use strict;
use warnings;
-use Carp 'confess';
-use Scalar::Util 'blessed', 'reftype', 'weaken';
-
-our $VERSION = '0.01';
-
-sub meta {
- require Class::MOP::Class;
- Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
+use Scalar::Util 'weaken', 'blessed';
+
+our $VERSION = '0.64';
+our $AUTHORITY = 'cpan:STEVAN';
+
+use base 'Class::MOP::Object';
+
+sub new {
+ my ($class, $meta, @attrs) = @_;
+ my @slots = map { $_->slots } @attrs;
+ my $instance = bless {
+ # NOTE:
+ # I am not sure that it makes
+ # sense to pass in the meta
+ # The ideal would be to just
+ # pass in the class name, but
+ # that is placing too much of
+ # an assumption on bless(),
+ # which is *probably* a safe
+ # assumption,.. but you can
+ # never tell <:)
+ '$!meta' => $meta,
+ '@!slots' => { map { $_ => undef } @slots },
+ } => $class;
+
+ weaken($instance->{'$!meta'});
+
+ return $instance;
}
-sub new {
- my ( $class, $meta ) = @_;
- bless {
- meta => $meta,
- instance_layout => {}
- } => $class;
-}
+sub associated_metaclass { (shift)->{'$!meta'} }
sub create_instance {
- my ( $self, $class ) = @_;
-
- # rely on autovivification
- $self->bless_instance_structure( {}, $class );
+ my $self = shift;
+ $self->bless_instance_structure({});
}
sub bless_instance_structure {
- my ( $self, $instance_structure, $class ) = @_;
- $class ||= $self->{meta}->name;
- bless $instance_structure, $class;
+ my ($self, $instance_structure) = @_;
+ bless $instance_structure, $self->associated_metaclass->name;
}
-sub get_all_parents {
- my $self = shift;
- my @parents = $self->{meta}->class_precedence_list;
- shift @parents; # shift off ourselves
- return map { $_->get_meta_instance } map { $_->meta || () } @parents;
+sub clone_instance {
+ my ($self, $instance) = @_;
+ $self->bless_instance_structure({ %$instance });
}
# operations on meta instance
-sub add_slot {
- my ($self, $slot_name ) = @_;
- confess "The slot '$slot_name' already exists"
- if 0 && $self->has_slot_recursively( $slot_name ); # FIXME
- $self->{instance_layout}->{$slot_name} = undef;
-}
-
sub get_all_slots {
my $self = shift;
- keys %{ $self->{instance_layout} };
-}
-
-sub get_all_slots_recursively {
- my $self = shift;
- return (
- $self->get_all_slots,
- map { $_->get_all_slots } $self->get_all_parents,
- ),
+ return keys %{$self->{'@!slots'}};
}
-sub has_slot {
+sub is_valid_slot {
my ($self, $slot_name) = @_;
- exists $self->{instance_layout}->{$slot_name} ? 1 : 0;
-}
-
-sub has_slot_recursively {
- my ( $self, $slot_name ) = @_;
- return 1 if $self->has_slot($slot_name);
- $_->has_slot_recursively($slot_name) && return 1 for $self->get_all_parents;
- return 0;
+ exists $self->{'@!slots'}->{$slot_name};
}
-sub remove_slot {
- my ( $self, $slot_name ) = @_;
- # NOTE:
- # this does not search recursively cause
- # that is not the domain of this meta-instance
- # it is specific to this class ...
- confess "The slot '$slot_name' does not exist (maybe it's inherited?)"
- if 0 && $self->has_slot( $slot_name ); # FIXME
- delete $self->{instance_layout}->{$slot_name};
-}
-
-
# operations on created instances
sub get_slot_value {
my ($self, $instance, $slot_name) = @_;
- return $instance->{$slot_name};
+ $instance->{$slot_name};
}
-# can be called only after initialize_slot_value
sub set_slot_value {
my ($self, $instance, $slot_name, $value) = @_;
$instance->{$slot_name} = $value;
}
-sub set_weak_slot_value {
- my ( $self, $instance, $slot_name, $value) = @_;
- $self->set_slot_value( $instance, $slot_name, $value );
- $self->weeaken_slot_value( $instance, $slot_name );
+sub initialize_slot {
+ my ($self, $instance, $slot_name) = @_;
+ #$self->set_slot_value($instance, $slot_name, undef);
}
-sub weaken_slot_value {
- my ( $self, $instance, $slot_name ) = @_;
- weaken( $instance->{$slot_name} );
+sub deinitialize_slot {
+ my ( $self, $instance, $slot_name ) = @_;
+ delete $instance->{$slot_name};
}
-# convenience method
-# non autovivifying stores will have this as { initialize_slot unless slot_initlized; set_slot_value }
-sub set_slot_value_with_init {
- my ( $self, $instance, $slot_name, $value ) = @_;
- $self->set_slot_value( $instance, $slot_name, $value );
+sub initialize_all_slots {
+ my ($self, $instance) = @_;
+ foreach my $slot_name ($self->get_all_slots) {
+ $self->initialize_slot($instance, $slot_name);
+ }
}
-sub initialize_slot {
- my ( $self, $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 slot_initialized {
+sub weaken_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ weaken $instance->{$slot_name};
+}
+
+sub strengthen_slot_value {
my ($self, $instance, $slot_name) = @_;
- exists $instance->{$slot_name} ? 1 : 0;
+ $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name));
}
+sub rebless_instance_structure {
+ my ($self, $instance, $metaclass) = @_;
+ bless $instance, $metaclass->name;
+}
# inlinable operation snippets
-sub inline_get_slot_value {
+sub is_inlinable { 1 }
+
+sub inline_create_instance {
+ my ($self, $class_variable) = @_;
+ 'bless {} => ' . $class_variable;
+}
+
+sub inline_slot_access {
my ($self, $instance, $slot_name) = @_;
sprintf "%s->{%s}", $instance, $slot_name;
}
-sub inline_set_slot_value {
- my ($self, $instance, $slot_name, $value) = @_;
