8 our $VERSION = '0.091011'; # 0.91.11
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 {
72 _load_module($_) for @_;
73 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
74 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
75 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
76 delete _getstash($target)->{new};
77 Moo->_constructor_maker_for($target)
78 ->register_attribute_specs(%{$old->all_attribute_specs});
80 no warnings 'once'; # piss off. -- mst
81 $Moo::HandleMoose::MOUSE{$target} = [
82 grep defined, map Mouse::Util::find_meta($_), @_
83 ] if $INC{"Mouse.pm"};
86 sub _maybe_reset_handlemoose {
87 my ($class, $target) = @_;
88 if ($INC{"Moo/HandleMoose.pm"}) {
89 Moo::HandleMoose::maybe_reinject_fake_metaclass_for($target);
93 sub _accessor_maker_for {
94 my ($class, $target) = @_;
95 return unless $MAKERS{$target};
96 $MAKERS{$target}{accessor} ||= do {
97 my $maker_class = do {
99 if (my $defer_target =
100 (Sub::Defer::defer_info($target->can('new'))||[])->[0]
102 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
103 $MAKERS{$pkg} && $MAKERS{$pkg}{accessor};
110 require Method::Generate::Accessor;
111 'Method::Generate::Accessor'
118 sub _constructor_maker_for {
119 my ($class, $target, $select_super) = @_;
120 return unless $MAKERS{$target};
121 $MAKERS{$target}{constructor} ||= do {
122 require Method::Generate::Constructor;
124 my ($moo_constructor, $con);
126 if ($select_super && $MAKERS{$select_super}) {
127 $moo_constructor = 1;
128 $con = $MAKERS{$select_super}{constructor};
130 my $t_new = $target->can('new');
132 if ($t_new == Moo::Object->can('new')) {
133 $moo_constructor = 1;
134 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
135 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
137 $moo_constructor = 1;
138 $con = $MAKERS{$pkg}{constructor};
142 $moo_constructor = 1; # no other constructor, make a Moo one
145 ($con ? ref($con) : 'Method::Generate::Constructor')
148 accessor_generator => $class->_accessor_maker_for($target),
149 construction_string => (
151 ? ($con ? $con->construction_string : undef)
152 : ('$class->'.$target.'::SUPER::new(@_)')
154 subconstructor_handler => (
155 ' if ($Moo::MAKERS{$class}) {'."\n"
156 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
157 .' return $class->new(@_)'.";\n"
158 .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n"
159 .' return $meta->new_object(@_);'."\n"
164 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
175 Moo - Minimalist Object Orientation (with Moose compatiblity)
186 my $amount = shift || 1;
188 $self->pounds( $self->pounds - $amount );
198 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
204 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
211 my $full = Cat::Food->new(
212 taste => 'DELICIOUS.',
213 brand => 'SWEET-TREATZ',
223 This module is an extremely light-weight, high-performance L<Moose> replacement.
224 It also avoids depending on any XS modules to allow simple deployments. The
225 name C<Moo> is based on the idea that it provides almost -but not quite- two
228 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
229 L</INCOMPATIBILITIES> for more details.
231 =head1 WHY MOO EXISTS
233 If you want a full object system with a rich Metaprotocol, L<Moose> is
236 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
237 takes longer to load than most of my Moo based CGI scripts take to run.
239 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
240 you want "as little as possible" - which means "no metaprotocol", which is
243 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
244 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
247 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
248 to make it smooth to upgrade to L<Moose> when you need more than minimal
251 =head1 Moo and Moose - NEW, EXPERIMENTAL
253 If L<Moo> detects L<Moose> being loaded, it will automatically register
254 metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able
255 to use them in L<Moose> code without it ever realising you aren't using
258 Extending a L<Moose> class or consuming a L<Moose::Role> should also work.
260 So should extending a L<Mouse> class or consuming a L<Mouse::Role>.
262 This means that there is no need for anything like L<Any::Moose> for Moo
263 code - Moo and Moose code should simply interoperate without problem. To
264 handle L<Mouse> code, you'll likely need an empty Moo role or class consuming
265 or extending the L<Mouse> stuff since it doesn't register true L<Moose>
266 metaclasses like we do.
268 However, these features are new as of 0.91.0 (0.091000) so while serviceable,
269 they are absolutely certain to not be 100% yet; please do report bugs.
271 If you need to disable the metaclass creation, add:
275 to your code before Moose is loaded, but bear in mind that this switch is
276 currently global and turns the mechanism off entirely, so don't put this
277 in library code, only in a top level script as a temporary measure while
278 you send a bug report.
