X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose.pm;h=1747b9cc898c5a897f28cb3698da21c5d58a0203;hb=26fbace8d6e64e26057f3778161dd7029f517b6a;hp=eaf420c4225393123d8103ebca93d7948de4dabb;hpb=74f6d830e86967e28a6c072e10732b13d8d00e71;p=gitmo%2FMoose.git diff --git a/lib/Moose.pm b/lib/Moose.pm index eaf420c..1747b9c 100644 --- a/lib/Moose.pm +++ b/lib/Moose.pm @@ -4,16 +4,17 @@ package Moose; use strict; use warnings; -our $VERSION = '0.06'; +our $VERSION = '0.28'; +our $AUTHORITY = 'cpan:STEVAN'; use Scalar::Util 'blessed', 'reftype'; use Carp 'confess'; use Sub::Name 'subname'; +use B 'svref_2object'; -use UNIVERSAL::require; use Sub::Exporter; -use Class::MOP; +use Class::MOP 0.39; use Moose::Meta::Class; use Moose::Meta::TypeConstraint; @@ -21,235 +22,264 @@ use Moose::Meta::TypeCoercion; use Moose::Meta::Attribute; use Moose::Meta::Instance; +use Moose::Meta::Role; + use Moose::Object; use Moose::Util::TypeConstraints; { my $CALLER; - sub _init_meta { - my $class = $CALLER; + sub init_meta { + my ( $class, $base_class, $metaclass ) = @_; + $base_class = $class unless defined $base_class; + $metaclass = 'Moose::Meta::Class' unless defined $metaclass; + + confess + "The Metaclass $metaclass must be a subclass of Moose::Meta::Class." + unless $metaclass->isa('Moose::Meta::Class'); # make a subtype for each Moose class - subtype $class - => as 'Object' - => where { $_->isa($class) } + subtype $class => as 'Object' => where { $_->isa($class) } => + optimize_as { blessed( $_[0] ) && $_[0]->isa($class) } unless find_type_constraint($class); my $meta; - if ($class->can('meta')) { + if ( $class->can('meta') ) { # NOTE: - # this is the case where the metaclass pragma - # was used before the 'use Moose' statement to + # this is the case where the metaclass pragma + # was used before the 'use Moose' statement to # override a specific class $meta = $class->meta(); - (blessed($meta) && $meta->isa('Moose::Meta::Class')) - || confess "Whoops, not møøsey enough"; + ( blessed($meta) && $meta->isa('Moose::Meta::Class') ) + || confess +"You already have a &meta function, but it does not return a Moose::Meta::Class"; } else { # NOTE: - # this is broken currently, we actually need - # to allow the possiblity of an inherited - # meta, which will not be visible until the - # user 'extends' first. This needs to have - # more intelligence to it - $meta = Moose::Meta::Class->initialize($class); - $meta->add_method('meta' => sub { - # re-initialize so it inherits properly - Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]); - }) + # this is broken currently, we actually need + # to allow the possiblity of an inherited + # meta, which will not be visible until the + # user 'extends' first. This needs to have + # more intelligence to it + $meta = $metaclass->initialize($class); + $meta->add_method( + 'meta' => sub { + + # re-initialize so it inherits properly + $metaclass->initialize( blessed( $_[0] ) || $_[0] ); + } + ); } # make sure they inherit from Moose::Object - $meta->superclasses('Moose::Object') - unless $meta->superclasses(); + $meta->superclasses($base_class) + unless $meta->superclasses(); } my %exports = ( extends => sub { my $class = $CALLER; - return subname 'Moose::extends' => sub { - _load_all_classes(@_); - my $meta = $class->meta; - foreach my $super (@_) { - # don't bother if it does not have a meta. - next unless $super->can('meta'); - # if it's meta is a vanilla Moose, - # then we can safely ignore it. - next if blessed($super->meta) eq 'Moose::Meta::Class'; - # but if we have anything else, - # we need to check it out ... - unless (# see if of our metaclass is incompatible - ($meta->isa(blessed($super->meta)) && - # and see if our instance metaclass is incompatible - $meta->instance_metaclass->isa($super->meta->instance_metaclass)) && - # ... and if we are just a vanilla Moose - $meta->isa('Moose::Meta::Class')) { - # re-initialize the meta ... - my $super_meta = $super->meta; - # NOTE: - # We might want to consider actually - # transfering any attributes from the - # original meta into this one, but in - # general you should not have any there - # at this point anyway, so it's very - # much an obscure edge case anyway - $meta = $super_meta->reinitialize($class => ( - ':attribute_metaclass' => $super_meta->attribute_metaclass, - ':method_metaclass' => $super_meta->method_metaclass, - ':instance_metaclass' => $super_meta->instance_metaclass, - )); - } - } + return subname 'Moose::extends' => sub (@) { + confess "Must derive