2 use lib '/Users/stevan/Projects/CPAN/Class-MOP/Class-MOP/lib/';
9 our $VERSION = '0.09_03';
11 use Scalar::Util 'blessed', 'reftype';
13 use Sub::Name 'subname';
15 use UNIVERSAL::require;
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 unless find_type_constraint($class);
42 if ($class->can('meta')) {
44 # this is the case where the metaclass pragma
45 # was used before the 'use Moose' statement to
46 # override a specific class
47 $meta = $class->meta();
48 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
49 || confess "Whoops, not møøsey enough";
53 # this is broken currently, we actually need
54 # to allow the possiblity of an inherited
55 # meta, which will not be visible until the
56 # user 'extends' first. This needs to have
57 # more intelligence to it
58 $meta = Moose::Meta::Class->initialize($class);
59 $meta->add_method('meta' => sub {
60 # re-initialize so it inherits properly
61 Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]);
65 # make sure they inherit from Moose::Object
66 $meta->superclasses('Moose::Object')
67 unless $meta->superclasses();
73 return subname 'Moose::extends' => sub (@) {
74 confess "Must derive at least one class" unless @_;
75 _load_all_classes(@_);
76 # this checks the metaclass to make sure
77 # it is correct, sometimes it can get out
78 # of sync when the classes are being built
79 my $meta = $class->meta->_fix_metaclass_incompatability(@_);
80 $meta->superclasses(@_);
85 return subname 'Moose::with' => sub (@) {
87 confess "Must specify at least one role" unless @roles;
88 _load_all_classes(@roles);
89 $class->meta->_apply_all_roles(@roles);
94 return subname 'Moose::has' => sub ($;%) {
95 my ($name, %options) = @_;
96 $class->meta->_process_attribute($name, %options);
101 return subname 'Moose::before' => sub (@&) {
103 my $meta = $class->meta;
104 $meta->add_before_method_modifier($_, $code) for @_;
109 return subname 'Moose::after' => sub (@&) {
111 my $meta = $class->meta;
112 $meta->add_after_method_modifier($_, $code) for @_;
117 return subname 'Moose::around' => sub (@&) {
119 my $meta = $class->meta;
120 $meta->add_around_method_modifier($_, $code) for @_;
124 return subname 'Moose::super' => sub {};
128 return subname 'Moose::override' => sub ($&) {
129 my ($name, $method) = @_;
130 $class->meta->add_override_method_modifier($name => $method);
134 return subname 'Moose::inner' => sub {};
138 return subname 'Moose::augment' => sub (@&) {
139 my ($name, $method) = @_;
140 $class->meta->add_augment_method_modifier($name => $method);
144 return \&Carp::confess;
147 return \&Scalar::Util::blessed;
151 my $exporter = Sub::Exporter::build_exporter({
152 exports => \%exports,
164 # we should never export to main
165 return if $CALLER eq 'main';
175 sub _load_all_classes {
176 foreach my $super (@_) {
177 # see if this is already
178 # loaded in the symbol table
179 next if _is_class_already_loaded($super);
180 # otherwise require it ...
182 || confess "Could not load module '$super' because : " . $UNIVERSAL::require::ERROR;
186 sub _is_class_already_loaded {
189 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
190 foreach (keys %{"${name}::"}) {
191 next if substr($_, -2, 2) eq '::';
192 return 1 if defined &{"${name}::$_"};
205 Moose - Moose, it's the new Camel
214 has 'x' => (is => 'rw', isa => 'Int');
215 has 'y' => (is => 'rw', isa => 'Int');
230 has 'z' => (is => 'rw', isa => 'Int');
232 after 'clear' => sub {
239 Moose is a rapidly maturing module, and is already being used by
240 a number of people. It's test suite is growing larger by the day,
241 and the docs should soon follow.
243 This said, Moose is not yet finished, and should still be considered
244 to be evolving. Much of the outer API is stable, but the internals
245 are still subject to change (although not without serious thought
248 For more details, please refer to the L<FUTURE PLANS> section of
253 Moose is an extension of the Perl 5 object system.
255 =head2 Another object system!?!?
