9 use Scalar::Util 'blessed', 'reftype';
11 use Sub::Name 'subname';
13 use UNIVERSAL::require;
17 use Moose::Meta::Class;
18 use Moose::Meta::Attribute;
19 use Moose::Meta::TypeConstraint;
20 use Moose::Meta::TypeCoercion;
23 use Moose::Util::TypeConstraints;
29 # we should never export to main
30 return if $pkg eq 'main';
32 Moose::Util::TypeConstraints->import($pkg);
34 # make a subtype for each Moose class
37 => where { $_->isa($pkg) };
40 if ($pkg->can('meta')) {
42 (blessed($meta) && $meta->isa('Class::MOP::Class'))
43 || confess "Whoops, not møøsey enough";
46 $meta = Moose::Meta::Class->initialize($pkg => (
47 ':attribute_metaclass' => 'Moose::Meta::Attribute'
49 $meta->add_method('meta' => sub {
50 # re-initialize so it inherits properly
51 Moose::Meta::Class->initialize($pkg => (
52 ':attribute_metaclass' => 'Moose::Meta::Attribute'
58 # &alias_method will install the method, but it
59 # will not name it with
62 $meta->alias_method('extends' => subname 'Moose::extends' => sub {
63 foreach my $super (@_) {
64 # see if this is already
65 # loaded in the symbol table
66 next if _is_class_already_loaded($super);
67 # otherwise require it ...
69 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
71 $meta->superclasses(@_)
75 $meta->alias_method('has' => subname 'Moose::has' => sub {
76 my ($name, %options) = @_;
77 if (exists $options{is}) {
78 if ($options{is} eq 'ro') {
79 $options{reader} = $name;
81 elsif ($options{is} eq 'rw') {
82 $options{accessor} = $name;
85 if (exists $options{isa}) {
86 # allow for anon-subtypes here ...
87 if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) {
88 $options{type_constraint} = $options{isa};
91 # otherwise assume it is a constraint
92 my $constraint = find_type_constraint($options{isa});
93 # if the constraing it not found ....
94 unless (defined $constraint) {
95 # assume it is a foreign class, and make
96 # an anon constraint for it
97 $constraint = subtype Object => where { $_->isa($options{isa}) };
99 $options{type_constraint} = $constraint;
102 $meta->add_attribute($name, %options)
105 # handle method modifers
106 $meta->alias_method('before' => subname 'Moose::before' => sub {
108 $meta->add_before_method_modifier($_, $code) for @_;
110 $meta->alias_method('after' => subname 'Moose::after' => sub {
112 $meta->add_after_method_modifier($_, $code) for @_;
114 $meta->alias_method('around' => subname 'Moose::around' => sub {
116 $meta->add_around_method_modifier($_, $code) for @_;
119 # make sure they inherit from Moose::Object
120 $meta->superclasses('Moose::Object')
121 unless $meta->superclasses();
123 # we recommend using these things
124 # so export them for them
125 $meta->alias_method('confess' => \&Carp::confess);
126 $meta->alias_method('blessed' => \&Scalar::Util::blessed);
129 sub _is_class_already_loaded {
132 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
133 foreach (keys %{"${name}::"}) {
134 next if substr($_, -2, 2) eq '::';
135 return 1 if defined &{"${name}::$_"};
148 Moose - Moose, it's the new Camel
155 has 'x' => (isa => 'Int', is => 'rw');
156 has 'y' => (isa => 'Int', is => 'rw');
169 has 'z' => (isa => 'Int');
171 after 'clear' => sub {
178 This is a B<very> early release of this module, it still needs
179 some fine tuning and B<lots> more documentation. I am adopting
180 the I<release early and release often> approach with this module,
181 so keep an eye on your favorite CPAN mirror!
185 Moose is an extension of the Perl 5 object system.
187 =head2 Another object system!?!?
189 Yes, I know there has been an explosion recently of new ways to
190 build object's in Perl 5, most of them based on inside-out objects,
191 and other such things. Moose is different because it is not a new
192 object system for Perl 5, but instead an extension of the existing
195 Moose is built on top of L<Class::MOP>, which is a metaclass system
196 for Perl 5. This means that Moose not only makes building normal
197 Perl 5 objects better, but it also provides the power of metaclass
200 =head2 What does Moose stand for??
