed($_[0]) || $_[0]) }
-
# Creation
-
+
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' => $package_name, @_);
+ || confess "You must pass a package name and it cannot be blessed";
+ return Class::MOP::get_metaclass_by_name($package_name)
+ || $class->construct_class_instance('package' => $package_name, @_);
}
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";
+ || 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
+ $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
+# 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'};
+ my $package_name = $options{'package'};
(defined $package_name && $package_name)
- || confess "You must pass a package name";
+ || confess "You must pass a package name";
# NOTE:
- # return the metaclass if we have it cached,
- # and it is still defined (it has not been
- # reaped by DESTROY yet, which can happen
+ # return the metaclass if we have it cached,
+ # and it is still defined (it has not been
+ # reaped by DESTROY yet, which can happen
# annoyingly enough during global destruction)
- return Class::MOP::get_metaclass_by_name($package_name)
- if Class::MOP::does_metaclass_exist($package_name);
+
+ 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
+ # 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
# now create the metaclass
my $meta;
- if ($class =~ /^Class::MOP::Class$/) {
- no strict 'refs';
- $meta = bless {
+ if ($class eq 'Class::MOP::Class') {
+ no strict 'refs';
+ $meta = bless {
# inherited from Class::MOP::Package
- '$:package' => $package_name,
-
+ 'package' => $package_name,
+
# NOTE:
- # since the following attributes will
- # actually be loaded from the symbol
+ # since the following attributes will
+ # actually be loaded from the symbol
# table, and actually bypass the instance
# entirely, we can just leave these things
# listed here for reference, because they
- # should not actually have a value associated
+ # should not actually have a value associated
# with the slot.
- '%:namespace' => \undef,
+ 'namespace' => \undef,
# inherited from Class::MOP::Module
- '$:version' => \undef,
- '$:authority' => \undef,
+ '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' => $options{'instance_metaclass'} || 'Class::MOP::Instance',
- '%:methods' => {},
- '%:attributes' => {},
- '$:attribute_metaclass' => $options{':attribute_metaclass'} || 'Class::MOP::Attribute',
- '$:method_metaclass' => $options{':method_metaclass'} || 'Class::MOP::Method',
- '$:instance_metaclass' => $options{':instance_metaclass'} || 'Class::MOP::Instance',
+ ## uber-private variables
+ # NOTE:
+ # this starts out as undef so that
+ # we can tell the first time the
+ # methods are fetched
+ # - SL
+ '_package_cache_flag' => undef,
+ '_meta_instance' => undef,
} => $class;
}
else {
# NOTE:
# it is safe to use meta here because
- # class will always be a subclass of
+ # 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();
-
+ $meta->check_metaclass_compatability();
+
Class::MOP::store_metaclass_by_name($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;
-}
-
+
+ $meta;
+}
+
+sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
+sub update_package_cache_flag {
+ my $self = shift;
+ # NOTE:
+ # we can manually update the cache number
+ # since we are actually adding the method
+ # to our cache as well. This avoids us
+ # having to regenerate the method_map.
+ # - SL
+ $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
+}
+
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;
+ my @class_list = $self->linearized_isa;
shift @class_list; # shift off $self->name
- foreach my $class_name (@class_list) {
+ foreach my $class_name (@class_list) {
my $meta = Class::MOP::get_metaclass_by_name($class_name) || next;
-
+
# NOTE:
- # we need to deal with the possibility
- # of class immutability here, and then
- # get the name of the class appropriately
+ # 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));
-
+ : blessed($meta));
+
($self->isa($meta_type))
- || confess $self->name . "->meta => (" . (blessed($self)) . ")" .
- " is not compatible with the " .
+ || confess $self->name . "->meta => (" . (blessed($self)) . ")" .
+ " is not compatible with the " .
$class_name . "->meta => (" . ($meta_type) . ")";
# NOTE:
# we also need to check that instance metaclasses
# are compatabile in the same the class.
($self->instance_metaclass->isa($meta->instance_metaclass))
- || confess $self->name . "->meta => (" . ($self->instance_metaclass) . ")" .
- " is not compatible with the " .
