11 use Scalar::Util 'blessed';
12 use Class::Method::Modifiers ();
14 use Mouse::Meta::Attribute;
15 use Mouse::Meta::Class;
17 use Mouse::TypeRegistry;
24 my $meta = Mouse::Meta::Class->initialize($CALLER);
31 $caller->meta->superclasses(@_);
39 my $meta = $caller->meta;
42 $names = [$names] if !ref($names);
44 for my $name (@$names) {
45 if ($name =~ s/^\+//) {
46 Mouse::Meta::Attribute->clone_parent($meta, $name, @_);
49 Mouse::Meta::Attribute->create($meta, $name, @_);
64 return \&Class::Method::Modifiers::before;
68 return \&Class::Method::Modifiers::after;
72 return \&Class::Method::Modifiers::around;
80 my $class = $caller->meta;
82 confess "Mouse::Role only supports 'with' on individual roles at a time" if @_;
84 Mouse::load_class($role);
85 $role->meta->apply($class);
90 my $exporter = Sub::Exporter::build_exporter({
92 groups => { default => [':all'] },
101 my $meta = Mouse::Meta::Class->initialize($CALLER);
102 $meta->superclasses('Mouse::Object')
103 unless $meta->superclasses;
112 for my $keyword (keys %exports) {
113 next if $keyword eq 'meta'; # we don't delete this one
114 delete ${ $caller . '::' }{$keyword};
122 if (ref($class) || !defined($class) || !length($class)) {
123 my $display = defined($class) ? $class : 'undef';
124 confess "Invalid class name ($display)";
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.
215 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
216 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
217 over 97%. Even the error messages are taken from Moose. The Mouse code just
218 runs the test suite 3x-4x faster.
220 The idea is that, if you need the extra power, you should be able to run
221 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
222 nothingmuch has written L<Squirrel> (part of this distribution) which will act
223 as Mouse unless Moose is loaded, in which case it will act as Moose.
225 Mouse also has the blessings of Moose's author, stevan.
227 =head2 MISSING FEATURES
231 We're working on fixing this one! stevan has suggested an implementation
232 strategy. Mouse currently ignores methods, so that needs to be fixed next.
233 Roles that consist entirely of attributes may be usable in this very version.
237 User-defined type constraints and parameterized types may be implemented. Type
238 coercions probably not (patches welcome).
240 =head3 Bootstrapped meta world
242 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
244 =head3 Modification of attribute metaclass
246 When you declare an attribute with L</has>, you get the inlined accessors
247 installed immediately. Modifying the attribute metaclass, even if possible,
256 =head2 meta -> Mouse::Meta::Class
258 Returns this class' metaclass instance.
260 =head2 extends superclasses
262 Sets this class' superclasses.
264 =head2 before (method|methods) => Code
266 Installs a "before" method modifier. See L<Moose/before> or
267 L<Class::Method::Modifiers/before>.
269 =head2 after (method|methods) => Code
271 Installs an "after" method modifier. See L<Moose/after> or
272 L<Class::Method::Modifiers/after>.
274 =head2 around (method|methods) => Code
276 Installs an "around" method modifier. See L<Moose/around> or
277 L<Class::Method::Modifiers/around>.
279 =head2 has (name|names) => parameters
281 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
288 If specified, inlines a read-only/read-write accessor with the same name as
291 =item isa => TypeConstraint
293 Provides basic type checking in the constructor and accessor. Basic types such
294 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
295 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
298 =item required => 0|1
300 Whether this attribute is required to have a value. If the attribute is lazy or
301 has a builder, then providing a value for the attribute in the constructor is
304 =item init_arg => Str
306 Allows you to use a different key name in the constructor.
308 =item default => Value | CodeRef
310 Sets the default value of the attribute. If the default is a coderef, it will
311 be invoked to get the default value. Due to quirks of Perl, any bare reference
312 is forbidden, you must wrap the reference in a coderef. Otherwise, all
313 instances will share the same reference.
317 If specified, the default is calculated on demand instead of in the
320 =item predicate => Str
322 Lets you specify a method name for installing a predicate method, which checks
323 that the attribute has a value. It will not invoke a lazy default or builder
328 Lets you specify a method name for installing a clearer method, which clears
329 the attribute's value from the instance. On the next read, lazy or builder will
332 =item handles => HashRef|ArrayRef
334 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
335 given method names to method calls on the attribute. HashRef maps local method
336 names to remote method names called on the attribute. Other forms of
337 L</handles>, such as regular expression and coderef, are not yet supported.
339 =item weak_ref => 0|1
341 Lets you automatically weaken any reference stored in the attribute.
343 =item trigger => CodeRef | HashRef
345 Triggers are like method modifiers for setting attribute values. You can have
346 a "before" and an "after" trigger, each of which receive as arguments the instance, the new value, and the attribute metaclass. Historically, triggers have
347 only been "after" modifiers, so if you use a coderef for the C<trigger> option,
348 it will maintain that compatibility. Like method modifiers, you can't really
349 affect the act of setting the attribute value, and the return values of the
350 modifiers are ignored.
352 There's also an "around" trigger which you can use to change the value that
353 is being set on the attribute, or even prevent the attribute from being
354 updated. The around trigger receives as arguments a code reference to invoke
355 to set the attribute's value (which expects as arguments the instance and
356 the new value), the instance, the new value, and the attribute metaclass.
360 Defines a method name to be called to provide the default value of the
361 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
362 C<< default => sub { $_[0]->build_foo } >>.
364 =item auto_deref => 0|1
366 Allows you to automatically dereference ArrayRef and HashRef attributes in list
367 context. In scalar context, the reference is returned (NOT the list length or
368 bucket status). You must specify an appropriate type constraint to use
373 =head2 confess error -> BOOM
375 L<Carp/confess> for your convenience.
377 =head2 blessed value -> ClassName | undef
379 L<Scalar::Util/blessed> for your convenience.
385 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
386 You may use L</extends> to replace the superclass list.
390 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
391 keywords (such as L</extends>) it will break loudly instead breaking subtly.
395 =head2 load_class Class::Name
397 This will load a given C<Class::Name> (or die if it's not loadable).
398 This function can be used in place of tricks like
399 C<eval "use $module"> or using C<require>.
401 =head2 is_class_loaded Class::Name -> Bool
403 Returns whether this class is actually loaded or not. It uses a heuristic which
404 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
405 locally-defined method.
409 Shawn M Moore, C<< <sartak at gmail.com> >>
411 with plenty of code borrowed from L<Class::MOP> and L<Moose>
417 Please report any bugs through RT: email
418 C<bug-mouse at rt.cpan.org>, or browse
419 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
421 =head1 COPYRIGHT AND LICENSE
423 Copyright 2008 Shawn M Moore.
425 This program is free software; you can redistribute it and/or modify it
426 under the same terms as Perl itself.