8 our $VERSION = '0.091014'; # 0.91.14
9 $VERSION = eval $VERSION;
11 require Moo::sification;
15 sub _install_tracked {
16 my ($target, $name, $code) = @_;
17 $MAKERS{$target}{exports}{$name} = $code;
18 _install_coderef "${target}::${name}" => "Moo::${name}" => $code;
25 return if $MAKERS{$target}; # already exported into this package
26 $MAKERS{$target} = {};
27 _install_tracked $target => extends => sub {
28 $class->_set_superclasses($target, @_);
29 $class->_maybe_reset_handlemoose($target);
32 _install_tracked $target => with => sub {
34 Moo::Role->apply_roles_to_package($target, @_);
35 $class->_maybe_reset_handlemoose($target);
37 _install_tracked $target => has => sub {
38 my ($name, %spec) = @_;
39 $class->_constructor_maker_for($target)
40 ->register_attribute_specs($name, \%spec);
41 $class->_accessor_maker_for($target)
42 ->generate_method($target, $name, \%spec);
43 $class->_maybe_reset_handlemoose($target);
46 foreach my $type (qw(before after around)) {
47 _install_tracked $target => $type => sub {
48 require Class::Method::Modifiers;
49 _install_modifier($target, $type, @_);
55 @{"${target}::ISA"} = do {
56 require Moo::Object; ('Moo::Object');
57 } unless @{"${target}::ISA"};
59 if ($INC{'Moo/HandleMoose.pm'}) {
60 Moo::HandleMoose::inject_fake_metaclass_for($target);
66 _unimport_coderefs($target, $MAKERS{$target});
69 sub _set_superclasses {
74 if ($INC{"Role/Tiny.pm"} && $Role::Tiny::INFO{$_}) {
76 Carp::croak("Can't extend role '$_'");
79 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
80 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
81 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
82 delete _getstash($target)->{new};
83 Moo->_constructor_maker_for($target)
84 ->register_attribute_specs(%{$old->all_attribute_specs});
86 no warnings 'once'; # piss off. -- mst
87 $Moo::HandleMoose::MOUSE{$target} = [
88 grep defined, map Mouse::Util::find_meta($_), @_
89 ] if $INC{"Mouse.pm"};
92 sub _maybe_reset_handlemoose {
93 my ($class, $target) = @_;
94 if ($INC{"Moo/HandleMoose.pm"}) {
95 Moo::HandleMoose::maybe_reinject_fake_metaclass_for($target);
99 sub _accessor_maker_for {
100 my ($class, $target) = @_;
101 return unless $MAKERS{$target};
102 $MAKERS{$target}{accessor} ||= do {
103 my $maker_class = do {
105 if (my $defer_target =
106 (Sub::Defer::defer_info($target->can('new'))||[])->[0]
108 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
109 $MAKERS{$pkg} && $MAKERS{$pkg}{accessor};
116 require Method::Generate::Accessor;
117 'Method::Generate::Accessor'
124 sub _constructor_maker_for {
125 my ($class, $target, $select_super) = @_;
126 return unless $MAKERS{$target};
127 $MAKERS{$target}{constructor} ||= do {
128 require Method::Generate::Constructor;
130 my ($moo_constructor, $con);
132 if ($select_super && $MAKERS{$select_super}) {
133 $moo_constructor = 1;
134 $con = $MAKERS{$select_super}{constructor};
136 my $t_new = $target->can('new');
138 if ($t_new == Moo::Object->can('new')) {
139 $moo_constructor = 1;
140 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
141 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
143 $moo_constructor = 1;
144 $con = $MAKERS{$pkg}{constructor};
148 $moo_constructor = 1; # no other constructor, make a Moo one
151 ($con ? ref($con) : 'Method::Generate::Constructor')
154 accessor_generator => $class->_accessor_maker_for($target),
155 construction_string => (
157 ? ($con ? $con->construction_string : undef)
158 : ('$class->'.$target.'::SUPER::new(@_)')
160 subconstructor_handler => (
161 ' if ($Moo::MAKERS{$class}) {'."\n"
162 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
163 .' return $class->new(@_)'.";\n"
164 .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n"
165 .' return $meta->new_object(@_);'."\n"
170 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
181 Moo - Minimalist Object Orientation (with Moose compatiblity)
192 my $amount = shift || 1;
194 $self->pounds( $self->pounds - $amount );
