7 our $VERSION = '0.009_016'; # 0.9.16
8 $VERSION = eval $VERSION;
10 require Moo::sification;
18 return if $MAKERS{$target}; # already exported into this package
19 *{_getglob("${target}::extends")} = sub {
20 _load_module($_) for @_;
21 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
22 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
24 *{_getglob("${target}::with")} = sub {
26 Moo::Role->apply_roles_to_package($target, $_[0]);
28 $MAKERS{$target} = {};
29 *{_getglob("${target}::has")} = sub {
30 my ($name, %spec) = @_;
31 ($MAKERS{$target}{accessor} ||= do {
32 require Method::Generate::Accessor;
33 Method::Generate::Accessor->new
34 })->generate_method($target, $name, \%spec);
35 $class->_constructor_maker_for($target)
36 ->register_attribute_specs($name, \%spec);
38 foreach my $type (qw(before after around)) {
39 *{_getglob "${target}::${type}"} = sub {
40 require Class::Method::Modifiers;
41 _install_modifier($target, $type, @_);
46 @{"${target}::ISA"} = do {
47 require Moo::Object; ('Moo::Object');
48 } unless @{"${target}::ISA"};
50 if ($INC{'Moo/HandleMoose.pm'}) {
51 Moo::HandleMoose::inject_fake_metaclass_for($target);
55 sub _constructor_maker_for {
56 my ($class, $target, $select_super) = @_;
57 return unless $MAKERS{$target};
58 $MAKERS{$target}{constructor} ||= do {
59 require Method::Generate::Constructor;
61 my ($moo_constructor, $con);
63 if ($select_super && $MAKERS{$select_super}) {
65 $con = $MAKERS{$select_super}{constructor};
67 my $t_new = $target->can('new');
69 if ($t_new == Moo::Object->can('new')) {
71 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
72 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
75 $con = $MAKERS{$pkg}{constructor};
79 $moo_constructor = 1; # no other constructor, make a Moo one
82 Method::Generate::Constructor
85 accessor_generator => do {
86 require Method::Generate::Accessor;
87 Method::Generate::Accessor->new;
89 construction_string => (
91 ? ($con ? $con->construction_string : undef)
92 : ('$class->'.$target.'::SUPER::new(@_)')
94 subconstructor_handler => (
95 ' if ($Moo::MAKERS{$class}) {'."\n"
96 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
97 .' return $class->new(@_)'.";\n"
102 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
113 Moo - Minimalist Object Orientation (with Moose compatiblity)
124 my $amount = shift || 1;
126 $self->pounds( $self->pounds - $amount );
136 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
142 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
149 my $full = Cat::Food->new(
150 taste => 'DELICIOUS.',
151 brand => 'SWEET-TREATZ',
161 This module is an extremely light-weight, high-performance L<Moose> replacement.
162 It also avoids depending on any XS modules to allow simple deployments. The
163 name C<Moo> is based on the idea that it provides almost -but not quite- two
166 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
167 L</INCOMPATIBILITIES> for more details.
169 =head1 WHY MOO EXISTS
171 If you want a full object system with a rich Metaprotocol, L<Moose> is
174 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
175 takes longer to load than most of my Moo based CGI scripts take to run.
177 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
178 you want "as little as possible" - which means "no metaprotocol", which is
181 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
182 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
185 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
186 to make it smooth to upgrade to L<Moose> when you need more than minimal
189 =head1 IMPORTED METHODS
193 Foo::Bar->new( attr1 => 3 );
197 Foo::Bar->new({ attr1 => 3 });
201 around BUILDARGS => sub {
203 my ( $class, @args ) = @_;
205 unshift @args, "attr1" if @args % 2 == 1;
207 return $class->$orig(@args);
212 The default implementation of this method accepts a hash or hash reference of
213 named parameters. If it receives a single argument that isn't a hash reference
216 You can override this method in your class to handle other types of options
217 passed to the constructor.
219 This method should always return a hash reference of named options.
223 Define a C<BUILD> method on your class and the constructor will automatically
224 call the C<BUILD> method from parent down to child after the object has
225 been instantiated. Typically this is used for object validation or possibly
230 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
231 a C<DESTROY> method is created on first object construction which will call
232 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
233 method from child upwards to parents.
235 Note that the C<DESTROY> method is created on first construction of an object
236 of your class in order to not add overhead to classes without C<DEMOLISH>
237 methods; this may prove slightly surprising if you try and define your own.
241 if ($foo->does('Some::Role1')) {
245 Returns true if the object composes in the passed role.
247 =head1 IMPORTED SUBROUTINES
251 extends 'Parent::Class';
253 Declares base class. Multiple superclasses can be passed for multiple
254 inheritance (but please use roles instead).
256 Calling extends more than once will REPLACE your superclasses, not add to
257 them like 'use base' would.
264 Composes a L<Role::Tiny> into current class. Only one role may be composed in
265 at a time to allow the code to remain as simple as possible.
273 Declares an attribute for the class.
275 The options for C<has> are as follows:
281 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
282 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
283 will create a perlish getter/setter.
