instance-protocol

[gitmo/Class-MOP.git] / lib / Class / MOP / Attribute.pm

diff --git a/lib/Class/MOP/Attribute.pm b/lib/Class/MOP/Attribute.pm
index c780a1d..0677448 100644 (file)
--- a/lib/Class/MOP/Attribute.pm
+++ b/lib/Class/MOP/Attribute.pm
@@ -7,11 +7,11 @@ use warnings;
 use Carp         'confess';
 use Scalar::Util 'blessed', 'reftype', 'weaken';
 
-our $VERSION = '0.02';
+our $VERSION = '0.08';
 
 sub meta { 
     require Class::MOP::Class;
-    Class::MOP::Class->initialize($_[0]) 
+    Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
 }
 
 # NOTE: (meta-circularity)
@@ -30,11 +30,8 @@ sub new {
         
     (defined $name && $name)
         || confess "You must provide a name for the attribute";
-    (!exists $options{reader} && !exists $options{writer})
-        || confess "You cannot declare an accessor and reader and/or writer functions"
-            if exists $options{accessor};
-    
-    $options{init_arg} = $name if not exists $options{init_arg};
+    $options{init_arg} = $name 
+        if not exists $options{init_arg};
             
     bless {
         name      => $name,
@@ -51,6 +48,33 @@ sub new {
 }
 
 # NOTE:
+# this is a primative (and kludgy) clone operation 
+# for now, it will be repleace in the Class::MOP
+# bootstrap with a proper one, however we know 
+# that this one will work fine for now.
+sub clone {
+    my $self    = shift;
+    my %options = @_;
+    (blessed($self))
+        || confess "Can only clone an instance";
+    return bless { %{$self}, %options } => blessed($self);
+}
+
+sub initialize_instance_slot {
+    my ($self, $class, $meta_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 = $self->default($meta_instance->get_instance); 
+    }            
+    $meta_instance->add_slot($self->name, $val);    
+}
+
+# NOTE:
 # the next bunch of methods will get bootstrapped 
 # away in the Class::MOP bootstrapping section
 
@@ -104,36 +128,43 @@ sub detach_from_class {
 
 sub generate_accessor_method {
     my ($self, $attr_name) = @_;
-    eval qq{sub {
-        \$_[0]->{'$attr_name'} = \$_[1] if scalar(\@_) == 2;
-        \$_[0]->{'$attr_name'};
-    }};
+    my $meta_instance = $self->associated_class->instance_metaclass;
+    sub {
+        $meta_instance->set_slot_value($_[0], $attr_name, $_[1]) if scalar(@_) == 2;
+        $meta_instance->get_slot_value($_[0], $attr_name);
+    };
 }
 
 sub generate_reader_method {
     my ($self, $attr_name) = @_; 
-    eval qq{sub {
-        \$_[0]->{'$attr_name'};
-    }};   
+    my $meta_instance = $self->associated_class->instance_metaclass;
+    sub { 
+        confess "Cannot assign a value to a read-only accessor" if @_ > 1;
+        $meta_instance->get_slot_value($_[0], $attr_name); 
+    };   
 }
 
 sub generate_writer_method {
     my ($self, $attr_name) = @_; 
-    eval qq{sub {
-        \$_[0]->{'$attr_name'} = \$_[1];
-    }};
+    my $meta_instance = $self->associated_class->instance_metaclass;    
+    sub { 
+        $meta_instance->set_slot_value($_[0], $attr_name, $_[1]);
+    };
 }
 
 sub generate_predicate_method {
     my ($self, $attr_name) = @_; 
-    eval qq{sub {
-        defined \$_[0]->{'$attr_name'} ? 1 : 0;
-    }};
+    my $meta_instance = $self->associated_class->instance_metaclass;    
+    sub { 
+        $meta_instance->has_slot_value($_[0], $attr_name);
+    };
 }
 
 sub process_accessors {
     my ($self, $type, $accessor) = @_;
-    if (reftype($accessor) && reftype($accessor) eq 'HASH') {
+    if (reftype($accessor)) {
+        (reftype($accessor) eq 'HASH')
+            || confess "bad accessor/reader/writer/predicate format, must be a HASH ref";
         my ($name, $method) = each %{$accessor};
         return ($name, Class::MOP::Attribute::Accessor->wrap($method));        
     }
@@ -364,6 +395,10 @@ defined, and false (C<0>) otherwise.
 
 =back
 
+=item B<clone (%options)>
+
+=item B<initialize_instance_slot ($instance, $params)>
+
 =back 
 
 =head2 Informational