- $self->_inline_slot_lvalue( $instance, $slot_name ) . " = $value",
+sub inline_get_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_slot_access($instance, $slot_name);
}
-sub inline_set_weak_slot_value {
- my ( $self, $instance, $slot_name, $value ) = @_;
- return ""
- . $self->inline_set_slot_value( $instance, $slot_name, $value )
- . "; "
- . $self->inline_weaken_slot_value( $instance, $slot_name );
+sub inline_set_slot_value {
+ my ($self, $instance, $slot_name, $value) = @_;
+ $self->inline_slot_access($instance, $slot_name) . " = $value",
}
-sub inline_weaken_slot_value {
- my ( $self, $instance, $slot_name ) = @_;
- return 'Scalar::Util::weaken( ' . $self->_inline_slot_lvalue( $instance, $slot_name ) . ')';
+sub inline_initialize_slot {
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_set_slot_value($instance, $slot_name, 'undef'),
}
-sub inline_set_slot_value_with_init {
- my ( $self, $instance, $slot_name, $value) = @_;
- $self->inline_set_slot_value( $instance, $slot_name, $value ) . ";";
+sub inline_deinitialize_slot {
+ my ($self, $instance, $slot_name) = @_;
+ "delete " . $self->inline_slot_access($instance, $slot_name);
}
-
-sub inline_initialize_slot {
- return "";
+sub inline_is_slot_initialized {
+ my ($self, $instance, $slot_name) = @_;
+ "exists " . $self->inline_slot_access($instance, $slot_name);
}
-sub inline_slot_initialized {
+sub inline_weaken_slot_value {
my ($self, $instance, $slot_name) = @_;
- "exists " . $self->inline_get_slot_value;
+ sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name);
}
-sub _inline_slot_lvalue {
+sub inline_strengthen_slot_value {
my ($self, $instance, $slot_name) = @_;
- $self->inline_get_slot_value( $instance, $slot_name );
+ $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name));
}
1;
=pod
-=head1 NAME
+=head1 NAME
Class::MOP::Instance - Instance Meta Object
-=head1 SYNOPSIS
-
=head1 DESCRIPTION
+The meta instance is used by attributes for low level storage.
+
+Using this API generally violates attribute encapsulation and is not
+recommended, instead look at L<Class::MOP::Attribute/get_value>,
+L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with
+attribute values in a generic way, independent of how/whether accessors have
+been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>.
+
+This may seem like over-abstraction, but by abstracting
+this process into a sub-protocol we make it possible to
+easily switch the details of how an object's instance is
+stored with minimal impact. In most cases just subclassing
+this class will be all you need to do (see the examples;
+F<examples/ArrayBasedStorage.pod> and
+F<examples/InsideOutClass.pod> for details).
+
=head1 METHODS
=over 4
-=item B<new>
+=item B<new ($meta, @attrs)>
-=item B<add_slot>
+Creates a new instance meta-object and gathers all the slots from
+the list of C<@attrs> given.
-=item B<bless_instance_structure>
+=item B<meta>
-=item B<create_instance>
+This will return a B<Class::MOP::Class> instance which is related
+to this class.
+
+=back
-=item B<get_all_parents>
+=head2 Creation of Instances
-=item B<get_slot_value>
+=over 4
-=item B<has_slot>
+=item B<create_instance>
-=item B<has_slot_recursively>
+This creates the appropriate structure needed for the instance and
+then calls C<bless_instance_structure> to bless it into the class.
-=item B<initialize_slot>
+=item B<bless_instance_structure ($instance_structure)>
-=item B<inline_get_slot_value>
+This does just exactly what it says it does.
-=item B<inline_initialize_slot>
+=item B<clone_instance ($instance_structure)>
-=item B<inline_set_slot_value>
+This too does just exactly what it says it does.
-=item B<inline_set_slot_value_with_init>
+=back
-=item B<inline_slot_initialized>
+=head2 Introspection
-=item B<remove_slot>
+NOTE: There might be more methods added to this part of the API,
+we will add then when we need them basically.
-=item B<set_slot_value>
+=over 4
-=item B<set_slot_value_with_init>
+=item B<associated_metaclass>
-=item B<slot_initialized>
+This returns the metaclass associated with this instance.
=item B<get_all_slots>
-=item B<get_all_slots_recursively>
+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.
=back
-=head2 Introspection
+=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<$instance_structure> is passed into them.
+
+The names of these methods pretty much explain exactly
+what they do, if that is not enough then I suggest reading
+the source, it is very straightfoward.
=over 4
-=item B<meta>
+=item B<get_slot_value ($instance_structure, $slot_name)>
-This will return a B<Class::MOP::Class> instance which is related
-to this class.
+=item B<set_slot_value ($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, $new_metaclass)>
=back
-=head1 AUTHOR
+=head2 Inlineable Instance Operations
+
+=over 4
+
+=item B<is_inlinable>
+
+Each meta-instance should override this method to tell Class::MOP if it's
+possible to inline the slot access. This is currently only used by
+L<Class::MOP::Immutable> when performing optimizations.
+
+=item B<inline_create_instance>
+
+=item B<inline_slot_access ($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
+
projects / gitmo/Class-MOP.git / blobdiff