8 our $VERSION = '0.091009'; # 0.91.9
9 $VERSION = eval $VERSION;
11 require Moo::sification;
19 return if $MAKERS{$target}; # already exported into this package
20 _install_coderef "${target}::extends" => "Moo::extends" => sub {
21 _load_module($_) for @_;
22 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
23 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
24 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
25 delete _getstash($target)->{new};
26 Moo->_constructor_maker_for($target)
27 ->register_attribute_specs(%{$old->all_attribute_specs});
29 no warnings 'once'; # piss off. -- mst
30 $Moo::HandleMoose::MOUSE{$target} = [
31 grep defined, map Mouse::Util::find_meta($_), @_
32 ] if $INC{"Mouse.pm"};
33 $class->_maybe_reset_handlemoose($target);
36 _install_coderef "${target}::with" => "Moo::with" => sub {
38 Moo::Role->apply_roles_to_package($target, @_);
39 $class->_maybe_reset_handlemoose($target);
41 $MAKERS{$target} = {};
42 _install_coderef "${target}::has" => "Moo::has" => sub {
43 my ($name, %spec) = @_;
44 $class->_constructor_maker_for($target)
45 ->register_attribute_specs($name, \%spec);
46 $class->_accessor_maker_for($target)
47 ->generate_method($target, $name, \%spec);
48 $class->_maybe_reset_handlemoose($target);
51 foreach my $type (qw(before after around)) {
52 _install_coderef "${target}::${type}" => "Moo::${type}" => sub {
53 require Class::Method::Modifiers;
54 _install_modifier($target, $type, @_);
60 @{"${target}::ISA"} = do {
61 require Moo::Object; ('Moo::Object');
62 } unless @{"${target}::ISA"};
64 if ($INC{'Moo/HandleMoose.pm'}) {
65 Moo::HandleMoose::inject_fake_metaclass_for($target);
69 sub _maybe_reset_handlemoose {
70 my ($class, $target) = @_;
71 if ($INC{"Moo/HandleMoose.pm"}) {
72 Moo::HandleMoose::maybe_reinject_fake_metaclass_for($target);
76 sub _accessor_maker_for {
77 my ($class, $target) = @_;
78 return unless $MAKERS{$target};
79 $MAKERS{$target}{accessor} ||= do {
80 my $maker_class = do {
82 if (my $defer_target =
83 (Sub::Defer::defer_info($target->can('new'))||[])->[0]
85 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
86 $MAKERS{$pkg} && $MAKERS{$pkg}{accessor};
93 require Method::Generate::Accessor;
94 'Method::Generate::Accessor'
101 sub _constructor_maker_for {
102 my ($class, $target, $select_super) = @_;
103 return unless $MAKERS{$target};
104 $MAKERS{$target}{constructor} ||= do {
105 require Method::Generate::Constructor;
107 my ($moo_constructor, $con);
109 if ($select_super && $MAKERS{$select_super}) {
110 $moo_constructor = 1;
111 $con = $MAKERS{$select_super}{constructor};
113 my $t_new = $target->can('new');
115 if ($t_new == Moo::Object->can('new')) {
116 $moo_constructor = 1;
117 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
118 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
120 $moo_constructor = 1;
121 $con = $MAKERS{$pkg}{constructor};
125 $moo_constructor = 1; # no other constructor, make a Moo one
128 ($con ? ref($con) : 'Method::Generate::Constructor')
131 accessor_generator => $class->_accessor_maker_for($target),
132 construction_string => (
134 ? ($con ? $con->construction_string : undef)
135 : ('$class->'.$target.'::SUPER::new(@_)')
137 subconstructor_handler => (
138 ' if ($Moo::MAKERS{$class}) {'."\n"
139 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
140 .' return $class->new(@_)'.";\n"
141 .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n"
142 .' return $meta->new_object(@_);'."\n"
147 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
158 Moo - Minimalist Object Orientation (with Moose compatiblity)
169 my $amount = shift || 1;
171 $self->pounds( $self->pounds - $amount );