202 Moose doesn't stand for one thing in particular, however, if you
203 want, here are a few of my favorites, feel free to contribute
208 =item Make Other Object Systems Envious
210 =item Makes Object Orientation So Easy
212 =item Makes Object Orientation Spiffy- Er (sorry ingy)
214 =item Most Other Object Systems Emasculate
216 =item My Overcraft Overfilled (with) Some Eels
218 =item Moose Often Ovulate Sorta Early
220 =item Many Overloaded Object Systems Exists
222 =item Moose Offers Often Super Extensions
226 =head1 BUILDING CLASSES WITH MOOSE
228 Moose makes every attempt to provide as much convience during class
229 construction/definition, but still stay out of your way if you want
230 it to. Here are some of the features Moose provides:
232 Unless specified with C<extends>, any class which uses Moose will
233 inherit from L<Moose::Object>.
235 Moose will also manage all attributes (including inherited ones) that
236 are defined with C<has>. And assuming that you call C<new> which is
237 inherited from L<Moose::Object>, then this includes properly initializing
238 all instance slots, setting defaults where approprtiate and performing any
239 type constraint checking or coercion.
241 =head1 EXPORTED FUNCTIONS
243 Moose will export a number of functions into the class's namespace, which
244 can then be used to set up the class. These functions all work directly
245 on the current class.
251 This is a method which provides access to the current class's metaclass.
253 =item B<extends (@superclasses)>
255 This function will set the superclass(es) for the current class.
257 This approach is recommended instead of C<use base>, because C<use base>
258 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
259 replace it. This is important to ensure that classes which do not have
260 superclasses properly inherit from L<Moose::Object>.
262 =item B<has ($name, %options)>
264 This will install an attribute of a given C<$name> into the current class.
265 The list of C<%options> are the same as those provided by both
266 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
267 few convience ones provided by Moose which are listed below:
271 =item I<is =E<gt> 'rw'|'ro'>
273 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
274 only). These will create either a read/write accessor or a read-only
275 accessor respectively, using the same name as the C<$name> of the attribute.
277 If you need more control over how your accessors are named, you can use the
278 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
280 =item I<isa =E<gt> $type_name>
282 The I<isa> option uses Moose's type constraint facilities to set up runtime
283 type checking for this attribute. Moose will perform the checks during class
284 construction, and within any accessors. The C<$type_name> argument must be a
285 string. The string can be either a class name, or a type defined using
286 Moose's type defintion features.
290 =item B<before $name|@names =E<gt> sub { ... }>
292 =item B<after $name|@names =E<gt> sub { ... }>
294 =item B<around $name|@names =E<gt> sub { ... }>
296 This three items are syntactic sugar for the before, after and around method
297 modifier features that L<Class::MOP> provides. More information on these can
298 be found in the L<Class::MOP> documentation for now.
302 This is the C<Carp::confess> function, and exported here beause I use it
303 all the time. This feature may change in the future, so you have been warned.
307 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
308 use it all the time. It is highly recommended that this is used instead of
309 C<ref> anywhere you need to test for an object's class name.
313 =head1 ACKNOWLEDGEMENTS
317 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
319 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
321 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
322 and it certainly wouldn't have this name ;P
324 =item The basis of the TypeContraints module was Rob Kinyon's idea
325 originally, I just ran with it.
327 =item Thanks to mst & chansen and the whole #moose poose for all the
328 ideas/feature-requests/encouragement
336 =item L<Class::MOP> documentation
338 =item The #moose channel on irc.perl.org
340 =item L<http://forum2.org/moose/>
346 All complex software has bugs lurking in it, and this module is no
347 exception. If you find a bug please either email me, or add the bug
352 Stevan Little E<lt>stevan@iinteractive.comE<gt>
354 =head1 COPYRIGHT AND LICENSE
356 Copyright 2006 by Infinity Interactive, Inc.
358 L<http://www.iinteractive.com>
360 This library is free software; you can redistribute it and/or modify
361 it under the same terms as Perl itself.