X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FMOP%2FInstance.pm;h=56d9a300fe3cca8ab125bd471be036e0c03ec96c;hb=5fb4edd5750aadf2d20fdf45e95149272d48343a;hp=fb0dca182d920075e3421e57f9a8c0dc16884a6a;hpb=7fe03d203ea938d46cfb8f546181ef271d5a81bd;p=gitmo%2FClass-MOP.git diff --git a/lib/Class/MOP/Instance.pm b/lib/Class/MOP/Instance.pm index fb0dca1..56d9a30 100644 --- a/lib/Class/MOP/Instance.pm +++ b/lib/Class/MOP/Instance.pm @@ -6,15 +6,47 @@ use warnings; use Scalar::Util 'weaken', 'blessed'; -our $VERSION = '0.64'; +our $VERSION = '0.88'; +$VERSION = eval $VERSION; our $AUTHORITY = 'cpan:STEVAN'; use base 'Class::MOP::Object'; +sub BUILDARGS { + my ($class, @args) = @_; + + if ( @args == 1 ) { + unshift @args, "associated_metaclass"; + } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) { + # compat mode + my ( $meta, @attrs ) = @args; + @args = ( associated_metaclass => $meta, attributes => \@attrs ); + } + + my %options = @args; + # FIXME lazy_build + $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ]; + $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build + + return \%options; +} + sub new { - my ($class, $meta, @attrs) = @_; - my @slots = map { $_->slots } @attrs; - my $instance = bless { + my $class = shift; + my $options = $class->BUILDARGS(@_); + + # FIXME replace with a proper constructor + my $instance = $class->_new(%$options); + + # FIXME weak_ref => 1, + weaken($instance->{'associated_metaclass'}); + + return $instance; +} + +sub _new { + my ( $class, %options ) = @_; + bless { # NOTE: # I am not sure that it makes # sense to pass in the meta @@ -25,42 +57,51 @@ sub new { # which is *probably* a safe # assumption,.. but you can # never tell <:) - '$!meta' => $meta, - '@!slots' => { map { $_ => undef } @slots }, + 'associated_metaclass' => $options{associated_metaclass}, + 'attributes' => $options{attributes}, + 'slots' => $options{slots}, + 'slot_hash' => $options{slot_hash}, } => $class; - - weaken($instance->{'$!meta'}); - - return $instance; } -sub associated_metaclass { (shift)->{'$!meta'} } +sub _class_name { $_[0]->{_class_name} ||= $_[0]->associated_metaclass->name } + +sub associated_metaclass { $_[0]{'associated_metaclass'} } sub create_instance { my $self = shift; - $self->bless_instance_structure({}); + bless {}, $self->_class_name; } +# for compatibility sub bless_instance_structure { + Carp::cluck('The bless_instance_structure method is deprecated.' + . " It will be removed in a future release.\n"); + my ($self, $instance_structure) = @_; - bless $instance_structure, $self->associated_metaclass->name; + bless $instance_structure, $self->_class_name; } sub clone_instance { my ($self, $instance) = @_; - $self->bless_instance_structure({ %$instance }); + bless { %$instance }, $self->_class_name; } # operations on meta instance sub get_all_slots { my $self = shift; - return keys %{$self->{'@!slots'}}; + return @{$self->{'slots'}}; +} + +sub get_all_attributes { + my $self = shift; + return @{$self->{attributes}}; } sub is_valid_slot { my ($self, $slot_name) = @_; - exists $self->{'@!slots'}->{$slot_name}; + exists $self->{'slot_hash'}->{$slot_name}; } # operations on created instances @@ -77,7 +118,7 @@ sub set_slot_value { sub initialize_slot { my ($self, $instance, $slot_name) = @_; - #$self->set_slot_value($instance, $slot_name, undef); + return; } sub deinitialize_slot { @@ -116,7 +157,13 @@ sub strengthen_slot_value { sub rebless_instance_structure { my ($self, $instance, $metaclass) = @_; - bless $instance, $metaclass->name; + + # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8 + bless $_[1], $metaclass->name; +} + +sub is_dependent_on_superclasses { + return; # for meta instances that require updates on inherited slot changes } # inlinable operation snippets @@ -130,7 +177,7 @@ sub inline_create_instance { sub inline_slot_access { my ($self, $instance, $slot_name) = @_; - sprintf "%s->{%s}", $instance, $slot_name; + sprintf q[%s->{'%s'}], $instance, quotemeta($slot_name); } sub inline_get_slot_value { @@ -145,7 +192,7 @@ sub inline_set_slot_value { sub