use MRO::Compat;
use Carp 'confess';
-use Scalar::Util 'weaken', 'reftype', 'blessed';
+use Scalar::Util 'weaken', 'isweak', 'reftype', 'blessed';
+use Data::OptList;
+use Try::Tiny;
+use Class::MOP::Mixin::AttributeCore;
+use Class::MOP::Mixin::HasAttributes;
+use Class::MOP::Mixin::HasMethods;
use Class::MOP::Class;
use Class::MOP::Attribute;
use Class::MOP::Method;
? sub () { 0 }
: sub () { 1 };
- sub HAVE_ISAREV () {
- Carp::cluck("Class::MOP::HAVE_ISAREV is deprecated and will be removed in a future release. It has always returned 1 anyway.");
- return 1;
- }
-
# this is either part of core or set up appropriately by MRO::Compat
*check_package_cache_flag = \&mro::get_pkg_gen;
}
-our $VERSION = '0.83';
+our $VERSION = '1.11';
our $XS_VERSION = $VERSION;
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
require XSLoader;
XSLoader::load( __PACKAGE__, $XS_VERSION );
-
{
# Metaclasses are singletons, so we cache them here.
# there is no need to worry about destruction though
# because they should die only when the program dies.
# After all, do package definitions even get reaped?
+ # Anonymous classes manage their own destruction.
my %METAS;
- # means of accessing all the metaclasses that have
- # been initialized thus far (for mugwumps obj browser)
sub get_all_metaclasses { %METAS }
sub get_all_metaclass_instances { values %METAS }
sub get_all_metaclass_names { keys %METAS }
sub get_metaclass_by_name { $METAS{$_[0]} }
sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] }
sub weaken_metaclass { weaken($METAS{$_[0]}) }
+ sub metaclass_is_weak { isweak($METAS{$_[0]}) }
sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} }
- sub remove_metaclass_by_name { $METAS{$_[0]} = undef }
+ sub remove_metaclass_by_name { delete $METAS{$_[0]}; return }
# This handles instances as well as class names
sub class_of {
}
sub load_first_existing_class {
- my @classes = @_
- or return;
+ my $classes = Data::OptList::mkopt(\@_)
+ or return;
- foreach my $class (@classes) {
- unless ( _is_valid_class_name($class) ) {
- my $display = defined($class) ? $class : 'undef';
+ foreach my $class (@{ $classes }) {
+ my $name = $class->[0];
+ unless ( _is_valid_class_name($name) ) {
+ my $display = defined($name) ? $name : 'undef';
confess "Invalid class name ($display)";
}
}
my $found;
my %exceptions;
- for my $class (@classes) {
- my $pmfile = _class_to_pmfile($class);
- my $e = _try_load_one_class($class);
- if ($e) {
- $exceptions{$class} = $e;
- last if $e !~ /^Can't locate \Q$pmfile\E in \@INC/;
+ for my $class (@{ $classes }) {
+ my ($name, $options) = @{ $class };
+
+ if ($options) {
+ return $name if is_class_loaded($name, $options);
+ if (is_class_loaded($name)) {
+ # we already know it's loaded and too old, but we call
+ # ->VERSION anyway to generate the exception for us
+ $name->VERSION($options->{-version});
+ }
}
else {
- $found = $class;
- last;
+ return $name if is_class_loaded($name);
}
- }
-
- return $found if $found;
- confess join(
- "\n",
- map {
- sprintf(
- "Could not load class (%s) because : %s", $_,
- $exceptions{$_}
- )
+ my $file = _class_to_pmfile($name);
+ return $name if try {
+ local $SIG{__DIE__};
+ require $file;
+ $name->VERSION($options->{-version})
+ if defined $options->{-version};
+ return 1;
+ }
+ catch {
+ unless (/^Can't locate \Q$file\E in \@INC/) {
+ confess "Couldn't load class ($name) because: $_";
}
- grep {
- exists $exceptions{$_}
- } @classes
- );
-}
-
-sub _try_load_one_class {
- my $class = shift;
- return if is_class_loaded($class);
-
- my $file = _class_to_pmfile($class);
+ return;
+ };
+ }
- return do {
- local $@;
- eval { require($file) };
- $@;
- };
+ if ( @{ $classes } > 1 ) {
+ my @list = map { $_->[0] } @{ $classes };
+ confess "Can't locate any of @list in \@INC (\@INC contains: @INC).";
+ } else {
+ confess "Can't locate " . _class_to_pmfile($classes->[0]->[0]) . " in \@INC (\@INC contains: @INC).";
+ }
}
sub load_class {
- my $class = load_first_existing_class($_[0]);
- return get_metaclass_by_name($class) || $class;
+ load_first_existing_class($_[0], ref $_[1] ? $_[1] : ());
+
+ # This is done to avoid breaking code which checked the return value. Said
+ # code is dumb. The return value was _always_ true, since it dies on
+ # failure!