280 =head1 IMPORTED METHODS
284 Foo::Bar->new( attr1 => 3 );
288 Foo::Bar->new({ attr1 => 3 });
293 my ( $class, @args ) = @_;
295 unshift @args, "attr1" if @args % 2 == 1;
302 The default implementation of this method accepts a hash or hash reference of
303 named parameters. If it receives a single argument that isn't a hash reference
306 You can override this method in your class to handle other types of options
307 passed to the constructor.
309 This method should always return a hash reference of named options.
313 Define a C<BUILD> method on your class and the constructor will automatically
314 call the C<BUILD> method from parent down to child after the object has
315 been instantiated. Typically this is used for object validation or possibly
320 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
321 a C<DESTROY> method is created on first object construction which will call
322 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
323 method from child upwards to parents.
325 Note that the C<DESTROY> method is created on first construction of an object
326 of your class in order to not add overhead to classes without C<DEMOLISH>
327 methods; this may prove slightly surprising if you try and define your own.
331 if ($foo->does('Some::Role1')) {
335 Returns true if the object composes in the passed role.
337 =head1 IMPORTED SUBROUTINES
341 extends 'Parent::Class';
343 Declares base class. Multiple superclasses can be passed for multiple
344 inheritance (but please use roles instead).
346 Calling extends more than once will REPLACE your superclasses, not add to
347 them like 'use base' would.
355 with 'Some::Role1', 'Some::Role2';
357 Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current
358 class. An error will be raised if these roles have conflicting methods.
366 Declares an attribute for the class.
368 The options for C<has> are as follows:
374 B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>.
376 C<ro> generates an accessor that dies if you attempt to write to it - i.e.
377 a getter only - by defaulting C<reader> to the name of the attribute.
379 C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and
380 C<builder> to C<_build_${attribute_name}> to allow on-demand generated
381 attributes. This feature was my attempt to fix my incompetence when
382 originally designing C<lazy_build>, and is also implemented by
383 L<MooseX::AttributeShortcuts>.
385 C<rwp> generates a reader like C<ro>, but also sets C<writer> to
386 C<_set_${attribute_name}> for attributes that are designed to be written
387 from inside of the class, but read-only from outside.
388 This feature comes from L<MooseX::AttributeShortcuts>.
390 C<rw> generates a normal getter/setter by defaulting C<accessor> to the
391 name of the attribute.
395 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
396 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
400 die "$_[0] is not a number!" unless looks_like_number $_[0]
403 L<Sub::Quote aware|/SUB QUOTE AWARE>
405 Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion
406 subroutine has been supplied, C<isa> checks are not structural to your code
407 and can, if desired, be omitted on non-debug builds (although if this results
408 in an uncaught bug causing your program to break, the L<Moo> authors guarantee
409 nothing except that you get to keep both halves).
411 If you want L<MooseX::Types> style named types, look at
412 L<MooX::Types::MooseLike>.
414 To cause your C<isa> entries to be automatically mapped to named
415 L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour
416 of creating an anonymous type), set:
418 $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub {
419 require MooseX::Types::Something;
420 return MooseX::Types::Something::TypeName();
423 Note that this example is purely illustrative; anything that returns a
424 L<Moose::Meta::TypeConstraint> object or something similar enough to it to
425 make L<Moose> happy is fine.
429 Takes a coderef which is meant to coerce the attribute. The basic idea is to
430 do something like the following:
432 coerce => quote_sub q{
433 $_[0] + 1 unless $_[0] % 2
436 Note that L<Moo> will always fire your coercion - this is to permit
437 isa entries to be used purely for bug trapping, whereas coercions are
438 always structural to your code. We do, however, apply any supplied C<isa>
439 check after the coercion has run to ensure that it returned a valid value.
441 L<Sub::Quote aware|/SUB QUOTE AWARE>
447 handles => 'RobotRole'
449 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
450 becomes the list of methods to handle.
452 Takes a list of methods
454 handles => [ qw( one two ) ]
464 Takes a coderef which will get called any time the attribute is set. This
465 includes the constructor. Coderef will be invoked against the object with the
466 new value as an argument.
468 If you set this to just C<1>, it generates a trigger which calls the
469 C<_trigger_${attr_name}> method on C<$self>. This feature comes from
470 L<MooseX::AttributeShortcuts>.
472 Note that Moose also passes the old value, if any; this feature is not yet
475 L<Sub::Quote aware|/SUB QUOTE AWARE>
479 Takes a coderef which will get called with $self as its only argument
480 to populate an attribute if no value is supplied to the constructor - or
481 if the attribute is lazy, when the attribute is first retrieved if no
482 value has yet been provided.
484 Note that if your default is fired during new() there is no guarantee that
485 other attributes have been populated yet so you should not rely on their
488 L<Sub::Quote aware|/SUB QUOTE AWARE>
492 Takes a method name which will return true if an attribute has a value.
494 If you set this to just C<1>, the predicate is automatically named
495 C<has_${attr_name}> if your attribute's name does not start with an
496 underscore, or <_has_${attr_name_without_the_underscore}> if it does.
