14 if ($ENV{MOUSE_DEBUG}) {
20 if (! defined $PurePerl && $ENV{MOUSE_PUREPERL} && $ENV{MOUSE_PUREPERL} =~ /^(.+)$/) {
28 $PurePerl = ! eval{ XSLoader::load(__PACKAGE__, $VERSION); 1 };
29 warn "Failed to load XS mode: $@" if $@; # && Mouse::DEBUG();
34 use Mouse::Util 'blessed';
36 use Mouse::Meta::Attribute;
37 use Mouse::Meta::Class;
39 use Mouse::TypeRegistry;
41 our @EXPORT = qw(extends has before after around blessed confess with);
43 sub extends { Mouse::Meta::Class->initialize(caller)->superclasses(@_) }
46 my $meta = Mouse::Meta::Class->initialize(caller);
49 $names = [$names] if !ref($names);
51 for my $name (@$names) {
52 if ($name =~ s/^\+//) {
53 Mouse::Meta::Attribute->clone_parent($meta, $name, @_);
56 Mouse::Meta::Attribute->create($meta, $name, @_);
62 my $meta = Mouse::Meta::Class->initialize(caller);
67 $meta->add_before_method_modifier($_ => $code);
72 my $meta = Mouse::Meta::Class->initialize(caller);
77 $meta->add_after_method_modifier($_ => $code);
82 my $meta = Mouse::Meta::Class->initialize(caller);
87 $meta->add_around_method_modifier($_ => $code);
92 my $meta = Mouse::Meta::Class->initialize(caller);
95 my $args = shift || {};
97 confess "Mouse::Role only supports 'with' on individual roles at a time" if @_ || !ref $args;
99 Mouse::load_class($role);
100 $role->meta->apply($meta, %$args);
109 my $meta = Mouse::Meta::Class->initialize($caller);
110 $meta->superclasses('Mouse::Object')
111 unless $meta->superclasses;
114 no warnings 'redefine';
115 *{$caller.'::meta'} = sub { $meta };
117 __PACKAGE__->export_to_level( 1, @_);
124 for my $keyword (@EXPORT) {
125 delete ${ $caller . '::' }{$keyword};
132 if (ref($class) || !defined($class) || !length($class)) {
133 my $display = defined($class) ? $class : 'undef';
134 confess "Invalid class name ($display)";
137 return 1 if is_class_loaded($class);
139 (my $file = "$class.pm") =~ s{::}{/}g;
141 eval { CORE::require($file) };
142 confess "Could not load class ($class) because : $@" if $@;
147 sub is_class_loaded {
150 return 0 if ref($class) || !defined($class) || !length($class);
152 # walk the symbol table tree to avoid autovififying
153 # \*{${main::}{"Foo::"}} == \*main::Foo::
156 foreach my $part (split('::', $class)) {
157 return 0 unless exists ${$$pack}{"${part}::"};
158 $pack = \*{${$$pack}{"${part}::"}};
161 # check for $VERSION or @ISA
162 return 1 if exists ${$$pack}{VERSION}
163 && defined *{${$$pack}{VERSION}}{SCALAR};
164 return 1 if exists ${$$pack}{ISA}
165 && defined *{${$$pack}{ISA}}{ARRAY};
167 # check for any method
168 foreach ( keys %{$$pack} ) {
169 next if substr($_, -2, 2) eq '::';
170 return 1 if defined *{${$$pack}{$_}}{CODE};
183 Mouse - Moose minus the antlers
188 use Mouse; # automatically turns on strict and warnings
190 has 'x' => (is => 'rw', isa => 'Int');
191 has 'y' => (is => 'rw', isa => 'Int');
204 has 'z' => (is => 'rw', isa => 'Int');
206 after 'clear' => sub {
213 L<Moose> is wonderful.
215 Unfortunately, it's a little slow. Though significant progress has been made
216 over the years, the compile time penalty is a non-starter for some
219 Mouse aims to alleviate this by providing a subset of Moose's
220 functionality, faster. In particular, L<Moose/has> is missing only a few
221 expert-level features.
223 We're also going as light on dependencies as possible. Most functions we use
224 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
225 you'd like weak references; there's simply no way to do it from pure Perl.
226 L<Class::Method::Modifiers> is required if you want support for L</before>,
227 L</after>, and L</around>.
231 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
232 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
233 over 96%. Even the error messages are taken from Moose. The Mouse code just
234 runs the test suite 4x faster.
236 The idea is that, if you need the extra power, you should be able to run
237 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
238 nothingmuch has written L<Squirrel> (part of this distribution) which will act
239 as Mouse unless Moose is loaded, in which case it will act as Moose.