at least one class" unless @_; + Class::MOP::load_class($_) for @_; + + # this checks the metaclass to make sure + # it is correct, sometimes it can get out + # of sync when the classes are being built + my $meta = $class->meta->_fix_metaclass_incompatability(@_); $meta->superclasses(@_); }; }, with => sub { my $class = $CALLER; - return subname 'Moose::with' => sub { + return subname 'Moose::with' => sub (@) { my (@roles) = @_; - _load_all_classes(@roles); - ($_->can('meta') && $_->meta->isa('Moose::Meta::Role')) - || confess "You can only consume roles, $_ is not a Moose role" - foreach @roles; - if (scalar @roles == 1) { - $roles[0]->meta->apply($class->meta); - } - else { - Moose::Meta::Role->combine( - map { $_->meta } @roles - )->apply($class->meta); - } + confess "Must specify at least one role" unless @roles; + Class::MOP::load_class($_) for @roles; + $class->meta->_apply_all_roles(@roles); }; }, has => sub { my $class = $CALLER; - return subname 'Moose::has' => sub { - my ($name, %options) = @_; - my $meta = $class->meta; - if ($name =~ /^\+(.*)/) { - my $inherited_attr = $meta->find_attribute_by_name($1); - (defined $inherited_attr) - || confess "Could not find an attribute by the name of '$1' to inherit from"; - my $new_attr; - if ($inherited_attr->isa('Moose::Meta::Attribute')) { - $new_attr = $inherited_attr->clone_and_inherit_options(%options); - } - else { - # NOTE: - # kind of a kludge to handle Class::MOP::Attributes - $new_attr = Moose::Meta::Attribute::clone_and_inherit_options( - $inherited_attr, %options - ); - } - $meta->add_attribute($new_attr); - } - else { - if ($options{metaclass}) { - _load_all_classes($options{metaclass}); - $meta->add_attribute($options{metaclass}->new($name, %options)); - } - else { - $meta->add_attribute($name, %options); - } - } + return subname 'Moose::has' => sub ($;%) { + my ( $name, %options ) = @_; + my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; + $class->meta->_process_attribute( $_, %options ) for @$attrs; }; }, before => sub { my $class = $CALLER; - return subname 'Moose::before' => sub { + return subname 'Moose::before' => sub (@&) { my $code = pop @_; my $meta = $class->meta; - $meta->add_before_method_modifier($_, $code) for @_; + $meta->add_before_method_modifier( $_, $code ) for @_; }; }, after => sub { my $class = $CALLER; - return subname 'Moose::after' => sub { + return subname 'Moose::after' => sub (@&) { my $code = pop @_; my $meta = $class->meta; - $meta->add_after_method_modifier($_, $code) for @_; + $meta->add_after_method_modifier( $_, $code ) for @_; }; }, around => sub { - my $class = $CALLER; - return subname 'Moose::around' => sub { + my $class = $CALLER; + return subname 'Moose::around' => sub (@&) { my $code = pop @_; my $meta = $class->meta; - $meta->add_around_method_modifier($_, $code) for @_; + $meta->add_around_method_modifier( $_, $code ) for @_; }; }, super => sub { - return subname 'Moose::super' => sub {}; + { + our %SUPER_SLOT; + no strict 'refs'; + $SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"}; + } + return subname 'Moose::super' => sub { }; }, override => sub { my $class = $CALLER; - return subname 'Moose::override' => sub { - my ($name, $method) = @_; - $class->meta->add_override_method_modifier($name => $method); + return subname 'Moose::override' => sub ($&) { + my ( $name, $method ) = @_; + $class->meta->add_override_method_modifier( $name => $method ); }; }, inner => sub { - return subname 'Moose::inner' => sub {}; + { + our %INNER_SLOT; + no strict 'refs'; + $INNER_SLOT{$CALLER} = \*{"${CALLER}::inner"}; + } + return subname 'Moose::inner' => sub { }; }, augment => sub { my $class = $CALLER; - return subname 'Moose::augment' => sub { - my ($name, $method) = @_; - $class->meta->add_augment_method_modifier($name => $method); + return subname 'Moose::augment' => sub (@&) { + my ( $name, $method ) = @_; + $class->meta->add_augment_method_modifier( $name => $method ); }; }, + + # NOTE: + # this is experimental, but I am not + # happy with it. If you want to try + # it, you will have to uncomment it + # yourself. + # There is a really good chance that + # this will be deprecated, dont get + # too attached + # self => sub { + # return subname 'Moose::self' => sub {}; + # }, + # method => sub { + # my $class = $CALLER; + # return subname 'Moose::method' => sub { + # my ($name, $method) = @_; + # $class->meta->add_method($name, sub { + # my $self = shift; + # no strict 'refs'; + # no warnings 'redefine'; + # local *{$class->meta->name . '::self'} = sub { $self }; + # $method->(@_); + # }); + # }; + # }, + confess => sub { return \&Carp::confess; }, blessed => sub { return \&Scalar::Util::blessed; - } + }, ); - my $exporter = Sub::Exporter::build_exporter({ - exports => \%exports, - groups => { - default => [':all'] + my $exporter = Sub::Exporter::build_exporter( + { + exports => \%exports, + groups => { default => [':all'] } } - }); - - sub import { - $CALLER = caller(); + ); + + # 1 extra level because it's called by import so there's a layer of indirection + sub _get_caller{ + my $offset = 1; + return + ref $_[1] && defined $_[1]->{into} + ? $_[1]->{into} + : ref $_[1] && defined $_[1]->{into_level} + ? caller($offset + $_[1]->{into_level}) + : caller($offset); + } + + sub import { + $CALLER = _get_caller(@_); + + strict->import; + warnings->import; # we should never export to main return if $CALLER eq 'main'; - - _init_meta(); - + + init_meta( $CALLER, 'Moose::Object' ); + goto $exporter; } -} -## Utility functions - -sub _load_all_classes { - foreach my $super (@_) { - # see if this is already - # loaded in the symbol table - next if _is_class_already_loaded($super); - # otherwise require it ... - ($super->require) - || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR; - } -} + sub unimport { + no strict 'refs'; + my $class = _get_caller(@_); + + # loop through the exports ... + foreach my $name ( keys %exports ) { + + # if we find one ... + if ( defined &{ $class . '::' . $name } ) { + my $keyword = \&{ $class . '::' . $name }; + + # make sure it is from Moose + my $pkg_name = + eval { svref_2object($keyword)->GV->STASH->NAME }; + next if $@; + next if $pkg_name ne 'Moose'; + + # and if it is from Moose then undef the slot + delete ${ $class . '::' }{$name}; + } + } + } -sub _is_class_already_loaded { - my $name = shift; - no strict 'refs'; - return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"}; - foreach (keys %{"${name}::"}) { - next if substr($_, -2, 2) eq '::'; - return 1 if defined &{"${name}::$_"}; - } - return 0; } +## make 'em all immutable + +$_->meta->make_immutable( + inline_constructor => 0, + inline_accessors => 1, # these are Class::MOP accessors, so they need inlining + ) + for ( + 'Moose::Meta::Attribute', + 'Moose::Meta::Class', + 'Moose::Meta::Instance', + + 'Moose::Meta::TypeConstraint', + 'Moose::Meta::TypeConstraint::Union', + 'Moose::Meta::TypeConstraint::Parameterized', + 'Moose::Meta::TypeCoercion', + + 'Moose::Meta::Method', + 'Moose::Meta::Method::Accessor', + 'Moose::Meta::Method::Constructor', + 'Moose::Meta::Method::Destructor', + 'Moose::Meta::Method::Overriden', + + 'Moose::Meta::Role', + 'Moose::Meta::Role::Method', + 'Moose::Meta::Role::Method::Required', + ); + 1; __END__ @@ -258,107 +288,95 @@ __END__ =head1 NAME -Moose - Moose, it's the new Camel +Moose - A complete modern object system for Perl 5 =head1 SYNOPSIS package Point; - use Moose; - - has 'x' => (isa => 'Int', is => 'rw'); - has 'y' => (isa => 'Int', is => 'rw'); - + use Moose; # automatically turns on strict and warnings + + has 'x' => (is => 'rw', isa => 'Int'); + has 'y' => (is => 'rw', isa => 'Int'); + sub clear { my $self = shift; $self->x(0); - $self->y(0); + $self->y(0); } - + package Point3D; use Moose; - + extends 'Point'; - - has 'z' => (isa => 'Int'); - + + has 'z' => (is => 'rw', isa => 'Int'); + after 'clear' => sub { my $self = shift; - $self->{z} = 0; + $self->z(0); }; - -=head1 CAVEAT - -This is an early release of this module, it still needs -some fine tuning and B more documentation. I am adopting -the I approach with this module, -so keep an eye on your favorite CPAN mirror! =head1 DESCRIPTION -Moose is an extension of the Perl 5 object system. +Moose is an extension of the Perl 5 object system. =head2 Another object system!?!? -Yes, I know there has been an explosion recently of new ways to -build object's in Perl 5, most of them based on inside-out objects, -and other such things. Moose is different because it is not a new -object system for Perl 5, but instead an extension of the existing +Yes, I know there has been an explosion recently of new ways to +build object's in Perl 5, most of them based on inside-out objects +and other such things. Moose is different because it is not a new +object system for Perl 5, but instead an extension of the existing object system. -Moose is built on top of L, which is a metaclass system -for Perl 5. This means that Moose not only makes building normal -Perl 5 objects