use Carp 'confess';
use Scalar::Util 'blessed', 'weaken';
-our $VERSION = '0.78_01';
+our $VERSION = '0.79';
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
# now create the metaclass
my $meta;
if ($class eq 'Class::MOP::Class') {
- no strict 'refs';
- $meta = $class->_new($options)
+ $meta = $class->_new($options);
}
else {
# NOTE:
: ref($super_meta);
($self->isa($super_meta_type))
- || confess $self->name . "->meta => (" . (ref($self)) . ")" .
- " is not compatible with the " .
- $superclass_name . "->meta => (" . ($super_meta_type) . ")";
+ || confess "Class::MOP::class_of(" . $self->name . ") => ("
+ . (ref($self)) . ")" . " is not compatible with the " .
+ "Class::MOP::class_of(".$superclass_name . ") => ("
+ . ($super_meta_type) . ")";
# NOTE:
# we also need to check that instance metaclasses
# are compatibile in the same the class.
($self->instance_metaclass->isa($super_meta->instance_metaclass))
- || confess $self->name . "->meta->instance_metaclass => (" . ($self->instance_metaclass) . ")" .
+ || confess "Class::MOP::class_of(" . $self->name . ")->instance_metaclass => (" . ($self->instance_metaclass) . ")" .
" is not compatible with the " .
- $superclass_name . "->meta->instance_metaclass => (" . ($super_meta->instance_metaclass) . ")";
+ "Class::MOP::class_of(" . $superclass_name . ")->instance_metaclass => (" . ($super_meta->instance_metaclass) . ")";
}
}
sub rebless_instance {
my ($self, $instance, %params) = @_;
- my $old_metaclass;
- if ($instance->can('meta')) {
- ($instance->meta->isa('Class::MOP::Class'))
- || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
- $old_metaclass = $instance->meta;
- }
- else {
- $old_metaclass = $self->initialize(ref($instance));
- }
+ my $old_metaclass = Class::MOP::class_of($instance);
- my $meta_instance = $self->get_meta_instance();
+ my $old_class = $old_metaclass ? $old_metaclass->name : blessed($instance);
+ $self->name->isa($old_class)
+ || confess "You may rebless only into a subclass of ($old_class), of which (". $self->name .") isn't.";
- $self->name->isa($old_metaclass->name)
- || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
+ $old_metaclass->rebless_instance_away($instance, $self, %params)
+ if $old_metaclass;
+
+ my $meta_instance = $self->get_meta_instance();
# rebless!
# we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8
$instance;
}
+sub rebless_instance_away {
+ # this intentionally does nothing, it is just a hook
+}
+
# Inheritance
sub superclasses {
sub is_mutable { 1 }
sub is_immutable { 0 }
-# NOTE:
-# Why I changed this (groditi)
-# - One Metaclass may have many Classes through many Metaclass instances
-# - One Metaclass should only have one Immutable Transformer instance
-# - Each Class may have different Immutabilizing options
-# - Therefore each Metaclass instance may have different Immutabilizing options
-# - We need to store one Immutable Transformer instance per Metaclass
-# - We need to store one set of Immutable Transformer options per Class
-# - Upon make_mutable we may delete the Immutabilizing options
-# - We could clean the immutable Transformer instance when there is no more
-# immutable Classes of that type, but we can also keep it in case
-# another class with this same Metaclass becomes immutable. It is a case
-# of trading of storing an instance to avoid unnecessary instantiations of
-# Immutable Transformers. You may view this as a memory leak, however
-# Because we have few Metaclasses, in practice it seems acceptable
-# - To allow Immutable Transformers instances to be cleaned up we could weaken
-# the reference stored in $IMMUTABLE_TRANSFORMERS{$class} and ||= should DWIM
+sub immutable_transformer { $_[0]->{immutable_transformer} }
+sub _set_immutable_transformer { $_[0]->{immutable_transformer} = $_[1] }
-{
-
- my %IMMUTABLE_TRANSFORMERS;
- my %IMMUTABLE_OPTIONS;
-
- sub get_immutable_options {
- my $self = shift;
- return if $self->is_mutable;
- confess "unable to find immutabilizing options"
- unless exists $IMMUTABLE_OPTIONS{$self->name};
- my %options = %{$IMMUTABLE_OPTIONS{$self->name}};
- delete $options{IMMUTABLE_TRANSFORMER};
- return \%options;
- }
-
- sub get_immutable_transformer {
- my $self = shift;
- if( $self->is_mutable ){
