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 override super 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], @_);
85 # This check avoids a recursion loop - see
86 # t/100_bugs/020_super_recursion.t
87 return if defined $SUPER_PACKAGE && $SUPER_PACKAGE ne caller();
88 return unless $SUPER_BODY; $SUPER_BODY->(@SUPER_ARGS);
92 my $meta = Mouse::Meta::Class->initialize(caller);
93 my $pkg = $meta->name;
98 my $body = $pkg->can($name)
99 or confess "You cannot override '$name' because it has no super method";
101 $meta->add_method($name => sub {
102 local $SUPER_PACKAGE = $pkg;
103 local @SUPER_ARGS = @_;
104 local $SUPER_BODY = $body;
118 # we should never export to main
119 if ($caller eq 'main') {
120 warn qq{$class does not export its sugar to the 'main' package.\n};
124 my $meta = Mouse::Meta::Class->initialize($caller);
125 $meta->superclasses('Mouse::Object')
126 unless $meta->superclasses;
129 no warnings 'redefine';
130 *{$caller.'::meta'} = sub { $meta };
133 __PACKAGE__->export_to_level( 1, $class, @_);
135 # shortcut for the common case of no type character
137 for my $keyword (@EXPORT) {
138 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
147 for my $keyword (@EXPORT) {
148 delete ${ $caller . '::' }{$keyword};
155 if (ref($class) || !defined($class) || !length($class)) {
156 my $display = defined($class) ? $class : 'undef';
157 confess "Invalid class name ($display)";
160 return 1 if $class eq 'Mouse::Object';
161 return 1 if is_class_loaded($class);
163 (my $file = "$class.pm") =~ s{::}{/}g;
165 eval { CORE::require($file) };
166 confess "Could not load class ($class) because : $@" if $@;
171 sub is_class_loaded {
174 return 0 if ref($class) || !defined($class) || !length($class);
176 # walk the symbol table tree to avoid autovififying
177 # \*{${main::}{"Foo::"}} == \*main::Foo::
180 foreach my $part (split('::', $class)) {
181 return 0 unless exists ${$$pack}{"${part}::"};
182 $pack = \*{${$$pack}{"${part}::"}};
185 # check for $VERSION or @ISA
186 return 1 if exists ${$$pack}{VERSION}
187 && defined *{${$$pack}{VERSION}}{SCALAR};
188 return 1 if exists ${$$pack}{ISA}
189 && defined *{${$$pack}{ISA}}{ARRAY};
191 # check for any method
192 foreach ( keys %{$$pack} ) {
193 next if substr($_, -2, 2) eq '::';
194 return 1 if defined *{${$$pack}{$_}}{CODE};
207 Mouse - Moose minus the antlers
212 use Mouse; # automatically turns on strict and warnings
214 has 'x' => (is => 'rw', isa => 'Int');
215 has 'y' => (is => 'rw', isa => 'Int');
228 has 'z' => (is => 'rw', isa => 'Int');
230 after 'clear' => sub {
237 L<Moose> is wonderful.
239 Unfortunately, it's a little slow. Though significant progress has been made
240 over the years, the compile time penalty is a non-starter for some
243 Mouse aims to alleviate this by providing a subset of Moose's
244 functionality, faster. In particular, L<Moose/has> is missing only a few
245 expert-level features.
247 We're also going as light on dependencies as possible. Most functions we use
248 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
249 you'd like weak references; there's simply no way to do it from pure Perl.
250 L<Class::Method::Modifiers> is required if you want support for L</before>,
251 L</after>, and L</around>.
255 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
256 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
257 over 96%. Even the error messages are taken from Moose. The Mouse code just
258 runs the test suite 4x faster.
260 The idea is that, if you need the extra power, you should be able to run
261 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
262 nothingmuch has written L<Squirrel> (part of this distribution) which will act
263 as Mouse unless Moose is loaded, in which case it will act as Moose.
265 Mouse also has the blessings of Moose's author, stevan.
269 Please don't copy MooseX code to MouseX. If you need extensions, you really
270 should upgrade to Moose. We don't need two parallel sets of extensions!