+ return 1;
}
sub _is_valid_class_name {
# inherit them using _construct_instance
## --------------------------------------------------------
+## Class::MOP::Mixin::HasMethods
+
+Class::MOP::Mixin::HasMethods->meta->add_attribute(
+ Class::MOP::Attribute->new('_methods' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ '_method_map' => \&Class::MOP::Mixin::HasMethods::_method_map
+ },
+ default => sub { {} }
+ ))
+);
+
+Class::MOP::Mixin::HasMethods->meta->add_attribute(
+ Class::MOP::Attribute->new('method_metaclass' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'method_metaclass' => \&Class::MOP::Mixin::HasMethods::method_metaclass
+ },
+ default => 'Class::MOP::Method',
+ ))
+);
+
+Class::MOP::Mixin::HasMethods->meta->add_attribute(
+ Class::MOP::Attribute->new('wrapped_method_metaclass' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'wrapped_method_metaclass' => \&Class::MOP::Mixin::HasMethods::wrapped_method_metaclass
+ },
+ default => 'Class::MOP::Method::Wrapped',
+ ))
+);
+
+## --------------------------------------------------------
+## Class::MOP::Mixin::HasMethods
+
+Class::MOP::Mixin::HasAttributes->meta->add_attribute(
+ Class::MOP::Attribute->new('attributes' => (
+ reader => {
+ # NOTE: we need to do this in order
+ # for the instance meta-object to
+ # not fall into meta-circular death
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ '_attribute_map' => \&Class::MOP::Mixin::HasAttributes::_attribute_map
+ },
+ default => sub { {} }
+ ))
+);
+
+Class::MOP::Mixin::HasAttributes->meta->add_attribute(
+ Class::MOP::Attribute->new('attribute_metaclass' => (
+ reader => {
+ # NOTE:
+ # we just alias the original method
+ # rather than re-produce it here
+ 'attribute_metaclass' => \&Class::MOP::Mixin::HasAttributes::attribute_metaclass
+ },
+ default => 'Class::MOP::Attribute',
+ ))
+);
+
+## --------------------------------------------------------
## Class::MOP::Package
Class::MOP::Package->meta->add_attribute(
## Class::MOP::Class
Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('attributes' => (
- reader => {
- # NOTE: we need to do this in order
- # for the instance meta-object to
- # not fall into meta-circular death
- #
- # we just alias the original method
- # rather than re-produce it here
- 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map
- },
- default => sub { {} }
- ))
-);
-
-Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('methods' => (
- reader => {
- # NOTE:
- # we just alias the original method
- # rather than re-produce it here
- 'get_method_map' => \&Class::MOP::Class::get_method_map
- },
- default => sub { {} }
- ))
-);
-
-Class::MOP::Class->meta->add_attribute(
Class::MOP::Attribute->new('superclasses' => (
accessor => {
# NOTE:
);
Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('attribute_metaclass' => (
- reader => {
- # NOTE:
- # we just alias the original method
- # rather than re-produce it here
- 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass
- },
- default => 'Class::MOP::Attribute',
- ))
-);
-
-Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('method_metaclass' => (
- reader => {
- # NOTE:
- # we just alias the original method
- # rather than re-produce it here
- 'method_metaclass' => \&Class::MOP::Class::method_metaclass
- },
- default => 'Class::MOP::Method',
- ))
-);
-
-Class::MOP::Class->meta->add_attribute(
- Class::MOP::Attribute->new('wrapped_method_metaclass' => (
- reader => {
- # NOTE:
- # we just alias the original method
- # rather than re-produce it here
- 'wrapped_method_metaclass' => \&Class::MOP::Class::wrapped_method_metaclass
- },
- default => 'Class::MOP::Method::Wrapped',
- ))
-);