- $class_name . "->meta => (" . ($meta->instance_metaclass) . ")";
- }
-}
+ || 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
+ # 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
+ # 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::';
+ my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
sub is_anon_class {
my $self = shift;
- $self->name =~ /^$ANON_CLASS_PREFIX/ ? 1 : 0;
+ no warnings 'uninitialized';
+ $self->name =~ /^$ANON_CLASS_PREFIX/ ? 1 : 0;
}
sub create_anon_class {
- my ($class, %options) = @_;
+ my ($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
+ # 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 create {
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 " .
+ || confess "You much pass all parameters as name => value pairs " .
"(I found an uneven number of params in \@_)";
my (%options) = @_;
+ (ref $options{superclasses} eq 'ARRAY')
+ || confess "You must pass an ARRAY ref of superclasses"
+ if exists $options{superclasses};
+
+ (ref $options{attributes} eq 'ARRAY')
+ || confess "You must pass an ARRAY ref of attributes"
+ if exists $options{attributes};
+
+ (ref $options{methods} eq 'HASH')
+ || confess "You must pass an HASH ref of methods"
+ if exists $options{methods};
+
my $code = "package $package_name;";
- $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';"
+ $code .= "\$$package_name\:\:VERSION = '" . $options{version} . "';"
if exists $options{version};
- $code .= "\$$package_name\:\:AUTHORITY = '" . $options{authority} . "';"
- if exists $options{authority};
-
+ $code .= "\$$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 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 {
+sub get_method_map {
my $self = shift;
- my $map = $self->{'%:methods'};
+ if (defined $self->{'_package_cache_flag'} &&
+ $self->{'_package_cache_flag'} == Class::MOP::check_package_cache_flag($self->name)) {
+ return $self->{'methods'};
+ }
+
+ 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__';
+
+ my %all_code = $self->get_all_package_symbols('CODE');
+
+ foreach my $symbol (keys %all_code) {
+ my $code = $all_code{$symbol};
+
+ next if exists $map->{$symbol} &&
+ defined $map->{$symbol} &&
+ $map->{$symbol}->body == $code;
+
+ my ($pkg, $name) = Class::MOP::get_code_info($code);
- $map->{$symbol} = $method_metaclass->wrap($code);
+ # NOTE:
+ # in 5.10 constant.pm the constants show up
+ # as being in the right package, but in pre-5.10
+ # they show up as constant::__ANON__ so we
+ # make an exception here to be sure that things
+ # work as expected in both.
+ # - SL
+ unless ($pkg eq 'constant' && $name eq '__ANON__') {
+ next if ($pkg || '') ne $class_name ||
+ (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
+ }
+
+ $map->{$symbol} = $method_metaclass->wrap(
+ $code,
+ package_name => $class_name,
+ name => $symbol,
+ );
}
-
+
return $map;
}
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) {
+ (Scalar::Util::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->compute_all_applicable_attributes()
+ my $self = shift;
+ # NOTE:
+ # just about any fiddling with @ISA or
+ # any fiddling with attributes will
+ # also fiddle with the symbol table
+ # and therefore invalidate the package
+ # cache, in which case we should blow
+ # away the meta-instance cache. Of course
+ # this will invalidate it more often then
+ # is probably needed, but better safe
+ # then sorry.
+ # - SL
+ $self->{'_meta_instance'} = undef
+ if defined $self->{'_package_cache_flag'} &&
+ $self->{'_package_cache_flag'} == Class::MOP::check_package_cache_flag($self->name);
+ $self->{'_meta_instance'} ||= $self->instance_metaclass->new(
+ $self,
+ $self->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 . ")";
+ || confess "You must pass an instance of the metaclass (" . $class->name . "), not ($instance)";
+
# 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, @_);
}
sub clone_instance {
my ($class, $instance, %params) = @_;
(blessed($instance))
- || confess "You can only clone instances, \$self is not a blessed instance";
+ || confess "You can only clone instances, ($instance) is not a blessed instance";
my $meta_instance = $class->get_meta_instance();
- my $clone = $meta_instance->clone_instance($instance);
- foreach my $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 ( defined( my $init_arg = $attr->init_arg ) ) {
+ if (exists $params{$init_arg}) {
+ $attr->set_value($clone, $params{$init_arg});
+ }
+ }
}
- return $clone;
+ return $clone;
+}
+
+sub rebless_instance {
+ my ($self, $instance, %params) = @_;
+
+ my $old_metaclass;
+ if ($instance->can('meta')) {
+ ($instance->meta->isa('Class::MOP::Class'))
+ || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
+ $old_metaclass = $instance->meta;
+ }
+ else {
+ $old_metaclass = $self->initialize(blessed($instance));
+ }
+
+ my $meta_instance = $self->get_meta_instance();
+
+ $self->name->isa($old_metaclass->name)
+ || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
+
+ # rebless!
