8 our $VERSION = '0.091010'; # 0.91.10
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 $target => extends => sub {
28 _load_module($_) for @_;
29 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
30 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
31 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
32 delete _getstash($target)->{new};
33 Moo->_constructor_maker_for($target)
34 ->register_attribute_specs(%{$old->all_attribute_specs});
36 no warnings 'once'; # piss off. -- mst
37 $Moo::HandleMoose::MOUSE{$target} = [
38 grep defined, map Mouse::Util::find_meta($_), @_
39 ] if $INC{"Mouse.pm"};
40 $class->_maybe_reset_handlemoose($target);
43 _install_tracked $target => with => sub {
45 Moo::Role->apply_roles_to_package($target, @_);
46 $class->_maybe_reset_handlemoose($target);
48 _install_tracked $target => has => sub {
49 my ($name, %spec) = @_;
50 $class->_constructor_maker_for($target)
51 ->register_attribute_specs($name, \%spec);
52 $class->_accessor_maker_for($target)
53 ->generate_method($target, $name, \%spec);
54 $class->_maybe_reset_handlemoose($target);
57 foreach my $type (qw(before after around)) {
58 _install_tracked $target => $type => sub {
59 require Class::Method::Modifiers;
60 _install_modifier($target, $type, @_);
66 @{"${target}::ISA"} = do {
67 require Moo::Object; ('Moo::Object');
68 } unless @{"${target}::ISA"};
70 if ($INC{'Moo/HandleMoose.pm'}) {
71 Moo::HandleMoose::inject_fake_metaclass_for($target);
77 _unimport_coderefs($target, $MAKERS{$target});
80 sub _maybe_reset_handlemoose {
81 my ($class, $target) = @_;
82 if ($INC{"Moo/HandleMoose.pm"}) {
83 Moo::HandleMoose::maybe_reinject_fake_metaclass_for($target);
87 sub _accessor_maker_for {
88 my ($class, $target) = @_;
89 return unless $MAKERS{$target};
90 $MAKERS{$target}{accessor} ||= do {
91 my $maker_class = do {
93 if (my $defer_target =
94 (Sub::Defer::defer_info($target->can('new'))||[])->[0]
96 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
97 $MAKERS{$pkg} && $MAKERS{$pkg}{accessor};
104 require Method::Generate::Accessor;
105 'Method::Generate::Accessor'
112 sub _constructor_maker_for {
113 my ($class, $target, $select_super) = @_;
114 return unless $MAKERS{$target};
115 $MAKERS{$target}{constructor} ||= do {
116 require Method::Generate::Constructor;
118 my ($moo_constructor, $con);
120 if ($select_super && $MAKERS{$select_super}) {
121 $moo_constructor = 1;
122 $con = $MAKERS{$select_super}{constructor};
124 my $t_new = $target->can('new');
126 if ($t_new == Moo::Object->can('new')) {
127 $moo_constructor = 1;
128 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
129 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
131 $moo_constructor = 1;
132 $con = $MAKERS{$pkg}{constructor};
136 $moo_constructor = 1; # no other constructor, make a Moo one
139 ($con ? ref($con) : 'Method::Generate::Constructor')
142 accessor_generator => $class->_accessor_maker_for($target),
143 construction_string => (
145 ? ($con ? $con->construction_string : undef)
146 : ('$class->'.$target.'::SUPER::new(@_)')
148 subconstructor_handler => (
149 ' if ($Moo::MAKERS{$class}) {'."\n"
150 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
151 .' return $class->new(@_)'.";\n"
152 .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n"
153 .' return $meta->new_object(@_);'."\n"
158 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
169 Moo - Minimalist Object Orientation (with Moose compatiblity)
180 my $amount = shift || 1;
182 $self->pounds( $self->pounds - $amount );
192 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
198 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
205 my $full = Cat::Food->new(
206 taste => 'DELICIOUS.',
207 brand => 'SWEET-TREATZ',
217 This module is an extremely light-weight, high-performance L<Moose> replacement.
218 It also avoids depending on any XS modules to allow simple deployments. The
219 name C<Moo> is based on the idea that it provides almost -but not quite- two
222 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
223 L</INCOMPATIBILITIES> for more details.
225 =head1 WHY MOO EXISTS
227 If you want a full object system with a rich Metaprotocol, L<Moose> is
230 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
231 takes longer to load than most of my Moo based CGI scripts take to run.
233 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
234 you want "as little as possible" - which means "no metaprotocol", which is
237 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
238 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
241 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
242 to make it smooth to upgrade to L<Moose> when you need more than minimal
245 =head1 Moo and Moose - NEW, EXPERIMENTAL
247 If L<Moo> detects L<Moose> being loaded, it will automatically register
248 metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able
249 to use them in L<Moose> code without it ever realising you aren't using
252 Extending a L<Moose> class or consuming a L<Moose::Role> should also work.
254 So should extending a L<Mouse> class or consuming a L<Mouse::Role>.
256 This means that there is no need for anything like L<Any::Moose> for Moo
257 code - Moo and Moose code should simply interoperate without problem. To
258 handle L<Mouse> code, you'll likely need an empty Moo role or class consuming
259 or extending the L<Mouse> stuff since it doesn't register true L<Moose>
260 metaclasses like we do.