-
-Class::MOP::Class->meta->add_attribute(
Class::MOP::Attribute->new('instance_metaclass' => (
reader => {
# NOTE: we need to do this in order
# _construct_class_instance method.
## --------------------------------------------------------
-## Class::MOP::Attribute
-
-Class::MOP::Attribute->meta->add_attribute(
+## Class::MOP::Mixin::AttributeCore
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('name' => (
reader => {
# NOTE: we need to do this in order
#
# we just alias the original method
# rather than re-produce it here
- 'name' => \&Class::MOP::Attribute::name
+ 'name' => \&Class::MOP::Mixin::AttributeCore::name
}
))
);
-Class::MOP::Attribute->meta->add_attribute(
- Class::MOP::Attribute->new('associated_class' => (
- reader => {
- # NOTE: we need to do this in order
- # for the instance meta-object to
- # not fall into meta-circular death
- #
- # we just alias the original method
- # rather than re-produce it here
- 'associated_class' => \&Class::MOP::Attribute::associated_class
- }
- ))
-);
-
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('accessor' => (
- reader => { 'accessor' => \&Class::MOP::Attribute::accessor },
- predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor },
+ reader => { 'accessor' => \&Class::MOP::Mixin::AttributeCore::accessor },
+ predicate => { 'has_accessor' => \&Class::MOP::Mixin::AttributeCore::has_accessor },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('reader' => (
- reader => { 'reader' => \&Class::MOP::Attribute::reader },
- predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader },
+ reader => { 'reader' => \&Class::MOP::Mixin::AttributeCore::reader },
+ predicate => { 'has_reader' => \&Class::MOP::Mixin::AttributeCore::has_reader },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('initializer' => (
- reader => { 'initializer' => \&Class::MOP::Attribute::initializer },
- predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer },
+ reader => { 'initializer' => \&Class::MOP::Mixin::AttributeCore::initializer },
+ predicate => { 'has_initializer' => \&Class::MOP::Mixin::AttributeCore::has_initializer },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('definition_context' => (
- reader => { 'definition_context' => \&Class::MOP::Attribute::definition_context },
+ reader => { 'definition_context' => \&Class::MOP::Mixin::AttributeCore::definition_context },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('writer' => (
- reader => { 'writer' => \&Class::MOP::Attribute::writer },
- predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer },
+ reader => { 'writer' => \&Class::MOP::Mixin::AttributeCore::writer },
+ predicate => { 'has_writer' => \&Class::MOP::Mixin::AttributeCore::has_writer },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('predicate' => (
- reader => { 'predicate' => \&Class::MOP::Attribute::predicate },
- predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate },
+ reader => { 'predicate' => \&Class::MOP::Mixin::AttributeCore::predicate },
+ predicate => { 'has_predicate' => \&Class::MOP::Mixin::AttributeCore::has_predicate },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('clearer' => (
- reader => { 'clearer' => \&Class::MOP::Attribute::clearer },
- predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer },
+ reader => { 'clearer' => \&Class::MOP::Mixin::AttributeCore::clearer },
+ predicate => { 'has_clearer' => \&Class::MOP::Mixin::AttributeCore::has_clearer },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('builder' => (
- reader => { 'builder' => \&Class::MOP::Attribute::builder },
- predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder },
+ reader => { 'builder' => \&Class::MOP::Mixin::AttributeCore::builder },
+ predicate => { 'has_builder' => \&Class::MOP::Mixin::AttributeCore::has_builder },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('init_arg' => (
- reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg },
- predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg },
+ reader => { 'init_arg' => \&Class::MOP::Mixin::AttributeCore::init_arg },
+ predicate => { 'has_init_arg' => \&Class::MOP::Mixin::AttributeCore::has_init_arg },
))
);
