use Scalar::Util 'weaken', 'blessed';
-our $VERSION = '0.64_02';
+our $VERSION = '1.12';
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
use base 'Class::MOP::Object';
+# make this not a valid method name, to avoid (most) attribute conflicts
+my $RESERVED_MOP_SLOT = '<<MOP>>';
+
sub BUILDARGS {
my ($class, @args) = @_;
}
sub _new {
- my ( $class, %options ) = @_;
- bless {
+ my $class = shift;
+ return Class::MOP::Class->initialize($class)->new_object(@_)
+ if $class ne __PACKAGE__;
+
+ my $params = @_ == 1 ? $_[0] : {@_};
+ return bless {
# NOTE:
# I am not sure that it makes
# sense to pass in the meta
# which is *probably* a safe
# assumption,.. but you can
# never tell <:)
- 'associated_metaclass' => $options{associated_metaclass},
- 'attributes' => $options{attributes},
- 'slots' => $options{slots},
- 'slot_hash' => $options{slot_hash},
+ 'associated_metaclass' => $params->{associated_metaclass},
+ 'attributes' => $params->{attributes},
+ 'slots' => $params->{slots},
+ 'slot_hash' => $params->{slot_hash},
} => $class;
}
sub _class_name { $_[0]->{_class_name} ||= $_[0]->associated_metaclass->name }
-sub associated_metaclass { $_[0]{'associated_metaclass'} }
-
sub create_instance {
my $self = shift;
bless {}, $self->_class_name;
}
-# for compatibility
-sub bless_instance_structure {
- my ($self, $instance_structure) = @_;
- bless $instance_structure, $self->_class_name;
-}
-
sub clone_instance {
my ($self, $instance) = @_;
bless { %$instance }, $self->_class_name;
sub rebless_instance_structure {
my ($self, $instance, $metaclass) = @_;
- bless $instance, $metaclass->name;
+
+ # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8
+ bless $_[1], $metaclass->name;
}
sub is_dependent_on_superclasses {
return; # for meta instances that require updates on inherited slot changes
}
+sub _get_mop_slot {
+ my ($self, $instance) = @_;
+ $self->get_slot_value($instance, $RESERVED_MOP_SLOT);
+}
+
+sub _set_mop_slot {
+ my ($self, $instance, $value) = @_;
+ $self->set_slot_value($instance, $RESERVED_MOP_SLOT, $value);
+}
+
+sub _clear_mop_slot {
+ my ($self, $instance) = @_;
+ $self->deinitialize_slot($instance, $RESERVED_MOP_SLOT);
+}
+
# inlinable operation snippets
sub is_inlinable { 1 }
sub inline_slot_access {
my ($self, $instance, $slot_name) = @_;
- sprintf "%s->{%s}", $instance, $slot_name;
+ sprintf q[%s->{"%s"}], $instance, quotemeta($slot_name);
}
+sub inline_get_is_lvalue { 1 }
+
sub inline_get_slot_value {
my ($self, $instance, $slot_name) = @_;
$self->inline_slot_access($instance, $slot_name);
$self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name));
}
+sub inline_rebless_instance_structure {
+ my ($self, $instance, $class_variable) = @_;
+ "bless $instance => $class_variable";
+}
+
+sub _inline_get_mop_slot {
+ my ($self, $instance) = @_;
+ $self->inline_get_slot_value($instance, $RESERVED_MOP_SLOT);
+}
+
+sub _inline_set_mop_slot {
+ my ($self, $instance, $value) = @_;
+ $self->inline_set_slot_value($instance, $RESERVED_MOP_SLOT, $value);
+}
+
+sub _inline_clear_mop_slot {
+ my ($self, $instance) = @_;
+ $self->inline_deinitialize_slot($instance, $RESERVED_MOP_SLOT);
+}
+
1;
__END__
=head1 DESCRIPTION
-The meta instance is used by attributes for low level storage.
+The Instance Protocol controls the creation of object instances, and
+the storage of attribute values in those instances.
-Using this API generally violates attribute encapsulation and is not
-recommended, instead look at L<Class::MOP::Attribute/get_value>,
-L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with
-attribute values in a generic way, independent of how/whether accessors have
-been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>.
+Using this API directly in your own code violates encapsulation, and
+we recommend that you use the appropriate APIs in L<Class::MOP::Class>
+and L<Class::MOP::Attribute> instead. Those APIs in turn call the
+methods in this class as appropriate.
