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 =head2 after (method|methods) => Code
263 Installs an "after" method modifier. See L<Moose/after> or
264 L<Class::Method::Modifiers/after>.
266 =head2 around (method|methods) => Code
268 Installs an "around" method modifier. See L<Moose/around> or
269 L<Class::Method::Modifiers/around>.
271 =head2 has (name|names) => parameters
273 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
280 If specified, inlines a read-only/read-write accessor with the same name as
283 =item isa => TypeConstraint
285 Provides basic type checking in the constructor and accessor. Basic types such
286 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
287 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
290 =item required => 0|1
292 Whether this attribute is required to have a value. If the attribute is lazy or
293 has a builder, then providing a value for the attribute in the constructor is
296 =item init_arg => Str
298 Allows you to use a different key name in the constructor.
300 =item default => Value | CodeRef
302 Sets the default value of the attribute. If the default is a coderef, it will
303 be invoked to get the default value. Due to quirks of Perl, any bare reference
304 is forbidden, you must wrap the reference in a coderef. Otherwise, all
305 instances will share the same reference.
309 If specified, the default is calculated on demand instead of in the
312 =item predicate => Str
314 Lets you specify a method name for installing a predicate method, which checks
315 that the attribute has a value. It will not invoke a lazy default or builder
320 Lets you specify a method name for installing a clearer method, which clears
321 the attribute's value from the instance. On the next read, lazy or builder will
324 =item handles => HashRef|ArrayRef
326 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
327 given method names to method calls on the attribute. HashRef maps local method
328 names to remote method names called on the attribute. Other forms of
329 L</handles>, such as regular expression and coderef, are not yet supported.
331 =item weak_ref => 0|1
333 Lets you automatically weaken any reference stored in the attribute.
335 =item trigger => CodeRef
337 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.
339 Mouse 0.05 supported more complex triggers, but this behavior is now deprecated.
343 Defines a method name to be called to provide the default value of the
344 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
345 C<< default => sub { $_[0]->build_foo } >>.
347 =item auto_deref => 0|1
349 Allows you to automatically dereference ArrayRef and HashRef attributes in list
350 context. In scalar context, the reference is returned (NOT the list length or
351 bucket status). You must specify an appropriate type constraint to use
356 =head2 confess error -> BOOM
358 L<Carp/confess> for your convenience.
360 =head2 blessed value -> ClassName | undef
362 L<Scalar::Util/blessed> for your convenience.
368 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
369 You may use L</extends> to replace the superclass list.
373 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
374 keywords (such as L</extends>) it will break loudly instead breaking subtly.
378 =head2 load_class Class::Name
380 This will load a given C<Class::Name> (or die if it's not loadable).
381 This function can be used in place of tricks like
382 C<eval "use $module"> or using C<require>.
384 =head2 is_class_loaded Class::Name -> Bool
386 Returns whether this class is actually loaded or not. It uses a heuristic which
387 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
388 locally-defined method.
392 Shawn M Moore, C<< <sartak at gmail.com> >>
394 with plenty of code borrowed from L<Class::MOP> and L<Moose>
400 Please report any bugs through RT: email
401 C<bug-mouse at rt.cpan.org>, or browse
402 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
404 =head1 COPYRIGHT AND LICENSE
406 Copyright 2008 Shawn M Moore.
408 This program is free software; you can redistribute it and/or modify it
409 under the same terms as Perl itself.