use Carp 'confess';
use Scalar::Util 'blessed';
-use Sub::Name 'subname';
-our $VERSION = '0.06';
+our $VERSION = '0.78_02';
+$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
use base 'Class::MOP::Object';
sub new {
- my ($class, $metaclass, $options) = @_;
-
- my $self = bless {
- '$!metaclass' => $metaclass,
- '%!options' => $options,
- '$!immutable_metaclass' => undef,
- } => $class;
+ my ($class, @args) = @_;
+
+ unshift @args, 'metaclass' if @args % 2 == 1;
+
+ my %options = (
+ inline_accessors => 1,
+ inline_constructor => 1,
+ inline_destructor => 0,
+ constructor_name => 'new',
+ constructor_class => 'Class::MOP::Method::Constructor',
+ debug => 0,
+ @args,
+ );
- # NOTE:
- # we initialize the immutable
- # version of the metaclass here
- $self->create_immutable_metaclass;
+ my $self = $class->_new(
+ 'metaclass' => delete $options{metaclass},
+ 'options' => \%options,
+ 'immutable_metaclass' => undef,
+ 'inlined_constructor' => undef,
+ );
return $self;
}
-sub immutable_metaclass { (shift)->{'$!immutable_metaclass'} }
-sub metaclass { (shift)->{'$!metaclass'} }
-sub options { (shift)->{'%!options'} }
+sub _new {
+ my $class = shift;
+ my $options = @_ == 1 ? $_[0] : {@_};
+
+ bless $options, $class;
+}
-sub create_immutable_metaclass {
+sub immutable_metaclass {
my $self = shift;
- # NOTE:
- # The immutable version of the
- # metaclass is just a anon-class
- # which shadows the methods
- # appropriately
- $self->{'$!immutable_metaclass'} = Class::MOP::Class->create_anon_class(
+ return $self->{'immutable_metaclass'} ||= $self->_create_immutable_metaclass;
+}
+
+sub metaclass { (shift)->{'metaclass'} }
+sub options { (shift)->{'options'} }
+sub inlined_constructor { (shift)->{'inlined_constructor'} }
+
+sub _create_immutable_metaclass {
+ my $self = shift;
+
+ # NOTE: The immutable version of the metaclass is just a
+ # anon-class which shadows the methods appropriately
+ return Class::MOP::Class->create_anon_class(
superclasses => [ blessed($self->metaclass) ],
- methods => $self->create_methods_for_immutable_metaclass,
+ methods => $self->_create_methods_for_immutable_metaclass,
+ );
+}
+
+sub make_metaclass_immutable {
+ my $self = shift;
+
+ $self->_inline_accessors;
+ $self->_inline_constructor;
+ $self->_inline_destructor;
+ $self->_check_memoized_methods;
+
+ my $metaclass = $self->metaclass;
+
+ $metaclass->{'___original_class'} = blessed($metaclass);
+ bless $metaclass => $self->immutable_metaclass->name;
+}
+
+sub _inline_accessors {
+ my $self = shift;
+
+ return unless $self->options->{inline_accessors};
+
+ foreach my $attr_name ( $self->metaclass->get_attribute_list ) {
+ $self->metaclass->get_attribute($attr_name)->install_accessors(1);
+ }
+}
+
+sub _inline_constructor {
+ my $self = shift;
+
+ return unless $self->options->{inline_constructor};
+
+ return
+ unless $self->options->{replace_constructor}
+ or !$self->metaclass->has_method(
+ $self->options->{constructor_name}
+ );
+
+ my $constructor_class = $self->options->{constructor_class};
+
+ my $constructor = $constructor_class->new(
+ options => $self->options,
+ metaclass => $self->metaclass,
+ is_inline => 1,
+ package_name => $self->metaclass->name,
+ name => $self->options->{constructor_name},
+ );
+
+ if ( $self->options->{replace_constructor}
+ or $constructor->can_be_inlined ) {
+ $self->metaclass->add_method(
+ $self->options->{constructor_name} => $constructor );
+ $self->{inlined_constructor} = $constructor;
+ }
+}
+
+sub _inline_destructor {
+ my $self = shift;
+
+ return unless $self->options->{inline_destructor};
+
+ ( exists $self->options->{destructor_class} )
+ || confess "The 'inline_destructor' option is present, but "
+ . "no destructor class was specified";
