12 if ($ENV{MOUSE_DEBUG}) {
20 use Scalar::Util 'blessed';
23 use Mouse::Meta::Attribute;
24 use Mouse::Meta::Class;
26 use Mouse::TypeRegistry;
28 our @EXPORT = qw(extends has before after around blessed confess with);
30 sub extends { Mouse::Meta::Class->initialize(caller)->superclasses(@_) }
33 my $meta = Mouse::Meta::Class->initialize(caller);
36 $names = [$names] if !ref($names);
38 for my $name (@$names) {
39 if ($name =~ s/^\+//) {
40 Mouse::Meta::Attribute->clone_parent($meta, $name, @_);
43 Mouse::Meta::Attribute->create($meta, $name, @_);
49 my $meta = Mouse::Meta::Class->initialize(caller);
54 $meta->add_before_method_modifier($_ => $code);
59 my $meta = Mouse::Meta::Class->initialize(caller);
64 $meta->add_after_method_modifier($_ => $code);
69 my $meta = Mouse::Meta::Class->initialize(caller);
74 $meta->add_around_method_modifier($_ => $code);
79 Mouse::Util::apply_all_roles((caller)[0], @_);
90 my $meta = Mouse::Meta::Class->initialize($caller);
91 $meta->superclasses('Mouse::Object')
92 unless $meta->superclasses;
95 no warnings 'redefine';
96 *{$caller.'::meta'} = sub { $meta };
99 __PACKAGE__->export_to_level( 1, $class, @_);
101 # shortcut for the common case of no type character
103 for my $keyword (@EXPORT) {
104 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
113 for my $keyword (@EXPORT) {
114 delete ${ $caller . '::' }{$keyword};
121 if (ref($class) || !defined($class) || !length($class)) {
122 my $display = defined($class) ? $class : 'undef';
123 confess "Invalid class name ($display)";
126 return 1 if $class eq 'Mouse::Object';
127 return 1 if is_class_loaded($class);
129 (my $file = "$class.pm") =~ s{::}{/}g;
131 eval { CORE::require($file) };
132 confess "Could not load class ($class) because : $@" if $@;
137 sub is_class_loaded {
140 return 0 if ref($class) || !defined($class) || !length($class);
142 # walk the symbol table tree to avoid autovififying
143 # \*{${main::}{"Foo::"}} == \*main::Foo::
146 foreach my $part (split('::', $class)) {
147 return 0 unless exists ${$$pack}{"${part}::"};
148 $pack = \*{${$$pack}{"${part}::"}};
151 # check for $VERSION or @ISA
152 return 1 if exists ${$$pack}{VERSION}
153 && defined *{${$$pack}{VERSION}}{SCALAR};
154 return 1 if exists ${$$pack}{ISA}
155 && defined *{${$$pack}{ISA}}{ARRAY};
157 # check for any method
158 foreach ( keys %{$$pack} ) {
159 next if substr($_, -2, 2) eq '::';
160 return 1 if defined *{${$$pack}{$_}}{CODE};
173 Mouse - Moose minus the antlers
178 use Mouse; # automatically turns on strict and warnings
180 has 'x' => (is => 'rw', isa => 'Int');
181 has 'y' => (is => 'rw', isa => 'Int');
194 has 'z' => (is => 'rw', isa => 'Int');
196 after 'clear' => sub {
203 L<Moose> is wonderful.
205 Unfortunately, it's a little slow. Though significant progress has been made
206 over the years, the compile time penalty is a non-starter for some
209 Mouse aims to alleviate this by providing a subset of Moose's
210 functionality, faster. In particular, L<Moose/has> is missing only a few
211 expert-level features.
213 We're also going as light on dependencies as possible. Most functions we use
214 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
215 you'd like weak references; there's simply no way to do it from pure Perl.
216 L<Class::Method::Modifiers> is required if you want support for L</before>,
217 L</after>, and L</around>.
221 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
222 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
223 over 96%. Even the error messages are taken from Moose. The Mouse code just
224 runs the test suite 4x faster.
226 The idea is that, if you need the extra power, you should be able to run
227 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
228 nothingmuch has written L<Squirrel> (part of this distribution) which will act
229 as Mouse unless Moose is loaded, in which case it will act as Moose.
231 Mouse also has the blessings of Moose's author, stevan.
233 =head2 MISSING FEATURES
237 We're working on fixing this one! stevan has suggested an implementation
238 strategy. Mouse currently ignores methods, so that needs to be fixed next.
