use strict;
use warnings;
-use Carp 'confess';
-use Scalar::Util 'blessed', 'reftype', 'weaken';
+use Scalar::Util 'weaken', 'blessed';
-our $VERSION = '0.01';
+our $VERSION = '0.75';
+$VERSION = eval $VERSION;
+our $AUTHORITY = 'cpan:STEVAN';
-sub meta {
- require Class::MOP::Class;
- Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
+use base 'Class::MOP::Object';
+
+sub BUILDARGS {
+ my ($class, @args) = @_;
+
+ if ( @args == 1 ) {
+ unshift @args, "associated_metaclass";
+ } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) {
+ # compat mode
+ my ( $meta, @attrs ) = @args;
+ @args = ( associated_metaclass => $meta, attributes => \@attrs );
+ }
+
+ my %options = @args;
+ # FIXME lazy_build
+ $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ];
+ $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build
+
+ return \%options;
}
-sub new {
+sub new {
my $class = shift;
- my $meta = shift;
+ my $options = $class->BUILDARGS(@_);
+
+ # FIXME replace with a proper constructor
+ my $instance = $class->_new(%$options);
+
+ # FIXME weak_ref => 1,
+ weaken($instance->{'associated_metaclass'});
+
+ return $instance;
+}
+
+sub _new {
+ my ( $class, %options ) = @_;
bless {
- instance => (bless {} => $meta->name)
- } => $class;
+ # NOTE:
+ # I am not sure that it makes
+ # sense to pass in the meta
+ # The ideal would be to just
+ # pass in the class name, but
+ # that is placing too much of
+ # an assumption on bless(),
+ # 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},
+ } => $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, $self->_class_name;
}
-sub add_slot {
- my ($self, $slot_name, $value) = @_;
- return $self->{instance}->{$slot_name} = $value;
+sub clone_instance {
+ my ($self, $instance) = @_;
+ bless { %$instance }, $self->_class_name;
}
-sub has_slot {
+# operations on meta instance
+
+sub get_all_slots {
+ my $self = shift;
+ return @{$self->{'slots'}};
+}
+
+sub get_all_attributes {
+ my $self = shift;
+ return @{$self->{attributes}};
+}
+
+sub is_valid_slot {
my ($self, $slot_name) = @_;
- exists $self->{instance}->{$slot_name} ? 1 : 0;
+ exists $self->{'slot_hash'}->{$slot_name};
}
+# operations on created instances
+
sub get_slot_value {
- my ($self, $slot_name) = @_;
- return $self->{instance}->{$slot_name};
+ my ($self, $instance, $slot_name) = @_;
+ $instance->{$slot_name};
}
-*set_slot_value = \&add_slot;
+sub set_slot_value {
+ my ($self, $instance, $slot_name, $value) = @_;
+ $instance->{$slot_name} = $value;
+}
-sub get_instance { (shift)->{instance} }
+sub initialize_slot {
+ my ($self, $instance, $slot_name) = @_;
+ return;
+}
+
+sub deinitialize_slot {
+ my ( $self, $instance, $slot_name ) = @_;
+ delete $instance->{$slot_name};
+}
+
+sub initialize_all_slots {
+ my ($self, $instance) = @_;
+ foreach my $slot_name ($self->get_all_slots) {
+ $self->initialize_slot($instance, $slot_name);
+ }
+}
+
+sub deinitialize_all_slots {
+ my ($self, $instance) = @_;
+ foreach my $slot_name ($self->get_all_slots) {
+ $self->deinitialize_slot($instance, $slot_name);
+ }
+}
+
+sub is_slot_initialized {
+ my ($self, $instance, $slot_name, $value) = @_;
+ exists $instance->{$slot_name};
+}
+
+sub weaken_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ weaken $instance->{$slot_name};
+}
+
+sub strengthen_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name));
+}
+
+sub rebless_instance_structure {
+ my ($self, $instance, $metaclass) = @_;
+ bless $instance, $metaclass->name;
+}
+
+sub is_dependent_on_superclasses {
+ return; # for meta instances that require updates on inherited slot changes
+}
+
+# inlinable operation snippets
+
+sub is_inlinable { 1 }
+
+sub inline_create_instance {
+ my ($self, $class_variable) = @_;
+ 'bless {} => ' . $class_variable;
+}
+
+sub inline_slot_access {
+ my ($self, $instance, $slot_name) = @_;
+ sprintf "%s->{%s}", $instance, $slot_name;
+}
+
+sub inline_get_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_slot_access($instance, $slot_name);
+}
+
+sub inline_set_slot_value {
+ my ($self, $instance, $slot_name, $value) = @_;
+ $self->inline_slot_access($instance, $slot_name) . " = $value",
+}
+
+sub inline_initialize_slot {
+ my ($self, $instance, $slot_name) = @_;
+ return '';
+}
+
+sub inline_deinitialize_slot {
+ my ($self, $instance, $slot_name) = @_;
+ "delete " . $self->inline_slot_access($instance, $slot_name);
+}
+sub inline_is_slot_initialized {
+ my ($self, $instance, $slot_name) = @_;
+ "exists " . $self->inline_slot_access($instance, $slot_name);
+}
+
+sub inline_weaken_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name);
+}
+
+sub inline_strengthen_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name));
+}
1;
=pod
-=head1 NAME
+=head1 NAME
Class::MOP::Instance - Instance Meta Object
-=head1 SYNOPSIS
-
=head1 DESCRIPTION
+The meta instance is used by attributes for low level storage.