+
+ my $destructor_class = $self->options->{destructor_class};
+
+ return unless $destructor_class->is_needed( $self->metaclass );
+
+ my $destructor = $destructor_class->new(
+ options => $self->options,
+ metaclass => $self->metaclass,
+ package_name => $self->metaclass->name,
+ name => 'DESTROY'
);
+
+ $self->metaclass->add_method( 'DESTROY' => $destructor );
}
+sub _check_memoized_methods {
+ my $self = shift;
+ my $memoized_methods = $self->options->{memoize};
+ foreach my $method_name ( keys %{$memoized_methods} ) {
+ my $type = $memoized_methods->{$method_name};
+
+ ( $self->metaclass->can($method_name) )
+ || confess "Could not find the method '$method_name' in "
+ . $self->metaclass->name;
+ }
+}
my %DEFAULT_METHODS = (
# I don't really understand this, but removing it breaks tests (groditi)
meta => sub {
return Class::MOP::Class->initialize($self) unless blessed($self);
# otherwise, they are asking for the metaclass
# which has been made immutable, which is itself
- return $self;
+ # except in the cases where it is a metaclass itself
+ # that has been made immutable and for that we need
+ # to dig a bit ...
+ if ($self->isa('Class::MOP::Class')) {
+ return $self->{'___original_class'}->meta;
+ }
+ else {
+ return $self;
+ }
},
is_mutable => sub { 0 },
is_immutable => sub { 1 },
make_immutable => sub { () },
);
-# NOTE:
-# this will actually convert the
-# existing metaclass to an immutable
-# version of itself
-sub make_metaclass_immutable {
- my ($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]};
- }
+sub _create_methods_for_immutable_metaclass {
+ my $self = shift;
- my %options = %$options;
+ my $metaclass = $self->metaclass;
+ my $meta = $metaclass->meta;
+
+ return {
+ %DEFAULT_METHODS,
+ $self->_make_read_only_methods,
+ $self->_make_uncallable_methods,
+ $self->_make_memoized_methods,
+ $self->_make_wrapped_methods,
+ get_mutable_metaclass_name => sub { (shift)->{'___original_class'} },
+ immutable_transformer => sub {$self},
+ };
+}
- if ($options{inline_accessors}) {
- foreach my $attr_name ($metaclass->get_attribute_list) {
- # inline the accessors
- $metaclass->get_attribute($attr_name)
- ->install_accessors(1);
- }
- }
+sub _make_read_only_methods {
+ my $self = shift;
- if ($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,
- is_inline => 1,
- )
- ) unless $metaclass->has_method($options{constructor_name});
+ my $metameta = $self->metaclass->meta;
+
+ my %methods;
+ foreach my $read_only_method ( @{ $self->options->{read_only} } ) {
+ my $method = $metameta->find_method_by_name($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 &{ $method->body };
+ };
}
- if ($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;
+ return %methods;
+}
+
+sub _make_uncallable_methods {
+ my $self = shift;
+
+ my %methods;
+ 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};
+ return %methods;
+}
+
+sub _make_memoized_methods {
+ my $self = shift;
- ($metaclass->can($method_name))
- || confess "Could not find the method '$method_name' in " . $metaclass->name;
+ my %methods;
- if ($type eq 'ARRAY') {
- $metaclass->{'___' . $method_name} = [ $metaclass->$method_name ];
+ my $metameta = $self->metaclass->meta;
+
+ my $memoized_methods = $self->options->{memoize};
+ foreach my $method_name ( keys %{$memoized_methods} ) {
+ my $type = $memoized_methods->{$method_name};
+ my $key = '___' . $method_name;
+ my $method = $metameta->find_method_by_name($method_name);
+
+ if ( $type eq 'ARRAY' ) {
+ $methods{$method_name} = sub {
+ @{ $_[0]->{$key} } = $method->execute( $_[0] )
+ if !exists $_[0]->{$key};
+ return @{ $_[0]->{$key} };
+ };
}
- elsif ($type eq 'HASH') {
- $metaclass->{'___' . $method_name} = { $metaclass->$method_name };