497 This feature comes from L<MooseX::AttributeShortcuts>.
501 Takes a method name which will be called to create the attribute - functions
502 exactly like default except that instead of calling
510 If you set this to just C<1>, the predicate is automatically named
511 C<_build_${attr_name}>. This feature comes from L<MooseX::AttributeShortcuts>.
515 Takes a method name which will clear the attribute.
517 If you set this to just C<1>, the clearer is automatically named
518 C<clear_${attr_name}> if your attribute's name does not start with an
519 underscore, or <_clear_${attr_name_without_the_underscore}> if it does.
520 This feature comes from L<MooseX::AttributeShortcuts>.
524 B<Boolean>. Set this if you want values for the attribute to be grabbed
525 lazily. This is usually a good idea if you have a L</builder> which requires
526 another attribute to be set.
530 B<Boolean>. Set this if the attribute must be passed on instantiation.
534 The value of this attribute will be the name of the method to get the value of
535 the attribute. If you like Java style methods, you might set this to
540 The value of this attribute will be the name of the method to set the value of
541 the attribute. If you like Java style methods, you might set this to
546 B<Boolean>. Set this if you want the reference that the attribute contains to
547 be weakened; use this when circular references are possible, which will cause
552 Takes the name of the key to look for at instantiation time of the object. A
553 common use of this is to make an underscored attribute have a non-underscored
554 initialization name. C<undef> means that passing the value in on instantiation
561 before foo => sub { ... };
563 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
568 around foo => sub { ... };
570 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
575 after foo => sub { ... };
577 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
580 =head1 SUB QUOTE AWARE
582 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
583 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
584 aware can take advantage of this.
586 =head1 INCOMPATIBILITIES WITH MOOSE
588 There is no built in type system. C<isa> is verified with a coderef, if you
589 need complex types, just make a library of coderefs, or better yet, functions
590 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
591 to L<MooseX::Types::Moose> so that you can write
593 has days_to_live => (is => 'ro', isa => Int);
595 and have it work with both; it is hoped that providing only subrefs as an
596 API will encourage the use of other type systems as well, since it's
597 probably the weakest part of Moose design-wise.
599 C<initializer> is not supported in core since the author considers it to be a
600 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
601 C<coerce> are more likely to be able to fulfill your needs.
603 There is no meta object. If you need this level of complexity you wanted
604 L<Moose> - Moo succeeds at being small because it explicitly does not
605 provide a metaprotocol. However, if you load L<Moose>, then
607 Class::MOP::class_of($moo_class_or_role)
609 will return an appropriate metaclass pre-populated by L<Moo>.
611 No support for C<super>, C<override>, C<inner>, or C<augment> - the author
612 considers augment to be a bad idea, and override can be translated:
614 override foo => sub {
621 my ($orig, $self) = (shift, shift);
627 The C<dump> method is not provided by default. The author suggests loading
628 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
629 using C<$obj-E<gt>$::Dwarn()> instead.
631 L</default> only supports coderefs, because doing otherwise is usually a
634 C<lazy_build> is not supported; you are instead encouraged to use the
635 C<is => 'lazy'> option supported by L<Moo> and L<MooseX::AttributeShortcuts>.
637 C<auto_deref> is not supported since the author considers it a bad idea.
639 C<documentation> will show up in a L<Moose> metaclass created from your class
640 but is otherwise ignored. Then again, L<Moose> ignores it as well, so this
641 is arguably not an incompatibility.
643 Since C<coerce> does not require C<isa> to be defined but L<Moose> does
644 require it, the metaclass inflation for coerce-alone is a trifle insane
645 and if you attempt to subtype the result will almost certainly break.
647 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
648 similar invocation for L<Moose> would be:
651 use warnings FATAL => "all";
653 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
654 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
655 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
660 The nearest L<Moose> invocation would be:
665 use warnings FATAL => "all";
666 use MooseX::AttributeShortcuts;
668 or, if you're inheriting from a non-Moose class,
673 use MooseX::NonMoose;
674 use warnings FATAL => "all";
675 use MooseX::AttributeShortcuts;
677 Finally, Moose requires you to call
679 __PACKAGE__->meta->make_immutable;
681 at the end of your class to get an inlined (i.e. not horribly slow)
682 constructor. Moo does it automatically the first time ->new is called
687 Users' IRC: #moose on irc.perl.org
689 Development and contribution IRC: #web-simple on irc.perl.org
693 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
697 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
699 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
701 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
703 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
705 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
707 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
709 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
711 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
713 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
715 Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com>
719 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
724 This library is free software and may be distributed under the same terms