257 Yes, I know there has been an explosion recently of new ways to
258 build object's in Perl 5, most of them based on inside-out objects,
259 and other such things. Moose is different because it is not a new
260 object system for Perl 5, but instead an extension of the existing
263 Moose is built on top of L<Class::MOP>, which is a metaclass system
264 for Perl 5. This means that Moose not only makes building normal
265 Perl 5 objects better, but it also provides the power of metaclass
268 =head2 Can I use this in production? Or is this just an experiment?
270 Moose is I<based> on the prototypes and experiments I did for the Perl 6
271 meta-model, however Moose is B<NOT> an experiment/prototype, it is
272 for B<real>. I will be deploying Moose into production environments later
273 this year, and I have all intentions of using it as my de-facto class
276 =head2 Is Moose just Perl 6 in Perl 5?
278 No. While Moose is very much inspired by Perl 6, it is not. Instead, it
279 is an OO system for Perl 5. I built Moose because I was tired or writing
280 the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
281 instead of switching to Ruby, I wrote Moose :)
283 =head1 BUILDING CLASSES WITH MOOSE
285 Moose makes every attempt to provide as much convience during class
286 construction/definition, but still stay out of your way if you want
287 it to. Here are a few items to note when building classes with Moose.
289 Unless specified with C<extends>, any class which uses Moose will
290 inherit from L<Moose::Object>.
292 Moose will also manage all attributes (including inherited ones) that
293 are defined with C<has>. And assuming that you call C<new> which is
294 inherited from L<Moose::Object>, then this includes properly initializing
295 all instance slots, setting defaults where approprtiate and performing any
296 type constraint checking or coercion.
298 =head1 EXPORTED FUNCTIONS
300 Moose will export a number of functions into the class's namespace, which
301 can then be used to set up the class. These functions all work directly
302 on the current class.
308 This is a method which provides access to the current class's metaclass.
310 =item B<extends (@superclasses)>
312 This function will set the superclass(es) for the current class.
314 This approach is recommended instead of C<use base>, because C<use base>
315 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
316 replace it. This is important to ensure that classes which do not have
317 superclasses properly inherit from L<Moose::Object>.
319 =item B<with (@roles)>
321 This will apply a given set of C<@roles> to the local class. Role support
322 is currently under heavy development, see L<Moose::Role> for more details.
324 =item B<has ($name, %options)>
326 This will install an attribute of a given C<$name> into the current class.
327 The list of C<%options> are the same as those provided by
328 L<Class::MOP::Attribute>, in addition to the list below which are provided
329 by Moose (L<Moose::Meta::Attribute> to be more specific):
333 =item I<is =E<gt> 'rw'|'ro'>
335 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
336 only). These will create either a read/write accessor or a read-only
337 accessor respectively, using the same name as the C<$name> of the attribute.
339 If you need more control over how your accessors are named, you can use the
340 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
342 =item I<isa =E<gt> $type_name>
344 The I<isa> option uses Moose's type constraint facilities to set up runtime
345 type checking for this attribute. Moose will perform the checks during class
346 construction, and within any accessors. The C<$type_name> argument must be a
347 string. The string can be either a class name, or a type defined using
348 Moose's type defintion features.
350 =item I<coerce =E<gt> (1|0)>
352 This will attempt to use coercion with the supplied type constraint to change
353 the value passed into any accessors of constructors. You B<must> have supplied
354 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
355 for an example usage.
357 =item I<does =E<gt> $role_name>
359 This will accept the name of a role which the value stored in this attribute
360 is expected to have consumed.
362 =item I<required =E<gt> (1|0)>
364 This marks the attribute as being required. This means a value must be supplied
365 during class construction, and the attribute can never be set to C<undef> with
368 =item I<weak_ref =E<gt> (1|0)>
370 This will tell the class to strore the value of this attribute as a weakened
371 reference. If an attribute is a weakened reference, it can B<not> also be coerced.
373 =item I<lazy =E<gt> (1|0)>
375 This will tell the class to not create this slot until absolutely nessecary.
376 If an attribute is marked as lazy it B<must> have a default supplied.
378 =item I<auto_deref =E<gt> (1|0)>
380 This tells the accessor whether to automatically de-reference the value returned.
381 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
383 =item I<trigger =E<gt> $code>
385 The trigger option is a CODE reference which will be called after the value of
386 the attribute is set. The CODE ref will be passed the instance itself, the
387 updated value and the attribute meta-object (this is for more advanced fiddling
388 and can typically be ignored in most cases). You can B<not> have a trigger on
389 a read-only attribute.