- return $IMMUTABLE_TRANSFORMERS{$self->name} ||= $self->create_immutable_transformer;
- }
- confess "unable to find transformer for immutable class"
- unless exists $IMMUTABLE_OPTIONS{$self->name};
- return $IMMUTABLE_OPTIONS{$self->name}->{IMMUTABLE_TRANSFORMER};
- }
-
- sub make_immutable {
- my $self = shift;
- my %options = @_;
+sub make_immutable {
+ my $self = shift;
- my $transformer = $self->get_immutable_transformer;
- $transformer->make_metaclass_immutable($self, \%options);
- $IMMUTABLE_OPTIONS{$self->name} =
- { %options, IMMUTABLE_TRANSFORMER => $transformer };
+ return if $self->is_immutable;
- if( exists $options{debug} && $options{debug} ){
- print STDERR "# of Metaclass options: ", keys %IMMUTABLE_OPTIONS;
- print STDERR "# of Immutable transformers: ", keys %IMMUTABLE_TRANSFORMERS;
- }
+ my $transformer = $self->immutable_transformer
+ || $self->_make_immutable_transformer(@_);
- 1;
- }
+ $self->_set_immutable_transformer($transformer);
- sub make_mutable{
- my $self = shift;
- return if $self->is_mutable;
- my $options = delete $IMMUTABLE_OPTIONS{$self->name};
- confess "unable to find immutabilizing options" unless ref $options;
- my $transformer = delete $options->{IMMUTABLE_TRANSFORMER};
- $transformer->make_metaclass_mutable($self, $options);
- 1;
- }
+ $transformer->make_metaclass_immutable;
}
-sub create_immutable_transformer {
- my $self = shift;
- my $class = Class::MOP::Immutable->new($self, {
+{
+ my %Default_Immutable_Options = (
read_only => [qw/superclasses/],
- cannot_call => [qw/
- add_method
- alias_method
- remove_method
- add_attribute
- remove_attribute
- remove_package_symbol
- /],
- memoize => {
- class_precedence_list => 'ARRAY',
- linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
- get_all_methods => 'ARRAY',
- get_all_method_names => 'ARRAY',
- #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
- compute_all_applicable_attributes => 'ARRAY',
- get_meta_instance => 'SCALAR',
- get_method_map => 'SCALAR',
+ cannot_call => [
+ qw(
+ add_method
+ alias_method
+ remove_method
+ add_attribute
+ remove_attribute
+ remove_package_symbol
+ )
+ ],
+ memoize => {
+ class_precedence_list => 'ARRAY',
+ # FIXME perl 5.10 memoizes this on its own, no need?
+ linearized_isa => 'ARRAY',
+ get_all_methods => 'ARRAY',
+ get_all_method_names => 'ARRAY',
+ compute_all_applicable_attributes => 'ARRAY',
+ get_meta_instance => 'SCALAR',
+ get_method_map => 'SCALAR',
},
+
# NOTE:
- # this is ugly, but so are typeglobs,
+ # this is ugly, but so are typeglobs,
# so whattayahgonnadoboutit
# - SL
- wrapped => {
+ wrapped => {
add_package_symbol => sub {
my $original = shift;
- confess "Cannot add package symbols to an immutable metaclass"
- unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
+ confess "Cannot add package symbols to an immutable metaclass"
+ unless ( caller(2) )[3] eq
+ 'Class::MOP::Package::get_package_symbol';
# This is a workaround for a bug in 5.8.1 which thinks that
# goto $original->body
goto $body;
},
},
- });
- return $class;
+ );
+
+ sub _default_immutable_transformer_options {
+ return %Default_Immutable_Options;
+ }
+}
+
+sub _make_immutable_transformer {
+ my $self = shift;
+
+ Class::MOP::Immutable->new(
+ $self,
+ $self->_default_immutable_transformer_options,
+ @_
+ );
+}
+
+sub make_mutable {
+ my $self = shift;
+
+ return if $self->is_mutable;
+
+ $self->immutable_transformer->make_metaclass_mutable;
}
1;
attributes. Any existing attributes that are already set will be
overwritten.
+Before reblessing the instance, this method will call
+C<rebless_instance_away> on the instance's current metaclass. This method
+will be passed the instance, the new metaclass, and any parameters
+specified to C<rebless_instance>. By default, C<rebless_instance_away>
+does nothing; it is merely a hook.
+
=item B<< $metaclass->new_object(%params) >>
This method is used to create a new object of the metaclass's
Calling this method reverse the immutabilization transformation.
-=item B<< $metaclass->get_immutable_transformer >>
+=item B<< $metaclass->immutable_transformer >>
If the class has been made immutable previously, this returns the
L<Class::MOP::Immutable> object that was created to do the