239 Roles that consist entirely of attributes may be usable in this very version.
243 User-defined type constraints and parameterized types may be implemented. Type
244 coercions probably not (patches welcome).
246 =head3 Bootstrapped meta world
248 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
250 =head3 Modification of attribute metaclass
252 When you declare an attribute with L</has>, you get the inlined accessors
253 installed immediately. Modifying the attribute metaclass, even if possible,
262 =head2 meta -> Mouse::Meta::Class
264 Returns this class' metaclass instance.
266 =head2 extends superclasses
268 Sets this class' superclasses.
270 =head2 before (method|methods) => Code
272 Installs a "before" method modifier. See L<Moose/before> or
273 L<Class::Method::Modifiers/before>.
275 Use of this feature requires L<Class::Method::Modifiers>!
277 =head2 after (method|methods) => Code
279 Installs an "after" method modifier. See L<Moose/after> or
280 L<Class::Method::Modifiers/after>.
282 Use of this feature requires L<Class::Method::Modifiers>!
284 =head2 around (method|methods) => Code
286 Installs an "around" method modifier. See L<Moose/around> or
287 L<Class::Method::Modifiers/around>.
289 Use of this feature requires L<Class::Method::Modifiers>!
291 =head2 has (name|names) => parameters
293 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
300 If specified, inlines a read-only/read-write accessor with the same name as
303 =item isa => TypeConstraint
305 Provides basic type checking in the constructor and accessor. Basic types such
306 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
307 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
310 =item required => 0|1
312 Whether this attribute is required to have a value. If the attribute is lazy or
313 has a builder, then providing a value for the attribute in the constructor is
316 =item init_arg => Str | Undef
318 Allows you to use a different key name in the constructor. If undef, the
319 attribue can't be passed to the constructor.
321 =item default => Value | CodeRef
323 Sets the default value of the attribute. If the default is a coderef, it will
324 be invoked to get the default value. Due to quirks of Perl, any bare reference
325 is forbidden, you must wrap the reference in a coderef. Otherwise, all
326 instances will share the same reference.
330 If specified, the default is calculated on demand instead of in the
333 =item predicate => Str
335 Lets you specify a method name for installing a predicate method, which checks
336 that the attribute has a value. It will not invoke a lazy default or builder
341 Lets you specify a method name for installing a clearer method, which clears
342 the attribute's value from the instance. On the next read, lazy or builder will
345 =item handles => HashRef|ArrayRef
347 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
348 given method names to method calls on the attribute. HashRef maps local method
349 names to remote method names called on the attribute. Other forms of
350 L</handles>, such as regular expression and coderef, are not yet supported.
352 =item weak_ref => 0|1
354 Lets you automatically weaken any reference stored in the attribute.
356 Use of this feature requires L<Scalar::Util>!
358 =item trigger => CodeRef
360 Any time the attribute's value is set (either through the accessor or the constructor), the trigger is called on it. The trigger receives as arguments the instance, the new value, and the attribute instance.
362 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
366 Defines a method name to be called to provide the default value of the
367 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
368 C<< default => sub { $_[0]->build_foo } >>.
370 =item auto_deref => 0|1
372 Allows you to automatically dereference ArrayRef and HashRef attributes in list
373 context. In scalar context, the reference is returned (NOT the list length or
374 bucket status). You must specify an appropriate type constraint to use
377 =item lazy_build => 0|1
379 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
380 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
384 =head2 confess error -> BOOM
386 L<Carp/confess> for your convenience.
388 =head2 blessed value -> ClassName | undef
390 L<Scalar::Util/blessed> for your convenience.
396 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
397 You may use L</extends> to replace the superclass list.
401 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
402 keywords (such as L</extends>) it will break loudly instead breaking subtly.
406 =head2 load_class Class::Name
408 This will load a given C<Class::Name> (or die if it's not loadable).
409 This function can be used in place of tricks like
410 C<eval "use $module"> or using C<require>.
412 =head2 is_class_loaded Class::Name -> Bool
414 Returns whether this class is actually loaded or not. It uses a heuristic which
415 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
416 locally-defined method.
420 Shawn M Moore, C<< <sartak at gmail.com> >>
422 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
424 with plenty of code borrowed from L<Class::MOP> and L<Moose>
430 Please report any bugs through RT: email
431 C<bug-mouse at rt.cpan.org>, or browse
432 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
434 =head1 COPYRIGHT AND LICENSE
436 Copyright 2008 Shawn M Moore.
438 This program is free software; you can redistribute it and/or modify it
439 under the same terms as Perl itself.