1 files changed, 88 insertions, 0 deletions
diff --git a/lib/MooseX/ArrayRef/Meta/Role/Instance.pm b/lib/MooseX/ArrayRef/Meta/Role/Instance.pm
new file mode 100644
index 0000000..1258e79
--- /dev/null
+++ b/lib/MooseX/ArrayRef/Meta/Role/Instance.pm
@@ -0,0 +1,88 @@
+package MooseX::ArrayRef::Meta::Role::Instance;
+use Moose::Role;
+
+my $NOT_EXISTS = \undef;
+
+has slot_mapping => (
+    traits  => ['Hash'],
+    isa     => 'HashRef[Int]',
+    lazy    => 1,
+    default => sub {
+        my $self = shift;
+        my @order = $self->_sorted_slots;
+        return { map { $order[$_] => $_ } 0..$#order };
+    },
+    handles => {
+        slot_index => 'get',
+        num_slots  => 'count',
+    },
+);
+
+sub _sorted_attributes {
+    my $self = shift;
+    return sort {
+        my ($a_name, $b_name) = map { $_->associated_class->name } ($a, $b);
+        $a_name eq $b_name
+            ? $a->insertion_order <=> $b->insertion_order
+            : $a_name->isa($b_name)
+            ?  1
+            : -1;
+
+    } $self->get_all_attributes;
+}
+
+sub _sorted_slots {
+    my $self = shift;
+    return map { sort $_->slots } $self->_sorted_attributes;
+}
+
+sub create_instance {
+    my $self = shift;
+    bless [($NOT_EXISTS) x $self->num_slots], $self->_class_name;
+}
+
+sub clone_instance {
+    my ($self, $instance) = @_;
+    bless [ @$instance ], $self->_class_name;
+}
+
+sub get_slot_value {
+    my ($self, $instance, $slot_name) = @_;
+    my $val = $instance->[$self->slot_index($slot_name)];
+    return $val unless ref($val);
+    return undef if $val == $NOT_EXISTS;
+    return $val;
+}
+
+sub set_slot_value {
+    my ($self, $instance, $slot_name, $value) = @_;
+    $instance->[$self->slot_index($slot_name)] = $value;
+}
+
+sub initialize_slot {
+    my ($self, $instance, $slot_name) = @_;
+    $instance->[$self->slot_index($slot_name)] = $NOT_EXISTS;
+}
+
+sub deinitialize_slot {
+    my ($self, $instance, $slot_name) = @_;
+    $instance->[$self->slot_index($slot_name)] = $NOT_EXISTS;
+}
+
+sub is_slot_initialized {
+    my ($self, $instance, $slot_name) = @_;
+    my $val = $instance->[$self->slot_index($slot_name)];
+    !ref($val) || $val != $NOT_EXISTS;
+}
+
+sub weaken_slot_value {
+    my ($self, $instance, $slot_name) = @_;
+    weaken $instance->[$self->slot_index($slot_name)];
+}
+
+# TODO
+sub is_inlinable { 0 }
+
+no Moose::Role;
+
+1;