241 Mouse also has the blessings of Moose's author, stevan.
243 =head2 MISSING FEATURES
247 We're working on fixing this one! stevan has suggested an implementation
248 strategy. Mouse currently ignores methods, so that needs to be fixed next.
249 Roles that consist entirely of attributes may be usable in this very version.
253 User-defined type constraints and parameterized types may be implemented. Type
254 coercions probably not (patches welcome).
256 =head3 Bootstrapped meta world
258 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
260 =head3 Modification of attribute metaclass
262 When you declare an attribute with L</has>, you get the inlined accessors
263 installed immediately. Modifying the attribute metaclass, even if possible,
272 =head2 meta -> Mouse::Meta::Class
274 Returns this class' metaclass instance.
276 =head2 extends superclasses
278 Sets this class' superclasses.
280 =head2 before (method|methods) => Code
282 Installs a "before" method modifier. See L<Moose/before> or
283 L<Class::Method::Modifiers/before>.
285 Use of this feature requires L<Class::Method::Modifiers>!
287 =head2 after (method|methods) => Code
289 Installs an "after" method modifier. See L<Moose/after> or
290 L<Class::Method::Modifiers/after>.
292 Use of this feature requires L<Class::Method::Modifiers>!
294 =head2 around (method|methods) => Code
296 Installs an "around" method modifier. See L<Moose/around> or
297 L<Class::Method::Modifiers/around>.
299 Use of this feature requires L<Class::Method::Modifiers>!
301 =head2 has (name|names) => parameters
303 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
310 If specified, inlines a read-only/read-write accessor with the same name as
313 =item isa => TypeConstraint
315 Provides basic type checking in the constructor and accessor. Basic types such
316 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
317 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
320 =item required => 0|1
322 Whether this attribute is required to have a value. If the attribute is lazy or
323 has a builder, then providing a value for the attribute in the constructor is
326 =item init_arg => Str | Undef
328 Allows you to use a different key name in the constructor. If undef, the
329 attribue can't be passed to the constructor.
331 =item default => Value | CodeRef
333 Sets the default value of the attribute. If the default is a coderef, it will
334 be invoked to get the default value. Due to quirks of Perl, any bare reference
335 is forbidden, you must wrap the reference in a coderef. Otherwise, all
336 instances will share the same reference.
340 If specified, the default is calculated on demand instead of in the
343 =item predicate => Str
345 Lets you specify a method name for installing a predicate method, which checks
346 that the attribute has a value. It will not invoke a lazy default or builder
351 Lets you specify a method name for installing a clearer method, which clears
352 the attribute's value from the instance. On the next read, lazy or builder will
355 =item handles => HashRef|ArrayRef
357 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
358 given method names to method calls on the attribute. HashRef maps local method
359 names to remote method names called on the attribute. Other forms of
360 L</handles>, such as regular expression and coderef, are not yet supported.
362 =item weak_ref => 0|1
364 Lets you automatically weaken any reference stored in the attribute.
366 Use of this feature requires L<Scalar::Util>!
368 =item trigger => CodeRef
370 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.
372 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
376 Defines a method name to be called to provide the default value of the
377 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
378 C<< default => sub { $_[0]->build_foo } >>.
380 =item auto_deref => 0|1
382 Allows you to automatically dereference ArrayRef and HashRef attributes in list
383 context. In scalar context, the reference is returned (NOT the list length or
384 bucket status). You must specify an appropriate type constraint to use
387 =item lazy_build => 0|1
389 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
390 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
394 =head2 confess error -> BOOM
396 L<Carp/confess> for your convenience.
398 =head2 blessed value -> ClassName | undef
400 L<Scalar::Util/blessed> for your convenience.
406 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
407 You may use L</extends> to replace the superclass list.
411 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
412 keywords (such as L</extends>) it will break loudly instead breaking subtly.
416 =head2 load_class Class::Name
418 This will load a given C<Class::Name> (or die if it's not loadable).
419 This function can be used in place of tricks like
420 C<eval "use $module"> or using C<require>.
422 =head2 is_class_loaded Class::Name -> Bool
424 Returns whether this class is actually loaded or not. It uses a heuristic which
425 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
426 locally-defined method.
430 Shawn M Moore, C<< <sartak at gmail.com> >>
432 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
434 with plenty of code borrowed from L<Class::MOP> and L<Moose>
440 Please report any bugs through RT: email
441 C<bug-mouse at rt.cpan.org>, or browse
442 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
444 =head1 COPYRIGHT AND LICENSE
446 Copyright 2008 Shawn M Moore.
448 This program is free software; you can redistribute it and/or modify it
449 under the same terms as Perl itself.