204 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
210 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
217 my $full = Cat::Food->new(
218 taste => 'DELICIOUS.',
219 brand => 'SWEET-TREATZ',
229 This module is an extremely light-weight, high-performance L<Moose> replacement.
230 It also avoids depending on any XS modules to allow simple deployments. The
231 name C<Moo> is based on the idea that it provides almost -but not quite- two
234 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
235 L</INCOMPATIBILITIES> for more details.
237 =head1 WHY MOO EXISTS
239 If you want a full object system with a rich Metaprotocol, L<Moose> is
242 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
243 takes longer to load than most of my Moo based CGI scripts take to run.
245 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
246 you want "as little as possible" - which means "no metaprotocol", which is
249 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
250 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
253 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
254 to make it smooth to upgrade to L<Moose> when you need more than minimal
259 If L<Moo> detects L<Moose> being loaded, it will automatically register
260 metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able
261 to use them in L<Moose> code without anybody ever noticing you aren't using
264 Extending a L<Moose> class or consuming a L<Moose::Role> will also work.
266 So will extending a L<Mouse> class or consuming a L<Mouse::Role> - but note
267 that we don't provide L<Mouse> metaclasses or metaroles so the other way
268 around doesn't work. This feature exists for L<Any::Moose> users porting to
269 L<Moo>, enabling L<Mouse> users to use L<Moo> classes is not a priority for us.
271 This means that there is no need for anything like L<Any::Moose> for Moo
272 code - Moo and Moose code should simply interoperate without problem. To
273 handle L<Mouse> code, you'll likely need an empty Moo role or class consuming
274 or extending the L<Mouse> stuff since it doesn't register true L<Moose>
275 metaclasses like we do.
277 If you need to disable the metaclass creation, add:
281 to your code before Moose is loaded, but bear in mind that this switch is
282 currently global and turns the mechanism off entirely so don't put this
285 =head1 IMPORTED METHODS
289 Foo::Bar->new( attr1 => 3 );
293 Foo::Bar->new({ attr1 => 3 });
298 my ( $class, @args ) = @_;
300 unshift @args, "attr1" if @args % 2 == 1;
307 The default implementation of this method accepts a hash or hash reference of
308 named parameters. If it receives a single argument that isn't a hash reference
311 You can override this method in your class to handle other types of options
312 passed to the constructor.
314 This method should always return a hash reference of named options.
318 Define a C<BUILD> method on your class and the constructor will automatically
319 call the C<BUILD> method from parent down to child after the object has
320 been instantiated. Typically this is used for object validation or possibly
325 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
326 a C<DESTROY> method is created on first object construction which will call
327 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
328 method from child upwards to parents.
330 Note that the C<DESTROY> method is created on first construction of an object
331 of your class in order to not add overhead to classes without C<DEMOLISH>
332 methods; this may prove slightly surprising if you try and define your own.
336 if ($foo->does('Some::Role1')) {
340 Returns true if the object composes in the passed role.
342 =head1 IMPORTED SUBROUTINES
346 extends 'Parent::Class';
348 Declares base class. Multiple superclasses can be passed for multiple
349 inheritance (but please use roles instead).
351 Calling extends more than once will REPLACE your superclasses, not add to
352 them like 'use base' would.
360 with 'Some::Role1', 'Some::Role2';
362 Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current
363 class. An error will be raised if these roles have conflicting methods.
371 Declares an attribute for the class.
373 The options for C<has> are as follows:
379 B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>.
381 C<ro> generates an accessor that dies if you attempt to write to it - i.e.
382 a getter only - by defaulting C<reader> to the name of the attribute.