-This may seem like over-abstraction, but by abstracting
-this process into a sub-protocol we make it possible to
-easily switch the details of how an object's instance is
-stored with minimal impact. In most cases just subclassing
-this class will be all you need to do (see the examples;
-F<examples/ArrayBasedStorage.pod> and
-F<examples/InsideOutClass.pod> for details).
+This class also participates in generating inlined code by providing
+snippets of code to access an object instance.
=head1 METHODS
+=head2 Object construction
+
=over 4
-=item B<new %args>
+=item B<< Class::MOP::Instance->new(%options) >>
+
+This method creates a new meta-instance object.
-Creates a new instance meta-object and gathers all the slots from
-the list of C<@attrs> given.
+It accepts the following keys in C<%options>:
-=item B<BUILDARGS>
+=over 8
-Processes arguments for compatibility.
+=item * associated_metaclass
-=item B<meta>
+The L<Class::MOP::Class> object for which instances will be created.
-Returns the metaclass of L<Class::MOP::Instance>.
+=item * attributes
+
+An array reference of L<Class::MOP::Attribute> objects. These are the
+attributes which can be stored in each instance.
+
+=back
=back
-=head2 Creation of Instances
+=head2 Creating and altering instances
=over 4
-=item B<create_instance>
+=item B<< $metainstance->create_instance >>
+
+This method returns a reference blessed into the associated
+metaclass's class.
+
+The default is to use a hash reference. Subclasses can override this.
+
+=item B<< $metainstance->clone_instance($instance) >>
+
+Given an instance, this method creates a new object by making
+I<shallow> clone of the original.
-This creates the appropriate structure needed for the instance and blesses it.
+=back
+
+=head2 Introspection
-=item B<bless_instance_structure ($instance_structure)>
+=over 4
-This does just exactly what it says it does.
+=item B<< $metainstance->associated_metaclass >>
-This method has been deprecated but remains for compatibility reasons. None of
-the subclasses of L<Class::MOP::Instance> ever bothered to actually make use of
-it, so it was deemed unnecessary fluff.
+This returns the L<Class::MOP::Class> object associated with the
+meta-instance object.
-=item B<clone_instance ($instance_structure)>
+=item B<< $metainstance->get_all_slots >>
-Creates a shallow clone of $instance_structure.
+This returns a list of slot names stored in object instances. In
+almost all cases, slot names correspond directly attribute names.
+
+=item B<< $metainstance->is_valid_slot($slot_name) >>
+
+This will return true if C<$slot_name> is a valid slot name.
+
+=item B<< $metainstance->get_all_attributes >>
+
+This returns a list of attributes corresponding to the attributes
+passed to the constructor.
=back
-=head2 Introspection
+=head2 Operations on Instance Structures
-NOTE: There might be more methods added to this part of the API,
-we will add then when we need them basically.
+It's important to understand that the meta-instance object is a
+different entity from the actual instances it creates. For this
+reason, any operations on the C<$instance_structure> always require
+that the object instance be passed to the method.
=over 4
-=item B<associated_metaclass>
+=item B<< $metainstance->get_slot_value($instance_structure, $slot_name) >>
-This returns the metaclass associated with this instance.
+=item B<< $metainstance->set_slot_value($instance_structure, $slot_name, $value) >>
-=item B<get_all_slots>
+=item B<< $metainstance->initialize_slot($instance_structure, $slot_name) >>
-This will return the current list of slots based on what was
-given to this object in C<new>.
+=item B<< $metainstance->deinitialize_slot($instance_structure, $slot_name) >>
-=item B<is_valid_slot ($slot_name)>
+=item B<< $metainstance->initialize_all_slots($instance_structure) >>
-This will return true if C<$slot_name> is a valid slot name.
+=item B<< $metainstance->deinitialize_all_slots($instance_structure) >>
-=item B<is_dependent_on_superclasses>
+=item B<< $metainstance->is_slot_initialized($instance_structure, $slot_name) >>
-This method returns true when the meta instance must be recreated on any
-superclass changes.
+=item B<< $metainstance->weaken_slot_value($instance_structure, $slot_name) >>
-Defaults to false.
+=item B<< $metainstance->strengthen_slot_value($instance_structure, $slot_name) >>
-=item B<get_all_attributes>
+=item B<< $metainstance->rebless_instance_structure($instance_structure, $new_metaclass) >>
-This will return the current list of attributes (as
-Class::MOP::Attribute objects) based on what was given to this object
-in C<new>.
+The exact details of what each method does should be fairly obvious
+from the method name.
