2 use lib '/Users/stevan/Projects/Moose/Moose/Class-MOP/branches/Class-MOP-tranformations/lib';
11 use Scalar::Util 'blessed', 'reftype';
13 use Sub::Name 'subname';
14 use B 'svref_2object';
20 use Moose::Meta::Class;
21 use Moose::Meta::TypeConstraint;
22 use Moose::Meta::TypeCoercion;
23 use Moose::Meta::Attribute;
24 use Moose::Meta::Instance;
27 use Moose::Util::TypeConstraints;
35 # make a subtype for each Moose class
38 => where { $_->isa($class) }
39 => optimize_as { blessed($_[0]) && $_[0]->isa($class) }
40 unless find_type_constraint($class);
43 if ($class->can('meta')) {
45 # this is the case where the metaclass pragma
46 # was used before the 'use Moose' statement to
47 # override a specific class
48 $meta = $class->meta();
49 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
50 || confess "You already have a &meta function, but it does not return a Moose::Meta::Class";
54 # this is broken currently, we actually need
55 # to allow the possiblity of an inherited
56 # meta, which will not be visible until the
57 # user 'extends' first. This needs to have
58 # more intelligence to it
59 $meta = Moose::Meta::Class->initialize($class);
60 $meta->add_method('meta' => sub {
61 # re-initialize so it inherits properly
62 Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]);
66 # make sure they inherit from Moose::Object
67 $meta->superclasses('Moose::Object')
68 unless $meta->superclasses();
74 return subname 'Moose::extends' => sub (@) {
75 confess "Must derive at least one class" unless @_;
76 _load_all_classes(@_);
77 # this checks the metaclass to make sure
78 # it is correct, sometimes it can get out
79 # of sync when the classes are being built
80 my $meta = $class->meta->_fix_metaclass_incompatability(@_);
81 $meta->superclasses(@_);
86 return subname 'Moose::with' => sub (@) {
88 confess "Must specify at least one role" unless @roles;
89 _load_all_classes(@roles);
90 $class->meta->_apply_all_roles(@roles);
95 return subname 'Moose::has' => sub ($;%) {
96 my ($name, %options) = @_;
97 $class->meta->_process_attribute($name, %options);
102 return subname 'Moose::before' => sub (@&) {
104 my $meta = $class->meta;
105 $meta->add_before_method_modifier($_, $code) for @_;
110 return subname 'Moose::after' => sub (@&) {
112 my $meta = $class->meta;
113 $meta->add_after_method_modifier($_, $code) for @_;
118 return subname 'Moose::around' => sub (@&) {
120 my $meta = $class->meta;
121 $meta->add_around_method_modifier($_, $code) for @_;
125 return subname 'Moose::super' => sub {};
129 return subname 'Moose::override' => sub ($&) {
130 my ($name, $method) = @_;
131 $class->meta->add_override_method_modifier($name => $method);
135 return subname 'Moose::inner' => sub {};
139 return subname 'Moose::augment' => sub (@&) {
140 my ($name, $method) = @_;
141 $class->meta->add_augment_method_modifier($name => $method);
146 # this is experimental, but I am not
147 # happy with it. If you want to try
148 # it, you will have to uncomment it
150 # There is a really good chance that
151 # this will be deprecated, dont get
154 # return subname 'Moose::self' => sub {};
157 # my $class = $CALLER;
158 # return subname 'Moose::method' => sub {
159 # my ($name, $method) = @_;
160 # $class->meta->add_method($name, sub {
163 # no warnings 'redefine';
164 # local *{$class->meta->name . '::self'} = sub { $self };
171 return \&Carp::confess;
174 return \&Scalar::Util::blessed;
178 my $exporter = Sub::Exporter::build_exporter({
179 exports => \%exports,
191 # we should never export to main
192 return if $CALLER eq 'main';
201 my $class = caller();
202 # loop through the exports ...
203 foreach my $name (keys %exports) {
204 next if $name =~ /inner|super|self/;
207 if (defined &{$class . '::' . $name}) {
208 my $keyword = \&{$class . '::' . $name};
210 # make sure it is from Moose
211 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
213 next if $pkg_name ne 'Moose';
215 # and if it is from Moose then undef the slot
216 delete ${$class . '::'}{$name};
226 sub _load_all_classes {
227 foreach my $class (@_) {
228 # see if this is already
229 # loaded in the symbol table
230 next if _is_class_already_loaded($class);
231 # otherwise require it ...