384 C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and
385 C<builder> to C<_build_${attribute_name}> to allow on-demand generated
386 attributes. This feature was my attempt to fix my incompetence when
387 originally designing C<lazy_build>, and is also implemented by
388 L<MooseX::AttributeShortcuts>.
390 C<rwp> generates a reader like C<ro>, but also sets C<writer> to
391 C<_set_${attribute_name}> for attributes that are designed to be written
392 from inside of the class, but read-only from outside.
393 This feature comes from L<MooseX::AttributeShortcuts>.
395 C<rw> generates a normal getter/setter by defaulting C<accessor> to the
396 name of the attribute.
400 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
401 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
405 die "$_[0] is not a number!" unless looks_like_number $_[0]
408 L<Sub::Quote aware|/SUB QUOTE AWARE>
410 Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion
411 subroutine has been supplied, C<isa> checks are not structural to your code
412 and can, if desired, be omitted on non-debug builds (although if this results
413 in an uncaught bug causing your program to break, the L<Moo> authors guarantee
414 nothing except that you get to keep both halves).
416 If you want L<MooseX::Types> style named types, look at
417 L<MooX::Types::MooseLike>.
419 To cause your C<isa> entries to be automatically mapped to named
420 L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour
421 of creating an anonymous type), set:
423 $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub {
424 require MooseX::Types::Something;
425 return MooseX::Types::Something::TypeName();
428 Note that this example is purely illustrative; anything that returns a
429 L<Moose::Meta::TypeConstraint> object or something similar enough to it to
430 make L<Moose> happy is fine.
434 Takes a coderef which is meant to coerce the attribute. The basic idea is to
435 do something like the following:
437 coerce => quote_sub q{
438 $_[0] + 1 unless $_[0] % 2
441 Note that L<Moo> will always fire your coercion - this is to permit
442 isa entries to be used purely for bug trapping, whereas coercions are
443 always structural to your code. We do, however, apply any supplied C<isa>
444 check after the coercion has run to ensure that it returned a valid value.
446 L<Sub::Quote aware|/SUB QUOTE AWARE>
452 handles => 'RobotRole'
454 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
455 becomes the list of methods to handle.
457 Takes a list of methods
459 handles => [ qw( one two ) ]
469 Takes a coderef which will get called any time the attribute is set. This
470 includes the constructor. Coderef will be invoked against the object with the
471 new value as an argument.
473 If you set this to just C<1>, it generates a trigger which calls the
474 C<_trigger_${attr_name}> method on C<$self>. This feature comes from
475 L<MooseX::AttributeShortcuts>.
477 Note that Moose also passes the old value, if any; this feature is not yet
480 L<Sub::Quote aware|/SUB QUOTE AWARE>
484 Takes a coderef which will get called with $self as its only argument
485 to populate an attribute if no value is supplied to the constructor - or
486 if the attribute is lazy, when the attribute is first retrieved if no
487 value has yet been provided.
489 Note that if your default is fired during new() there is no guarantee that
490 other attributes have been populated yet so you should not rely on their
493 L<Sub::Quote aware|/SUB QUOTE AWARE>
497 Takes a method name which will return true if an attribute has a value.
499 If you set this to just C<1>, the predicate is automatically named
500 C<has_${attr_name}> if your attribute's name does not start with an
501 underscore, or <_has_${attr_name_without_the_underscore}> if it does.
502 This feature comes from L<MooseX::AttributeShortcuts>.
506 Takes a method name which will be called to create the attribute - functions
507 exactly like default except that instead of calling
515 If you set this to just C<1>, the predicate is automatically named
516 C<_build_${attr_name}>. This feature comes from L<MooseX::AttributeShortcuts>.
520 Takes a method name which will clear the attribute.
522 If you set this to just C<1>, the clearer is automatically named
523 C<clear_${attr_name}> if your attribute's name does not start with an
524 underscore, or <_clear_${attr_name_without_the_underscore}> if it does.
