11 use Scalar::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.
201 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
202 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
203 over 97%. Even the error messages are taken from Moose. The Mouse code just
204 runs the test suite 3x-4x faster.
206 The idea is that, if you need the extra power, you should be able to run
207 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
208 nothingmuch has written L<Squirrel> (part of this distribution) which will act
209 as Mouse unless Moose is loaded, in which case it will act as Moose.
211 Mouse also has the blessings of Moose's author, stevan.
213 =head2 MISSING FEATURES
217 We're working on fixing this one! stevan has suggested an implementation
218 strategy. Mouse currently ignores methods, so that needs to be fixed next.
219 Roles that consist entirely of attributes may be usable in this very version.
223 User-defined type constraints and parameterized types may be implemented. Type
224 coercions probably not (patches welcome).
226 =head3 Bootstrapped meta world
228 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
230 =head3 Modification of attribute metaclass
232 When you declare an attribute with L</has>, you get the inlined accessors
233 installed immediately. Modifying the attribute metaclass, even if possible,
242 =head2 meta -> Mouse::Meta::Class
244 Returns this class' metaclass instance.
246 =head2 extends superclasses
248 Sets this class' superclasses.
250 =head2 before (method|methods) => Code
252 Installs a "before" method modifier. See L<Moose/before> or
253 L<Class::Method::Modifiers/before>.
255 =head2 after (method|methods) => Code
257 Installs an "after" method modifier. See L<Moose/after> or
258 L<Class::Method::Modifiers/after>.
260 =head2 around (method|methods) => Code
262 Installs an "around" method modifier. See L<Moose/around> or
263 L<Class::Method::Modifiers/around>.
265 =head2 has (name|names) => parameters
267 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
274 If specified, inlines a read-only/read-write accessor with the same name as
277 =item isa => TypeConstraint
279 Provides basic type checking in the constructor and accessor. Basic types such
280 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
281 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
284 =item required => 0|1
286 Whether this attribute is required to have a value. If the attribute is lazy or
287 has a builder, then providing a value for the attribute in the constructor is
290 =item init_arg => Str
292 Allows you to use a different key name in the constructor.
294 =item default => Value | CodeRef
296 Sets the default value of the attribute. If the default is a coderef, it will
297 be invoked to get the default value. Due to quirks of Perl, any bare reference
298 is forbidden, you must wrap the reference in a coderef. Otherwise, all
299 instances will share the same reference.
303 If specified, the default is calculated on demand instead of in the
306 =item predicate => Str
308 Lets you specify a method name for installing a predicate method, which checks
309 that the attribute has a value. It will not invoke a lazy default or builder
314 Lets you specify a method name for installing a clearer method, which clears
315 the attribute's value from the instance. On the next read, lazy or builder will
318 =item handles => HashRef|ArrayRef
320 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
321 given method names to method calls on the attribute. HashRef maps local method
322 names to remote method names called on the attribute. Other forms of
323 L</handles>, such as regular expression and coderef, are not yet supported.
325 =item weak_ref => 0|1
327 Lets you automatically weaken any reference stored in the attribute.
329 =item trigger => CodeRef
331 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.
333 Mouse 0.05 supported more complex triggers, but this behavior is now deprecated.
337 Defines a method name to be called to provide the default value of the
338 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
339 C<< default => sub { $_[0]->build_foo } >>.
341 =item auto_deref => 0|1
343 Allows you to automatically dereference ArrayRef and HashRef attributes in list
344 context. In scalar context, the reference is returned (NOT the list length or
345 bucket status). You must specify an appropriate type constraint to use
350 =head2 confess error -> BOOM
352 L<Carp/confess> for your convenience.
354 =head2 blessed value -> ClassName | undef
356 L<Scalar::Util/blessed> for your convenience.
362 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
363 You may use L</extends> to replace the superclass list.
367 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
368 keywords (such as L</extends>) it will break loudly instead breaking subtly.
372 =head2 load_class Class::Name
374 This will load a given C<Class::Name> (or die if it's not loadable).
375 This function can be used in place of tricks like
376 C<eval "use $module"> or using C<require>.
378 =head2 is_class_loaded Class::Name -> Bool
380 Returns whether this class is actually loaded or not. It uses a heuristic which
381 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
382 locally-defined method.
386 Shawn M Moore, C<< <sartak at gmail.com> >>
388 with plenty of code borrowed from L<Class::MOP> and L<Moose>
394 Please report any bugs through RT: email
395 C<bug-mouse at rt.cpan.org>, or browse
396 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
398 =head1 COPYRIGHT AND LICENSE
400 Copyright 2008 Shawn M Moore.
402 This program is free software; you can redistribute it and/or modify it
403 under the same terms as Perl itself.