10 if ($ENV{MOUSE_DEBUG}) {
18 use Scalar::Util 'blessed';
21 use Mouse::Meta::Attribute;
22 use Mouse::Meta::Class;
24 use Mouse::Util::TypeConstraints;
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 $meta->add_around_method_modifier($_ => $code);
77 Mouse::Util::apply_all_roles((caller)[0], @_);
88 # we should never export to main
89 if ($caller eq 'main') {
90 warn qq{$class does not export its sugar to the 'main' package.\n};
94 my $meta = Mouse::Meta::Class->initialize($caller);
95 $meta->superclasses('Mouse::Object')
96 unless $meta->superclasses;
99 no warnings 'redefine';
100 *{$caller.'::meta'} = sub { $meta };
103 __PACKAGE__->export_to_level( 1, $class, @_);
105 # shortcut for the common case of no type character
107 for my $keyword (@EXPORT) {
108 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
117 for my $keyword (@EXPORT) {
118 delete ${ $caller . '::' }{$keyword};
125 if (ref($class) || !defined($class) || !length($class)) {
126 my $display = defined($class) ? $class : 'undef';
127 confess "Invalid class name ($display)";
130 return 1 if $class eq 'Mouse::Object';
131 return 1 if is_class_loaded($class);
133 (my $file = "$class.pm") =~ s{::}{/}g;
135 eval { CORE::require($file) };
136 confess "Could not load class ($class) because : $@" if $@;
141 sub is_class_loaded {
144 return 0 if ref($class) || !defined($class) || !length($class);
146 # walk the symbol table tree to avoid autovififying
147 # \*{${main::}{"Foo::"}} == \*main::Foo::
150 foreach my $part (split('::', $class)) {
151 return 0 unless exists ${$$pack}{"${part}::"};
152 $pack = \*{${$$pack}{"${part}::"}};
155 # check for $VERSION or @ISA
156 return 1 if exists ${$$pack}{VERSION}
157 && defined *{${$$pack}{VERSION}}{SCALAR};
158 return 1 if exists ${$$pack}{ISA}
159 && defined *{${$$pack}{ISA}}{ARRAY};
161 # check for any method
162 foreach ( keys %{$$pack} ) {
163 next if substr($_, -2, 2) eq '::';
164 return 1 if defined *{${$$pack}{$_}}{CODE};
177 Mouse - Moose minus the antlers
182 use Mouse; # automatically turns on strict and warnings
184 has 'x' => (is => 'rw', isa => 'Int');
185 has 'y' => (is => 'rw', isa => 'Int');
198 has 'z' => (is => 'rw', isa => 'Int');
200 after 'clear' => sub {
207 L<Moose> is wonderful.
209 Unfortunately, it's a little slow. Though significant progress has been made
210 over the years, the compile time penalty is a non-starter for some
213 Mouse aims to alleviate this by providing a subset of Moose's
214 functionality, faster. In particular, L<Moose/has> is missing only a few
215 expert-level features.
217 We're also going as light on dependencies as possible. Most functions we use
218 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
219 you'd like weak references; there's simply no way to do it from pure Perl.
220 L<Class::Method::Modifiers> is required if you want support for L</before>,
221 L</after>, and L</around>.
225 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
226 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
227 over 96%. Even the error messages are taken from Moose. The Mouse code just
228 runs the test suite 4x faster.
230 The idea is that, if you need the extra power, you should be able to run
231 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
232 nothingmuch has written L<Squirrel> (part of this distribution) which will act
233 as Mouse unless Moose is loaded, in which case it will act as Moose.
235 Mouse also has the blessings of Moose's author, stevan.
239 Please don't copy MooseX code to MouseX. If you need extensions, you really
240 should upgrade to Moose. We don't need two parallel sets of extensions!
242 If you really must write a Mouse extension, please contact the Moose mailing
243 list or #moose on IRC beforehand.