+ $meta_instance->rebless_instance_structure($instance, $self);
+
+ foreach my $attr ( $self->compute_all_applicable_attributes ) {
+ if ( $attr->has_value($instance) ) {
+ if ( defined( my $init_arg = $attr->init_arg ) ) {
+ $params{$init_arg} = $attr->get_value($instance)
+ unless exists $params{$init_arg};
+ }
+ else {
+ $attr->set_value($instance, $attr->get_value($instance));
+ }
+ }
+ }
+
+ foreach my $attr ($self->compute_all_applicable_attributes) {
+ $attr->initialize_instance_slot($meta_instance, $instance, \%params);
+ }
+
+ $instance;
}
# Inheritance
sub superclasses {
- my $self = shift;
+ my $self = shift;
+ my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
if (@_) {
my @supers = @_;
- @{$self->get_package_symbol('@ISA')} = @supers;
+ @{$self->get_package_symbol($var_spec)} = @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->get_package_symbol('@ISA')};
+ @{$self->get_package_symbol($var_spec)};
+}
+
+sub subclasses {
+ my $self = shift;
+
+ my $super_class = $self->name;
+ my @derived_classes;
+
+ my $find_derived_classes;
+ $find_derived_classes = sub {
+ my ($outer_class) = @_;
+
+ my $symbol_table_hashref = do { no strict 'refs'; \%{"${outer_class}::"} };
+
+ SYMBOL:
+ for my $symbol ( keys %$symbol_table_hashref ) {
+ next SYMBOL if $symbol !~ /\A (\w+):: \z/x;
+ my $inner_class = $1;
+
+ next SYMBOL if $inner_class eq 'SUPER'; # skip '*::SUPER'
+
+ my $class =
+ $outer_class
+ ? "${outer_class}::$inner_class"
+ : $inner_class;
+
+ if ( $class->isa($super_class) and $class ne $super_class ) {
+ push @derived_classes, $class;
+ }
+
+ next SYMBOL if $class eq 'main'; # skip 'main::*'
+
+ $find_derived_classes->($class);
+ }
+ };
+
+ my $root_class = q{};
+ $find_derived_classes->($root_class);
+
+ undef $find_derived_classes;
+
+ @derived_classes = sort { $a->isa($b) ? 1 : $b->isa($a) ? -1 : 0 } @derived_classes;
+
+ return @derived_classes;
+}
+
+
+sub linearized_isa {
+ return @{ mro::get_linear_isa( (shift)->name ) };
}
sub class_precedence_list {
my $self = shift;
- # NOTE:
- # We need to check for ciruclar inheirtance here.
- # This will do nothing if all is well, and blow
- # up otherwise. Yes, it's an ugly hack, better
- # suggestions are welcome.
- { ($self->name || return)->isa('This is a test for circular inheritance') }
- # ... and now back to our regularly scheduled program
- (
- $self->name,
- map {
- $self->initialize($_)->class_precedence_list()
- } $self->superclasses()
- );
+ my $name = $self->name;
+
+ unless (Class::MOP::IS_RUNNING_ON_5_10()) {
+ # NOTE:
+ # We need to check for circular inheritance here
+ # if we are are not on 5.10, cause 5.8 detects it
+ # late. This will do nothing if all is well, and
+ # blow up otherwise. Yes, it's an ugly hack, better
+ # suggestions are welcome.
+ # - SL
+ ($name || return)->isa('This is a test for circular inheritance')
+ }
+
+ # if our mro is c3, we can
+ # just grab the linear_isa
+ if (mro::get_mro($name) eq 'c3') {
+ return @{ mro::get_linear_isa($name) }
+ }
+ else {
+ # NOTE:
+ # we can't grab the linear_isa for dfs
+ # since it has all the duplicates
+ # already removed.
+ return (
+ $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";
-
+
my $body;
if (blessed($method)) {
- $body = $method->body;
+ $body = $method->body;
+ if ($method->package_name ne $self->name &&
+ $method->name ne $method_name) {
+ warn "Hello there, got something for you."