better, but it also provides the power of metaclass +Moose is built on top of L, which is a metaclass system +for Perl 5. This means that Moose not only makes building normal +Perl 5 objects better, but it also provides the power of metaclass programming. -=head2 What does Moose stand for?? - -Moose doesn't stand for one thing in particular, however, if you -want, here are a few of my favorites, feel free to contribute -more :) - -=over 4 - -=item Make Other Object Systems Envious - -=item Makes Object Orientation So Easy +=head2 Is this for real? Or is this just an experiment? -=item Makes Object Orientation Spiffy- Er (sorry ingy) +Moose is I on the prototypes and experiments I did for the Perl 6 +meta-model. However, Moose is B an experiment/prototype; it is for B. -=item Most Other Object Systems Emasculate +=head2 Is this ready for use in production? -=item My Overcraft Overfilled (with) Some Eels +Yes, I believe that it is. -=item Moose Often Ovulate Sorta Early +Moose has been used successfully in production environemnts by several people +and companies (including the one I work for). There are Moose applications +which have been in production with little or no issue now for over a year. +I consider it highly stable and we are commited to keeping it stable. -=item Many Overloaded Object Systems Exists +Of course, in the end, you need to make this call yourself. If you have +any questions or concerns, please feel free to email me, or even the list +or just stop by #moose and ask away. -=item Moose Offers Often Super Extensions +=head2 Is Moose just Perl 6 in Perl 5? -=item Meta Object Orientation Syntax Extensions - -=back +No. While Moose is very much inspired by Perl 6, it is not itself Perl 6. +Instead, it is an OO system for Perl 5. I built Moose because I was tired of +writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So +instead of switching to Ruby, I wrote Moose :) =head1 BUILDING CLASSES WITH MOOSE -Moose makes every attempt to provide as much convience during class -construction/definition, but still stay out of your way if you want -it to. Here are some of the features Moose provides: +Moose makes every attempt to provide as much convenience as possible during +class construction/definition, but still stay out of your way if you want it +to. Here are a few items to note when building classes with Moose. -Unless specified with C, any class which uses Moose will +Unless specified with C, any class which uses Moose will inherit from L. -Moose will also manage all attributes (including inherited ones) that -are defined with C. And assuming that you call C which is -inherited from L, then this includes properly initializing -all instance slots, setting defaults where approprtiate and performing any -type constraint checking or coercion. - -For more details, see the ever expanding L. +Moose will also manage all attributes (including inherited ones) that are +defined with C. And (assuming you call C, which is inherited from +L) this includes properly initializing all instance slots, +setting defaults where appropriate, and performing any type constraint checking +or coercion. =head1 EXPORTED FUNCTIONS -Moose will export a number of functions into the class's namespace, which -can then be used to set up the class. These functions all work directly +Moose will export a number of functions into the class's namespace which +may then be used to set up the class. These functions all work directly on the current class. =over 4 @@ -371,77 +389,267 @@ This is a method which provides access to the current class's metaclass. This function will set the superclass(es) for the current class. -This approach is recommended instead of C, because C -actually Ces onto the class's C<@ISA>, whereas C will -replace it. This is important to ensure that classes which do not have -superclasses properly inherit from L. +This approach is recommended instead of C, because C +actually Ces onto the class's C<@ISA>, whereas C will +replace it. This is important to ensure that classes which do not have +superclasses still properly inherit from L. -=item B +=item B -This will apply a given C<$role> to the local class. Role support is -currently very experimental, see L for more details. +This will apply a given set of C<@roles> to the local class. Role support +is currently under heavy development; see L for more details. -=item B +=item B %options> -This will install an attribute of a given C<$name> into the current class. -The list of C<%options> are