181 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
187 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
194 my $full = Cat::Food->new(
195 taste => 'DELICIOUS.',
196 brand => 'SWEET-TREATZ',
206 This module is an extremely light-weight, high-performance L<Moose> replacement.
207 It also avoids depending on any XS modules to allow simple deployments. The
208 name C<Moo> is based on the idea that it provides almost -but not quite- two
211 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
212 L</INCOMPATIBILITIES> for more details.
214 =head1 WHY MOO EXISTS
216 If you want a full object system with a rich Metaprotocol, L<Moose> is
219 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
220 takes longer to load than most of my Moo based CGI scripts take to run.
222 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
223 you want "as little as possible" - which means "no metaprotocol", which is
226 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
227 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
230 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
231 to make it smooth to upgrade to L<Moose> when you need more than minimal
234 =head1 Moo and Moose - NEW, EXPERIMENTAL
236 If L<Moo> detects L<Moose> being loaded, it will automatically register
237 metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able
238 to use them in L<Moose> code without it ever realising you aren't using
241 Extending a L<Moose> class or consuming a L<Moose::Role> should also work.
243 So should extending a L<Mouse> class or consuming a L<Mouse::Role>.
245 This means that there is no need for anything like L<Any::Moose> for Moo
246 code - Moo and Moose code should simply interoperate without problem. To
247 handle L<Mouse> code, you'll likely need an empty Moo role or class consuming
248 or extending the L<Mouse> stuff since it doesn't register true L<Moose>
249 metaclasses like we do.
251 However, these features are new as of 0.91.0 (0.091000) so while serviceable,
252 they are absolutely certain to not be 100% yet; please do report bugs.
254 If you need to disable the metaclass creation, add:
258 to your code before Moose is loaded, but bear in mind that this switch is
259 currently global and turns the mechanism off entirely, so don't put this
260 in library code, only in a top level script as a temporary measure while
261 you send a bug report.
263 =head1 IMPORTED METHODS
267 Foo::Bar->new( attr1 => 3 );
271 Foo::Bar->new({ attr1 => 3 });
276 my ( $class, @args ) = @_;
278 unshift @args, "attr1" if @args % 2 == 1;
285 The default implementation of this method accepts a hash or hash reference of
286 named parameters. If it receives a single argument that isn't a hash reference
289 You can override this method in your class to handle other types of options
290 passed to the constructor.
292 This method should always return a hash reference of named options.
296 Define a C<BUILD> method on your class and the constructor will automatically
297 call the C<BUILD> method from parent down to child after the object has
298 been instantiated. Typically this is used for object validation or possibly
303 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
304 a C<DESTROY> method is created on first object construction which will call
305 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
306 method from child upwards to parents.
308 Note that the C<DESTROY> method is created on first construction of an object
309 of your class in order to not add overhead to classes without C<DEMOLISH>
310 methods; this may prove slightly surprising if you try and define your own.
314 if ($foo->does('Some::Role1')) {
318 Returns true if the object composes in the passed role.
320 =head1 IMPORTED SUBROUTINES
324 extends 'Parent::Class';
326 Declares base class. Multiple superclasses can be passed for multiple
327 inheritance (but please use roles instead).
329 Calling extends more than once will REPLACE your superclasses, not add to
330 them like 'use base' would.
338 with 'Some::Role1', 'Some::Role2';
340 Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current
341 class. An error will be raised if these roles have conflicting methods.
349 Declares an attribute for the class.
351 The options for C<has> are as follows:
357 B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>.
359 C<ro> generates an accessor that dies if you attempt to write to it - i.e.
360 a getter only - by defaulting C<reader> to the name of the attribute.
