7 our $VERSION = '0.091001'; # 0.91.1
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 This means that there is no need for anything like L<Any::Moose> for Moo
204 code - Moo and Moose code should simply interoperate without problem.
206 However, these features are new as of 0.91.0 (0.091000) so while serviceable,
207 they are absolutely certain to not be 100% yet; please do report bugs.
209 If you need to disable the metaclass creation, add:
213 to your code before Moose is loaded, but bear in mind that this switch is
214 currently global and turns the mechanism off entirely, so don't put this
215 in library code, only in a top level script as a temporary measure while
216 you send a bug report.
218 =head1 IMPORTED METHODS
222 Foo::Bar->new( attr1 => 3 );
226 Foo::Bar->new({ attr1 => 3 });
231 my ( $class, @args ) = @_;
233 unshift @args, "attr1" if @args % 2 == 1;
240 The default implementation of this method accepts a hash or hash reference of
241 named parameters. If it receives a single argument that isn't a hash reference
244 You can override this method in your class to handle other types of options
245 passed to the constructor.
247 This method should always return a hash reference of named options.
251 Define a C<BUILD> method on your class and the constructor will automatically
252 call the C<BUILD> method from parent down to child after the object has
253 been instantiated. Typically this is used for object validation or possibly
258 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
259 a C<DESTROY> method is created on first object construction which will call
260 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
261 method from child upwards to parents.
263 Note that the C<DESTROY> method is created on first construction of an object
264 of your class in order to not add overhead to classes without C<DEMOLISH>
265 methods; this may prove slightly surprising if you try and define your own.
269 if ($foo->does('Some::Role1')) {
273 Returns true if the object composes in the passed role.
275 =head1 IMPORTED SUBROUTINES
279 extends 'Parent::Class';
281 Declares base class. Multiple superclasses can be passed for multiple
282 inheritance (but please use roles instead).
284 Calling extends more than once will REPLACE your superclasses, not add to
285 them like 'use base' would.
292 Composes a L<Role::Tiny> into current class. Only one role may be composed in
293 at a time to allow the code to remain as simple as possible.
301 Declares an attribute for the class.
303 The options for C<has> are as follows:
309 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
310 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
311 will create a perlish getter/setter.
315 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
316 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
320 die "$_[0] is not a number!" unless looks_like_number $_[0]
323 L<Sub::Quote aware|/SUB QUOTE AWARE>
327 Takes a coderef which is meant to coerce the attribute. The basic idea is to
328 do something like the following:
330 coerce => quote_sub q{
331 $_[0] + 1 unless $_[0] % 2
334 Coerce does not require C<isa> to be defined.
336 L<Sub::Quote aware|/SUB QUOTE AWARE>
342 handles => 'RobotRole'
344 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
345 becomes the list of methods to handle.
347 Takes a list of methods
349 handles => [ qw( one two ) ]
359 Takes a coderef which will get called any time the attribute is set. This
360 includes the constructor. Coderef will be invoked against the object with the
361 new value as an argument.
363 Note that Moose also passes the old value, if any; this feature is not yet
366 L<Sub::Quote aware|/SUB QUOTE AWARE>
370 Takes a coderef which will get called with $self as its only argument
371 to populate an attribute if no value is supplied to the constructor - or
372 if the attribute is lazy, when the attribute is first retrieved if no
373 value has yet been provided.
375 Note that if your default is fired during new() there is no guarantee that
376 other attributes have been populated yet so you should not rely on their
379 L<Sub::Quote aware|/SUB QUOTE AWARE>
383 Takes a method name which will return true if an attribute has a value.
385 A common example of this would be to call it C<has_$foo>, implying that the
386 object has a C<$foo> set.
390 Takes a method name which will be called to create the attribute - functions
391 exactly like default except that instead of calling
401 Takes a method name which will clear the attribute.
405 B<Boolean>. Set this if you want values for the attribute to be grabbed
406 lazily. This is usually a good idea if you have a L</builder> which requires
407 another attribute to be set.
411 B<Boolean>. Set this if the attribute must be passed on instantiation.
415 The value of this attribute will be the name of the method to get the value of
416 the attribute. If you like Java style methods, you might set this to
421 The value of this attribute will be the name of the method to set the value of
422 the attribute. If you like Java style methods, you might set this to
427 B<Boolean>. Set this if you want the reference that the attribute contains to
428 be weakened; use this when circular references are possible, which will cause
433 Takes the name of the key to look for at instantiation time of the object. A
434 common use of this is to make an underscored attribute have a non-underscored
435 initialization name. C<undef> means that passing the value in on instantiation
441 before foo => sub { ... };
443 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
448 around foo => sub { ... };
450 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
455 after foo => sub { ... };
457 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
460 =head1 SUB QUOTE AWARE
462 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
463 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
464 aware can take advantage of this.
466 =head1 INCOMPATIBILITIES WITH MOOSE
468 You can only compose one role at a time. If your application is large or
469 complex enough to warrant complex composition, you wanted L<Moose>. Note that
470 this does not mean you can only compose one role per class -
475 is absolutely fine, there's just currently no equivalent of Moose's
477 with 'FirstRole', 'SecondRole';
479 which composes the two roles together, and then applies them.
481 There is no built in type system. C<isa> is verified with a coderef, if you
482 need complex types, just make a library of coderefs, or better yet, functions
483 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
484 to L<MooseX::Types::Moose> so that you can write
486 has days_to_live => (is => 'ro', isa => Int);
488 and have it work with both; it is hoped that providing only subrefs as an
489 API will encourage the use of other type systems as well, since it's
490 probably the weakest part of Moose design-wise.
492 C<initializer> is not supported in core since the author considers it to be a
493 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
494 C<coerce> are more likely to be able to fulfill your needs.
496 There is no meta object. If you need this level of complexity you wanted
497 L<Moose> - Moo succeeds at being small because it explicitly does not
498 provide a metaprotocol.
500 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
501 be handled by around albeit with a little more typing, and the author considers
502 augment to be a bad idea.
504 The C<dump> method is not provided by default. The author suggests loading
505 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
506 using C<$obj-E<gt>$::Dwarn()> instead.
508 L</default> only supports coderefs, because doing otherwise is usually a
511 C<lazy_build> is not supported per se, but of course it will work if you
512 manually set all the options it implies.
514 C<auto_deref> is not supported since the author considers it a bad idea.
516 C<documentation> is not supported since it's a very poor replacement for POD.
518 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
519 similar invocation for L<Moose> would be:
522 use warnings FATAL => "all";
524 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
525 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
526 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
531 The nearest L<Moose> invocation would be:
536 use warnings FATAL => "all";
537 use MooseX::AttributeShortcuts;
539 or, if you're inheriting from a non-Moose class,
544 use MooseX::NonMoose;
545 use warnings FATAL => "all";
546 use MooseX::AttributeShortcuts;
548 Finally, Moose requires you to call
550 __PACKAGE__->meta->make_immutable;
552 at the end of your class to get an inlined (i.e. not horribly slow)
553 constructor. Moo does it automatically the first time ->new is called
558 IRC: #web-simple on irc.perl.org
562 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
566 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
568 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
570 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
572 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
574 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
576 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
578 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
580 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
582 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
586 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
591 This library is free software and may be distributed under the same terms