232 my $file = $class . '.pm';
234 eval { CORE::require($file) };
236 "Could not load module '$class' because : $@"
241 sub _is_class_already_loaded {
244 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
245 foreach (keys %{"${name}::"}) {
246 next if substr($_, -2, 2) eq '::';
247 return 1 if defined &{"${name}::$_"};
252 ## make 'em all immutable
254 $_->meta->make_immutable(
255 inline_constructor => 0,
256 inline_accessors => 0,
258 'Moose::Meta::Attribute',
259 'Moose::Meta::Class',
260 'Moose::Meta::Instance',
262 'Moose::Meta::TypeConstraint',
263 'Moose::Meta::TypeConstraint::Union',
264 'Moose::Meta::TypeCoercion',
266 'Moose::Meta::Method',
267 'Moose::Meta::Method::Accessor',
268 'Moose::Meta::Method::Constructor',
269 'Moose::Meta::Method::Overriden',
280 Moose - A complete modern object system for Perl 5
289 has 'x' => (is => 'rw', isa => 'Int');
290 has 'y' => (is => 'rw', isa => 'Int');
305 has 'z' => (is => 'rw', isa => 'Int');
307 after 'clear' => sub {
314 Moose is a rapidly maturing module, and is already being used by
315 a number of people. It's test suite is growing larger by the day,
316 and the docs should soon follow.
318 This said, Moose is not yet finished, and should still be considered
319 to be evolving. Much of the outer API is stable, but the internals
320 are still subject to change (although not without serious thought
325 Moose is an extension of the Perl 5 object system.
327 =head2 Another object system!?!?
329 Yes, I know there has been an explosion recently of new ways to
330 build object's in Perl 5, most of them based on inside-out objects
331 and other such things. Moose is different because it is not a new
332 object system for Perl 5, but instead an extension of the existing
335 Moose is built on top of L<Class::MOP>, which is a metaclass system
336 for Perl 5. This means that Moose not only makes building normal
337 Perl 5 objects better, but it also provides the power of metaclass
340 =head2 Can I use this in production? Or is this just an experiment?
342 Moose is I<based> on the prototypes and experiments I did for the Perl 6
343 meta-model; however Moose is B<NOT> an experiment/prototype, it is
344 for B<real>. I will be deploying Moose into production environments later
345 this year, and I have every intentions of using it as my de facto class
348 =head2 Is Moose just Perl 6 in Perl 5?
350 No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
351 Instead, it is an OO system for Perl 5. I built Moose because I was tired or
352 writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
353 instead of switching to Ruby, I wrote Moose :)
355 =head1 BUILDING CLASSES WITH MOOSE
357 Moose makes every attempt to provide as much convenience as possible during
358 class construction/definition, but still stay out of your way if you want it
359 to. Here are a few items to note when building classes with Moose.
361 Unless specified with C<extends>, any class which uses Moose will
362 inherit from L<Moose::Object>.
364 Moose will also manage all attributes (including inherited ones) that
365 are defined with C<has>. And assuming that you call C<new>, which is
366 inherited from L<Moose::Object>, then this includes properly initializing
367 all instance slots, setting defaults where appropriate, and performing any
368 type constraint checking or coercion.
370 =head1 EXPORTED FUNCTIONS
372 Moose will export a number of functions into the class's namespace which
373 can then be used to set up the class. These functions all work directly
374 on the current class.
380 This is a method which provides access to the current class's metaclass.
382 =item B<extends (@superclasses)>
384 This function will set the superclass(es) for the current class.
386 This approach is recommended instead of C<use base>, because C<use base>
387 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
388 replace it. This is important to ensure that classes which do not have
389 superclasses still properly inherit from L<Moose::Object>.
391 =item B<with (@roles)>
393 This will apply a given set of C<@roles> to the local class. Role support
394 is currently under heavy development; see L<Moose::Role> for more details.
396 =item B<has ($name, %options)>
398 This will install an attribute of a given C<$name> into the current class.
399 The list of C<%options> are the same as those provided by
400 L<Class::MOP::Attribute>, in addition to the list below which are provided
401 by Moose (L<Moose::Meta::Attribute> to be more specific):
405 =item I<is =E<gt> 'rw'|'ro'>
407 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
408 only). These will create either a read/write accessor or a read-only
409 accessor respectively, using the same name as the C<$name> of the attribute.
411 If you need more control over how your accessors are named, you can use the
412 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
414 =item I<isa =E<gt> $type_name>
416 The I<isa> option uses Moose's type constraint facilities to set up runtime
417 type checking for this attribute. Moose will perform the checks during class
418 construction, and within any accessors. The C<$type_name> argument must be a
419 string. The string can be either a class name or a type defined using
420 Moose's type definition features.
422 =item I<coerce =E<gt> (1|0)>
424 This will attempt to use coercion with the supplied type constraint to change
425 the value passed into any accessors or constructors. You B<must> have supplied
426 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
427 for an example usage.
429 =item I<does =E<gt> $role_name>
431 This will accept the name of a role which the value stored in this attribute
432 is expected to have consumed.
434 =item I<required =E<gt> (1|0)>
436 This marks the attribute as being required. This means a value must be supplied
437 during class construction, and the attribute can never be set to C<undef> with
440 =item I<weak_ref =E<gt> (1|0)>
442 This will tell the class to store the value of this attribute as a weakened
443 reference. If an attribute is a weakened reference, it B<cannot> also be
446 =item I<lazy =E<gt> (1|0)>
448 This will tell the class to not create this slot until absolutely necessary.
449 If an attribute is marked as lazy it B<must> have a default supplied.
451 =item I<auto_deref =E<gt> (1|0)>
453 This tells the accessor whether to automatically dereference the value returned.
454 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
456 =item I<trigger =E<gt> $code>
458 The trigger option is a CODE reference which will be called after the value of
459 the attribute is set. The CODE ref will be passed the instance itself, the
460 updated value and the attribute meta-object (this is for more advanced fiddling
461 and can typically be ignored in most cases). You B<cannot> have a trigger on
462 a read-only attribute.