+ . " Method says " . $method->package_name . " " . $method->name
+ . " Class says " . $self->name . " " . $method_name;
+ $method = $method->clone(
+ package_name => $self->name,
+ name => $method_name
+ ) if $method->can('clone');
+ }
}
- else {
+ else {
$body = $method;
- ('CODE' eq (reftype($body) || ''))
- || confess "Your code block must be a CODE reference";
- $method = $self->method_metaclass->wrap($body);
+ ('CODE' eq ref($body))
+ || confess "Your code block must be a CODE reference";
+ $method = $self->method_metaclass->wrap(
+ $body => (
+ package_name => $self->name,
+ name => $method_name
+ )
+ );
}
$self->get_method_map->{$method_name} = $method;
- my $full_method_name = ($self->name . '::' . $method_name);
- $self->add_package_symbol("&${method_name}" => subname $full_method_name => $body);
+ my $full_method_name = ($self->name . '::' . $method_name);
+ $self->add_package_symbol(
+ { sigil => '&', type => 'CODE', name => $method_name },
+ Class::MOP::subname($full_method_name => $body)
+ );
+ $self->update_package_cache_flag;
}
{
$method = $self->find_next_method_by_name($method_name);
# die if it does not exist
(defined $method)
- || confess "The method '$method_name' is not found in the inherience hierarchy for class " . $self->name;
- # and now make sure to wrap it
+ || confess "The method '$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);
+ $method->add_before_modifier(
+ Class::MOP::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);
+ $method->add_after_modifier(
+ Class::MOP::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);
- }
+ $method->add_around_modifier(
+ Class::MOP::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.
}
|| confess "You must define a method name";
my $body = (blessed($method) ? $method->body : $method);
- ('CODE' eq (reftype($body) || ''))
- || confess "Your code block must be a CODE reference";
-
- $self->add_package_symbol("&${method_name}" => $body);
+ ('CODE' eq ref($body))
+ || confess "Your code block must be a CODE reference";
+
+ $self->add_package_symbol(
+ { sigil => '&', type => 'CODE', name => $method_name } => $body
+ );
+ $self->update_package_cache_flag;
}
sub has_method {
my ($self, $method_name) = @_;
(defined $method_name && $method_name)
- || confess "You must define a method name";
-
- return 0 unless exists $self->get_method_map->{$method_name};
+ || confess "You must define a method name";
+
+ return 0 unless exists $self->get_method_map->{$method_name};
return 1;
}
my ($self, $method_name) = @_;
(defined $method_name && $method_name)
|| confess "You must define a method name";
-
+
# NOTE:
# I don't really need this here, because
- # if the method_map is missing a key it
+ # if the method_map is missing a key it
# will just return undef for me now
# return unless $self->has_method($method_name);
-
+
return $self->get_method_map->{$method_name};
}
my ($self, $method_name) = @_;
(defined $method_name && $method_name)
|| confess "You must define a method name";
+
+ my $removed_method = delete $self->get_method_map->{$method_name};
- my $removed_method = $self->get_method($method_name);
+ $self->remove_package_symbol(
+ { sigil => '&', type => 'CODE', name => $method_name }
+ );
- do {
- $self->remove_package_symbol("&${method_name}");
- delete $self->get_method_map->{$method_name};
- } if defined $removed_method;
-
+ $self->update_package_cache_flag;
+
return $removed_method;
}
sub find_method_by_name {
my ($self, $method_name) = @_;
(defined $method_name && $method_name)
- || confess "You must define a method name to find";
- # keep a record of what we have seen
- # here, this will handle all the
- # inheritence issues because we are
- # using the &class_precedence_list
- my %seen_class;
- my @cpl = $self->class_precedence_list();
- foreach my $class (@cpl) {
- next if $seen_class{$class};
- $seen_class{$class}++;
+ || 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)
+ 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
+ # 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
+
+ # 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} = $attribute;