=back
-=head2 Operations on Instance Structures
+=head2 Inlinable Instance Operations
-An important distinction of this sub-protocol is that the
-instance meta-object is a different entity from the actual
-instance it creates. For this reason, any actions on slots
-require that the C<$instance_structure> is passed into them.
+=over 4
-The names of these methods pretty much explain exactly
-what they do, if that is not enough then I suggest reading
-the source, it is very straightfoward.
+=item B<< $metainstance->is_inlinable >>
-=over 4
+This is a boolean that indicates whether or not slot access operations
+can be inlined. By default it is true, but subclasses can override
+this.
-=item B<get_slot_value ($instance_structure, $slot_name)>
+=item B<< $metainstance->inline_create_instance($class_variable) >>
-=item B<set_slot_value ($instance_structure, $slot_name, $value)>
+This method expects a string that, I<when inlined>, will become a
+class name. This would literally be something like C<'$class'>, not an
+actual class name.
-=item B<initialize_slot ($instance_structure, $slot_name)>
+It returns a snippet of code that creates a new object for the
+class. This is something like C< bless {}, $class_name >.
-=item B<deinitialize_slot ($instance_structure, $slot_name)>
+=item B<< $metainstance->inline_get_is_lvalue >>
-=item B<initialize_all_slots ($instance_structure)>
+Returns whether or not C<inline_get_slot_value> is a valid lvalue. This can be
+used to do extra optimizations when generating inlined methods.
-=item B<deinitialize_all_slots ($instance_structure)>
+=item B<< $metainstance->inline_slot_access($instance_variable, $slot_name) >>
-=item B<is_slot_initialized ($instance_structure, $slot_name)>
+=item B<< $metainstance->inline_get_slot_value($instance_variable, $slot_name) >>
-=item B<weaken_slot_value ($instance_structure, $slot_name)>
+=item B<< $metainstance->inline_set_slot_value($instance_variable, $slot_name, $value) >>
-=item B<strengthen_slot_value ($instance_structure, $slot_name)>
+=item B<< $metainstance->inline_initialize_slot($instance_variable, $slot_name) >>
-=item B<rebless_instance_structure ($instance_structure, $new_metaclass)>
+=item B<< $metainstance->inline_deinitialize_slot($instance_variable, $slot_name) >>
-=back
+=item B<< $metainstance->inline_is_slot_initialized($instance_variable, $slot_name) >>
-=head2 Inlineable Instance Operations
+=item B<< $metainstance->inline_weaken_slot_value($instance_variable, $slot_name) >>
-=over 4
+=item B<< $metainstance->inline_strengthen_slot_value($instance_variable, $slot_name) >>
-=item B<is_inlinable>
+These methods all expect two arguments. The first is the name of a
+variable, than when inlined, will represent the object
+instance. Typically this will be a literal string like C<'$_[0]'>.
-Each meta-instance should override this method to tell Class::MOP if it's
-possible to inline the slot access. This is currently only used by
-L<Class::MOP::Immutable> when performing optimizations.
+The second argument is a slot name.
-=item B<inline_create_instance>
+The method returns a snippet of code that, when inlined, performs some
+operation on the instance.
-=item B<inline_slot_access ($instance_structure, $slot_name)>
+=item B<< $metainstance->inline_rebless_instance_structure($instance_variable, $class_variable) >>
-=item B<inline_get_slot_value ($instance_structure, $slot_name)>
+This takes the name of a variable that will, when inlined, represent the object
+instance, and the name of a variable that will represent the class to rebless
+into, and returns code to rebless an instance into a class.
-=item B<inline_set_slot_value ($instance_structure, $slot_name, $value)>
+=back
-=item B<inline_initialize_slot ($instance_structure, $slot_name)>
+=head2 Introspection
-=item B<inline_deinitialize_slot ($instance_structure, $slot_name)>
+=over 4
-=item B<inline_is_slot_initialized ($instance_structure, $slot_name)>
+=item B<< Class::MOP::Instance->meta >>
-=item B<inline_weaken_slot_value ($instance_structure, $slot_name)>
+This will return a L<Class::MOP::Class> instance for this class.
-=item B<inline_strengthen_slot_value ($instance_structure, $slot_name)>
+It should also be noted that L<Class::MOP> will actually bootstrap
+this module by installing a number of attribute meta-objects into its
+metaclass.
=back
=head1 COPYRIGHT AND LICENSE
-Copyright 2006-2008 by Infinity Interactive, Inc.
+Copyright 2006-2010 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
projects / gitmo/Class-MOP.git / blobdiff