287 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
288 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
292 die "$_[0] is not a number!" unless looks_like_number $_[0]
295 L<Sub::Quote aware|/SUB QUOTE AWARE>
299 Takes a coderef which is meant to coerce the attribute. The basic idea is to
300 do something like the following:
302 coerce => quote_sub q{
303 $_[0] + 1 unless $_[0] % 2
306 Coerce does not require C<isa> to be defined.
308 L<Sub::Quote aware|/SUB QUOTE AWARE>
314 handles => 'RobotRole'
316 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
317 becomes the list of methods to handle.
319 Takes a list of methods
321 handles => [ qw( one two ) ]
331 Takes a coderef which will get called any time the attribute is set. This
332 includes the constructor. Coderef will be invoked against the object with the
333 new value as an argument.
335 Note that Moose also passes the old value, if any; this feature is not yet
338 L<Sub::Quote aware|/SUB QUOTE AWARE>
342 Takes a coderef which will get called with $self as its only argument
343 to populate an attribute if no value is supplied to the constructor - or
344 if the attribute is lazy, when the attribute is first retrieved if no
345 value has yet been provided.
347 Note that if your default is fired during new() there is no guarantee that
348 other attributes have been populated yet so you should not rely on their
351 L<Sub::Quote aware|/SUB QUOTE AWARE>
355 Takes a method name which will return true if an attribute has a value.
357 A common example of this would be to call it C<has_$foo>, implying that the
358 object has a C<$foo> set.
362 Takes a method name which will be called to create the attribute - functions
363 exactly like default except that instead of calling
373 Takes a method name which will clear the attribute.
377 B<Boolean>. Set this if you want values for the attribute to be grabbed
378 lazily. This is usually a good idea if you have a L</builder> which requires
379 another attribute to be set.
383 B<Boolean>. Set this if the attribute must be passed on instantiation.
387 The value of this attribute will be the name of the method to get the value of
388 the attribute. If you like Java style methods, you might set this to
393 The value of this attribute will be the name of the method to set the value of
394 the attribute. If you like Java style methods, you might set this to
399 B<Boolean>. Set this if you want the reference that the attribute contains to
400 be weakened; use this when circular references are possible, which will cause
405 Takes the name of the key to look for at instantiation time of the object. A
406 common use of this is to make an underscored attribute have a non-underscored
407 initialization name. C<undef> means that passing the value in on instantiation
413 before foo => sub { ... };
415 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
420 around foo => sub { ... };
422 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
427 after foo => sub { ... };
429 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
432 =head1 SUB QUOTE AWARE
434 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
435 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
436 aware can take advantage of this.
438 =head1 INCOMPATIBILITIES WITH MOOSE
440 You can only compose one role at a time. If your application is large or
441 complex enough to warrant complex composition, you wanted L<Moose>. Note that
442 this does not mean you can only compose one role per class -
447 is absolutely fine, there's just currently no equivalent of Moose's
449 with 'FirstRole', 'SecondRole';
451 which composes the two roles together, and then applies them.
453 There is no built in type system. C<isa> is verified with a coderef, if you
454 need complex types, just make a library of coderefs, or better yet, functions
455 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
456 to L<MooseX::Types::Moose> so that you can write
458 has days_to_live => (is => 'ro', isa => Int);
460 and have it work with both; it is hoped that providing only subrefs as an
461 API will encourage the use of other type systems as well, since it's
462 probably the weakest part of Moose design-wise.
464 C<initializer> is not supported in core since the author considers it to be a
465 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
466 C<coerce> are more likely to be able to fulfill your needs.
468 There is no meta object. If you need this level of complexity you wanted
469 L<Moose> - Moo succeeds at being small because it explicitly does not
470 provide a metaprotocol.
472 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
473 be handled by around albeit with a little more typing, and the author considers
474 augment to be a bad idea.
476 The C<dump> method is not provided by default. The author suggests loading
477 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
478 using C<$obj-E<gt>$::Dwarn()> instead.
480 L</default> only supports coderefs, because doing otherwise is usually a
483 C<lazy_build> is not supported per se, but of course it will work if you
484 manually set all the options it implies.
486 C<auto_deref> is not supported since the author considers it a bad idea.
488 C<documentation> is not supported since it's a very poor replacement for POD.
490 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
491 similar invocation for L<Moose> would be:
494 use warnings FATAL => "all";
496 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
497 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
498 module L<MooseX::AttributeShortcuts>. So if you:
503 The nearest L<Moose> invocation would be:
508 use warnings FATAL => "all";
509 use MooseX::AttributeShortcuts;
511 or, if you're inheriting from a non-Moose class,
516 use MooseX::NonMoose;
517 use warnings FATAL => "all";
518 use MooseX::AttributeShortcuts;
520 Finally, Moose requires you to call
522 __PACKAGE__->meta->make_immutable;
524 at the end of your class to get an inlined (i.e. not horribly slow)
525 constructor. Moo does it automatically the first time ->new is called
530 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
534 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
536 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
538 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
540 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
542 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
544 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
546 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
548 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
550 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
554 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
559 This library is free software and may be distributed under the same terms