464 =item I<handles =E<gt> [ @handles ]>
466 There is experimental support for attribute delegation using the C<handles>
467 option. More docs to come later.
471 =item B<before $name|@names =E<gt> sub { ... }>
473 =item B<after $name|@names =E<gt> sub { ... }>
475 =item B<around $name|@names =E<gt> sub { ... }>
477 This three items are syntactic sugar for the before, after, and around method
478 modifier features that L<Class::MOP> provides. More information on these can
479 be found in the L<Class::MOP> documentation for now.
483 The keyword C<super> is a no-op when called outside of an C<override> method. In
484 the context of an C<override> method, it will call the next most appropriate
485 superclass method with the same arguments as the original method.
487 =item B<override ($name, &sub)>
489 An C<override> method is a way of explicitly saying "I am overriding this
490 method from my superclass". You can call C<super> within this method, and
491 it will work as expected. The same thing I<can> be accomplished with a normal
492 method call and the C<SUPER::> pseudo-package; it is really your choice.
496 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
497 an C<augment> method. You can think of C<inner> as being the inverse of
498 C<super>; the details of how C<inner> and C<augment> work is best described in
499 the L<Moose::Cookbook>.
501 =item B<augment ($name, &sub)>
503 An C<augment> method, is a way of explicitly saying "I am augmenting this
504 method from my superclass". Once again, the details of how C<inner> and
505 C<augment> work is best described in the L<Moose::Cookbook>.
509 This is the C<Carp::confess> function, and exported here because I use it
510 all the time. This feature may change in the future, so you have been warned.
514 This is the C<Scalar::Uti::blessed> function, it is exported here because I
515 use it all the time. It is highly recommended that this is used instead of
516 C<ref> anywhere you need to test for an object's class name.
520 =head1 UNEXPORTING FUNCTIONS
524 Moose offers a way of removing the keywords it exports though the C<unimport>
525 method. You simply have to say C<no Moose> at the bottom of your code for this
526 to work. Here is an example:
531 has 'first_name' => (is => 'rw', isa => 'Str');
532 has 'last_name' => (is => 'rw', isa => 'Str');
536 $self->first_name . ' ' . $self->last_name
539 no Moose; # keywords are removed from the Person package
543 =head2 What does Moose stand for??
545 Moose doesn't stand for one thing in particular, however, if you
546 want, here are a few of my favorites; feel free to contribute
551 =item Make Other Object Systems Envious
553 =item Makes Object Orientation So Easy
555 =item Makes Object Orientation Spiffy- Er (sorry ingy)
557 =item Most Other Object Systems Emasculate
559 =item Moose Often Ovulate Sorta Early
561 =item Moose Offers Often Super Extensions
563 =item Meta Object Orientation Syntax Extensions
573 It should be noted that C<super> and C<inner> C<cannot> be used in the same
574 method. However, they can be combined together with the same class hierarchy;
575 see F<t/014_override_augment_inner_super.t> for an example.
577 The reason for this is that C<super> is only valid within a method
578 with the C<override> modifier, and C<inner> will never be valid within an
579 C<override> method. In fact, C<augment> will skip over any C<override> methods
580 when searching for its appropriate C<inner>.
582 This might seem like a restriction, but I am of the opinion that keeping these
583 two features separate (but interoperable) actually makes them easy to use, since
584 their behavior is then easier to predict. Time will tell if I am right or not.
588 =head1 ACKNOWLEDGEMENTS
592 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
594 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
596 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
597 and it certainly wouldn't have this name ;P
599 =item The basis of the TypeContraints module was Rob Kinyon's idea
600 originally, I just ran with it.
602 =item Thanks to mst & chansen and the whole #moose poose for all the
603 ideas/feature-requests/encouragement
605 =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes.
613 =item L<Class::MOP> documentation
615 =item The #moose channel on irc.perl.org
617 =item The Moose mailing list - moose@perl.org
619 =item L<http://forum2.org/moose/>
621 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
623 This paper (suggested by lbr on #moose) was what lead to the implementation
624 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
625 want to understand this feature, I suggest you read this.
631 All complex software has bugs lurking in it, and this module is no
632 exception. If you find a bug please either email me, or add the bug
637 Stevan Little E<lt>stevan@iinteractive.comE<gt>
639 Christian Hansen E<lt>chansen@cpan.orgE<gt>
641 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
643 =head1 COPYRIGHT AND LICENSE
645 Copyright 2006 by Infinity Interactive, Inc.
647 L<http://www.iinteractive.com>
649 This library is free software; you can redistribute it and/or modify
650 it under the same terms as Perl itself.