+
+Using this API generally violates attribute encapsulation and is not
+recommended, instead look at L<Class::MOP::Attribute/get_value>,
+L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with
+attribute values in a generic way, independent of how/whether accessors have
+been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>.
+
+This may seem like over-abstraction, but by abstracting
+this process into a sub-protocol we make it possible to
+easily switch the details of how an object's instance is
+stored with minimal impact. In most cases just subclassing
+this class will be all you need to do (see the examples;
+F<examples/ArrayBasedStorage.pod> and
+F<examples/InsideOutClass.pod> for details).
+
=head1 METHODS
=over 4
-=item B<new>
+=item B<new %args>
+
+Creates a new instance meta-object and gathers all the slots from
+the list of C<@attrs> given.
+
+=item B<BUILDARGS>
+
+Processes arguments for compatibility.
+
+=item B<meta>
+
+Returns the metaclass of L<Class::MOP::Instance>.
+
+=back
+
+=head2 Creation of Instances
+
+=over 4
+
+=item B<create_instance>
-=item B<add_slot>
+This creates the appropriate structure needed for the instance and blesses it.
-=item B<has_slot>
+=item B<bless_instance_structure ($instance_structure)>
-=item B<get_slot_value>
+This does just exactly what it says it does.
-=item B<set_slot_value>
+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.
-=item B<get_instance>
+=item B<clone_instance ($instance_structure)>
+
+Creates a shallow clone of $instance_structure.
=back
=head2 Introspection
+NOTE: There might be more methods added to this part of the API,
+we will add then when we need them basically.
+
=over 4
-=item B<meta>
+=item B<associated_metaclass>
+
+This returns the metaclass associated with this instance.
+
+=item B<get_all_slots>
+
+This will return the current list of slots based on what was
+given to this object in C<new>.
+
+=item B<is_valid_slot ($slot_name)>
+
+This will return true if C<$slot_name> is a valid slot name.
+
+=item B<is_dependent_on_superclasses>
+
+This method returns true when the meta instance must be recreated on any
+superclass changes.
-This will return a B<Class::MOP::Class> instance which is related
-to this class.
+Defaults to false.
+
+=item B<get_all_attributes>
+
+This will return the current list of attributes (as
+Class::MOP::Attribute objects) based on what was given to this object
+in C<new>.
=back
-=head1 AUTHOR
+=head2 Operations on Instance Structures
+
+An important distinction of this sub-protocol is that the
+instance meta-object is a different entity from the actual
+instance it creates. For this reason, any actions on slots
+require that the C<$instance_structure> is passed into them.
+
+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.
+
+=over 4
+
+=item B<get_slot_value ($instance_structure, $slot_name)>
+
+=item B<set_slot_value ($instance_structure, $slot_name, $value)>
+
+=item B<initialize_slot ($instance_structure, $slot_name)>
+
+=item B<deinitialize_slot ($instance_structure, $slot_name)>
+
+=item B<initialize_all_slots ($instance_structure)>
+
+=item B<deinitialize_all_slots ($instance_structure)>
+
+=item B<is_slot_initialized ($instance_structure, $slot_name)>
+
+=item B<weaken_slot_value ($instance_structure, $slot_name)>
+
+=item B<strengthen_slot_value ($instance_structure, $slot_name)>
+
+=item B<rebless_instance_structure ($instance_structure, $new_metaclass)>
+
+=back
+
+=head2 Inlineable Instance Operations
+
+=over 4
+
+=item B<is_inlinable>
+
+Each meta-instance should override this method to tell Class::MOP if it's
+possible to inline the slot access. This is currently only used by
+L<Class::MOP::Immutable> when performing optimizations.
+
+=item B<inline_create_instance>
+
+=item B<inline_slot_access ($instance_structure, $slot_name)>
+
+=item B<inline_get_slot_value ($instance_structure, $slot_name)>
+
+=item B<inline_set_slot_value ($instance_structure, $slot_name, $value)>
+
+=item B<inline_initialize_slot ($instance_structure, $slot_name)>
+
+=item B<inline_deinitialize_slot ($instance_structure, $slot_name)>
+
+=item B<inline_is_slot_initialized ($instance_structure, $slot_name)>
+
+=item B<inline_weaken_slot_value ($instance_structure, $slot_name)>
+
+=item B<inline_strengthen_slot_value ($instance_structure, $slot_name)>
+
+=back
+
+=head1 AUTHORS
+
+Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
Stevan Little E<lt>stevan@iinteractive.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
-=cut
\ No newline at end of file
projects / gitmo/Class-MOP.git / blobdiff