11 use Mouse::Util 'blessed';
13 use Mouse::Meta::Attribute;
14 use Mouse::Meta::Class;
16 use Mouse::TypeRegistry;
18 our @EXPORT = qw(extends has before after around blessed confess with);
20 sub extends { Mouse::Meta::Class->initialize(caller)->superclasses(@_) }
23 my $meta = Mouse::Meta::Class->initialize(caller);
26 $names = [$names] if !ref($names);
28 for my $name (@$names) {
29 if ($name =~ s/^\+//) {
30 Mouse::Meta::Attribute->clone_parent($meta, $name, @_);
33 Mouse::Meta::Attribute->create($meta, $name, @_);
39 my $meta = Mouse::Meta::Class->initialize(caller);
44 $meta->add_before_method_modifier($_ => $code);
49 my $meta = Mouse::Meta::Class->initialize(caller);
54 $meta->add_after_method_modifier($_ => $code);
59 my $meta = Mouse::Meta::Class->initialize(caller);
64 $meta->add_around_method_modifier($_ => $code);
69 my $meta = Mouse::Meta::Class->initialize(caller);
73 confess "Mouse::Role only supports 'with' on individual roles at a time" if @_;
75 Mouse::load_class($role);
76 $role->meta->apply($meta);
85 my $meta = Mouse::Meta::Class->initialize($caller);
86 $meta->superclasses('Mouse::Object')
87 unless $meta->superclasses;
90 no warnings 'redefine';
91 *{$caller.'::meta'} = sub { $meta };
93 Mouse->export_to_level(1, @_);
100 for my $keyword (@EXPORT) {
101 delete ${ $caller . '::' }{$keyword};
108 if (ref($class) || !defined($class) || !length($class)) {
109 my $display = defined($class) ? $class : 'undef';
110 confess "Invalid class name ($display)";
113 return 1 if is_class_loaded($class);
115 (my $file = "$class.pm") =~ s{::}{/}g;
117 eval { CORE::require($file) };
118 confess "Could not load class ($class) because : $@" if $@;
123 sub is_class_loaded {
126 return 0 if ref($class) || !defined($class) || !length($class);
128 # walk the symbol table tree to avoid autovififying
129 # \*{${main::}{"Foo::"}} == \*main::Foo::
132 foreach my $part (split('::', $class)) {
133 return 0 unless exists ${$$pack}{"${part}::"};
134 $pack = \*{${$$pack}{"${part}::"}};
137 # check for $VERSION or @ISA
138 return 1 if exists ${$$pack}{VERSION}
139 && defined *{${$$pack}{VERSION}}{SCALAR};
140 return 1 if exists ${$$pack}{ISA}
141 && defined *{${$$pack}{ISA}}{ARRAY};
143 # check for any method
144 foreach ( keys %{$$pack} ) {
145 next if substr($_, -2, 2) eq '::';
146 return 1 if defined *{${$$pack}{$_}}{CODE};
159 Mouse - Moose minus the antlers
164 use Mouse; # automatically turns on strict and warnings
166 has 'x' => (is => 'rw', isa => 'Int');
167 has 'y' => (is => 'rw', isa => 'Int');
180 has 'z' => (is => 'rw', isa => 'Int');
182 after 'clear' => sub {
189 L<Moose> is wonderful.
191 Unfortunately, it's a little slow. Though significant progress has been made
192 over the years, the compile time penalty is a non-starter for some
195 Mouse aims to alleviate this by providing a subset of Moose's
196 functionality, faster. In particular, L<Moose/has> is missing only a few
197 expert-level features.
199 We're also going as light on dependencies as possible. Most functions we use
200 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
201 you'd like weak references; there's simply no way to do it from pure Perl.
202 L<Class::Method::Modifiers> is required if you want support for L</before>,
203 L</after>, and L</around>.
207 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
208 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
209 over 96%. Even the error messages are taken from Moose. The Mouse code just
210 runs the test suite 4x faster.
212 The idea is that, if you need the extra power, you should be able to run
213 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
214 nothingmuch has written L<Squirrel> (part of this distribution) which will act
215 as Mouse unless Moose is loaded, in which case it will act as Moose.
217 Mouse also has the blessings of Moose's author, stevan.
219 =head2 MISSING FEATURES
223 We're working on fixing this one! stevan has suggested an implementation
224 strategy. Mouse currently ignores methods, so that needs to be fixed next.
