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 Moo and Moose - NEW, EXPERIMENTAL
196 If L<Moo> detects L<Moose> being loaded, it will automatically register
197 metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able
198 to use them in L<Moose> code without it ever realising you aren't using
201 Extending a L<Moose> class or consuming a L<Moose::Role> should also work.
203 However, these features are new as of 0.91.0 (0.091000) so they may not
204 be 100% yet; please do report bugs.
206 If you need to disable the metaclass creation, add:
210 to your code before Moose is loaded, but bear in mind that this switch is
211 currently global and turns the mechanism off entirely, so don't put this
212 in library code, only in a top level script as a temporary measure while
213 you send a bug report.
215 =head1 IMPORTED METHODS
219 Foo::Bar->new( attr1 => 3 );
223 Foo::Bar->new({ attr1 => 3 });
228 my ( $class, @args ) = @_;
230 unshift @args, "attr1" if @args % 2 == 1;
237 The default implementation of this method accepts a hash or hash reference of
238 named parameters. If it receives a single argument that isn't a hash reference
241 You can override this method in your class to handle other types of options
242 passed to the constructor.
244 This method should always return a hash reference of named options.
248 Define a C<BUILD> method on your class and the constructor will automatically
249 call the C<BUILD> method from parent down to child after the object has
250 been instantiated. Typically this is used for object validation or possibly
255 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
256 a C<DESTROY> method is created on first object construction which will call
257 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
258 method from child upwards to parents.
260 Note that the C<DESTROY> method is created on first construction of an object
261 of your class in order to not add overhead to classes without C<DEMOLISH>
262 methods; this may prove slightly surprising if you try and define your own.
266 if ($foo->does('Some::Role1')) {
270 Returns true if the object composes in the passed role.
272 =head1 IMPORTED SUBROUTINES
276 extends 'Parent::Class';
278 Declares base class. Multiple superclasses can be passed for multiple
279 inheritance (but please use roles instead).
281 Calling extends more than once will REPLACE your superclasses, not add to
282 them like 'use base' would.
289 Composes a L<Role::Tiny> into current class. Only one role may be composed in
290 at a time to allow the code to remain as simple as possible.
298 Declares an attribute for the class.
300 The options for C<has> are as follows:
306 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
307 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
308 will create a perlish getter/setter.
312 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
313 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
317 die "$_[0] is not a number!" unless looks_like_number $_[0]
320 L<Sub::Quote aware|/SUB QUOTE AWARE>
324 Takes a coderef which is meant to coerce the attribute. The basic idea is to
325 do something like the following:
327 coerce => quote_sub q{
328 $_[0] + 1 unless $_[0] % 2
331 Coerce does not require C<isa> to be defined.
333 L<Sub::Quote aware|/SUB QUOTE AWARE>
339 handles => 'RobotRole'
341 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
342 becomes the list of methods to handle.
344 Takes a list of methods
346 handles => [ qw( one two ) ]
356 Takes a coderef which will get called any time the attribute is set. This
357 includes the constructor. Coderef will be invoked against the object with the
358 new value as an argument.
360 Note that Moose also passes the old value, if any; this feature is not yet
363 L<Sub::Quote aware|/SUB QUOTE AWARE>
367 Takes a coderef which will get called with $self as its only argument
368 to populate an attribute if no value is supplied to the constructor - or
369 if the attribute is lazy, when the attribute is first retrieved if no
370 value has yet been provided.
372 Note that if your default is fired during new() there is no guarantee that
373 other attributes have been populated yet so you should not rely on their
376 L<Sub::Quote aware|/SUB QUOTE AWARE>
380 Takes a method name which will return true if an attribute has a value.
382 A common example of this would be to call it C<has_$foo>, implying that the
383 object has a C<$foo> set.
387 Takes a method name which will be called to create the attribute - functions
388 exactly like default except that instead of calling
398 Takes a method name which will clear the attribute.
402 B<Boolean>. Set this if you want values for the attribute to be grabbed
403 lazily. This is usually a good idea if you have a L</builder> which requires
404 another attribute to be set.
408 B<Boolean>. Set this if the attribute must be passed on instantiation.
412 The value of this attribute will be the name of the method to get the value of
413 the attribute. If you like Java style methods, you might set this to
418 The value of this attribute will be the name of the method to set the value of
419 the attribute. If you like Java style methods, you might set this to
424 B<Boolean>. Set this if you want the reference that the attribute contains to
425 be weakened; use this when circular references are possible, which will cause
430 Takes the name of the key to look for at instantiation time of the object. A
431 common use of this is to make an underscored attribute have a non-underscored
432 initialization name. C<undef> means that passing the value in on instantiation
438 before foo => sub { ... };
440 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
445 around foo => sub { ... };
447 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
452 after foo => sub { ... };
454 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
457 =head1 SUB QUOTE AWARE
459 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
460 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
461 aware can take advantage of this.
463 =head1 INCOMPATIBILITIES WITH MOOSE
465 You can only compose one role at a time. If your application is large or
466 complex enough to warrant complex composition, you wanted L<Moose>. Note that
467 this does not mean you can only compose one role per class -
472 is absolutely fine, there's just currently no equivalent of Moose's
474 with 'FirstRole', 'SecondRole';
476 which composes the two roles together, and then applies them.
478 There is no built in type system. C<isa> is verified with a coderef, if you
479 need complex types, just make a library of coderefs, or better yet, functions
480 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
481 to L<MooseX::Types::Moose> so that you can write
483 has days_to_live => (is => 'ro', isa => Int);
485 and have it work with both; it is hoped that providing only subrefs as an
486 API will encourage the use of other type systems as well, since it's
487 probably the weakest part of Moose design-wise.
489 C<initializer> is not supported in core since the author considers it to be a
490 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
491 C<coerce> are more likely to be able to fulfill your needs.
493 There is no meta object. If you need this level of complexity you wanted
494 L<Moose> - Moo succeeds at being small because it explicitly does not
495 provide a metaprotocol.
497 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
498 be handled by around albeit with a little more typing, and the author considers
499 augment to be a bad idea.
501 The C<dump> method is not provided by default. The author suggests loading
502 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
503 using C<$obj-E<gt>$::Dwarn()> instead.
505 L</default> only supports coderefs, because doing otherwise is usually a
508 C<lazy_build> is not supported per se, but of course it will work if you
509 manually set all the options it implies.
511 C<auto_deref> is not supported since the author considers it a bad idea.
513 C<documentation> is not supported since it's a very poor replacement for POD.
515 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
516 similar invocation for L<Moose> would be:
519 use warnings FATAL => "all";
521 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
522 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
523 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
528 The nearest L<Moose> invocation would be:
533 use warnings FATAL => "all";
534 use MooseX::AttributeShortcuts;
536 or, if you're inheriting from a non-Moose class,
541 use MooseX::NonMoose;
542 use warnings FATAL => "all";
543 use MooseX::AttributeShortcuts;
545 Finally, Moose requires you to call
547 __PACKAGE__->meta->make_immutable;
549 at the end of your class to get an inlined (i.e. not horribly slow)
550 constructor. Moo does it automatically the first time ->new is called
555 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
559 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
561 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
563 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
565 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
567 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
569 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
571 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
573 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
575 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
579 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
584 This library is free software and may be distributed under the same terms