X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=examples%2FArrayBasedStorage.pod;h=bff9baaec231d2ea62041ea11e578135ca0c5e28;hb=202ccce01fee680d3637144e98308de85323a1cc;hp=aa174dba5836c5f12d2930c24b604abef657a7e7;hpb=62189f8484905d2cceec70b0a2a508a104e781d7;p=gitmo%2FClass-MOP.git

diff --git a/examples/ArrayBasedStorage.pod b/examples/ArrayBasedStorage.pod
index aa174db..bff9baa 100644
--- a/examples/ArrayBasedStorage.pod
+++ b/examples/ArrayBasedStorage.pod
@@ -1,84 +1,15 @@
-
-package # hide the package from PAUSE
-    ArrayBasedStorage::Attribute;
-    
-use strict;
-use warnings;
-
-use Carp 'confess';
-
-our $VERSION = '0.01';
-
-use base 'Class::MOP::Attribute';
-
-sub initialize_instance_slot {
-    my ($self, $meta_instance, $instance, $params) = @_;
-    my $init_arg = $self->{init_arg};
-    # try to fetch the init arg from the %params ...
-    my $val;        
-    $val = $params->{$init_arg} if exists $params->{$init_arg};
-    # if nothing was in the %params, we can use the 
-    # attribute's default value (if it has one)
-    if (!defined $val && defined $self->{default}) {
-        $val = $self->default($instance);
-    }
-    $meta_instance->set_slot_value($instance, $self->name, $val);
-}
-
-sub generate_accessor_method {
-    my $self = shift;
-    my $meta_class = $self->associated_class;    
-    my $attr_name  = $self->name;
-    return sub {
-        my $meta_instance = $meta_class->initialize(Scalar::Util::blessed($_[0]))->get_meta_instance;
-        $meta_instance->set_slot_value($_[0], $attr_name, $_[1]) if scalar(@_) == 2;
-        $meta_instance->get_slot_value($_[0], $attr_name);
-    };
-}
-
-sub generate_reader_method {
-    my $self = shift;
-    my $meta_class = $self->associated_class;    
-    my $attr_name  = $self->name;
-    return sub { 
-        confess "Cannot assign a value to a read-only accessor" if @_ > 1;
-        $meta_class->initialize(Scalar::Util::blessed($_[0]))
-                   ->get_meta_instance
-                   ->get_slot_value($_[0], $attr_name); 
-    };   
-}
-
-sub generate_writer_method {
-    my $self = shift;
-    my $meta_class = $self->associated_class;    
-    my $attr_name  = $self->name;
-    return sub { 
-        $meta_class->initialize(Scalar::Util::blessed($_[0]))
-                   ->get_meta_instance
-                   ->set_slot_value($_[0], $attr_name, $_[1]);
-    };
-}
-
-sub generate_predicate_method {
-    my $self = shift;
-    my $meta_class = $self->associated_class;    
-    my $attr_name  = $self->name;
-    return sub { 
-        defined $meta_class->initialize(Scalar::Util::blessed($_[0]))
-                           ->get_meta_instance
-                           ->get_slot_value($_[0], $attr_name) ? 1 : 0;
-    };
-}    
-
+  
 package # hide the package from PAUSE
     ArrayBasedStorage::Instance;
 
 use strict;
 use warnings;
+use Scalar::Util qw/refaddr/;
 
 use Carp 'confess';
 
 our $VERSION = '0.01';
+my $unbound = \'empty-slot-value';
 
 use base 'Class::MOP::Instance';
 
@@ -86,45 +17,62 @@ sub new {
     my ($class, $meta, @attrs) = @_;
     my $self = $class->SUPER::new($meta, @attrs);
     my $index = 0;
-    $self->{slot_index_map} = { map { $_ => $index++ } $self->get_all_slots };
+    $self->{'slot_index_map'} = { map { $_ => $index++ } $self->get_all_slots };
     return $self;
 }
 
 sub create_instance {
     my $self = shift;
-    $self->bless_instance_structure([]);
+    my $instance = $self->bless_instance_structure([]);
+    $self->initialize_all_slots($instance);
+    return $instance;
+}
+
+sub clone_instance {
+    my ($self, $instance) = shift;
+    $self->bless_instance_structure([ @$instance ]);
 }
 
 # operations on meta instance
 
-sub get_slot_index_map { (shift)->{slot_index_map} }
+sub get_slot_index_map { (shift)->{'slot_index_map'} }
+
+sub initialize_slot {
+    my ($self, $instance, $slot_name) = @_;
+    $self->set_slot_value($instance, $slot_name, $unbound);
+}
+
+sub deinitialize_slot {
+    my ( $self, $instance, $slot_name ) = @_;
+    $self->set_slot_value($instance, $slot_name, $unbound);
+}
 
 sub get_all_slots {
     my $self = shift;
-    return sort @{$self->{slots}};
+    return sort $self->SUPER::get_all_slots;
 }
 
 sub get_slot_value {
     my ($self, $instance, $slot_name) = @_;
-    return $instance->[ $self->{slot_index_map}->{$slot_name} ];
+    my $value = $instance->[ $self->{'slot_index_map'}->{$slot_name} ];
+    return $value unless ref $value;
+    refaddr $value eq refaddr $unbound ? undef : $value;
 }
 
 sub set_slot_value {
     my ($self, $instance, $slot_name, $value) = @_;
-    $instance->[ $self->{slot_index_map}->{$slot_name} ] = $value;
+    $instance->[ $self->{'slot_index_map'}->{$slot_name} ] = $value;
 }
 
-sub initialize_slot {
+sub is_slot_initialized {
     my ($self, $instance, $slot_name) = @_;
-    $instance->[ $self->{slot_index_map}->{$slot_name} ] = undef;
+    # NOTE: maybe use CLOS's *special-unbound-value* for this?
+    my $value = $instance->[ $self->{'slot_index_map'}->{$slot_name} ];
+    return 1 unless ref $value;
+    refaddr $value eq refaddr $unbound ? 0 : 1;
 }
 
-sub is_slot_initialized {
-    # NOTE:
-    # maybe use CLOS's *special-unbound-value*
-    # for this ?
-    confess "Cannot really tell this for sure";
-}
+sub is_dependent_on_superclasses { 1 }
 
 1;
 
@@ -165,15 +113,17 @@ This is very similar now to the InsideOutClass example, and
 in fact, they both share the exact same test suite, with 
 the only difference being the Instance metaclass they use.
 
-=head1 AUTHOR
+=head1 AUTHORS
 
 Stevan Little E<lt>stevan@iinteractive.comE<gt>
 
+Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
+
 =head1 SEE ALSO
 
 =head1 COPYRIGHT AND LICENSE
 
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006-2008 by Infinity Interactive, Inc.
 
 L<http://www.iinteractive.com>