use strict;
use warnings;
-use Carp 'confess';
-use Scalar::Util 'blessed', 'reftype', 'weaken';
+use Scalar::Util 'weaken', 'blessed';
-our $VERSION = '0.01';
+our $VERSION = '0.04';
+our $AUTHORITY = 'cpan:STEVAN';
-sub meta {
+sub meta {
require Class::MOP::Class;
Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
}
-sub new {
+sub new {
my ($class, $meta, @attrs) = @_;
my @slots = map { $_->slots } @attrs;
- bless {
+ my $instance = bless {
# 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(),
+ # 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
+ # assumption,.. but you can
# never tell <:)
- meta => $meta,
- slots => \@slots,
- } => $class;
+ '$!meta' => $meta,
+ '@!slots' => { map { $_ => undef } @slots },
+ } => $class;
+
+ weaken($instance->{'$!meta'});
+
+ return $instance;
}
+sub associated_metaclass { (shift)->{'$!meta'} }
+
sub create_instance {
my $self = shift;
$self->bless_instance_structure({});
sub bless_instance_structure {
my ($self, $instance_structure) = @_;
- bless $instance_structure, $self->{meta}->name;
+ bless $instance_structure, $self->associated_metaclass->name;
+}
+
+sub clone_instance {
+ my ($self, $instance) = @_;
+ $self->bless_instance_structure({ %$instance });
}
# operations on meta instance
sub get_all_slots {
my $self = shift;
- return @{$self->{slots}};
+ return keys %{$self->{'@!slots'}};
+}
+
+sub is_valid_slot {
+ my ($self, $slot_name) = @_;
+ exists $self->{'@!slots'}->{$slot_name};
}
# operations on created instances
sub get_slot_value {
my ($self, $instance, $slot_name) = @_;
- return $instance->{$slot_name};
+ $instance->{$slot_name};
}
sub set_slot_value {
sub initialize_slot {
my ($self, $instance, $slot_name) = @_;
- $instance->{$slot_name} = undef;
+ #$self->set_slot_value($instance, $slot_name, undef);
+}
+
+sub deinitialize_slot {
+ my ( $self, $instance, $slot_name ) = @_;
+ delete $instance->{$slot_name};
}
sub initialize_all_slots {
}
}
+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} ? 1 : 0;
+ 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, $metaclass->name;
+}
+
+# inlinable operation snippets
+
+sub is_inlinable { 1 }
+
+sub inline_create_instance {
+ my ($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) = @_;
+ $self->inline_set_slot_value($instance, $slot_name, 'undef'),
+}
+
+sub inline_deinitialize_slot {
+ my ($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, $slot_name));
}
1;
=pod
-=head1 NAME
+=head1 NAME
Class::MOP::Instance - Instance Meta Object
-=head1 SYNOPSIS
-
=head1 DESCRIPTION
+The meta instance is used by attributes for low level storage.
+
+Using this API generally violates attribute encapsulation and is not
+reccomended, instead look at L<Class::MOP::Attribute/get_value>,
+L<Class::MOP::Attribute/set_value> for the reccomended way to fiddle with
+attribute values in a generic way, independant of how/whether accessors have
+been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>.
+
+This may seem like over-abstraction, but by abstracting
+this process into a sub-protocol we make it possible to
+easily switch the details of how an object's instance is
+stored with minimal impact. In most cases just subclassing
+this class will be all you need to do (see the examples;
+F<examples/ArrayBasedStorage.pod> and
+F<examples/InsideOutClass.pod> for details).
+
=head1 METHODS
=over 4
-=item B<new>
+=item B<new ($meta, @attrs)>
+
+Creates a new instance meta-object and gathers all the slots from
+the list of C<@attrs> given.
+
+=item B<meta>
+
+This will return a B<Class::MOP::Class> instance which is related
+to this class.
+
+=back
+
+=head2 Creation of Instances
+
+=over 4
=item B<create_instance>
-=item B<bless_instance_structure>
+This creates the appropriate structure needed for the instance and
+then calls C<bless_instance_structure> to bless it into the class.
+
+=item B<bless_instance_structure ($instance_structure)>
+
+This does just exactly what it says it does.
+
+=item B<clone_instance ($instance_structure)>
+
+This too does just exactly what it says it does.
+
+=back
+
+=head2 Instrospection
+
+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<associated_metaclass>
+
+This returns the metaclass associated with this instance.
=item B<get_all_slots>
-=item B<initialize_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<get_slot_value>
+=back
+
+=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, $slot_name)>
-=item B<set_slot_value>
+=item B<weaken_slot_value ($instance_structure, $slot_name)>
-=item B<initialize_slot>
+=item B<strengthen_slot_value ($instance_structure, $slot_name)>
-=item B<is_slot_initialized>
+=item B<rebless_instance_structure ($instance_structure, $new_metaclass)>
=back
-=head2 Introspection
+=head2 Inlineable Instance Operations
=over 4
-=item B<meta>
+=item B<is_inlinable>
-This will return a B<Class::MOP::Class> instance which is related
-to this class.
+Each meta-instance should override this method to tell Class::MOP if it's
+possible to inline the slot access. This is currently only used by
+L<Class::MOP::Immutable> when performing optimizations.
+
+=item B<inline_create_instance>
+
+=item B<inline_slot_access ($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 AUTHOR
+=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
+
projects / gitmo/Class-MOP.git / blobdiff