362 C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and
363 C<builder> to C<_build_${attribute_name}> to allow on-demand generated
364 attributes. This feature was my attempt to fix my incompetence when
365 originally designing C<lazy_build>, and is also implemented by
366 L<MooseX::AttributeShortcuts>.
368 C<rwp> generates a reader like C<ro>, but also sets C<writer> to
369 C<_set_${attribute_name}> for attributes that are designed to be written
370 from inside of the class, but read-only from outside.
371 This feature comes from L<MooseX::AttributeShortcuts>.
373 C<rw> generates a normal getter/setter by defaulting C<accessor> to the
374 name of the attribute.
378 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
379 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
383 die "$_[0] is not a number!" unless looks_like_number $_[0]
386 L<Sub::Quote aware|/SUB QUOTE AWARE>
388 Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion
389 subroutine has been supplied, C<isa> checks are not structural to your code
390 and can, if desired, be omitted on non-debug builds (although if this results
391 in an uncaught bug causing your program to break, the L<Moo> authors guarantee
392 nothing except that you get to keep both halves).
394 If you want L<MooseX::Types> style named types, look at
395 L<MooX::Types::MooseLike>.
397 To cause your C<isa> entries to be automatically mapped to named
398 L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour
399 of creating an anonymous type), set:
401 $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub {
402 require MooseX::Types::Something;
403 return MooseX::Types::Something::TypeName();
406 Note that this example is purely illustrative; anything that returns a
407 L<Moose::Meta::TypeConstraint> object or something similar enough to it to
408 make L<Moose> happy is fine.
412 Takes a coderef which is meant to coerce the attribute. The basic idea is to
413 do something like the following:
415 coerce => quote_sub q{
416 $_[0] + 1 unless $_[0] % 2
419 Note that L<Moo> will always fire your coercion - this is to permit
420 isa entries to be used purely for bug trapping, whereas coercions are
421 always structural to your code. We do, however, apply any supplied C<isa>
422 check after the coercion has run to ensure that it returned a valid value.
424 L<Sub::Quote aware|/SUB QUOTE AWARE>
430 handles => 'RobotRole'
432 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
433 becomes the list of methods to handle.
435 Takes a list of methods
437 handles => [ qw( one two ) ]
447 Takes a coderef which will get called any time the attribute is set. This
448 includes the constructor. Coderef will be invoked against the object with the
449 new value as an argument.
451 If you set this to just C<1>, it generates a trigger which calls the
452 C<_trigger_${attr_name}> method on C<$self>. This feature comes from
453 L<MooseX::AttributeShortcuts>.
455 Note that Moose also passes the old value, if any; this feature is not yet
458 L<Sub::Quote aware|/SUB QUOTE AWARE>
462 Takes a coderef which will get called with $self as its only argument
463 to populate an attribute if no value is supplied to the constructor - or
464 if the attribute is lazy, when the attribute is first retrieved if no
465 value has yet been provided.
467 Note that if your default is fired during new() there is no guarantee that
468 other attributes have been populated yet so you should not rely on their
471 L<Sub::Quote aware|/SUB QUOTE AWARE>
475 Takes a method name which will return true if an attribute has a value.
477 If you set this to just C<1>, the predicate is automatically named
478 C<has_${attr_name}> if your attribute's name does not start with an
479 underscore, or <_has_${attr_name_without_the_underscore}> if it does.
480 This feature comes from L<MooseX::AttributeShortcuts>.
484 Takes a method name which will be called to create the attribute - functions
485 exactly like default except that instead of calling
493 If you set this to just C<1>, the predicate is automatically named
494 C<_build_${attr_name}>. This feature comes from L<MooseX::AttributeShortcuts>.
498 Takes a method name which will clear the attribute.
500 If you set this to just C<1>, the clearer is automatically named
501 C<clear_${attr_name}> if your attribute's name does not start with an
502 underscore, or <_clear_${attr_name_without_the_underscore}> if it does.
