use Carp 'confess';
use Scalar::Util 'blessed';
-our $VERSION = '0.01';
+our $VERSION = '0.63';
our $AUTHORITY = 'cpan:STEVAN';
-sub new {
+use base 'Class::MOP::Object';
+
+sub new {
my ($class, $metaclass, $options) = @_;
-
+
my $self = bless {
'$!metaclass' => $metaclass,
'%!options' => $options,
'$!immutable_metaclass' => undef,
} => $class;
-
+
# NOTE:
- # we initialize the immutable
+ # we initialize the immutable
# version of the metaclass here
$self->create_immutable_metaclass;
-
+
return $self;
}
my $self = shift;
# NOTE:
- # The immutable version of the
+ # The immutable version of the
# metaclass is just a anon-class
- # which shadows the methods
+ # which shadows the methods
# appropriately
$self->{'$!immutable_metaclass'} = Class::MOP::Class->create_anon_class(
superclasses => [ blessed($self->metaclass) ],
methods => $self->create_methods_for_immutable_metaclass,
- );
+ );
}
+
my %DEFAULT_METHODS = (
- meta => sub {
+ # I don't really understand this, but removing it breaks tests (groditi)
+ meta => sub {
my $self = shift;
- # if it is not blessed, then someone is asking
- # for the meta of Class::MOP::Class::Immutable
+ # if it is not blessed, then someone is asking
+ # for the meta of Class::MOP::Immutable
return Class::MOP::Class->initialize($self) unless blessed($self);
- # otherwise, they are asking for the metaclass
+ # otherwise, they are asking for the metaclass
# which has been made immutable, which is itself
return $self;
},
- is_mutable => sub { 0 },
- is_immutable => sub { 1 },
- make_immutable => sub { ( ) },
+ is_mutable => sub { 0 },
+ is_immutable => sub { 1 },
+ make_immutable => sub { () },
);
# NOTE:
-# this will actually convert the
-# existing metaclass to an immutable
+# this will actually convert the
+# existing metaclass to an immutable
# version of itself
sub make_metaclass_immutable {
- my ($self, $metaclass, %options) = @_;
-
- $options{inline_accessors} = 1 unless exists $options{inline_accessors};
- $options{inline_constructor} = 1 unless exists $options{inline_constructor};
- $options{inline_destructor} = 0 unless exists $options{inline_destructor};
- $options{constructor_name} = 'new' unless exists $options{constructor_name};
- $options{debug} = 0 unless exists $options{debug};
-
+ my ($self, $metaclass, $options) = @_;
+
+ foreach my $pair (
+ [ inline_accessors => 1 ],
+ [ inline_constructor => 1 ],
+ [ inline_destructor => 0 ],
+ [ constructor_name => 'new' ],
+ [ debug => 0 ],
+ ) {
+ $options->{$pair->[0]} = $pair->[1] unless exists $options->{$pair->[0]};
+ }
+
+ my %options = %$options;
+
if ($options{inline_accessors}) {
foreach my $attr_name ($metaclass->get_attribute_list) {
# inline the accessors
$metaclass->get_attribute($attr_name)
- ->install_accessors(1);
- }
+ ->install_accessors(1);
+ }
}
- if ($options{inline_constructor}) {
+ if ($options{inline_constructor}) {
my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor';
-
$metaclass->add_method(
$options{constructor_name},
$constructor_class->new(
- options => \%options,
- metaclass => $metaclass,
+ options => \%options,
+ metaclass => $metaclass,
+ is_inline => 1,
+ package_name => $metaclass->name,
+ name => $options{constructor_name}
)
) unless $metaclass->has_method($options{constructor_name});
- }
-
- if ($options{inline_destructor}) {
+ }
+
+ if ($options{inline_destructor}) {
(exists $options{destructor_class})
|| confess "The 'inline_destructor' option is present, but "
. "no destructor class was specified";
-
+
my $destructor_class = $options{destructor_class};
-
- my $destructor = $destructor_class->new(
- options => \%options,
- metaclass => $metaclass,
- );
-
- $metaclass->add_method('DESTROY' => $destructor)
- # NOTE:
- # we allow the destructor to determine
- # if it is needed or not, it can perform