my ($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}
+ return $self->get_attribute_map->{$attribute_name}
# NOTE:
# this will return undef anyway, so no need ...
- # if $self->has_attribute($attribute_name);
- #return;
-}
+ # 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)
sub is_mutable { 1 }
sub is_immutable { 0 }
-sub make_immutable {
- return Class::MOP::Class::Immutable->make_metaclass_immutable(@_);
+# 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
+
+{
+
+ my %IMMUTABLE_TRANSFORMERS;
+ my %IMMUTABLE_OPTIONS;
+
+ sub get_immutable_options {
+ my $self = shift;
+ return if $self->is_mutable;
+ confess "unable to find immutabilizing options"
+ unless exists $IMMUTABLE_OPTIONS{$self->name};
+ my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
+ delete $options{IMMUTABLE_TRANSFORMER};
+ return \%options;
+ }
+
+ sub get_immutable_transformer {
+ my $self = shift;
+ if( $self->is_mutable ){
+ my $class = blessed $self || $self;
+ return $IMMUTABLE_TRANSFORMERS{$class} ||= $self->create_immutable_transformer;
+ }
+ confess "unable to find transformer for immutable class"
+ unless exists $IMMUTABLE_OPTIONS{$self->name};
+ return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
+ }
+
+ sub make_immutable {
+ my $self = shift;
+ my %options = @_;
+
+ my $transformer = $self->get_immutable_transformer;
+ $transformer->make_metaclass_immutable($self, \%options);
+ $IMMUTABLE_OPTIONS{$self->name} =
+ { %options, IMMUTABLE_TRANSFORMER => $transformer };
+
+ if( exists $options{debug} && $options{debug} ){
+ print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
+ print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
+ }
+
+ 1;
+ }
+
+ sub make_mutable{
+ my $self = shift;
+ return if $self->is_mutable;
+ my $options = delete $IMMUTABLE_OPTIONS{$self->name};
+ confess "unable to find immutabilizing options" unless ref $options;
+ my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
+ $transformer->make_metaclass_mutable($self, $options);
+ 1;
+ }
+}
+
+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
+ remove_package_symbol
+ /],
+ memoize => {
+ class_precedence_list => 'ARRAY',
+ linearized_isa => 'ARRAY',
+ compute_all_applicable_attributes => 'ARRAY',
+ get_meta_instance => 'SCALAR',
+ get_method_map => 'SCALAR',
+ },
+ # NOTE:
+ # this is ugly, but so are typeglobs,
+ # so whattayahgonnadoboutit
+ # - SL
+ wrapped => {
+ add_package_symbol => sub {
+ my $original = shift;
+ confess "Cannot add package symbols to an immutable metaclass"
+ unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
+ goto $original->body;
+ },
+ },
+ });
+ return $class;
}
1;
=pod
-=head1 NAME
+=head1 NAME
Class::MOP::Class - Class Meta Object
=head1 SYNOPSIS
- # assuming that class Foo
+ # assuming that class Foo
# has been defined, you can
-
+
# use this for introspection ...
-
+
# add a method to Foo ...
Foo->meta->add_method('bar' => sub { ... })
-
- # get a list of all the classes searched
- # the method dispatcher in the correct order
+
+ # get a list of all the classes searched
+ # the method dispatcher in the correct order
Foo->meta->class_precedence_list()
-
+
# remove a method from Foo
Foo->meta->remove_method('bar');
-
+
# or use this to actually create classes ...
-
+
Class::MOP::Class->create('Bar' => (
version => '0.01',
superclasses => [ 'Foo' ],
attributes => [
Class::MOP:::Attribute->new('$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.
+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 ($package_name,
- version =E<gt> ?$version,
- authority =E<gt> ?$authority,
- superclasses =E<gt> ?@superclasses,
- methods =E<gt> ?%methods,
+=item B<create ($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<$package_name> into existence and adding any of the C<$version>,
-C<$authority>, C<@superclasses>, C<%methods> and C<%attributes> to
+This returns a B<Class::MOP::Class> object, bringing the specified
+C<$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>.
+=item B<update_package_cache_flag>
+
+This will reset the package cache flag for this particular metaclass
+it is basically the value of the C<Class::MOP::get_package_cache_flag>
+function. This is very rarely needed from outside of C<Class::MOP::Class>
+but in some cases you might want to use it, so it is here.
+
+=item B<reset_package_cache_flag>
+
+Clears the package cache flag to announce to the internals that we need
+to rebuild the method map.
+
=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<instance_metaclass>
+Returns the class name of the instance metaclass, see L<Class::MOP::Instance>
+for more information on the instance metaclasses.
+
=item B<get_meta_instance>
+Returns an instance of L<Class::MOP::Instance> to be used in the construction
+of a new instance of the class.
