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 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 "You already have a &meta function, but it does not return a Moose::Meta::Class";
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);
145 # this is experimental, but I am not
146 # happy with it. If you want to try
147 # it, you will have to uncomment it
149 # There is a really good chance that
150 # this will be deprecated, dont get
153 # return subname 'Moose::self' => sub {};
156 # my $class = $CALLER;
157 # return subname 'Moose::method' => sub {
158 # my ($name, $method) = @_;
159 # $class->meta->add_method($name, sub {
162 # no warnings 'redefine';
163 # local *{$class->meta->name . '::self'} = sub { $self };
170 return \&Carp::confess;
173 return \&Scalar::Util::blessed;
177 my $exporter = Sub::Exporter::build_exporter({
178 exports => \%exports,
190 # we should never export to main
191 return if $CALLER eq 'main';
200 my $class = caller();
201 # loop through the exports ...
202 foreach my $name (keys %exports) {
203 next if $name =~ /inner|super|self/;
206 if (defined &{$class . '::' . $name}) {
207 my $keyword = \&{$class . '::' . $name};
209 # make sure it is from Moose
210 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
212 next if $pkg_name ne 'Moose';
214 # and if it is from Moose then undef the slot
215 delete ${$class . '::'}{$name};
225 sub _load_all_classes {
226 foreach my $class (@_) {
227 # see if this is already
228 # loaded in the symbol table
229 next if _is_class_already_loaded($class);
230 # otherwise require it ...
231 my $file = $class . '.pm';
233 eval { CORE::require($file) };
235 "Could not load module '$class' because : $@"
240 sub _is_class_already_loaded {
243 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
244 foreach (keys %{"${name}::"}) {
245 next if substr($_, -2, 2) eq '::';
246 return 1 if defined &{"${name}::$_"};
259 Moose - A complete modern object system for Perl 5
268 has 'x' => (is => 'rw', isa => 'Int');
269 has 'y' => (is => 'rw', isa => 'Int');
284 has 'z' => (is => 'rw', isa => 'Int');
286 after 'clear' => sub {
293 Moose is a rapidly maturing module, and is already being used by
294 a number of people. It's test suite is growing larger by the day,
295 and the docs should soon follow.
297 This said, Moose is not yet finished, and should still be considered
298 to be evolving. Much of the outer API is stable, but the internals
299 are still subject to change (although not without serious thought
304 Moose is an extension of the Perl 5 object system.
306 =head2 Another object system!?!?
308 Yes, I know there has been an explosion recently of new ways to
309 build object's in Perl 5, most of them based on inside-out objects
310 and other such things. Moose is different because it is not a new
311 object system for Perl 5, but instead an extension of the existing
314 Moose is built on top of L<Class::MOP>, which is a metaclass system
315 for Perl 5. This means that Moose not only makes building normal
316 Perl 5 objects better, but it also provides the power of metaclass
319 =head2 Can I use this in production? Or is this just an experiment?
321 Moose is I<based> on the prototypes and experiments I did for the Perl 6
322 meta-model; however Moose is B<NOT> an experiment/prototype, it is
323 for B<real>. I will be deploying Moose into production environments later
324 this year, and I have every intentions of using it as my de facto class
327 =head2 Is Moose just Perl 6 in Perl 5?
329 No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
330 Instead, it is an OO system for Perl 5. I built Moose because I was tired or
331 writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
332 instead of switching to Ruby, I wrote Moose :)
334 =head1 BUILDING CLASSES WITH MOOSE
336 Moose makes every attempt to provide as much convenience as possible during
337 class construction/definition, but still stay out of your way if you want it
338 to. Here are a few items to note when building classes with Moose.
340 Unless specified with C<extends>, any class which uses Moose will
341 inherit from L<Moose::Object>.
343 Moose will also manage all attributes (including inherited ones) that
344 are defined with C<has>. And assuming that you call C<new>, which is
345 inherited from L<Moose::Object>, then this includes properly initializing
346 all instance slots, setting defaults where appropriate, and performing any
347 type constraint checking or coercion.
349 =head1 EXPORTED FUNCTIONS
351 Moose will export a number of functions into the class's namespace which
352 can then be used to set up the class. These functions all work directly
353 on the current class.
359 This is a method which provides access to the current class's metaclass.
361 =item B<extends (@superclasses)>
363 This function will set the superclass(es) for the current class.
365 This approach is recommended instead of C<use base>, because C<use base>
366 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
367 replace it. This is important to ensure that classes which do not have
368 superclasses still properly inherit from L<Moose::Object>.
370 =item B<with (@roles)>
372 This will apply a given set of C<@roles> to the local class. Role support
373 is currently under heavy development; see L<Moose::Role> for more details.
375 =item B<has ($name, %options)>
377 This will install an attribute of a given C<$name> into the current class.
378 The list of C<%options> are the same as those provided by
379 L<Class::MOP::Attribute>, in addition to the list below which are provided
380 by Moose (L<Moose::Meta::Attribute> to be more specific):
384 =item I<is =E<gt> 'rw'|'ro'>
386 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
387 only). These will create either a read/write accessor or a read-only
388 accessor respectively, using the same name as the C<$name> of the attribute.
390 If you need more control over how your accessors are named, you can use the
391 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
393 =item I<isa =E<gt> $type_name>
395 The I<isa> option uses Moose's type constraint facilities to set up runtime
396 type checking for this attribute. Moose will perform the checks during class
397 construction, and within any accessors. The C<$type_name> argument must be a
398 string. The string can be either a class name or a type defined using
399 Moose's type definition features.
401 =item I<coerce =E<gt> (1|0)>
403 This will attempt to use coercion with the supplied type constraint to change
404 the value passed into any accessors or constructors. You B<must> have supplied
405 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
406 for an example usage.