225 Roles that consist entirely of attributes may be usable in this very version.
229 User-defined type constraints and parameterized types may be implemented. Type
230 coercions probably not (patches welcome).
232 =head3 Bootstrapped meta world
234 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
236 =head3 Modification of attribute metaclass
238 When you declare an attribute with L</has>, you get the inlined accessors
239 installed immediately. Modifying the attribute metaclass, even if possible,
248 =head2 meta -> Mouse::Meta::Class
250 Returns this class' metaclass instance.
252 =head2 extends superclasses
254 Sets this class' superclasses.
256 =head2 before (method|methods) => Code
258 Installs a "before" method modifier. See L<Moose/before> or
259 L<Class::Method::Modifiers/before>.
261 Use of this feature requires L<Class::Method::Modifiers>!
263 =head2 after (method|methods) => Code
265 Installs an "after" method modifier. See L<Moose/after> or
266 L<Class::Method::Modifiers/after>.
268 Use of this feature requires L<Class::Method::Modifiers>!
270 =head2 around (method|methods) => Code
272 Installs an "around" method modifier. See L<Moose/around> or
273 L<Class::Method::Modifiers/around>.
275 Use of this feature requires L<Class::Method::Modifiers>!
277 =head2 has (name|names) => parameters
279 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
286 If specified, inlines a read-only/read-write accessor with the same name as
289 =item isa => TypeConstraint
291 Provides basic type checking in the constructor and accessor. Basic types such
292 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
293 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
296 =item required => 0|1
298 Whether this attribute is required to have a value. If the attribute is lazy or
299 has a builder, then providing a value for the attribute in the constructor is
302 =item init_arg => Str | Undef
304 Allows you to use a different key name in the constructor. If undef, the
305 attribue can't be passed to the constructor.
307 =item default => Value | CodeRef
309 Sets the default value of the attribute. If the default is a coderef, it will
310 be invoked to get the default value. Due to quirks of Perl, any bare reference
311 is forbidden, you must wrap the reference in a coderef. Otherwise, all
312 instances will share the same reference.
316 If specified, the default is calculated on demand instead of in the
319 =item predicate => Str
321 Lets you specify a method name for installing a predicate method, which checks
322 that the attribute has a value. It will not invoke a lazy default or builder
327 Lets you specify a method name for installing a clearer method, which clears
328 the attribute's value from the instance. On the next read, lazy or builder will
331 =item handles => HashRef|ArrayRef
333 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
334 given method names to method calls on the attribute. HashRef maps local method
335 names to remote method names called on the attribute. Other forms of
336 L</handles>, such as regular expression and coderef, are not yet supported.
338 =item weak_ref => 0|1
340 Lets you automatically weaken any reference stored in the attribute.
342 Use of this feature requires L<Scalar::Util>!
344 =item trigger => CodeRef
346 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.
348 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
352 Defines a method name to be called to provide the default value of the
353 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
354 C<< default => sub { $_[0]->build_foo } >>.
356 =item auto_deref => 0|1
358 Allows you to automatically dereference ArrayRef and HashRef attributes in list
359 context. In scalar context, the reference is returned (NOT the list length or
360 bucket status). You must specify an appropriate type constraint to use
363 =item lazy_build => 0|1
365 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
366 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
370 =head2 confess error -> BOOM
372 L<Carp/confess> for your convenience.
374 =head2 blessed value -> ClassName | undef
376 L<Scalar::Util/blessed> for your convenience.
382 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
383 You may use L</extends> to replace the superclass list.
387 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
388 keywords (such as L</extends>) it will break loudly instead breaking subtly.
392 =head2 load_class Class::Name
394 This will load a given C<Class::Name> (or die if it's not loadable).
395 This function can be used in place of tricks like
396 C<eval "use $module"> or using C<require>.
398 =head2 is_class_loaded Class::Name -> Bool
400 Returns whether this class is actually loaded or not. It uses a heuristic which
401 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
402 locally-defined method.
406 Shawn M Moore, C<< <sartak at gmail.com> >>
408 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
410 with plenty of code borrowed from L<Class::MOP> and L<Moose>
416 Please report any bugs through RT: email
417 C<bug-mouse at rt.cpan.org>, or browse
418 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
420 =head1 COPYRIGHT AND LICENSE
422 Copyright 2008 Shawn M Moore.
424 This program is free software; you can redistribute it and/or modify it
425 under the same terms as Perl itself.