- # all sorts of checks because it has the
- # metaclass instance
- if $destructor->is_needed;
- }
-
+
+ # NOTE:
+ # we allow the destructor to determine
+ # if it is needed or not before we actually
+ # create the destructor too
+ # - SL
+ if ($destructor_class->is_needed($metaclass)) {
+ my $destructor = $destructor_class->new(
+ options => \%options,
+ metaclass => $metaclass,
+ package_name => $metaclass->name,
+ name => 'DESTROY'
+ );
+
+ $metaclass->add_method('DESTROY' => $destructor)
+ # NOTE:
+ # we allow the destructor to determine
+ # if it is needed or not, it can perform
+ # all sorts of checks because it has the
+ # metaclass instance
+ if $destructor->is_needed;
+ }
+ }
+
my $memoized_methods = $self->options->{memoize};
foreach my $method_name (keys %{$memoized_methods}) {
my $type = $memoized_methods->{$method_name};
-
+
($metaclass->can($method_name))
- || confess "Could not find the method '$method_name' in " . $metaclass->name;
-
- my $memoized_method;
+ || confess "Could not find the method '$method_name' in " . $metaclass->name;
+
if ($type eq 'ARRAY') {
$metaclass->{'___' . $method_name} = [ $metaclass->$method_name ];
}
elsif ($type eq 'HASH') {
- $metaclass->{'___' . $method_name} = { $metaclass->$method_name };
+ $metaclass->{'___' . $method_name} = { $metaclass->$method_name };
}
elsif ($type eq 'SCALAR') {
$metaclass->{'___' . $method_name} = $metaclass->$method_name;
}
- }
- $metaclass->{'___original_class'} = blessed($metaclass);
+ }
+ $metaclass->{'___original_class'} = blessed($metaclass);
bless $metaclass => $self->immutable_metaclass->name;
}
+sub make_metaclass_mutable {
+ my ($self, $immutable, $options) = @_;
+
+ my %options = %$options;
+
+ my $original_class = $immutable->get_mutable_metaclass_name;
+ delete $immutable->{'___original_class'} ;
+ bless $immutable => $original_class;
+
+ my $memoized_methods = $self->options->{memoize};
+ foreach my $method_name (keys %{$memoized_methods}) {
+ my $type = $memoized_methods->{$method_name};
+
+ ($immutable->can($method_name))
+ || confess "Could not find the method '$method_name' in " . $immutable->name;
+ if ($type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) {
+ delete $immutable->{'___' . $method_name};
+ }
+ }
+
+ if ($options{inline_destructor} && $immutable->has_method('DESTROY')) {
+ $immutable->remove_method('DESTROY')
+ if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class};
+ }
+
+ # NOTE:
+ # 14:01 <@stevan> nah,. you shouldnt
+ # 14:01 <@stevan> they are just inlined
+ # 14:01 <@stevan> which is the default in Moose anyway
+ # 14:02 <@stevan> and adding new attributes will just DWIM
+ # 14:02 <@stevan> and you really cant change an attribute anyway
+ # if ($options{inline_accessors}) {
+ # foreach my $attr_name ($immutable->get_attribute_list) {
+ # my $attr = $immutable->get_attribute($attr_name);
+ # $attr->remove_accessors;
+ # $attr->install_accessors(0);
+ # }
+ # }
+
+ # 14:26 <@stevan> the only user of ::Method::Constructor is immutable
+ # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi
+ # 14:27 <@stevan> so I am not worried
+ if ($options{inline_constructor} && $immutable->has_method($options{constructor_name})) {
+ my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor';
+ $immutable->remove_method( $options{constructor_name} )
+ if blessed($immutable->get_method($options{constructor_name})) eq $constructor_class;
+ }
+}
+
sub create_methods_for_immutable_metaclass {
my $self = shift;
-
+
my %methods = %DEFAULT_METHODS;
-
+
foreach my $read_only_method (@{$self->options->{read_only}}) {
my $method = $self->metaclass->meta->find_method_by_name($read_only_method);
-
+
(defined $method)
|| confess "Could not find the method '$read_only_method' in " . $self->metaclass->name;