+ elsif ( $type eq 'HASH' ) {
+ $methods{$method_name} = sub {
+ %{ $_[0]->{$key} } = $method->execute( $_[0] )
+ if !exists $_[0]->{$key};
+ return %{ $_[0]->{$key} };
+ };
}
- elsif ($type eq 'SCALAR') {
- $metaclass->{'___' . $method_name} = $metaclass->$method_name;
+ elsif ( $type eq 'SCALAR' ) {
+ $methods{$method_name} = sub {
+ $_[0]->{$key} = $method->execute( $_[0] )
+ if !exists $_[0]->{$key};
+ return $_[0]->{$key};
+ };
}
}
- $metaclass->{'___original_class'} = blessed($metaclass);
- bless $metaclass => $self->immutable_metaclass->name;
+ return %methods;
+}
+
+sub _make_wrapped_methods {
+ my $self = shift;
+
+ my %methods;
+
+ my $wrapped_methods = $self->options->{wrapped};
+
+ my $metameta = $self->metaclass->meta;
+
+ foreach my $method_name ( keys %{$wrapped_methods} ) {
+ my $method = $metameta->find_method_by_name($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->( $method, @_ ) };
+ }
+
+ return %methods;
}
sub make_metaclass_mutable {
- my ($self, $immutable, $options) = @_;
+ my $self = shift;
- my %options = %$options;
+ my $metaclass = $self->metaclass;
- my $original_class = $immutable->get_mutable_metaclass_name;
- delete $immutable->{'___original_class'} ;
- bless $immutable => $original_class;
+ my $original_class = $metaclass->get_mutable_metaclass_name;
+ delete $metaclass->{'___original_class'};
+ bless $metaclass => $original_class;
my $memoized_methods = $self->options->{memoize};
- foreach my $method_name (keys %{$memoized_methods}) {
+ 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};
+ ( $metaclass->can($method_name) )
+ || confess "Could not find the method '$method_name' in "
+ . $metaclass->name;
+ if ( $type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) {
+ delete $metaclass->{ '___' . $method_name };
}
}
- if ($options{inline_destructor} && $immutable->has_method('DESTROY')) {
- $immutable->remove_method('DESTROY')
- if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class};
+ if ( $self->options->{inline_destructor}
+ && $metaclass->has_method('DESTROY') ) {
+ $metaclass->remove_method('DESTROY')
+ if blessed( $metaclass->get_method('DESTROY') ) eq
+ $self->options->{destructor_class};
}
# NOTE:
# 14:26 <@stevan> the only user of ::Method::Constructor is immutable
# 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi
# 14:27 <@stevan> so I am not worried
- if ($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') {
- $methods{$method_name} = sub { @{$_[0]->{'___' . $method_name}} };
- }
- elsif ($type eq 'HASH') {
- $methods{$method_name} = sub { %{$_[0]->{'___' . $method_name}} };
- }
- elsif ($type eq 'SCALAR') {
- $methods{$method_name} = sub { $_[0]->{'___' . $method_name} };
+ if ( $self->options->{inline_constructor}
+ && $metaclass->has_method( $self->options->{constructor_name} ) ) {
+ my $constructor_class = $self->options->{constructor_class}
+ || 'Class::MOP::Method::Constructor';
+
+ if (
+ blessed(
+ $metaclass->get_method( $self->options->{constructor_name} )
+ ) eq $constructor_class
+ ) {
+ $metaclass->remove_method( $self->options->{constructor_name} );
+ $self->{inlined_constructor} = undef;
}
}
-
- 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;
}
1;
}
});
- $immutable_metaclass->make_metaclass_immutable(@_)
+ $immutable_metaclass->make_metaclass_immutable;
=head1 DESCRIPTION
-This is basically a module for applying a transformation on a given
-metaclass. Current features include making methods read-only,
-making methods un-callable and memoizing methods (in a type specific
-way too).
+This class encapsulates the logic behind immutabilization.
+
+This class provides generic immutabilization logic. Decisions about
+I<what> gets transformed are up to the caller.