-Class::MOP::Attribute->meta->add_attribute(
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
Class::MOP::Attribute->new('default' => (
# default has a custom 'reader' method ...
- predicate => { 'has_default' => \&Class::MOP::Attribute::has_default },
+ predicate => { 'has_default' => \&Class::MOP::Mixin::AttributeCore::has_default },
+ ))
+);
+
+Class::MOP::Mixin::AttributeCore->meta->add_attribute(
+ Class::MOP::Attribute->new('insertion_order' => (
+ reader => { 'insertion_order' => \&Class::MOP::Mixin::AttributeCore::insertion_order },
+ writer => { '_set_insertion_order' => \&Class::MOP::Mixin::AttributeCore::_set_insertion_order },
+ predicate => { 'has_insertion_order' => \&Class::MOP::Mixin::AttributeCore::has_insertion_order },
+ ))
+);
+
+## --------------------------------------------------------
+## Class::MOP::Attribute
+Class::MOP::Attribute->meta->add_attribute(
+ Class::MOP::Attribute->new('associated_class' => (
+ reader => {
+ # NOTE: we need to do this in order
+ # for the instance meta-object to
+ # not fall into meta-circular death
+ #
+ # we just alias the original method
+ # rather than re-produce it here
+ 'associated_class' => \&Class::MOP::Attribute::associated_class
+ }
))
);
))
);
-Class::MOP::Method->meta->add_method('clone' => sub {
- my $self = shift;
- my $clone = $self->meta->clone_object($self, @_);
- $clone->_set_original_method($self);
- return $clone;
-});
-
## --------------------------------------------------------
## Class::MOP::Method::Wrapped
),
);
+## --------------------------------------------------------
+## Class::MOP::Object
+
+# need to replace the meta method there with a real meta method object
+Class::MOP::Object->meta->_add_meta_method('meta');
+
+## --------------------------------------------------------
+## Class::MOP::Mixin
+
+# need to replace the meta method there with a real meta method object
+Class::MOP::Mixin->meta->_add_meta_method('meta');
+
+require Class::MOP::Deprecated unless our $no_deprecated;
# we need the meta instance of the meta instance to be created now, in order
# for the constructor to be able to use it
# NOTE: we don't need to inline the the accessors this only lengthens
# the compile time of the MOP, and gives us no actual benefits.
-# this is just nitpicking to ensure Class::MOP::Class->meta == ->meta->meta
-Class::MOP::Class->meta->_immutable_metaclass;
-$Class::MOP::Class::immutable_metaclass_cache{"Class::MOP::Class"}{"Class::MOP::Class::Immutable::Trait"} = Class::MOP::Class::Immutable::Class::MOP::Class->meta;
-
$_->meta->make_immutable(
- inline_constructor => 1,
- replace_constructor => 1,
+ inline_constructor => 0,
constructor_name => "_new",
inline_accessors => 0,
) for qw/
Class::MOP::Package
Class::MOP::Module
Class::MOP::Class
- Class::MOP::Class::Immutable::Trait
- Class::MOP::Class::Immutable::Class::MOP::Class
Class::MOP::Attribute
Class::MOP::Method
Class::MOP::Method::Accessor
Class::MOP::Method::Constructor
Class::MOP::Method::Wrapped
+
+ Class::MOP::Method::Meta
+/;
+
+$_->meta->make_immutable(
+ inline_constructor => 0,
+ constructor_name => undef,
+ inline_accessors => 0,
+) for qw/
+ Class::MOP::Mixin
+ Class::MOP::Mixin::AttributeCore
+ Class::MOP::Mixin::HasAttributes
+ Class::MOP::Mixin::HasMethods
/;
1;
| A |<----| B |
+---------+ +---------+
+In actuality, I<all> of a class's metaclasses must be compatible,
+not just the class metaclass. That includes the instance, attribute,
+and method metaclasses, as well as the constructor and destructor
+classes.