503 This feature comes from L<MooseX::AttributeShortcuts>.
507 B<Boolean>. Set this if you want values for the attribute to be grabbed
508 lazily. This is usually a good idea if you have a L</builder> which requires
509 another attribute to be set.
513 B<Boolean>. Set this if the attribute must be passed on instantiation.
517 The value of this attribute will be the name of the method to get the value of
518 the attribute. If you like Java style methods, you might set this to
523 The value of this attribute will be the name of the method to set the value of
524 the attribute. If you like Java style methods, you might set this to
529 B<Boolean>. Set this if you want the reference that the attribute contains to
530 be weakened; use this when circular references are possible, which will cause
535 Takes the name of the key to look for at instantiation time of the object. A
536 common use of this is to make an underscored attribute have a non-underscored
537 initialization name. C<undef> means that passing the value in on instantiation
544 before foo => sub { ... };
546 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
551 around foo => sub { ... };
553 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
558 after foo => sub { ... };
560 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
563 =head1 SUB QUOTE AWARE
565 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
566 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
567 aware can take advantage of this.
569 =head1 INCOMPATIBILITIES WITH MOOSE
571 There is no built in type system. C<isa> is verified with a coderef, if you
572 need complex types, just make a library of coderefs, or better yet, functions
573 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
574 to L<MooseX::Types::Moose> so that you can write
576 has days_to_live => (is => 'ro', isa => Int);
578 and have it work with both; it is hoped that providing only subrefs as an
579 API will encourage the use of other type systems as well, since it's
580 probably the weakest part of Moose design-wise.
582 C<initializer> is not supported in core since the author considers it to be a
583 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
584 C<coerce> are more likely to be able to fulfill your needs.
586 There is no meta object. If you need this level of complexity you wanted
587 L<Moose> - Moo succeeds at being small because it explicitly does not
588 provide a metaprotocol. However, if you load L<Moose>, then
590 Class::MOP::class_of($moo_class_or_role)
592 will return an appropriate metaclass pre-populated by L<Moo>.
594 No support for C<super>, C<override>, C<inner>, or C<augment> - the author
595 considers augment to be a bad idea, and override can be translated:
597 override foo => sub {
604 my ($orig, $self) = (shift, shift);
610 The C<dump> method is not provided by default. The author suggests loading
611 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
612 using C<$obj-E<gt>$::Dwarn()> instead.
614 L</default> only supports coderefs, because doing otherwise is usually a
617 C<lazy_build> is not supported; you are instead encouraged to use the
618 C<is => 'lazy'> option supported by L<Moo> and L<MooseX::AttributeShortcuts>.
620 C<auto_deref> is not supported since the author considers it a bad idea.
622 C<documentation> will show up in a L<Moose> metaclass created from your class
623 but is otherwise ignored. Then again, L<Moose> ignores it as well, so this
624 is arguably not an incompatibility.
626 Since C<coerce> does not require C<isa> to be defined but L<Moose> does
627 require it, the metaclass inflation for coerce-alone is a trifle insane
628 and if you attempt to subtype the result will almost certainly break.
630 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
631 similar invocation for L<Moose> would be:
634 use warnings FATAL => "all";
636 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
637 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
638 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
643 The nearest L<Moose> invocation would be:
648 use warnings FATAL => "all";
649 use MooseX::AttributeShortcuts;
651 or, if you're inheriting from a non-Moose class,
656 use MooseX::NonMoose;
657 use warnings FATAL => "all";
658 use MooseX::AttributeShortcuts;
660 Finally, Moose requires you to call
662 __PACKAGE__->meta->make_immutable;
664 at the end of your class to get an inlined (i.e. not horribly slow)
665 constructor. Moo does it automatically the first time ->new is called
670 IRC: #web-simple on irc.perl.org
674 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
678 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
680 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
682 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
684 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
686 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
688 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
690 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
692 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
694 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
698 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
703 This library is free software and may be distributed under the same terms