inline_initialize_slot { my ($self, $instance, $slot_name) = @_; - $self->inline_set_slot_value($instance, $slot_name, 'undef'), + return ''; } sub inline_deinitialize_slot { @@ -167,6 +214,11 @@ sub inline_strengthen_slot_value { $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); } +sub inline_rebless_instance_structure { + my ($self, $instance, $class_variable) = @_; + "bless $instance => $class_variable"; +} + 1; __END__ @@ -179,141 +231,184 @@ Class::MOP::Instance - Instance Meta Object =head1 DESCRIPTION -The meta instance is used by attributes for low level storage. +The Instance Protocol controls the creation of object instances, and +the storage of attribute values in those instances. -Using this API generally violates attribute encapsulation and is not -recommended, instead look at L, -L for the recommended way to fiddle with -attribute values in a generic way, independent of how/whether accessors have -been defined. Accessors can be found using L. +Using this API directly in your own code violates encapsulation, and +we recommend that you use the appropriate APIs in L +and L instead. Those APIs in turn call the +methods in this class as appropriate. -This may seem like over-abstraction, but by abstracting -this process into a sub-protocol we make it possible to -easily switch the details of how an object's instance is -stored with minimal impact. In most cases just subclassing -this class will be all you need to do (see the examples; -F and -F for details). +This class also participates in generating inlined code by providing +snippets of code to access an object instance. =head1 METHODS +=head2 Object construction + =over 4 -=item B +=item B<< Class::MOP::Instance->new(%options) >> + +This method creates a new meta-instance object. -Creates a new instance meta-object and gathers all the slots from -the list of C<@attrs> given. +It accepts the following keys in C<%options>: -=item B +=over 8 -This will return a B instance which is related -to this class. +=item * associated_metaclass + +The L object for which instances will be created. + +=item * attributes + +An array reference of L objects. These are the +attributes which can be stored in each instance. =back -=head2 Creation of Instances +=back -=over 4 +=head2 Creating and altering instances -=item B +=over 4 -This creates the appropriate structure needed for the instance and -then calls C to bless it into the class. +=item B<< $metainstance->create_instance >> -=item B +This method returns a reference blessed into the associated +metaclass's class. -This does just exactly what it says it does. +The default is to use a hash reference. Subclasses can override this. -=item B +=item B<< $metainstance->clone_instance($instance) >> -This too does just exactly what it says it does. +Given an instance, this method creates a new object by making +I clone of the original. =back =head2 Introspection -NOTE: There might be more methods added to this part of the API, -we will add then when we need them basically. - =over 4 -=item B +=item B<< $metainstance->associated_metaclass >> -This returns the metaclass associated with this instance. +This returns the L object associated with the +meta-instance object. -=item B +=item B<< $metainstance->get_all_slots >> -This will return the current list of slots based on what was -given to this object in C. +This returns a list of slot names stored in object instances. In +almost all cases, slot names correspond directly attribute names. -=item B +=item B<< $metainstance->is_valid_slot($slot_name) >> This will return true if C<$slot_name> is a valid slot name. +=item B<< $metainstance->get_all_attributes >> + +This returns a list of attributes corresponding to the attributes +passed to the constructor. + =back =head2 Operations on Instance Structures -An important distinction of this sub-protocol is that the -instance meta-object is a different entity from the actual -instance it creates. For this reason, any actions on slots -require that the C<$instance_structure> is passed into them. - -The names of these methods