391 =item I<handles =E<gt> [ @handles ]>
393 There is experimental support for attribute delegation using the C<handles>
394 option. More docs to come later.
398 =item B<before $name|@names =E<gt> sub { ... }>
400 =item B<after $name|@names =E<gt> sub { ... }>
402 =item B<around $name|@names =E<gt> sub { ... }>
404 This three items are syntactic sugar for the before, after and around method
405 modifier features that L<Class::MOP> provides. More information on these can
406 be found in the L<Class::MOP> documentation for now.
410 The keyword C<super> is a noop when called outside of an C<override> method. In
411 the context of an C<override> method, it will call the next most appropriate
412 superclass method with the same arguments as the original method.
414 =item B<override ($name, &sub)>
416 An C<override> method, is a way of explictly saying "I am overriding this
417 method from my superclass". You can call C<super> within this method, and
418 it will work as expected. The same thing I<can> be accomplished with a normal
419 method call and the C<SUPER::> pseudo-package, it is really your choice.
423 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
424 an C<augment> method. You can think of C<inner> as being the inverse of
425 C<super>, the details of how C<inner> and C<augment> work is best described in
426 the L<Moose::Cookbook>.
428 =item B<augment ($name, &sub)>
430 An C<augment> method, is a way of explictly saying "I am augmenting this
431 method from my superclass". Once again, the details of how C<inner> and
432 C<augment> work is best described in the L<Moose::Cookbook>.
436 This is the C<Carp::confess> function, and exported here beause I use it
437 all the time. This feature may change in the future, so you have been warned.
441 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
442 use it all the time. It is highly recommended that this is used instead of
443 C<ref> anywhere you need to test for an object's class name.
449 Here is just a sampling of the plans we have in store for Moose:
455 Compiling Moose classes/roles into C<.pmc> files for faster loading and execution.
459 Supporting sealed and finalized classes in Moose. This will allow greater control
460 of the extensions of frameworks and such.
466 =head2 What does Moose stand for??
468 Moose doesn't stand for one thing in particular, however, if you
469 want, here are a few of my favorites, feel free to contribute
474 =item Make Other Object Systems Envious
476 =item Makes Object Orientation So Easy
478 =item Makes Object Orientation Spiffy- Er (sorry ingy)
480 =item Most Other Object Systems Emasculate
482 =item Moose Often Ovulate Sorta Early
484 =item Moose Offers Often Super Extensions
486 =item Meta Object Orientation Syntax Extensions
496 It should be noted that C<super> and C<inner> can B<not> be used in the same
497 method. However, they can be combined together with the same class hierarchy,
498 see F<t/014_override_augment_inner_super.t> for an example.
500 The reason that this is so is because C<super> is only valid within a method
501 with the C<override> modifier, and C<inner> will never be valid within an
502 C<override> method. In fact, C<augment> will skip over any C<override> methods
503 when searching for it's appropriate C<inner>.
505 This might seem like a restriction, but I am of the opinion that keeping these
506 two features seperate (but interoperable) actually makes them easy to use since
507 their behavior is then easier to predict. Time will tell if I am right or not.
511 =head1 ACKNOWLEDGEMENTS
515 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
517 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
519 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
520 and it certainly wouldn't have this name ;P
522 =item The basis of the TypeContraints module was Rob Kinyon's idea
523 originally, I just ran with it.
525 =item Thanks to mst & chansen and the whole #moose poose for all the
526 ideas/feature-requests/encouragement
534 =item L<Class::MOP> documentation
536 =item The #moose channel on irc.perl.org
538 =item L<http://forum2.org/moose/>
540 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
542 This paper (suggested by lbr on #moose) was what lead to the implementation
543 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
544 want to understand this feature, I suggest you read this.
550 All complex software has bugs lurking in it, and this module is no
551 exception. If you find a bug please either email me, or add the bug
556 Stevan Little E<lt>stevan@iinteractive.comE<gt>
558 Christian Hansen E<lt>chansen@cpan.orgE<gt>
560 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
562 =head1 COPYRIGHT AND LICENSE
564 Copyright 2006 by Infinity Interactive, Inc.
566 L<http://www.iinteractive.com>
568 This library is free software; you can redistribute it and/or modify
569 it under the same terms as Perl itself.