the same as those provided by both -L and L, in addition to a -few convience ones provided by Moose which are listed below: +This will install an attribute of a given C<$name> into the current class. +The C<%options> are the same as those provided by +L, in addition to the list below which are provided +by Moose (L to be more specific): =over 4 =item I 'rw'|'ro'> -The I option accepts either I (for read/write) or I (for read -only). These will create either a read/write accessor or a read-only +The I option accepts either I (for read/write) or I (for read +only). These will create either a read/write accessor or a read-only accessor respectively, using the same name as the C<$name> of the attribute. -If you need more control over how your accessors are named, you can use the -I, I and I options inherited from L. +If you need more control over how your accessors are named, you can use the +I, I and I options inherited from +L. =item I $type_name> -The I option uses Moose's type constraint facilities to set up runtime -type checking for this attribute. Moose will perform the checks during class -construction, and within any accessors. The C<$type_name> argument must be a -string. The string can be either a class name, or a type defined using -Moose's type defintion features. +The I option uses Moose's type constraint facilities to set up runtime +type checking for this attribute. Moose will perform the checks during class +construction, and within any accessors. The C<$type_name> argument must be a +string. The string may be either a class name or a type defined using +Moose's type definition features. (Refer to L +for information on how to define a new type, and how to retrieve type meta-data). =item I (1|0)> -This will attempt to use coercion with the supplied type constraint to change -the value passed into any accessors of constructors. You B have supplied +This will attempt to use coercion with the supplied type constraint to change +the value passed into any accessors or constructors. You B have supplied a type constraint in order for this to work. See L -for an example usage. +for an example. =item I $role_name> -This will accept the name of a role which the value stored in this attribute +This will accept the name of a role which the value stored in this attribute is expected to have consumed. =item I (1|0)> -This marks the attribute as being required. This means a value must be supplied -during class construction, and the attribute can never be set to C with -an accessor. +This marks the attribute as being required. This means a I value must be +supplied during class construction, and the attribute may never be set to +C with an accessor. =item I (1|0)> -This will tell the class to strore the value of this attribute as a weakened -reference. If an attribute is a weakened reference, it can B also be coerced. +This will tell the class to store the value of this attribute as a weakened +reference. If an attribute is a weakened reference, it B also be +coerced. =item I (1|0)> -This will tell the class to not create this slot until absolutely nessecary. +This will tell the class to not create this slot until absolutely necessary. If an attribute is marked as lazy it B have a default supplied. +=item I (1|0)> + +This tells the accessor whether to automatically dereference the value returned. +This is only legal if your C option is either C or C. + +=item I $metaclass_name> + +This tells the class to use a custom attribute metaclass for this particular +attribute. Custom attribute metaclasses are useful for extending the +capabilities of the I keyword: they are the simplest way to extend the MOP, +but they are still a fairly advanced topic and too much to cover here. I will +try and write a recipe on them soon. + +The default behavior here is to just load C<$metaclass_name>; however, we also +have a way to alias to a shorter name. This will first look to see if +B exists. If it does, Moose +will then check to see if that has the method C, which +should return the actual name of the custom attribute metaclass. If there is no +C method, it will fall back to using +B as the metaclass name. + =item I $code> -The trigger option is a CODE reference which will be called after the value of -the attribute is set. The CODE ref will be passed the instance itself, the +The I option is a CODE reference which will be called after the value of +the attribute is set. The CODE ref will be passed the instance itself, the updated value and the