7 our $VERSION = '0.009_017'; # 0.9.17
8 $VERSION = eval $VERSION;
10 require Moo::sification;
18 return if $MAKERS{$target}; # already exported into this package
19 _install_coderef "${target}::extends" => sub {
20 _load_module($_) for @_;
21 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
22 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
23 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
24 delete _getstash($target)->{new};
25 Moo->_constructor_maker_for($target)
26 ->register_attribute_specs(%{$old->all_attribute_specs});
29 _install_coderef "${target}::with" => sub {
31 Moo::Role->apply_roles_to_package($target, $_[0]);
33 $MAKERS{$target} = {};
34 _install_coderef "${target}::has" => sub {
35 my ($name, %spec) = @_;
36 ($MAKERS{$target}{accessor} ||= do {
37 require Method::Generate::Accessor;
38 Method::Generate::Accessor->new
39 })->generate_method($target, $name, \%spec);
40 $class->_constructor_maker_for($target)
41 ->register_attribute_specs($name, \%spec);
43 foreach my $type (qw(before after around)) {
44 _install_coderef "${target}::${type}" => sub {
45 require Class::Method::Modifiers;
46 _install_modifier($target, $type, @_);
51 @{"${target}::ISA"} = do {
52 require Moo::Object; ('Moo::Object');
53 } unless @{"${target}::ISA"};
55 if ($INC{'Moo/HandleMoose.pm'}) {
56 Moo::HandleMoose::inject_fake_metaclass_for($target);
60 sub _constructor_maker_for {
61 my ($class, $target, $select_super) = @_;
62 return unless $MAKERS{$target};
63 $MAKERS{$target}{constructor} ||= do {
64 require Method::Generate::Constructor;
66 my ($moo_constructor, $con);
68 if ($select_super && $MAKERS{$select_super}) {
70 $con = $MAKERS{$select_super}{constructor};
72 my $t_new = $target->can('new');
74 if ($t_new == Moo::Object->can('new')) {
76 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
77 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
80 $con = $MAKERS{$pkg}{constructor};
84 $moo_constructor = 1; # no other constructor, make a Moo one
87 Method::Generate::Constructor
90 accessor_generator => do {
91 require Method::Generate::Accessor;
92 Method::Generate::Accessor->new;
94 construction_string => (
96 ? ($con ? $con->construction_string : undef)
97 : ('$class->'.$target.'::SUPER::new(@_)')
99 subconstructor_handler => (
100 ' if ($Moo::MAKERS{$class}) {'."\n"
101 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
102 .' return $class->new(@_)'.";\n"
107 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
118 Moo - Minimalist Object Orientation (with Moose compatiblity)
129 my $amount = shift || 1;
131 $self->pounds( $self->pounds - $amount );
141 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
147 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
154 my $full = Cat::Food->new(
155 taste => 'DELICIOUS.',
156 brand => 'SWEET-TREATZ',
166 This module is an extremely light-weight, high-performance L<Moose> replacement.
167 It also avoids depending on any XS modules to allow simple deployments. The
168 name C<Moo> is based on the idea that it provides almost -but not quite- two
171 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
172 L</INCOMPATIBILITIES> for more details.
174 =head1 WHY MOO EXISTS
176 If you want a full object system with a rich Metaprotocol, L<Moose> is
179 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
180 takes longer to load than most of my Moo based CGI scripts take to run.
182 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
183 you want "as little as possible" - which means "no metaprotocol", which is
186 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
187 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
190 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
191 to make it smooth to upgrade to L<Moose> when you need more than minimal
194 =head1 IMPORTED METHODS
198 Foo::Bar->new( attr1 => 3 );
202 Foo::Bar->new({ attr1 => 3 });
207 my ( $class, @args ) = @_;
209 unshift @args, "attr1" if @args % 2 == 1;
216 The default implementation of this method accepts a hash or hash reference of
217 named parameters. If it receives a single argument that isn't a hash reference
220 You can override this method in your class to handle other types of options
221 passed to the constructor.
223 This method should always return a hash reference of named options.
227 Define a C<BUILD> method on your class and the constructor will automatically
228 call the C<BUILD> method from parent down to child after the object has
229 been instantiated. Typically this is used for object validation or possibly
234 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
235 a C<DESTROY> method is created on first object construction which will call
236 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
237 method from child upwards to parents.
239 Note that the C<DESTROY> method is created on first construction of an object
240 of your class in order to not add overhead to classes without C<DEMOLISH>
241 methods; this may prove slightly surprising if you try and define your own.
245 if ($foo->does('Some::Role1')) {
249 Returns true if the object composes in the passed role.
251 =head1 IMPORTED SUBROUTINES
255 extends 'Parent::Class';
257 Declares base class. Multiple superclasses can be passed for multiple
258 inheritance (but please use roles instead).
260 Calling extends more than once will REPLACE your superclasses, not add to
261 them like 'use base' would.
268 Composes a L<Role::Tiny> into current class. Only one role may be composed in
269 at a time to allow the code to remain as simple as possible.
277 Declares an attribute for the class.
279 The options for C<has> are as follows:
285 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
286 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
287 will create a perlish getter/setter.
