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);
111 my $meta = Mouse::Meta::Class->initialize($caller);
112 $meta->superclasses('Mouse::Object')
113 unless $meta->superclasses;
116 no warnings 'redefine';
117 *{$caller.'::meta'} = sub { $meta };
120 __PACKAGE__->export_to_level( 1, $class, @_);
122 # shortcut for the common case of no type character
124 for my $keyword (@EXPORT) {
125 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
134 for my $keyword (@EXPORT) {
135 delete ${ $caller . '::' }{$keyword};
142 if (ref($class) || !defined($class) || !length($class)) {
143 my $display = defined($class) ? $class : 'undef';
144 confess "Invalid class name ($display)";
147 return 1 if is_class_loaded($class);
149 (my $file = "$class.pm") =~ s{::}{/}g;
151 eval { CORE::require($file) };
152 confess "Could not load class ($class) because : $@" if $@;
157 sub is_class_loaded {
160 return 0 if ref($class) || !defined($class) || !length($class);
162 # walk the symbol table tree to avoid autovififying
163 # \*{${main::}{"Foo::"}} == \*main::Foo::
166 foreach my $part (split('::', $class)) {
167 return 0 unless exists ${$$pack}{"${part}::"};
168 $pack = \*{${$$pack}{"${part}::"}};
171 # check for $VERSION or @ISA
172 return 1 if exists ${$$pack}{VERSION}
173 && defined *{${$$pack}{VERSION}}{SCALAR};
174 return 1 if exists ${$$pack}{ISA}
175 && defined *{${$$pack}{ISA}}{ARRAY};
177 # check for any method
178 foreach ( keys %{$$pack} ) {
179 next if substr($_, -2, 2) eq '::';
180 return 1 if defined *{${$$pack}{$_}}{CODE};
193 Mouse - Moose minus the antlers
198 use Mouse; # automatically turns on strict and warnings
200 has 'x' => (is => 'rw', isa => 'Int');
201 has 'y' => (is => 'rw', isa => 'Int');
214 has 'z' => (is => 'rw', isa => 'Int');
216 after 'clear' => sub {
223 L<Moose> is wonderful.
225 Unfortunately, it's a little slow. Though significant progress has been made
226 over the years, the compile time penalty is a non-starter for some
229 Mouse aims to alleviate this by providing a subset of Moose's
230 functionality, faster. In particular, L<Moose/has> is missing only a few
231 expert-level features.
233 We're also going as light on dependencies as possible. Most functions we use
234 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
235 you'd like weak references; there's simply no way to do it from pure Perl.
236 L<Class::Method::Modifiers> is required if you want support for L</before>,
237 L</after>, and L</around>.
241 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
242 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
243 over 96%. Even the error messages are taken from Moose. The Mouse code just
244 runs the test suite 4x faster.
246 The idea is that, if you need the extra power, you should be able to run
247 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
248 nothingmuch has written L<Squirrel> (part of this distribution) which will act
249 as Mouse unless Moose is loaded, in which case it will act as Moose.
251 Mouse also has the blessings of Moose's author, stevan.
253 =head2 MISSING FEATURES
257 We're working on fixing this one! stevan has suggested an implementation
258 strategy. Mouse currently ignores methods, so that needs to be fixed next.
259 Roles that consist entirely of attributes may be usable in this very version.
263 User-defined type constraints and parameterized types may be implemented. Type
264 coercions probably not (patches welcome).
266 =head3 Bootstrapped meta world
268 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
270 =head3 Modification of attribute metaclass
272 When you declare an attribute with L</has>, you get the inlined accessors
273 installed immediately. Modifying the attribute metaclass, even if possible,
282 =head2 meta -> Mouse::Meta::Class
284 Returns this class' metaclass instance.
286 =head2 extends superclasses
288 Sets this class' superclasses.
290 =head2 before (method|methods) => Code
292 Installs a "before" method modifier. See L<Moose/before> or
293 L<Class::Method::Modifiers/before>.
295 Use of this feature requires L<Class::Method::Modifiers>!
297 =head2 after (method|methods) => Code
299 Installs an "after" method modifier. See L<Moose/after> or
300 L<Class::Method::Modifiers/after>.
302 Use of this feature requires L<Class::Method::Modifiers>!
304 =head2 around (method|methods) => Code
306 Installs an "around" method modifier. See L<Moose/around> or
307 L<Class::Method::Modifiers/around>.
309 Use of this feature requires L<Class::Method::Modifiers>!
311 =head2 has (name|names) => parameters
313 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
320 If specified, inlines a read-only/read-write accessor with the same name as
323 =item isa => TypeConstraint
325 Provides basic type checking in the constructor and accessor. Basic types such
326 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
327 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
330 =item required => 0|1
332 Whether this attribute is required to have a value. If the attribute is lazy or
333 has a builder, then providing a value for the attribute in the constructor is
336 =item init_arg => Str | Undef
338 Allows you to use a different key name in the constructor. If undef, the
339 attribue can't be passed to the constructor.
341 =item default => Value | CodeRef
343 Sets the default value of the attribute. If the default is a coderef, it will
344 be invoked to get the default value. Due to quirks of Perl, any bare reference
345 is forbidden, you must wrap the reference in a coderef. Otherwise, all
346 instances will share the same reference.
350 If specified, the default is calculated on demand instead of in the
353 =item predicate => Str
355 Lets you specify a method name for installing a predicate method, which checks
356 that the attribute has a value. It will not invoke a lazy default or builder
361 Lets you specify a method name for installing a clearer method, which clears
362 the attribute's value from the instance. On the next read, lazy or builder will
365 =item handles => HashRef|ArrayRef
367 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
368 given method names to method calls on the attribute. HashRef maps local method
369 names to remote method names called on the attribute. Other forms of
370 L</handles>, such as regular expression and coderef, are not yet supported.
372 =item weak_ref => 0|1
374 Lets you automatically weaken any reference stored in the attribute.
376 Use of this feature requires L<Scalar::Util>!
378 =item trigger => CodeRef
380 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.
382 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
386 Defines a method name to be called to provide the default value of the
387 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
388 C<< default => sub { $_[0]->build_foo } >>.
390 =item auto_deref => 0|1
392 Allows you to automatically dereference ArrayRef and HashRef attributes in list
393 context. In scalar context, the reference is returned (NOT the list length or
394 bucket status). You must specify an appropriate type constraint to use
397 =item lazy_build => 0|1
399 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
400 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
404 =head2 confess error -> BOOM
406 L<Carp/confess> for your convenience.
408 =head2 blessed value -> ClassName | undef
410 L<Scalar::Util/blessed> for your convenience.
416 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
417 You may use L</extends> to replace the superclass list.
421 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
422 keywords (such as L</extends>) it will break loudly instead breaking subtly.
426 =head2 load_class Class::Name
428 This will load a given C<Class::Name> (or die if it's not loadable).
429 This function can be used in place of tricks like
430 C<eval "use $module"> or using C<require>.
432 =head2 is_class_loaded Class::Name -> Bool
434 Returns whether this class is actually loaded or not. It uses a heuristic which
435 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
436 locally-defined method.
440 Shawn M Moore, C<< <sartak at gmail.com> >>
442 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
444 with plenty of code borrowed from L<Class::MOP> and L<Moose>
450 Please report any bugs through RT: email
451 C<bug-mouse at rt.cpan.org>, or browse
452 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
454 =head1 COPYRIGHT AND LICENSE
456 Copyright 2008 Shawn M Moore.
458 This program is free software; you can redistribute it and/or modify it
459 under the same terms as Perl itself.