262 However, these features are new as of 0.91.0 (0.091000) so while serviceable,
263 they are absolutely certain to not be 100% yet; please do report bugs.
265 If you need to disable the metaclass creation, add:
269 to your code before Moose is loaded, but bear in mind that this switch is
270 currently global and turns the mechanism off entirely, so don't put this
271 in library code, only in a top level script as a temporary measure while
272 you send a bug report.
274 =head1 IMPORTED METHODS
278 Foo::Bar->new( attr1 => 3 );
282 Foo::Bar->new({ attr1 => 3 });
287 my ( $class, @args ) = @_;
289 unshift @args, "attr1" if @args % 2 == 1;
296 The default implementation of this method accepts a hash or hash reference of
297 named parameters. If it receives a single argument that isn't a hash reference
300 You can override this method in your class to handle other types of options
301 passed to the constructor.
303 This method should always return a hash reference of named options.
307 Define a C<BUILD> method on your class and the constructor will automatically
308 call the C<BUILD> method from parent down to child after the object has
309 been instantiated. Typically this is used for object validation or possibly
314 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
315 a C<DESTROY> method is created on first object construction which will call
316 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
317 method from child upwards to parents.
319 Note that the C<DESTROY> method is created on first construction of an object
320 of your class in order to not add overhead to classes without C<DEMOLISH>
321 methods; this may prove slightly surprising if you try and define your own.
325 if ($foo->does('Some::Role1')) {
329 Returns true if the object composes in the passed role.
331 =head1 IMPORTED SUBROUTINES
335 extends 'Parent::Class';
337 Declares base class. Multiple superclasses can be passed for multiple
338 inheritance (but please use roles instead).
340 Calling extends more than once will REPLACE your superclasses, not add to
341 them like 'use base' would.
349 with 'Some::Role1', 'Some::Role2';
351 Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current
352 class. An error will be raised if these roles have conflicting methods.
360 Declares an attribute for the class.
362 The options for C<has> are as follows:
368 B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>.
370 C<ro> generates an accessor that dies if you attempt to write to it - i.e.
371 a getter only - by defaulting C<reader> to the name of the attribute.
373 C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and
374 C<builder> to C<_build_${attribute_name}> to allow on-demand generated
375 attributes. This feature was my attempt to fix my incompetence when
376 originally designing C<lazy_build>, and is also implemented by
377 L<MooseX::AttributeShortcuts>.
379 C<rwp> generates a reader like C<ro>, but also sets C<writer> to
380 C<_set_${attribute_name}> for attributes that are designed to be written
381 from inside of the class, but read-only from outside.
382 This feature comes from L<MooseX::AttributeShortcuts>.
384 C<rw> generates a normal getter/setter by defaulting C<accessor> to the
385 name of the attribute.
389 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
390 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
394 die "$_[0] is not a number!" unless looks_like_number $_[0]
397 L<Sub::Quote aware|/SUB QUOTE AWARE>
399 Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion
400 subroutine has been supplied, C<isa> checks are not structural to your code
401 and can, if desired, be omitted on non-debug builds (although if this results
402 in an uncaught bug causing your program to break, the L<Moo> authors guarantee
403 nothing except that you get to keep both halves).
405 If you want L<MooseX::Types> style named types, look at
406 L<MooX::Types::MooseLike>.
408 To cause your C<isa> entries to be automatically mapped to named
409 L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour
410 of creating an anonymous type), set:
412 $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub {
413 require MooseX::Types::Something;
414 return MooseX::Types::Something::TypeName();
417 Note that this example is purely illustrative; anything that returns a
418 L<Moose::Meta::TypeConstraint> object or something similar enough to it to
419 make L<Moose> happy is fine.
423 Takes a coderef which is meant to coerce the attribute. The basic idea is to
424 do something like the following:
426 coerce => quote_sub q{
427 $_[0] + 1 unless $_[0] % 2
430 Note that L<Moo> will always fire your coercion - this is to permit
431 isa entries to be used purely for bug trapping, whereas coercions are
432 always structural to your code. We do, however, apply any supplied C<isa>
433 check after the coercion has run to ensure that it returned a valid value.
435 L<Sub::Quote aware|/SUB QUOTE AWARE>
441 handles => 'RobotRole'
443 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
444 becomes the list of methods to handle.
446 Takes a list of methods
448 handles => [ qw( one two ) ]
458 Takes a coderef which will get called any time the attribute is set. This
459 includes the constructor. Coderef will be invoked against the object with the
460 new value as an argument.
462 If you set this to just C<1>, it generates a trigger which calls the
463 C<_trigger_${attr_name}> method on C<$self>. This feature comes from
464 L<MooseX::AttributeShortcuts>.
466 Note that Moose also passes the old value, if any; this feature is not yet
469 L<Sub::Quote aware|/SUB QUOTE AWARE>
473 Takes a coderef which will get called with $self as its only argument
474 to populate an attribute if no value is supplied to the constructor - or
475 if the attribute is lazy, when the attribute is first retrieved if no
476 value has yet been provided.