attribute meta-object (this is for more advanced fiddling -and can typically be ignored in most cases). You can B have a trigger on -a read-only attribute. +and can typically be ignored). You B have a trigger on a read-only +attribute. + +=item I ARRAY | HASH | REGEXP | ROLE | CODE> + +The I option provides Moose classes with automated delegation features. +This is a pretty complex and powerful option. It accepts many different option +formats, each with its own benefits and drawbacks. + +B This feature is no longer experimental, but it may still have subtle +bugs lurking in the deeper corners. If you think you have found a bug, you +probably have, so please report it to me right away. + +B The class being delegated to does not need to be a Moose based class, +which is why this feature is especially useful when wrapping non-Moose classes. + +All I option formats share the following traits: + +You cannot override a locally defined method with a delegated method; an +exception will be thrown if you try. That is to say, if you define C in +your class, you cannot override it with a delegated C. This is almost never +something you would want to do, and if it is, you should do it by hand and not +use Moose. + +You cannot override any of the methods found in Moose::Object, or the C +and C methods. These will not throw an exception, but will silently +move on to the next method in the list. My reasoning for this is that you would +almost never want to do this, since it usually breaks your class. As with +overriding locally defined methods, if you do want to do this, you should do it +manually, not with Moose. + +Below is the documentation for each option format: + +=over 4 + +=item C + +This is the most common usage for I. You basically pass a list of +method names to be delegated, and Moose will install a delegation method +for each one. + +=item C + +This is the second most common usage for I. Instead of a list of +method names, you pass a HASH ref where each key is the method name you +want installed locally, and its value is the name of the original method +in the class being delegated to. + +This can be very useful for recursive classes like trees. Here is a +quick example (soon to be expanded into a Moose::Cookbook::Recipe): + + package Tree; + use Moose; + + has 'node' => (is => 'rw', isa => 'Any'); + + has 'children' => ( + is => 'ro', + isa => 'ArrayRef', + default => sub { [] } + ); + + has 'parent' => ( + is => 'rw', + isa => 'Tree', + is_weak_ref => 1, + handles => { + parent_node => 'node', + siblings => 'children', + } + ); + +In this example, the Tree package gets C and C methods, +which delegate to the C and C methods (respectively) of the Tree +instance stored in the C slot. + +=item C + +The regexp option works very similar to the ARRAY option, except that it builds +the list of methods for you. It starts by collecting all possible methods of the +class being delegated to, then filters that list using the regexp supplied here. + +B An I option is required when using the regexp option format. This +is so that we can determine (at compile time) the method list from the class. +Without an I this is just not possible. + +=item C + +With the role option, you specify the name of a role whose "interface" then +becomes the list of methods to handle. The "interface" can be defined as; the +methods of the role and any required methods of the role. It should be noted +that this does B include any method modifiers or generated attribute +methods (which is consistent with role composition). + +=item C + +This is the option to use when you really want to do something funky. You should +only use it if you really know what you are doing, as it involves manual +metaclass twiddling. + +This takes a code reference, which should expect two arguments. The first is the +attribute meta-object this I is attached to. The second is the +metaclass of the class being delegated to. It expects you to return a hash (not +a HASH ref) of the methods you want mapped. + +=back + +=back + +=item B %options> + +This is variation on the normal attibute creator C which allows you to +clone and extend an attribute from a superclass. Here is a quick example: + + package Foo; + use Moose; + + has 'message' => ( + is => 'rw', + isa => 'Str', + default => 'Hello, I am a Foo' + ); + + package My::Foo; + use Moose; + + extends 'Foo'; + + has '+message' => (default => 'Hello I am My::Foo'); + +What is happening here is that B is cloning the C attribute +from its