272 If you really must write a Mouse extension, please contact the Moose mailing
273 list or #moose on IRC beforehand.
277 =head2 meta -> Mouse::Meta::Class
279 Returns this class' metaclass instance.
281 =head2 extends superclasses
283 Sets this class' superclasses.
285 =head2 before (method|methods) => Code
287 Installs a "before" method modifier. See L<Moose/before> or
288 L<Class::Method::Modifiers/before>.
290 Use of this feature requires L<Class::Method::Modifiers>!
292 =head2 after (method|methods) => Code
294 Installs an "after" method modifier. See L<Moose/after> or
295 L<Class::Method::Modifiers/after>.
297 Use of this feature requires L<Class::Method::Modifiers>!
299 =head2 around (method|methods) => Code
301 Installs an "around" method modifier. See L<Moose/around> or
302 L<Class::Method::Modifiers/around>.
304 Use of this feature requires L<Class::Method::Modifiers>!
306 =head2 has (name|names) => parameters
308 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
315 If specified, inlines a read-only/read-write accessor with the same name as
318 =item isa => TypeConstraint
320 Provides basic type checking in the constructor and accessor. Basic types such
321 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
322 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
325 =item required => 0|1
327 Whether this attribute is required to have a value. If the attribute is lazy or
328 has a builder, then providing a value for the attribute in the constructor is
331 =item init_arg => Str | Undef
333 Allows you to use a different key name in the constructor. If undef, the
334 attribue can't be passed to the constructor.
336 =item default => Value | CodeRef
338 Sets the default value of the attribute. If the default is a coderef, it will
339 be invoked to get the default value. Due to quirks of Perl, any bare reference
340 is forbidden, you must wrap the reference in a coderef. Otherwise, all
341 instances will share the same reference.
345 If specified, the default is calculated on demand instead of in the
348 =item predicate => Str
350 Lets you specify a method name for installing a predicate method, which checks
351 that the attribute has a value. It will not invoke a lazy default or builder
356 Lets you specify a method name for installing a clearer method, which clears
357 the attribute's value from the instance. On the next read, lazy or builder will
360 =item handles => HashRef|ArrayRef
362 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
363 given method names to method calls on the attribute. HashRef maps local method
364 names to remote method names called on the attribute. Other forms of
365 L</handles>, such as regular expression and coderef, are not yet supported.
367 =item weak_ref => 0|1
369 Lets you automatically weaken any reference stored in the attribute.
371 Use of this feature requires L<Scalar::Util>!
373 =item trigger => CodeRef
375 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.
377 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
381 Defines a method name to be called to provide the default value of the
382 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
383 C<< default => sub { $_[0]->build_foo } >>.
385 =item auto_deref => 0|1
387 Allows you to automatically dereference ArrayRef and HashRef attributes in list
388 context. In scalar context, the reference is returned (NOT the list length or
389 bucket status). You must specify an appropriate type constraint to use
392 =item lazy_build => 0|1
394 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
395 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
399 =head2 confess error -> BOOM
401 L<Carp/confess> for your convenience.
403 =head2 blessed value -> ClassName | undef
405 L<Scalar::Util/blessed> for your convenience.
411 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
412 You may use L</extends> to replace the superclass list.
416 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
417 keywords (such as L</extends>) it will break loudly instead breaking subtly.
421 =head2 load_class Class::Name
423 This will load a given C<Class::Name> (or die if it's not loadable).
424 This function can be used in place of tricks like
425 C<eval "use $module"> or using C<require>.
427 =head2 is_class_loaded Class::Name -> Bool
429 Returns whether this class is actually loaded or not. It uses a heuristic which
430 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
431 locally-defined method.
435 Shawn M Moore, C<< <sartak at gmail.com> >>
437 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
443 with plenty of code borrowed from L<Class::MOP> and L<Moose>
449 Please report any bugs through RT: email
450 C<bug-mouse at rt.cpan.org>, or browse
451 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
453 =head1 COPYRIGHT AND LICENSE
455 Copyright 2008 Shawn M Moore.
457 This program is free software; you can redistribute it and/or modify it
458 under the same terms as Perl itself.