X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FMOP%2FInstance.pm;h=b2e406a8f4f60a1ff482e821d8892f91a47ae93b;hb=f0480c45f215203bc40abc794ac0c03622f02f1d;hp=7d1e573814d12e96b60e969d638365de77d6f4bb;hpb=24869f62f2c588b527cdb80aee59a9867e51f0ba;p=gitmo%2FClass-MOP.git

diff --git a/lib/Class/MOP/Instance.pm b/lib/Class/MOP/Instance.pm
index 7d1e573..b2e406a 100644
--- a/lib/Class/MOP/Instance.pm
+++ b/lib/Class/MOP/Instance.pm
@@ -4,10 +4,10 @@ package Class::MOP::Instance;
 use strict;
 use warnings;
 
-use Carp         'confess';
-use Scalar::Util 'blessed', 'reftype', 'weaken';
+use Scalar::Util 'weaken', 'blessed';
 
-our $VERSION = '0.01';
+our $VERSION   = '0.03';
+our $AUTHORITY = 'cpan:STEVAN';
 
 sub meta { 
     require Class::MOP::Class;
@@ -15,19 +15,149 @@ sub meta {
 }
 
 sub new { 
-    my $class = shift;
-    my $meta  = shift;
+    my ($class, $meta, @attrs) = @_;
+    my @slots = map { $_->slots } @attrs;
     bless {
-        instance => bless {} => $meta->name
+        # 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; 
 }
 
-sub add_slot {
-    my ($self, $slot_name, $value) = @_;
-    return $self->{instance}->{$slot_name} = $value;
+sub create_instance {
+    my $self = shift;
+    $self->bless_instance_structure({});
 }
 
-sub get_instance { (shift)->{instance} }
+sub bless_instance_structure {
+    my ($self, $instance_structure) = @_;
+    bless $instance_structure, $self->{meta}->name;
+}
+
+sub clone_instance {
+    my ($self, $instance) = @_;
+    $self->bless_instance_structure({ %$instance });
+}
+
+# operations on meta instance
+
+sub get_all_slots {
+    my $self = shift;
+    return keys %{$self->{slots}};
+}
+
+sub is_valid_slot {
+    my ($self, $slot_name) = @_;
+    exists $self->{slots}->{$slot_name} ? 1 : 0;
+}
+
+# operations on created instances
+
+sub get_slot_value {
+    my ($self, $instance, $slot_name) = @_;
+    return $instance->{$slot_name};
+}
+
+sub set_slot_value {
+    my ($self, $instance, $slot_name, $value) = @_;
+    $instance->{$slot_name} = $value;
+}
+
+sub initialize_slot {
+    my ($self, $instance, $slot_name) = @_;
+    $self->set_slot_value($instance, $slot_name, undef);
+}
+
+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} ? 1 : 0;
+}
+
+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, $slot_name));
+}
+
+# inlinable operation snippets
+
+sub is_inlinable { 1 }
+
+sub inline_create_instance {
+    my ($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, $slot_name) . " ? 1 : 0";
+}
+
+sub inline_weaken_slot_value {
+    my ($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;
 
@@ -41,32 +171,150 @@ Class::MOP::Instance - Instance Meta Object
 
 =head1 SYNOPSIS
 
+  # for the most part, this protocol is internal 
+  # and not for public usage, but this how one 
+  # might use it
+  
+  package Foo;
+  
+  use strict;
+  use warnings;
+  use metaclass (
+      ':instance_metaclass'  => 'ArrayBasedStorage::Instance',
+  );
+  
+  # now Foo->new produces blessed ARRAY ref based objects
+
 =head1 DESCRIPTION
 
+This is a sub-protocol which governs instance creation 
+and access to the slots of the instance structure.
+
+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<get_instance>
+=item B<meta>
+
+This will return a B<Class::MOP::Class> instance which is related 
+to this class.
 
 =back
 
-=head2 Introspection
+=head2 Creation of Instances
 
 =over 4
 
-=item B<meta>
+=item B<create_instance>
 
-This will return a B<Class::MOP::Class> instance which is related 
-to this class.
+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)>
+
+=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<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)>
 
 =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<$instance_structure> is passed into them.
+
+=over 4
+
+=item B<get_slot_value ($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, $slot_name)>
+
+=back
+
+=head2 Inlineable Instance Operations
+
+This part of the API is currently un-used. It is there for use 
+in future experiments in class finailization mostly. Best to 
+ignore this for now.
+
+=over 4
+
+=item B<is_inlinable>
+
+Each meta-instance should override this method to tell Class::MOP if it's 
+possible to inline the slot access. 
+
+This is currently only used by Class::MOP::Class::Immutable when performing 
+optimizations.
+
+=item B<inline_create_instance>
+
+=item B<inline_slot_access ($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>
 
@@ -79,4 +327,5 @@ 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. 
 
-=cut
\ No newline at end of file
+=cut
+