478 Note that if your default is fired during new() there is no guarantee that
479 other attributes have been populated yet so you should not rely on their
482 L<Sub::Quote aware|/SUB QUOTE AWARE>
486 Takes a method name which will return true if an attribute has a value.
488 If you set this to just C<1>, the predicate is automatically named
489 C<has_${attr_name}> if your attribute's name does not start with an
490 underscore, or <_has_${attr_name_without_the_underscore}> if it does.
491 This feature comes from L<MooseX::AttributeShortcuts>.
495 Takes a method name which will be called to create the attribute - functions
496 exactly like default except that instead of calling
504 If you set this to just C<1>, the predicate is automatically named
505 C<_build_${attr_name}>. This feature comes from L<MooseX::AttributeShortcuts>.
509 Takes a method name which will clear the attribute.
511 If you set this to just C<1>, the clearer is automatically named
512 C<clear_${attr_name}> if your attribute's name does not start with an
513 underscore, or <_clear_${attr_name_without_the_underscore}> if it does.
514 This feature comes from L<MooseX::AttributeShortcuts>.
518 B<Boolean>. Set this if you want values for the attribute to be grabbed
519 lazily. This is usually a good idea if you have a L</builder> which requires
520 another attribute to be set.
524 B<Boolean>. Set this if the attribute must be passed on instantiation.
528 The value of this attribute will be the name of the method to get the value of
529 the attribute. If you like Java style methods, you might set this to
534 The value of this attribute will be the name of the method to set the value of
535 the attribute. If you like Java style methods, you might set this to
540 B<Boolean>. Set this if you want the reference that the attribute contains to
541 be weakened; use this when circular references are possible, which will cause
546 Takes the name of the key to look for at instantiation time of the object. A
547 common use of this is to make an underscored attribute have a non-underscored
548 initialization name. C<undef> means that passing the value in on instantiation
555 before foo => sub { ... };
557 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
562 around foo => sub { ... };
564 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
569 after foo => sub { ... };
571 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
574 =head1 SUB QUOTE AWARE
576 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
577 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
578 aware can take advantage of this.
580 =head1 INCOMPATIBILITIES WITH MOOSE
582 There is no built in type system. C<isa> is verified with a coderef, if you
583 need complex types, just make a library of coderefs, or better yet, functions
584 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
585 to L<MooseX::Types::Moose> so that you can write
587 has days_to_live => (is => 'ro', isa => Int);
589 and have it work with both; it is hoped that providing only subrefs as an
590 API will encourage the use of other type systems as well, since it's
591 probably the weakest part of Moose design-wise.
593 C<initializer> is not supported in core since the author considers it to be a
594 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
595 C<coerce> are more likely to be able to fulfill your needs.
597 There is no meta object. If you need this level of complexity you wanted
598 L<Moose> - Moo succeeds at being small because it explicitly does not
599 provide a metaprotocol. However, if you load L<Moose>, then
601 Class::MOP::class_of($moo_class_or_role)
603 will return an appropriate metaclass pre-populated by L<Moo>.
605 No support for C<super>, C<override>, C<inner>, or C<augment> - the author
606 considers augment to be a bad idea, and override can be translated:
608 override foo => sub {
615 my ($orig, $self) = (shift, shift);
621 The C<dump> method is not provided by default. The author suggests loading
622 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
623 using C<$obj-E<gt>$::Dwarn()> instead.
625 L</default> only supports coderefs, because doing otherwise is usually a
628 C<lazy_build> is not supported; you are instead encouraged to use the
629 C<is => 'lazy'> option supported by L<Moo> and L<MooseX::AttributeShortcuts>.
631 C<auto_deref> is not supported since the author considers it a bad idea.
633 C<documentation> will show up in a L<Moose> metaclass created from your class
634 but is otherwise ignored. Then again, L<Moose> ignores it as well, so this
635 is arguably not an incompatibility.
637 Since C<coerce> does not require C<isa> to be defined but L<Moose> does
638 require it, the metaclass inflation for coerce-alone is a trifle insane
639 and if you attempt to subtype the result will almost certainly break.
641 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
642 similar invocation for L<Moose> would be:
645 use warnings FATAL => "all";
647 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
648 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
649 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
654 The nearest L<Moose> invocation would be:
659 use warnings FATAL => "all";
660 use MooseX::AttributeShortcuts;
662 or, if you're inheriting from a non-Moose class,
667 use MooseX::NonMoose;
668 use warnings FATAL => "all";
669 use MooseX::AttributeShortcuts;
671 Finally, Moose requires you to call
673 __PACKAGE__->meta->make_immutable;
675 at the end of your class to get an inlined (i.e. not horribly slow)
676 constructor. Moo does it automatically the first time ->new is called
681 Users' IRC: #moose on irc.perl.org
683 Development and contribution IRC: #web-simple on irc.perl.org
687 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
691 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
693 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
695 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
697 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
699 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
701 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
703 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
705 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
707 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
711 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
716 This library is free software and may be distributed under the same terms