-
+
$methods{$read_only_method} = sub {
confess "This method is read-only" if scalar @_ > 1;
goto &{$method->body}
};
}
-
+
foreach my $cannot_call_method (@{$self->options->{cannot_call}}) {
$methods{$cannot_call_method} = sub {
confess "This method ($cannot_call_method) cannot be called on an immutable instance";
};
- }
-
+ }
+
my $memoized_methods = $self->options->{memoize};
-
foreach my $method_name (keys %{$memoized_methods}) {
my $type = $memoized_methods->{$method_name};
if ($type eq 'ARRAY') {
}
elsif ($type eq 'SCALAR') {
$methods{$method_name} = sub { $_[0]->{'___' . $method_name} };
- }
- }
+ }
+ }
- $methods{get_mutable_metaclass_name} = sub { (shift)->{'___original_class'} };
+ my $wrapped_methods = $self->options->{wrapped};
+ foreach my $method_name (keys %{ $wrapped_methods }) {
+ my $method = $self->metaclass->meta->find_method_by_name($method_name);
+
+ (defined $method)
+ || confess "Could not find the method '$method_name' in " . $self->metaclass->name;
+
+ my $wrapper = $wrapped_methods->{$method_name};
+
+ $methods{$method_name} = sub { $wrapper->($method, @_) };
+ }
+
+ $methods{get_mutable_metaclass_name} = sub { (shift)->{'___original_class'} };
+
+ $methods{immutable_transformer} = sub { $self };
+
return \%methods;
}
=pod
-=head1 NAME
+=head1 NAME
Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses
=head1 SYNOPSIS
+ use Class::MOP::Immutable;
+
+ my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, {
+ read_only => [qw/superclasses/],
+ cannot_call => [qw/
+ add_method
+ alias_method
+ remove_method
+ add_attribute
+ remove_attribute
+ add_package_symbol
+ remove_package_symbol
+ /],
+ memoize => {
+ class_precedence_list => 'ARRAY',
+ compute_all_applicable_attributes => 'ARRAY',
+ get_meta_instance => 'SCALAR',
+ get_method_map => 'SCALAR',
+ }
+ });
+
+ $immutable_metaclass->make_metaclass_immutable(@_)
+
=head1 DESCRIPTION
+This is basically a module for applying a transformation on a given
+metaclass. Current features include making methods read-only,
+making methods un-callable and memoizing methods (in a type specific
+way too).
+
+This module is not for the feint of heart, it does some whacky things
+to the metaclass in order to make it immutable. If you are just curious,
+I suggest you turn back now, there is nothing to see here.
+
=head1 METHODS
=over 4
-=item B<new>
-
+=item B<new ($metaclass, \%options)>
+
+Given a C<$metaclass> and a set of C<%options> this module will
+prepare an immutable version of the C<$metaclass>, which can then
+be applied to the C<$metaclass> using the C<make_metaclass_immutable>
+method.
+
=item B<options>
+Returns the options HASH set in C<new>.
+
=item B<metaclass>
+Returns the metaclass set in C<new>.
+
=item B<immutable_metaclass>
+Returns the immutable metaclass created within C<new>.
+
=back
=over 4
=item B<create_immutable_metaclass>
+This will create the immutable version of the C<$metaclass>, but will
+not actually change the original metaclass.
+
=item B<create_methods_for_immutable_metaclass>
-=item B<make_metaclass_immutable>
+This will create all the methods for the immutable metaclass based
+on the C<%options> passed into C<new>.
+
+=item B<make_metaclass_immutable (%options)>
+
+This will actually change the C<$metaclass> into the immutable version.
+
+=item B<make_metaclass_mutable (%options)>
+
+This will change the C<$metaclass> into the mutable version by reversing
+the immutable process. C<%options> should be the same options that were
+given to make_metaclass_immutable.
=back
=head1 COPYRIGHT AND LICENSE
-Copyright 2006, 2007 by Infinity Interactive, Inc.
+Copyright 2006-2008 by Infinity Interactive, Inc.
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.
+it under the same terms as Perl itself.
=cut