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 Mouse::Util::apply_all_roles((caller)[0], @_);
103 my $meta = Mouse::Meta::Class->initialize($caller);
104 $meta->superclasses('Mouse::Object')
105 unless $meta->superclasses;
108 no warnings 'redefine';
109 *{$caller.'::meta'} = sub { $meta };
112 __PACKAGE__->export_to_level( 1, $class, @_);
114 # shortcut for the common case of no type character
116 for my $keyword (@EXPORT) {
117 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
126 for my $keyword (@EXPORT) {
127 delete ${ $caller . '::' }{$keyword};
134 if (ref($class) || !defined($class) || !length($class)) {
135 my $display = defined($class) ? $class : 'undef';
136 confess "Invalid class name ($display)";
139 return 1 if is_class_loaded($class);
141 (my $file = "$class.pm") =~ s{::}{/}g;
143 eval { CORE::require($file) };
144 confess "Could not load class ($class) because : $@" if $@;
149 sub is_class_loaded {
152 return 0 if ref($class) || !defined($class) || !length($class);
154 # walk the symbol table tree to avoid autovififying
155 # \*{${main::}{"Foo::"}} == \*main::Foo::
158 foreach my $part (split('::', $class)) {
159 return 0 unless exists ${$$pack}{"${part}::"};
160 $pack = \*{${$$pack}{"${part}::"}};
163 # check for $VERSION or @ISA
164 return 1 if exists ${$$pack}{VERSION}
165 && defined *{${$$pack}{VERSION}}{SCALAR};
166 return 1 if exists ${$$pack}{ISA}
167 && defined *{${$$pack}{ISA}}{ARRAY};
169 # check for any method
170 foreach ( keys %{$$pack} ) {
171 next if substr($_, -2, 2) eq '::';
172 return 1 if defined *{${$$pack}{$_}}{CODE};
185 Mouse - Moose minus the antlers
190 use Mouse; # automatically turns on strict and warnings
192 has 'x' => (is => 'rw', isa => 'Int');
193 has 'y' => (is => 'rw', isa => 'Int');
206 has 'z' => (is => 'rw', isa => 'Int');
208 after 'clear' => sub {
215 L<Moose> is wonderful.
217 Unfortunately, it's a little slow. Though significant progress has been made
218 over the years, the compile time penalty is a non-starter for some
221 Mouse aims to alleviate this by providing a subset of Moose's
222 functionality, faster. In particular, L<Moose/has> is missing only a few
223 expert-level features.
225 We're also going as light on dependencies as possible. Most functions we use
226 from L<Scalar::Util> are copied into this dist. L<Scalar::Util> is required if
227 you'd like weak references; there's simply no way to do it from pure Perl.
228 L<Class::Method::Modifiers> is required if you want support for L</before>,
229 L</after>, and L</around>.
233 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
234 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
235 over 96%. Even the error messages are taken from Moose. The Mouse code just
236 runs the test suite 4x faster.
238 The idea is that, if you need the extra power, you should be able to run
239 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
240 nothingmuch has written L<Squirrel> (part of this distribution) which will act
241 as Mouse unless Moose is loaded, in which case it will act as Moose.
243 Mouse also has the blessings of Moose's author, stevan.
245 =head2 MISSING FEATURES
249 We're working on fixing this one! stevan has suggested an implementation
250 strategy. Mouse currently ignores methods, so that needs to be fixed next.
251 Roles that consist entirely of attributes may be usable in this very version.
255 User-defined type constraints and parameterized types may be implemented. Type
256 coercions probably not (patches welcome).
