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 99%. 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 Fixing this one slightly less soon. stevan has suggested an implementation
232 strategy. Mouse currently mostly ignores methods.
236 User-defined type constraints and parameterized types may be implemented. Type
237 coercions probably not (patches welcome).
239 =head3 Bootstrapped meta world
241 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
243 =head3 Modification of attribute metaclass
245 When you declare an attribute with L</has>, you get the inlined accessors
246 installed immediately. Modifying the attribute metaclass, even if possible,
255 =head2 meta -> Mouse::Meta::Class
257 Returns this class' metaclass instance.
259 =head2 extends superclasses
261 Sets this class' superclasses.
263 =head2 before (method|methods) => Code
265 Installs a "before" method modifier. See L<Moose/before> or
266 L<Class::Method::Modifiers/before>.
268 =head2 after (method|methods) => Code
270 Installs an "after" method modifier. See L<Moose/after> or
271 L<Class::Method::Modifiers/after>.
273 =head2 around (method|methods) => Code
275 Installs an "around" method modifier. See L<Moose/around> or
276 L<Class::Method::Modifiers/around>.
278 =head2 has (name|names) => parameters
280 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
287 If specified, inlines a read-only/read-write accessor with the same name as
290 =item isa => TypeConstraint
292 Provides basic type checking in the constructor and accessor. Basic types such
293 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
294 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
297 =item required => 0|1
299 Whether this attribute is required to have a value. If the attribute is lazy or
300 has a builder, then providing a value for the attribute in the constructor is
303 =item init_arg => Str
305 Allows you to use a different key name in 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 =item trigger => CodeRef | HashRef
344 Triggers are like method modifiers for setting attribute values. You can have
345 a "before" and an "after" trigger, each of which receive as arguments the instance, the new value, and the attribute metaclass. Historically, triggers have
346 only been "after" modifiers, so if you use a coderef for the C<trigger> option,
347 it will maintain that compatibility. Like method modifiers, you can't really
348 affect the act of setting the attribute value, and the return values of the
349 modifiers are ignored.
351 There's also an "around" trigger which you can use to change the value that
352 is being set on the attribute, or even prevent the attribute from being
353 updated. The around trigger receives as arguments a code reference to invoke
354 to set the attribute's value (which expects as arguments the instance and
355 the new value), the instance, the new value, and the attribute metaclass.
359 Defines a method name to be called to provide the default value of the
360 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
361 C<< default => sub { $_[0]->build_foo } >>.
363 =item auto_deref => 0|1
365 Allows you to automatically dereference ArrayRef and HashRef attributes in list
366 context. In scalar context, the reference is returned (NOT the list length or
367 bucket status). You must specify an appropriate type constraint to use
372 =head2 confess error -> BOOM
374 L<Carp/confess> for your convenience.
376 =head2 blessed value -> ClassName | undef
378 L<Scalar::Util/blessed> for your convenience.
384 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
385 You may use L</extends> to replace the superclass list.
389 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
390 keywords (such as L</extends>) it will break loudly instead breaking subtly.
394 =head2 load_class Class::Name
396 This will load a given C<Class::Name> (or die if it's not loadable).
397 This function can be used in place of tricks like
398 C<eval "use $module"> or using C<require>.
400 =head2 is_class_loaded Class::Name -> Bool
402 Returns whether this class is actually loaded or not. It uses a heuristic which
403 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
404 locally-defined method.
408 Shawn M Moore, C<< <sartak at gmail.com> >>
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.