247 =head2 meta -> Mouse::Meta::Class
249 Returns this class' metaclass instance.
251 =head2 extends superclasses
253 Sets this class' superclasses.
255 =head2 before (method|methods) => Code
257 Installs a "before" method modifier. See L<Moose/before> or
258 L<Class::Method::Modifiers/before>.
260 Use of this feature requires L<Class::Method::Modifiers>!
262 =head2 after (method|methods) => Code
264 Installs an "after" method modifier. See L<Moose/after> or
265 L<Class::Method::Modifiers/after>.
267 Use of this feature requires L<Class::Method::Modifiers>!
269 =head2 around (method|methods) => Code
271 Installs an "around" method modifier. See L<Moose/around> or
272 L<Class::Method::Modifiers/around>.
274 Use of this feature requires L<Class::Method::Modifiers>!
276 =head2 has (name|names) => parameters
278 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
285 If specified, inlines a read-only/read-write accessor with the same name as
288 =item isa => TypeConstraint
290 Provides basic type checking in the constructor and accessor. Basic types such
291 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
292 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
295 =item required => 0|1
297 Whether this attribute is required to have a value. If the attribute is lazy or
298 has a builder, then providing a value for the attribute in the constructor is
301 =item init_arg => Str | Undef
303 Allows you to use a different key name in the constructor. If undef, the
304 attribue can't be passed to the constructor.
306 =item default => Value | CodeRef
308 Sets the default value of the attribute. If the default is a coderef, it will
309 be invoked to get the default value. Due to quirks of Perl, any bare reference
310 is forbidden, you must wrap the reference in a coderef. Otherwise, all
311 instances will share the same reference.
315 If specified, the default is calculated on demand instead of in the
318 =item predicate => Str
320 Lets you specify a method name for installing a predicate method, which checks
321 that the attribute has a value. It will not invoke a lazy default or builder
326 Lets you specify a method name for installing a clearer method, which clears
327 the attribute's value from the instance. On the next read, lazy or builder will
330 =item handles => HashRef|ArrayRef
332 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
333 given method names to method calls on the attribute. HashRef maps local method
334 names to remote method names called on the attribute. Other forms of
335 L</handles>, such as regular expression and coderef, are not yet supported.
337 =item weak_ref => 0|1
339 Lets you automatically weaken any reference stored in the attribute.
341 Use of this feature requires L<Scalar::Util>!
343 =item trigger => CodeRef
345 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.
347 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
351 Defines a method name to be called to provide the default value of the
352 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
353 C<< default => sub { $_[0]->build_foo } >>.
355 =item auto_deref => 0|1
357 Allows you to automatically dereference ArrayRef and HashRef attributes in list
358 context. In scalar context, the reference is returned (NOT the list length or
359 bucket status). You must specify an appropriate type constraint to use
362 =item lazy_build => 0|1
364 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
365 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
369 =head2 confess error -> BOOM
371 L<Carp/confess> for your convenience.
373 =head2 blessed value -> ClassName | undef
375 L<Scalar::Util/blessed> for your convenience.
381 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
382 You may use L</extends> to replace the superclass list.
386 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
387 keywords (such as L</extends>) it will break loudly instead breaking subtly.
391 =head2 load_class Class::Name
393 This will load a given C<Class::Name> (or die if it's not loadable).
394 This function can be used in place of tricks like
395 C<eval "use $module"> or using C<require>.
397 =head2 is_class_loaded Class::Name -> Bool
399 Returns whether this class is actually loaded or not. It uses a heuristic which
400 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
401 locally-defined method.
405 Shawn M Moore, C<< <sartak at gmail.com> >>
407 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
413 with plenty of code borrowed from L<Class::MOP> and L<Moose>
419 Please report any bugs through RT: email
420 C<bug-mouse at rt.cpan.org>, or browse
421 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
423 =head1 COPYRIGHT AND LICENSE
425 Copyright 2008 Shawn M Moore.
427 This program is free software; you can redistribute it and/or modify it
428 under the same terms as Perl itself.