+
=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) = @_;
$class->meta->new_object(%params);
}
-Of course the ideal place for this would actually be in C<UNIVERSAL::>
-but that is considered bad style, so we do not do that.
-
=item B<construct_instance (%params)>
-This method is used to construct an instace structure suitable for
-C<bless>-ing into your package of choice. It works in conjunction
+This method is used to construct an instance structure suitable for
+C<bless>-ing into your package of choice. It works in conjunction
with the Attribute protocol to collect all applicable attributes.
-This will construct and instance using a HASH ref as storage
-(currently only HASH references are supported). This will collect all
-the applicable attributes and layout out the fields in the HASH ref,
-it will then initialize them using either use the corresponding key
-in C<%params> or any default value or initializer found in the
+This will construct and instance using a HASH ref as storage
+(currently only HASH references are supported). This will collect all
+the applicable attributes and layout out the fields in the HASH ref,
+it will then initialize them using either use the corresponding key
+in C<%params> or any default value or initializer found in the
attribute meta-object.
=item B<clone_object ($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::>
-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<$instance> structure shallowly,
+as opposed to the deep cloning implemented in prior versions. After much
+thought, research and discussion, I have decided that anything but basic
+shallow cloning is outside the scope of the meta-object protocol. I
+think Yuval "nothingmuch" Kogman put it best when he said that cloning
is too I<context-specific> to be part of the MOP.
+=item B<rebless_instance($instance, ?%params)>
+
+This will change the class of C<$instance> to the class of the invoking
+C<Class::MOP::Class>. You may only rebless the instance to a subclass of
+itself. You may pass in optional C<%params> which are like constructor
+params and will override anything already defined in the instance.
+
=back
-=head2 Informational
+=head2 Informational
These are a few predicate methods for asking information about the class.
=item B<is_anon_class>
+This returns true if the class is a C<Class::MOP::Class> created anon class.
+
=item B<is_mutable>
+This returns true if the class is still mutable.
+
=item B<is_immutable>
+This returns true if the class has been made immutable.
+
=back
=head2 Inheritance Relationships
=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
-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
-what B<Class::ISA::super_path> does, but we don't remove duplicate names.
+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.
+
+=item B<subclasses>
+
+This returns a list of subclasses for this class.
=back
=item B<get_method_map>
+Returns a HASH ref of name to CODE reference mapping for this class.
+
=item B<method_metaclass>
+Returns the class name of the method metaclass, see L<Class::MOP::Method>
+for more information on the method metaclasses.
+
=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 ($method_name)>
-This will return a Class::MOP::Method instance related to the specified
+This will return a Class::MOP::Method instance related to the specified
C<$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
+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 ($method_name>
+=item B<find_method_by_name ($method_name)>
This will return a CODE reference of the specified C<$method_name>,
or return undef if that method does not exist.
=item B<remove_method ($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<attribute_metaclass>
+Returns the class name of the attribute metaclass, see L<Class::MOP::Attribute>
+for more information on the attribute metaclasses.
+
=item B<get_attribute_map>
-=item B<add_attribute ($attribute_name, $attribute_meta_object)>
+This returns a HASH ref of name to attribute meta-object mapping.
-This stores a C<$attribute_meta_object> in the B<Class::MOP::Class>
-instance associated with the given class, and associates it with
-the C<$attribute_name>. Unlike methods, attributes within the MOP
-are stored as meta-information only. They will be used later to
-construct instances from (see C<construct_instance> above).
-More details about the attribute meta-objects can be found in the
+=item B<add_attribute ($attribute_meta_object | ($attribute_name, %attribute_spec))>
+
+This stores the C<$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
+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 Class closing
+=head2 Class Immutability
=over 4
-=item B<make_immutable>
+=item B<make_immutable (%options)>
+
+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<make_mutable>
+
+This method will reverse tranforamtion upon the class which
+made it immutable.
+
+=item B<get_immutable_transformer>
+
+Return a transformer suitable for making this class immutable or, if this
+class is immutable, the transformer used to make it immutable.
+
+=item B<get_immutable_options>
+
+If the class is immutable, return the options used to make it immutable.
+
+=item B<create_immutable_transformer>
+
+Create a transformer suitable for making this class immutable
=back
Stevan Little E<lt>stevan@iinteractive.comE<gt>
-Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
-
=head1 COPYRIGHT AND LICENSE
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006-2008 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
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