258 =head3 Bootstrapped meta world
260 Very handy for extensions to the MOP. Not pressing, but would be nice to have.
262 =head3 Modification of attribute metaclass
264 When you declare an attribute with L</has>, you get the inlined accessors
265 installed immediately. Modifying the attribute metaclass, even if possible,
274 =head2 meta -> Mouse::Meta::Class
276 Returns this class' metaclass instance.
278 =head2 extends superclasses
280 Sets this class' superclasses.
282 =head2 before (method|methods) => Code
284 Installs a "before" method modifier. See L<Moose/before> or
285 L<Class::Method::Modifiers/before>.
287 Use of this feature requires L<Class::Method::Modifiers>!
289 =head2 after (method|methods) => Code
291 Installs an "after" method modifier. See L<Moose/after> or
292 L<Class::Method::Modifiers/after>.
294 Use of this feature requires L<Class::Method::Modifiers>!
296 =head2 around (method|methods) => Code
298 Installs an "around" method modifier. See L<Moose/around> or
299 L<Class::Method::Modifiers/around>.
301 Use of this feature requires L<Class::Method::Modifiers>!
303 =head2 has (name|names) => parameters
305 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
312 If specified, inlines a read-only/read-write accessor with the same name as
315 =item isa => TypeConstraint
317 Provides basic type checking in the constructor and accessor. Basic types such
318 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
319 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
322 =item required => 0|1
324 Whether this attribute is required to have a value. If the attribute is lazy or
325 has a builder, then providing a value for the attribute in the constructor is
328 =item init_arg => Str | Undef
330 Allows you to use a different key name in the constructor. If undef, the
331 attribue can't be passed to the constructor.
333 =item default => Value | CodeRef
335 Sets the default value of the attribute. If the default is a coderef, it will
336 be invoked to get the default value. Due to quirks of Perl, any bare reference
337 is forbidden, you must wrap the reference in a coderef. Otherwise, all
338 instances will share the same reference.
342 If specified, the default is calculated on demand instead of in the
345 =item predicate => Str
347 Lets you specify a method name for installing a predicate method, which checks
348 that the attribute has a value. It will not invoke a lazy default or builder
353 Lets you specify a method name for installing a clearer method, which clears
354 the attribute's value from the instance. On the next read, lazy or builder will
357 =item handles => HashRef|ArrayRef
359 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
360 given method names to method calls on the attribute. HashRef maps local method
361 names to remote method names called on the attribute. Other forms of
362 L</handles>, such as regular expression and coderef, are not yet supported.
364 =item weak_ref => 0|1
366 Lets you automatically weaken any reference stored in the attribute.
368 Use of this feature requires L<Scalar::Util>!
370 =item trigger => CodeRef
372 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.
374 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
378 Defines a method name to be called to provide the default value of the
379 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
380 C<< default => sub { $_[0]->build_foo } >>.
382 =item auto_deref => 0|1
384 Allows you to automatically dereference ArrayRef and HashRef attributes in list
385 context. In scalar context, the reference is returned (NOT the list length or
386 bucket status). You must specify an appropriate type constraint to use
389 =item lazy_build => 0|1
391 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
392 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
396 =head2 confess error -> BOOM
398 L<Carp/confess> for your convenience.
400 =head2 blessed value -> ClassName | undef
402 L<Scalar::Util/blessed> for your convenience.
408 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
409 You may use L</extends> to replace the superclass list.
413 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
414 keywords (such as L</extends>) it will break loudly instead breaking subtly.
418 =head2 load_class Class::Name
420 This will load a given C<Class::Name> (or die if it's not loadable).
421 This function can be used in place of tricks like
422 C<eval "use $module"> or using C<require>.
424 =head2 is_class_loaded Class::Name -> Bool
426 Returns whether this class is actually loaded or not. It uses a heuristic which
427 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
428 locally-defined method.
432 Shawn M Moore, C<< <sartak at gmail.com> >>
434 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
436 with plenty of code borrowed from L<Class::MOP> and L<Moose>
442 Please report any bugs through RT: email
443 C<bug-mouse at rt.cpan.org>, or browse
444 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
446 =head1 COPYRIGHT AND LICENSE
448 Copyright 2008 Shawn M Moore.
450 This program is free software; you can redistribute it and/or modify it
451 under the same terms as Perl itself.