parent class B, retaining the C 'rw'> and C +'Str'> characteristics, but changing the value in C. + +This feature is restricted somewhat, so as to try and force at least I +sanity into it. You are only allowed to change the following attributes: + +=over 4 + +=item I + +Change the default value of an attribute. + +=item I + +Change whether the attribute attempts to coerce a value passed to it. + +=item I + +Change if the attribute is required to have a value. + +=item I + +Change the documentation string associated with the attribute. + +=item I + +Change if the attribute lazily initializes the slot. + +=item I + +You I allowed to change the type, B the new type is a +subtype of the old type. + +=item I + +You are allowed to B a new C definition, but you are B +allowed to I one. =back @@ -451,67 +659,129 @@ a read-only attribute. =item B sub { ... }> -This three items are syntactic sugar for the before, after and around method -modifier features that L provides. More information on these can -be found in the L documentation for now. +This three items are syntactic sugar for the before, after, and around method +modifier features that L provides. More information on these may be +found in the L for now. =item B -The keyword C is a noop when called outside of an C method. In -the context of an C method, it will call the next most appropriate +The keyword C is a no-op when called outside of an C method. In +the context of an C method, it will call the next most appropriate superclass method with the same arguments as the original method. =item B -An C method, is a way of explictly saying "I am overriding this -method from my superclass". You can call C within this method, and -it will work as expected. The same thing I be accomplished with a normal -method call and the C pseudo-package, it is really your choice. +An C method is a way of explicitly saying "I am overriding this +method from my superclass". You can call C within this method, and +it will work as expected. The same thing I be accomplished with a normal +method call and the C pseudo-package; it is really your choice. =item B -The keyword C, much like C, is a no-op outside of the context of -an C method. You can think of C as being the inverse of -C, the details of how C and C work is best described in +The keyword C, much like C, is a no-op outside of the context of +an C method. You can think of C as being the inverse of +C; the details of how C and C work is best described in the L. =item B -An C method, is a way of explictly saying "I am augmenting this -method from my superclass". Once again, the details of how C and +An C method, is a way of explicitly saying "I am augmenting this +method from my superclass". Once again, the details of how C and C work is best described in the L. =item B -This is the C function, and exported here beause I use it -all the time. This feature may change in the future, so you have been warned. +This is the C function, and exported here because I use it +all the time. This feature may change in the future, so you have been warned. =item B -This is the C function, it is exported here beause I -use it all the time. It is highly recommended that this is used instead of +This is the C function, it is exported here because I +use it all the time. It is highly recommended that this is used instead of C anywhere you need to test for an object's class name. =back +=head1 UNIMPORTING FUNCTIONS + +=head2 B + +Moose offers a way to remove the keywords it exports, through the C +method. You simply have to say C at the bottom of your code for this +to work. Here is an example: + + package Person; + use Moose; + + has 'first_name' => (is => 'rw', isa => 'Str'); + has 'last_name' => (is => 'rw', isa => 'Str'); + + sub full_name { + my $self = shift; + $self->first_name . ' ' . $self->last_name + } + + no Moose; # keywords are removed from the Person package + +=head1 EXTENDING AND EMBEDDING MOOSE + +Moose also offers some options for extending or embedding it into your own +framework. The basic premise is to have something that sets up your class' +metaclass and export the moose declarators (C, C, C,...). +Here is an example: + + package MyFramework; + use Moose; + + sub import { + my $CALLER = caller(); + + strict->import; + warnings->import; + + # we should never export to main + return if $CALLER eq 'main'; + Moose::init_meta( $CALLER, 'MyFramework::Base' ); + Moose->import({into => $CALLER}); + + # Do my custom framework stuff + + return 1; + } + +=head2 