525 This feature comes from L<MooseX::AttributeShortcuts>.
529 B<Boolean>. Set this if you want values for the attribute to be grabbed
530 lazily. This is usually a good idea if you have a L</builder> which requires
531 another attribute to be set.
535 B<Boolean>. Set this if the attribute must be passed on instantiation.
539 The value of this attribute will be the name of the method to get the value of
540 the attribute. If you like Java style methods, you might set this to
545 The value of this attribute will be the name of the method to set the value of
546 the attribute. If you like Java style methods, you might set this to
551 B<Boolean>. Set this if you want the reference that the attribute contains to
552 be weakened; use this when circular references are possible, which will cause
557 Takes the name of the key to look for at instantiation time of the object. A
558 common use of this is to make an underscored attribute have a non-underscored
559 initialization name. C<undef> means that passing the value in on instantiation
566 before foo => sub { ... };
568 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
573 around foo => sub { ... };
575 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
580 after foo => sub { ... };
582 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
585 =head1 SUB QUOTE AWARE
587 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
588 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
589 aware can take advantage of this.
591 =head1 INCOMPATIBILITIES WITH MOOSE
593 There is no built in type system. C<isa> is verified with a coderef, if you
594 need complex types, just make a library of coderefs, or better yet, functions
595 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
596 to L<MooseX::Types::Moose> so that you can write
598 has days_to_live => (is => 'ro', isa => Int);
600 and have it work with both; it is hoped that providing only subrefs as an
601 API will encourage the use of other type systems as well, since it's
602 probably the weakest part of Moose design-wise.
604 C<initializer> is not supported in core since the author considers it to be a
605 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
606 C<coerce> are more likely to be able to fulfill your needs.
608 There is no meta object. If you need this level of complexity you wanted
609 L<Moose> - Moo succeeds at being small because it explicitly does not
610 provide a metaprotocol. However, if you load L<Moose>, then
612 Class::MOP::class_of($moo_class_or_role)
614 will return an appropriate metaclass pre-populated by L<Moo>.
616 No support for C<super>, C<override>, C<inner>, or C<augment> - the author
617 considers augment to be a bad idea, and override can be translated:
619 override foo => sub {
626 my ($orig, $self) = (shift, shift);
632 The C<dump> method is not provided by default. The author suggests loading
633 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
634 using C<$obj-E<gt>$::Dwarn()> instead.
636 L</default> only supports coderefs, because doing otherwise is usually a
639 C<lazy_build> is not supported; you are instead encouraged to use the
640 C<is => 'lazy'> option supported by L<Moo> and L<MooseX::AttributeShortcuts>.
642 C<auto_deref> is not supported since the author considers it a bad idea.
644 C<documentation> will show up in a L<Moose> metaclass created from your class
645 but is otherwise ignored. Then again, L<Moose> ignores it as well, so this
646 is arguably not an incompatibility.
648 Since C<coerce> does not require C<isa> to be defined but L<Moose> does
649 require it, the metaclass inflation for coerce-alone is a trifle insane
650 and if you attempt to subtype the result will almost certainly break.
652 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
653 similar invocation for L<Moose> would be:
656 use warnings FATAL => "all";
658 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
659 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
660 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
665 The nearest L<Moose> invocation would be:
670 use warnings FATAL => "all";
671 use MooseX::AttributeShortcuts;
673 or, if you're inheriting from a non-Moose class,
678 use MooseX::NonMoose;
679 use warnings FATAL => "all";
680 use MooseX::AttributeShortcuts;
682 Finally, Moose requires you to call
684 __PACKAGE__->meta->make_immutable;
686 at the end of your class to get an inlined (i.e. not horribly slow)
687 constructor. Moo does it automatically the first time ->new is called
692 Users' IRC: #moose on irc.perl.org
694 Development and contribution IRC: #web-simple on irc.perl.org
698 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
702 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
704 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
706 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
708 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
710 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
712 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
714 ajgb - Alex J. G. Burzyński (cpan:AJGB) <ajgb@cpan.org>
716 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
718 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
720 Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com>
722 ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org>
726 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
731 This library is free software and may be distributed under the same terms