10 if ($ENV{MOUSE_DEBUG}) {
18 use Scalar::Util 'blessed';
21 use Mouse::Meta::Attribute;
22 use Mouse::Meta::Class;
24 use Mouse::TypeRegistry;
26 our @EXPORT = qw(extends has before after around blessed confess with);
28 sub extends { Mouse::Meta::Class->initialize(caller)->superclasses(@_) }
31 my $meta = Mouse::Meta::Class->initialize(caller);
34 $names = [$names] if !ref($names);
36 for my $name (@$names) {
37 if ($name =~ s/^\+//) {
38 Mouse::Meta::Attribute->clone_parent($meta, $name, @_);
41 Mouse::Meta::Attribute->create($meta, $name, @_);
47 my $meta = Mouse::Meta::Class->initialize(caller);
52 $meta->add_before_method_modifier($_ => $code);
57 my $meta = Mouse::Meta::Class->initialize(caller);
62 $meta->add_after_method_modifier($_ => $code);
67 my $meta = Mouse::Meta::Class->initialize(caller);
72 $meta->add_around_method_modifier($_ => $code);
77 Mouse::Util::apply_all_roles((caller)[0], @_);
88 my $meta = Mouse::Meta::Class->initialize($caller);
89 $meta->superclasses('Mouse::Object')
90 unless $meta->superclasses;
93 no warnings 'redefine';
94 *{$caller.'::meta'} = sub { $meta };
97 __PACKAGE__->export_to_level( 1, $class, @_);
99 # shortcut for the common case of no type character
101 for my $keyword (@EXPORT) {
102 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
111 for my $keyword (@EXPORT) {
112 delete ${ $caller . '::' }{$keyword};
119 if (ref($class) || !defined($class) || !length($class)) {
120 my $display = defined($class) ? $class : 'undef';
121 confess "Invalid class name ($display)";
124 return 1 if $class eq 'Mouse::Object';
125 return 1 if is_class_loaded($class);
127 (my $file = "$class.pm") =~ s{::}{/}g;
129 eval { CORE::require($file) };
130 confess "Could not load class ($class) because : $@" if $@;
135 sub is_class_loaded {
138 return 0 if ref($class) || !defined($class) || !length($class);
140 # walk the symbol table tree to avoid autovififying
141 # \*{${main::}{"Foo::"}} == \*main::Foo::
144 foreach my $part (split('::', $class)) {
145 return 0 unless exists ${$$pack}{"${part}::"};
146 $pack = \*{${$$pack}{"${part}::"}};
149 # check for $VERSION or @ISA
150 return 1 if exists ${$$pack}{VERSION}
151 && defined *{${$$pack}{VERSION}}{SCALAR};
152 return 1 if exists ${$$pack}{ISA}
153 && defined *{${$$pack}{ISA}}{ARRAY};
155 # check for any method
156 foreach ( keys %{$$pack} ) {
157 next if substr($_, -2, 2) eq '::';
158 return 1 if defined *{${$$pack}{$_}}{CODE};
171 Mouse - Moose minus the antlers
176 use Mouse; # automatically turns on strict and warnings
178 has 'x' => (is => 'rw', isa => 'Int');
179 has 'y' => (is => 'rw', isa => 'Int');
192 has 'z' => (is => 'rw', isa => 'Int');
194 after 'clear' => sub {
201 L<Moose> is wonderful.
203 Unfortunately, it's a little slow. Though significant progress has been made
204 over the years, the compile time penalty is a non-starter for some
207 Mouse aims to alleviate this by providing a subset of Moose's
208 functionality, faster. In particular, L<Moose/has> is missing only a few
209 expert-level features.
211 We're also going as light on dependencies as possible. Most functions we use
212 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
213 you'd like weak references; there's simply no way to do it from pure Perl.
214 L<Class::Method::Modifiers> is required if you want support for L</before>,
215 L</after>, and L</around>.
219 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
220 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
221 over 96%. Even the error messages are taken from Moose. The Mouse code just
222 runs the test suite 4x faster.
224 The idea is that, if you need the extra power, you should be able to run
225 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
226 nothingmuch has written L<Squirrel> (part of this distribution) which will act
227 as Mouse unless Moose is loaded, in which case it will act as Moose.
229 Mouse also has the blessings of Moose's author, stevan.
231 =head2 MISSING FEATURES
235 We're working on fixing this one! stevan has suggested an implementation
236 strategy. Mouse currently ignores methods, so that needs to be fixed next.