408 =item I<does =E<gt> $role_name>
410 This will accept the name of a role which the value stored in this attribute
411 is expected to have consumed.
413 =item I<required =E<gt> (1|0)>
415 This marks the attribute as being required. This means a value must be supplied
416 during class construction, and the attribute can never be set to C<undef> with
419 =item I<weak_ref =E<gt> (1|0)>
421 This will tell the class to store the value of this attribute as a weakened
422 reference. If an attribute is a weakened reference, it B<cannot> also be
425 =item I<lazy =E<gt> (1|0)>
427 This will tell the class to not create this slot until absolutely necessary.
428 If an attribute is marked as lazy it B<must> have a default supplied.
430 =item I<auto_deref =E<gt> (1|0)>
432 This tells the accessor whether to automatically dereference the value returned.
433 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
435 =item I<trigger =E<gt> $code>
437 The trigger option is a CODE reference which will be called after the value of
438 the attribute is set. The CODE ref will be passed the instance itself, the
439 updated value and the attribute meta-object (this is for more advanced fiddling
440 and can typically be ignored in most cases). You B<cannot> have a trigger on
441 a read-only attribute.
443 =item I<handles =E<gt> [ @handles ]>
445 There is experimental support for attribute delegation using the C<handles>
446 option. More docs to come later.
450 =item B<before $name|@names =E<gt> sub { ... }>
452 =item B<after $name|@names =E<gt> sub { ... }>
454 =item B<around $name|@names =E<gt> sub { ... }>
456 This three items are syntactic sugar for the before, after, and around method
457 modifier features that L<Class::MOP> provides. More information on these can
458 be found in the L<Class::MOP> documentation for now.
462 The keyword C<super> is a no-op when called outside of an C<override> method. In
463 the context of an C<override> method, it will call the next most appropriate
464 superclass method with the same arguments as the original method.
466 =item B<override ($name, &sub)>
468 An C<override> method is a way of explicitly saying "I am overriding this
469 method from my superclass". You can call C<super> within this method, and
470 it will work as expected. The same thing I<can> be accomplished with a normal
471 method call and the C<SUPER::> pseudo-package; it is really your choice.
475 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
476 an C<augment> method. You can think of C<inner> as being the inverse of
477 C<super>; the details of how C<inner> and C<augment> work is best described in
478 the L<Moose::Cookbook>.
480 =item B<augment ($name, &sub)>
482 An C<augment> method, is a way of explicitly saying "I am augmenting this
483 method from my superclass". Once again, the details of how C<inner> and
484 C<augment> work is best described in the L<Moose::Cookbook>.
488 This is the C<Carp::confess> function, and exported here because I use it
489 all the time. This feature may change in the future, so you have been warned.
493 This is the C<Scalar::Uti::blessed> function, it is exported here because I
494 use it all the time. It is highly recommended that this is used instead of
495 C<ref> anywhere you need to test for an object's class name.
499 =head1 UNEXPORTING FUNCTIONS
503 Moose offers a way of removing the keywords it exports though the C<unimport>
504 method. You simply have to say C<no Moose> at the bottom of your code for this
505 to work. Here is an example:
510 has 'first_name' => (is => 'rw', isa => 'Str');
511 has 'last_name' => (is => 'rw', isa => 'Str');
515 $self->first_name . ' ' . $self->last_name
518 no Moose; # keywords are removed from the Person package
522 =head2 What does Moose stand for??
524 Moose doesn't stand for one thing in particular, however, if you
525 want, here are a few of my favorites; feel free to contribute
530 =item Make Other Object Systems Envious
532 =item Makes Object Orientation So Easy
534 =item Makes Object Orientation Spiffy- Er (sorry ingy)
536 =item Most Other Object Systems Emasculate
538 =item Moose Often Ovulate Sorta Early
540 =item Moose Offers Often Super Extensions
542 =item Meta Object Orientation Syntax Extensions
552 It should be noted that C<super> and C<inner> C<cannot> be used in the same
553 method. However, they can be combined together with the same class hierarchy;
554 see F<t/014_override_augment_inner_super.t> for an example.
556 The reason for this is that C<super> is only valid within a method
557 with the C<override> modifier, and C<inner> will never be valid within an
558 C<override> method. In fact, C<augment> will skip over any C<override> methods
559 when searching for its appropriate C<inner>.
561 This might seem like a restriction, but I am of the opinion that keeping these
562 two features separate (but interoperable) actually makes them easy to use, since
563 their behavior is then easier to predict. Time will tell if I am right or not.
567 =head1 ACKNOWLEDGEMENTS
571 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
573 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
575 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
576 and it certainly wouldn't have this name ;P
578 =item The basis of the TypeContraints module was Rob Kinyon's idea
579 originally, I just ran with it.
581 =item Thanks to mst & chansen and the whole #moose poose for all the
582 ideas/feature-requests/encouragement
584 =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes.
592 =item L<Class::MOP> documentation
594 =item The #moose channel on irc.perl.org
596 =item The Moose mailing list - moose@perl.org
598 =item L<http://forum2.org/moose/>
600 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
602 This paper (suggested by lbr on #moose) was what lead to the implementation
603 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
604 want to understand this feature, I suggest you read this.
610 All complex software has bugs lurking in it, and this module is no
611 exception. If you find a bug please either email me, or add the bug
616 Stevan Little E<lt>stevan@iinteractive.comE<gt>
618 Christian Hansen E<lt>chansen@cpan.orgE<gt>
620 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
622 =head1 COPYRIGHT AND LICENSE
624 Copyright 2006 by Infinity Interactive, Inc.
626 L<http://www.iinteractive.com>
628 This library is free software; you can redistribute it and/or modify
629 it under the same terms as Perl itself.