pretty much explain exactly -what they do, if that is not enough then I suggest reading -the source, it is very straightfoward. +It's important to understand that the meta-instance object is a +different entity from the actual instances it creates. For this +reason, any operations on the C<$instance_structure> always require +that the object instance be passed to the method. =over 4 -=item B +=item B<< $metainstance->get_slot_value($instance_structure, $slot_name) >> + +=item B<< $metainstance->set_slot_value($instance_structure, $slot_name, $value) >> -=item B +=item B<< $metainstance->initialize_slot($instance_structure, $slot_name) >> -=item B +=item B<< $metainstance->deinitialize_slot($instance_structure, $slot_name) >> -=item B +=item B<< $metainstance->initialize_all_slots($instance_structure) >> -=item B +=item B<< $metainstance->deinitialize_all_slots($instance_structure) >> -=item B +=item B<< $metainstance->is_slot_initialized($instance_structure, $slot_name) >> -=item B +=item B<< $metainstance->weaken_slot_value($instance_structure, $slot_name) >> -=item B +=item B<< $metainstance->strengthen_slot_value($instance_structure, $slot_name) >> -=item B +=item B<< $metainstance->rebless_instance_structure($instance_structure, $new_metaclass) >> -=item B +The exact details of what each method does should be fairly obvious +from the method name. =back -=head2 Inlineable Instance Operations +=head2 Inlinable Instance Operations =over 4 -=item B +=item B<< $metainstance->is_inlinable >> + +This is a boolean that indicates whether or not slot access operations +can be inlined. By default it is true, but subclasses can override +this. + +=item B<< $metainstance->inline_create_instance($class_variable) >> + +This method expects a string that, I, will become a +class name. This would literally be something like C<'$class'>, not an +actual class name. -Each meta-instance should override this method to tell Class::MOP if it's -possible to inline the slot access. This is currently only used by -L when performing optimizations. +It returns a snippet of code that creates a new object for the +class. This is something like C< bless {}, $class_name >. -=item B +=item B<< $metainstance->inline_slot_access($instance_variable, $slot_name) >> -=item B +=item B<< $metainstance->inline_get_slot_value($instance_variable, $slot_name) >> -=item B +=item B<< $metainstance->inline_set_slot_value($instance_variable, $slot_name, $value) >> -=item B +=item B<< $metainstance->inline_initialize_slot($instance_variable, $slot_name) >> -=item B +=item B<< $metainstance->inline_deinitialize_slot($instance_variable, $slot_name) >> -=item B +=item B<< $metainstance->inline_is_slot_initialized($instance_variable, $slot_name) >> + +=item B<< $metainstance->inline_weaken_slot_value($instance_variable, $slot_name) >> + +=item B<< $metainstance->inline_strengthen_slot_value($instance_variable, $slot_name) >> + +These methods all expect two arguments. The first is the name of a +variable, than when inlined, will represent the object +instance. Typically this will be a literal string like C<'$_[0]'>. + +The second argument is a slot name. + +The method returns a snippet of code that, when inlined, performs some +operation on the instance. + +=item B<< $metainstance->inline_rebless_instance_structure($instance_variable, $class_variable) >> + +This takes the name of a variable that will, when inlined, represent the object +instance, and the name of a variable that will represent the class to rebless +into, and returns code to rebless an instance into a class. + +=back + +=head2 Introspection + +=over 4 -=item B +=item B<< Class::MOP::Instance->meta >> -=item B +This will return a L instance for this class. -=item B +It should also be noted that L will actually bootstrap +this module by installing a number of attribute meta-objects into its +metaclass. =back @@ -325,7 +420,7 @@ Stevan Little Estevan@iinteractive.comE =head1 COPYRIGHT AND LICENSE -Copyright 2006-2008 by Infinity Interactive, Inc. +Copyright 2006-2009 by Infinity Interactive, Inc. L