B + +Moose's C method supports the L form of C<{into =E $pkg}> +and C<{into_level =E 1}> + +=head2 B + +Moose does some boot strapping: it creates a metaclass object for your class, +and then injects a C accessor into your class to retrieve it. Then it +sets your baseclass to Moose::Object or the value you pass in unless you already +have one. This is all done via C which takes the name of your class +and optionally a baseclass and a metaclass as arguments. + =head1 CAVEATS =over 4 =item * -It should be noted that C and C can B be used in the same -method. However, they can be combined together with the same class hierarchy, -see F for an example. +It should be noted that C and C B be used in the same +method. However, they may be combined within the same class hierarchy; see +F for an example. -The reason that this is so is because C is only valid within a method -with the C modifier, and C will never be valid within an -C method. In fact, C will skip over any C methods -when searching for it's appropriate C. +The reason for this is that C is only valid within a method +with the C modifier, and C will never be valid within an +C method. In fact, C will skip over any C methods +when searching for its appropriate C. -This might seem like a restriction, but I am of the opinion that keeping these -two features seperate (but interoperable) actually makes them easy to use since -their behavior is then easier to predict. Time will tell if I am right or not. +This might seem like a restriction, but I am of the opinion that keeping these +two features separate (yet interoperable) actually makes them easy to use, since +their behavior is then easier to predict. Time will tell whether I am right or +not (UPDATE: so far so good). =back @@ -523,14 +793,16 @@ their behavior is then easier to predict. Time will tell if I am right or not. =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6. -=item Without Yuval "nothingmuch" Kogman this module would not be possible, +=item Without Yuval "nothingmuch" Kogman this module would not be possible, and it certainly wouldn't have this name ;P -=item The basis of the TypeContraints module was Rob Kinyon's idea +=item The basis of the TypeContraints module was Rob Kinyon's idea originally, I just ran with it. -=item Thanks to mst & chansen and the whole #moose poose for all the -ideas/feature-requests/encouragement +=item Thanks to mst & chansen and the whole #moose poose for all the +early ideas/feature-requests/encouragement/bug-finding. + +=item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes. =back @@ -538,23 +810,37 @@ ideas/feature-requests/encouragement =over 4 +=item L + +This is the official web home of Moose, it contains links to our public SVN repo +as well as links to a number of talks and articles on Moose and Moose related +technologies. + =item L documentation =item The #moose channel on irc.perl.org -=item L +=item The Moose mailing list - moose@perl.org + +=item Moose stats on ohloh.net - L + +=back + +=head2 Papers + +=over 4 =item L -This paper (suggested by lbr on #moose) was what lead to the implementation -of the C/C and C/C features. If you really -want to understand this feature, I suggest you read this. +This paper (suggested by lbr on #moose) was what lead to the implementation +of the C/C and C/C features. If you really +want to understand them, I suggest you read this. =back =head1 BUGS -All complex software has bugs lurking in it, and this module is no +All complex software has bugs lurking in it, and this module is no exception. If you find a bug please either email me, or add the bug to cpan-RT. @@ -562,17 +848,55 @@ to cpan-RT. Stevan Little Estevan@iinteractive.comE -Christian Hansen Echansen@cpan.orgE +B + +Aankhen + +Adam (Alias) Kennedy + +Anders (Debolaz) Nor Berle + +Nathan (kolibre) Gray + +Christian (chansen) Hansen + +Hans Dieter (confound) Pearcey + +Eric (ewilhelm) Wilhelm + +Guillermo (groditi) Roditi + +Jess (castaway) Robinson + +Matt (mst) Trout + +Robert (phaylon) Sedlacek + +Robert (rlb3) Boone + +Scott (konobi) McWhirter + +Shlomi (rindolf) Fish + +Yuval (nothingmuch) Kogman + +Chris (perigrin) Prather + +Jonathan (jrockway) Rockway + +Piotr (dexter) Roszatycki + +Sam (mugwump) Vilain -Yuval Kogman Enothingmuch@woobling.orgE +... and many other #moose folks =head1 COPYRIGHT AND LICENSE -Copyright 2006 by Infinity Interactive, Inc. +Copyright 2006, 2007 by Infinity Interactive, Inc. L 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