237 Roles that consist entirely of attributes may be usable in this very version.
241 User-defined type constraints and parameterized types may be implemented. Type
242 coercions probably not (patches welcome).
244 =head3 Bootstrapped meta world
246 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
248 =head3 Modification of attribute metaclass
250 When you declare an attribute with L</has>, you get the inlined accessors
251 installed immediately. Modifying the attribute metaclass, even if possible,
260 =head2 meta -> Mouse::Meta::Class
262 Returns this class' metaclass instance.
264 =head2 extends superclasses
266 Sets this class' superclasses.
268 =head2 before (method|methods) => Code
270 Installs a "before" method modifier. See L<Moose/before> or
271 L<Class::Method::Modifiers/before>.
273 Use of this feature requires L<Class::Method::Modifiers>!
275 =head2 after (method|methods) => Code
277 Installs an "after" method modifier. See L<Moose/after> or
278 L<Class::Method::Modifiers/after>.
280 Use of this feature requires L<Class::Method::Modifiers>!
282 =head2 around (method|methods) => Code
284 Installs an "around" method modifier. See L<Moose/around> or
285 L<Class::Method::Modifiers/around>.
287 Use of this feature requires L<Class::Method::Modifiers>!
289 =head2 has (name|names) => parameters
291 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
298 If specified, inlines a read-only/read-write accessor with the same name as
301 =item isa => TypeConstraint
303 Provides basic type checking in the constructor and accessor. Basic types such
304 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
305 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
308 =item required => 0|1
310 Whether this attribute is required to have a value. If the attribute is lazy or
311 has a builder, then providing a value for the attribute in the constructor is
314 =item init_arg => Str | Undef
316 Allows you to use a different key name in the constructor. If undef, the
317 attribue can't be passed to the constructor.
319 =item default => Value | CodeRef
321 Sets the default value of the attribute. If the default is a coderef, it will
322 be invoked to get the default value. Due to quirks of Perl, any bare reference
323 is forbidden, you must wrap the reference in a coderef. Otherwise, all
324 instances will share the same reference.
328 If specified, the default is calculated on demand instead of in the
331 =item predicate => Str
333 Lets you specify a method name for installing a predicate method, which checks
334 that the attribute has a value. It will not invoke a lazy default or builder
339 Lets you specify a method name for installing a clearer method, which clears
340 the attribute's value from the instance. On the next read, lazy or builder will
343 =item handles => HashRef|ArrayRef
345 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
346 given method names to method calls on the attribute. HashRef maps local method
347 names to remote method names called on the attribute. Other forms of
348 L</handles>, such as regular expression and coderef, are not yet supported.
350 =item weak_ref => 0|1
352 Lets you automatically weaken any reference stored in the attribute.
354 Use of this feature requires L<Scalar::Util>!
356 =item trigger => CodeRef
358 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.
360 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
364 Defines a method name to be called to provide the default value of the
365 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
366 C<< default => sub { $_[0]->build_foo } >>.
368 =item auto_deref => 0|1
370 Allows you to automatically dereference ArrayRef and HashRef attributes in list
371 context. In scalar context, the reference is returned (NOT the list length or
372 bucket status). You must specify an appropriate type constraint to use
375 =item lazy_build => 0|1
377 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
378 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
382 =head2 confess error -> BOOM
384 L<Carp/confess> for your convenience.
386 =head2 blessed value -> ClassName | undef
388 L<Scalar::Util/blessed> for your convenience.
394 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
395 You may use L</extends> to replace the superclass list.
399 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
400 keywords (such as L</extends>) it will break loudly instead breaking subtly.
404 =head2 load_class Class::Name
406 This will load a given C<Class::Name> (or die if it's not loadable).
407 This function can be used in place of tricks like
408 C<eval "use $module"> or using C<require>.
410 =head2 is_class_loaded Class::Name -> Bool
412 Returns whether this class is actually loaded or not. It uses a heuristic which
413 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
414 locally-defined method.
418 Shawn M Moore, C<< <sartak at gmail.com> >>
420 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
426 with plenty of code borrowed from L<Class::MOP> and L<Moose>
432 Please report any bugs through RT: email
433 C<bug-mouse at rt.cpan.org>, or browse
434 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
436 =head1 COPYRIGHT AND LICENSE
438 Copyright 2008 Shawn M Moore.
440 This program is free software; you can redistribute it and/or modify it
441 under the same terms as Perl itself.