291 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
292 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
296 die "$_[0] is not a number!" unless looks_like_number $_[0]
299 L<Sub::Quote aware|/SUB QUOTE AWARE>
303 Takes a coderef which is meant to coerce the attribute. The basic idea is to
304 do something like the following:
306 coerce => quote_sub q{
307 $_[0] + 1 unless $_[0] % 2
310 Coerce does not require C<isa> to be defined.
312 L<Sub::Quote aware|/SUB QUOTE AWARE>
318 handles => 'RobotRole'
320 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
321 becomes the list of methods to handle.
323 Takes a list of methods
325 handles => [ qw( one two ) ]
335 Takes a coderef which will get called any time the attribute is set. This
336 includes the constructor. Coderef will be invoked against the object with the
337 new value as an argument.
339 Note that Moose also passes the old value, if any; this feature is not yet
342 L<Sub::Quote aware|/SUB QUOTE AWARE>
346 Takes a coderef which will get called with $self as its only argument
347 to populate an attribute if no value is supplied to the constructor - or
348 if the attribute is lazy, when the attribute is first retrieved if no
349 value has yet been provided.
351 Note that if your default is fired during new() there is no guarantee that
352 other attributes have been populated yet so you should not rely on their
355 L<Sub::Quote aware|/SUB QUOTE AWARE>
359 Takes a method name which will return true if an attribute has a value.
361 A common example of this would be to call it C<has_$foo>, implying that the
362 object has a C<$foo> set.
366 Takes a method name which will be called to create the attribute - functions
367 exactly like default except that instead of calling
377 Takes a method name which will clear the attribute.
381 B<Boolean>. Set this if you want values for the attribute to be grabbed
382 lazily. This is usually a good idea if you have a L</builder> which requires
383 another attribute to be set.
387 B<Boolean>. Set this if the attribute must be passed on instantiation.
391 The value of this attribute will be the name of the method to get the value of
392 the attribute. If you like Java style methods, you might set this to
397 The value of this attribute will be the name of the method to set the value of
398 the attribute. If you like Java style methods, you might set this to
403 B<Boolean>. Set this if you want the reference that the attribute contains to
404 be weakened; use this when circular references are possible, which will cause
409 Takes the name of the key to look for at instantiation time of the object. A
410 common use of this is to make an underscored attribute have a non-underscored
411 initialization name. C<undef> means that passing the value in on instantiation
417 before foo => sub { ... };
419 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
424 around foo => sub { ... };
426 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
431 after foo => sub { ... };
433 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
436 =head1 SUB QUOTE AWARE
438 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
439 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
440 aware can take advantage of this.
442 =head1 INCOMPATIBILITIES WITH MOOSE
444 You can only compose one role at a time. If your application is large or
445 complex enough to warrant complex composition, you wanted L<Moose>. Note that
446 this does not mean you can only compose one role per class -
451 is absolutely fine, there's just currently no equivalent of Moose's
453 with 'FirstRole', 'SecondRole';
455 which composes the two roles together, and then applies them.
457 There is no built in type system. C<isa> is verified with a coderef, if you
458 need complex types, just make a library of coderefs, or better yet, functions
459 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
460 to L<MooseX::Types::Moose> so that you can write
462 has days_to_live => (is => 'ro', isa => Int);
464 and have it work with both; it is hoped that providing only subrefs as an
465 API will encourage the use of other type systems as well, since it's
466 probably the weakest part of Moose design-wise.
468 C<initializer> is not supported in core since the author considers it to be a
469 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
470 C<coerce> are more likely to be able to fulfill your needs.
472 There is no meta object. If you need this level of complexity you wanted
473 L<Moose> - Moo succeeds at being small because it explicitly does not
474 provide a metaprotocol.
476 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
477 be handled by around albeit with a little more typing, and the author considers
478 augment to be a bad idea.
480 The C<dump> method is not provided by default. The author suggests loading
481 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
482 using C<$obj-E<gt>$::Dwarn()> instead.
484 L</default> only supports coderefs, because doing otherwise is usually a
487 C<lazy_build> is not supported per se, but of course it will work if you
488 manually set all the options it implies.
490 C<auto_deref> is not supported since the author considers it a bad idea.
492 C<documentation> is not supported since it's a very poor replacement for POD.
494 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
495 similar invocation for L<Moose> would be:
498 use warnings FATAL => "all";
500 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
501 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
502 module L<MooseX::AttributeShortcuts>. So if you:
507 The nearest L<Moose> invocation would be:
512 use warnings FATAL => "all";
513 use MooseX::AttributeShortcuts;
515 or, if you're inheriting from a non-Moose class,
520 use MooseX::NonMoose;
521 use warnings FATAL => "all";
522 use MooseX::AttributeShortcuts;
524 Finally, Moose requires you to call
526 __PACKAGE__->meta->make_immutable;
528 at the end of your class to get an inlined (i.e. not horribly slow)
529 constructor. Moo does it automatically the first time ->new is called
534 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
538 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
540 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
542 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
544 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
546 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
548 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
550 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
552 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
554 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
558 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
563 This library is free software and may be distributed under the same terms