+
+C<Class::MOP> will attempt to fix some simple types of
+incompatibilities. If all the metaclasses for the parent class are
+I<subclasses> of the child's metaclasses then we can simply replace
+the child's metaclasses with the parent's. In addition, if the child
+is missing a metaclass that the parent has, we can also just make the
+child use the parent's metaclass.
+
As I said this is a highly esoteric topic and one you will only run
into if you do a lot of subclassing of L<Class::MOP::Class>. If you
are interested in why this is an issue see the paper I<Uniform and
=over 4
-=item B<Class::MOP::load_class($class_name)>
+=item B<Class::MOP::load_class($class_name, \%options?)>
-This will load the specified C<$class_name>. This function can be used
+This will load the specified C<$class_name>, if it is not already
+loaded (as reported by C<is_class_loaded>). This function can be used
in place of tricks like C<eval "use $module"> or using C<require>
-unconditionally. This will return the metaclass of C<$class_name>.
+unconditionally.
-=item B<Class::MOP::is_class_loaded($class_name)>
+If the module cannot be loaded, an exception is thrown.
+
+You can pass a hash reference with options as second argument. The
+only option currently recognised is C<-version>, which will ensure
+that the loaded class has at least the required version.
+
+See also L</Class Loading Options>.
+
+For historical reasons, this function explicitly returns a true value.
+
+=item B<Class::MOP::is_class_loaded($class_name, \%options?)>
Returns a boolean indicating whether or not C<$class_name> has been
loaded.
This does a basic check of the symbol table to try and determine as
best it can if the C<$class_name> is loaded, it is probably correct
about 99% of the time, but it can be fooled into reporting false
-positives.
+positives. In particular, loading any of the core L<IO> modules will
+cause most of the rest of the core L<IO> modules to falsely report
+having been loaded, due to the way the base L<IO> module works.
+
+You can pass a hash reference with options as second argument. The
+only option currently recognised is C<-version>, which will ensure
+that the loaded class has at least the required version.
+
+See also L</Class Loading Options>.
=item B<Class::MOP::get_code_info($code)>
=item B<Class::MOP::class_of($instance_or_class_name)>
-This will return the metaclass of the given instance or class name.
-Even if the class lacks a metaclass, no metaclass will be initialized
-and C<undef> will be returned.
+This will return the metaclass of the given instance or class name. If the
+class lacks a metaclass, no metaclass will be initialized, and C<undef> will be
+returned.
=item B<Class::MOP::check_package_cache_flag($pkg)>
=item B<Class::MOP::load_first_existing_class(@class_names)>
+=item B<Class::MOP::load_first_existing_class($classA, \%optionsA?, $classB, ...)>
+
B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!>
Given a list of class names, this function will attempt to load each
If it finds a class it can load, it will return that class' name. If
none of the classes can be loaded, it will throw an exception.
+Additionally, you can pass a hash reference with options after each
+class name. Currently, only C<-version> is recognised and will ensure
+that the loaded class has at least the required version. If the class
+version is not sufficient, an exception will be raised.
+
+See also L</Class Loading Options>.
+
=back
=head2 Metaclass cache functions
function will weaken the reference to the metaclass stored
in C<$name>.
+=item B<Class::MOP::metaclass_is_weak($name)>
+
+Returns true if the metaclass for C<$name> has been weakened
+(via C<weaken_metaclass>).
+
=item B<Class::MOP::does_metaclass_exist($name)>
This will return true of there exists a metaclass stored in the
=back
+=head2 Class Loading Options
+
+=over 4
+
+=item -version
+
+Can be used to pass a minimum required version that will be checked
+against the class version after it was loaded.
+
+=back
+
=head1 SEE ALSO
=head2 Books
=over 4
-=item L<http://svn.openfoundry.org/pugs/perl5/Perl6-MetaModel>
+=item L<http://svn.openfoundry.org/pugs/misc/Perl-MetaModel/>
-=item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace>
+=item L<http://github.com/perl6/p5-modules/tree/master/Perl6-ObjectSpace/>
=back
Scott (konobi) McWhirter
+Dylan Hardison
+
=head1 COPYRIGHT AND LICENSE
-Copyright 2006-2009 by Infinity Interactive, Inc.
+Copyright 2006-2010 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>