-This module is not for the feint of heart, it does some whacky things
-to the metaclass in order to make it immutable. If you are just curious,
-I suggest you turn back now, there is nothing to see here.
+Immutabilization allows for a number of transformations. It can ask
+the calling metaclass to inline methods such as the constructor,
+destructor, or accessors. It can memoize metaclass accessors
+themselves. It can also turn read-write accessors in the metaclass
+into read-only methods, and make attempting to set these values an
+error. Finally, it can make some methods throw an exception when they
+are called. This is used to disable methods that can alter the class.
=head1 METHODS
=over 4
-=item B<new ($metaclass, \%options)>
+=item B<< Class::MOP::Immutable->new($metaclass, %options) >>
+
+This method takes a metaclass object (typically a L<Class::MOP::Class>
+object) and a hash of options.
+
+It returns a new transformer, but does not actually do any
+transforming yet.
+
+This method accepts the following options:
+
+=over 8
-Given a C<$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 * inline_accessors
-=item B<options>
+=item * inline_constructor
-Returns the options HASH set in C<new>.
+=item * inline_destructor
-=item B<metaclass>
+These are all booleans indicating whether the specified method(s)
+should be inlined.
-Returns the metaclass set in C<new>.
+By default, accessors and the constructor are inlined, but not the
+destructor.
-=item B<immutable_metaclass>
+=item * replace_constructor
-Returns the immutable metaclass created within C<new>.
+This is a boolean indicating whether an existing constructor should be
+replaced when inlining a constructor. This defaults to false.
+
+=item * constructor_name
+
+This is the constructor method name. This defaults to "new".
+
+=item * constructor_class
+
+The name of the method metaclass for constructors. It will be used to
+generate the inlined constructor. This defaults to
+"Class::MOP::Method::Constructor".
+
+=item * destructor_class
+
+The name of the method metaclass for destructors. It will be used to
+generate the inlined destructor. This defaults to
+"Class::MOP::Method::Denstructor".
+
+=item * memoize
+
+This option takes a hash reference. They keys are method names to be
+memoized, and the values are the type of data the method returns. This
+can be one of "SCALAR", "ARRAY", or "HASH".
+
+=item * read_only
+
+This option takes an array reference of read-write methods which will
+be made read-only. After they are transformed, attempting to set them
+will throw an error.
+
+=item * cannot_call
+
+This option takes an array reference of methods which cannot be called
+after immutabilization. Attempting to call these methods will throw an
+error.
+
+=item * wrapped
+
+This option takes a hash reference. The keys are method names and the
+body is a subroutine reference which will wrap the named method. This
+allows you to do some sort of custom transformation to a method.
=back
-=over 4
+=item B<< $transformer->options >>
+
+Returns a hash reference of the options passed to C<new>.
+
+=item B<< $transformer->metaclass >>
+
+Returns the metaclass object passed to C<new>.
-=item B<create_immutable_metaclass>
+=item B<< $transformer->immutable_metaclass >>
-This will create the immutable version of the C<$metaclass>, but will
-not actually change the original metaclass.
+Returns the immutable metaclass object that is created by the
+transformation process.
-=item B<create_methods_for_immutable_metaclass>
+=item B<< $transformer->inlined_constructor >>
-This will create all the methods for the immutable metaclass based
-on the C<%options> passed into C<new>.
+If the constructor was inlined, this returns the constructor method
+object that was created to do this.
-=item B<make_metaclass_immutable (%options)>
+=item B<< $transformer->make_metaclass_immutable >>
-This will actually change the C<$metaclass> into the immutable version.
+Makes the transformer's metaclass immutable.
-=item B<make_metaclass_mutable (%options)>
+=item B<< $transformer->make_metaclass_mutable >>
-This will change the C<$metaclass> into the mutable version by reversing
-the immutable process. C<%options> should be the same options that were
-given to make_metaclass_immutable.
+Makes the transformer's metaclass mutable.
=back
=head1 COPYRIGHT AND LICENSE
-Copyright 2006-2008 by Infinity Interactive, Inc.
+Copyright 2006-2009 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
projects / gitmo/Class-MOP.git / blobdiff