7 our $VERSION = '0.009013'; # 0.9.13
8 $VERSION = eval $VERSION;
16 return if $MAKERS{$target}; # already exported into this package
17 *{_getglob("${target}::extends")} = sub {
18 _load_module($_) for @_;
19 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
20 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
22 *{_getglob("${target}::with")} = sub {
24 die "Only one role supported at a time by with" if @_ > 1;
25 Moo::Role->apply_role_to_package($target, $_[0]);
27 $MAKERS{$target} = {};
28 *{_getglob("${target}::has")} = sub {
29 my ($name, %spec) = @_;
30 ($MAKERS{$target}{accessor} ||= do {
31 require Method::Generate::Accessor;
32 Method::Generate::Accessor->new
33 })->generate_method($target, $name, \%spec);
34 $class->_constructor_maker_for($target)
35 ->register_attribute_specs($name, \%spec);
37 foreach my $type (qw(before after around)) {
38 *{_getglob "${target}::${type}"} = sub {
39 require Class::Method::Modifiers;
40 _install_modifier($target, $type, @_);
45 @{"${target}::ISA"} = do {
46 require Moo::Object; ('Moo::Object');
47 } unless @{"${target}::ISA"};
51 sub _constructor_maker_for {
52 my ($class, $target, $select_super) = @_;
53 return unless $MAKERS{$target};
54 $MAKERS{$target}{constructor} ||= do {
55 require Method::Generate::Constructor;
57 my ($moo_constructor, $con);
59 if ($select_super && $MAKERS{$select_super}) {
61 $con = $MAKERS{$select_super}{constructor};
63 my $t_new = $target->can('new');
65 if ($t_new == Moo::Object->can('new')) {
67 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
68 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
71 $con = $MAKERS{$pkg}{constructor};
75 $moo_constructor = 1; # no other constructor, make a Moo one
78 Method::Generate::Constructor
81 accessor_generator => do {
82 require Method::Generate::Accessor;
83 Method::Generate::Accessor->new;
85 construction_string => (
87 ? ($con ? $con->construction_string : undef)
88 : ('$class->'.$target.'::SUPER::new(@_)')
90 subconstructor_generator => (
91 $class.'->_constructor_maker_for($class,'.perlstring($target).')'
95 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
106 Moo - Minimalist Object Orientation (with Moose compatiblity)
117 my $amount = shift || 1;
119 $self->pounds( $self->pounds - $amount );
129 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
135 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
142 my $full = Cat::Food->new(
143 taste => 'DELICIOUS.',
144 brand => 'SWEET-TREATZ',
154 This module is an extremely light-weight, high-performance L<Moose> replacement.
155 It also avoids depending on any XS modules to allow simple deployments. The
156 name C<Moo> is based on the idea that it provides almost -but not quite- two
159 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
160 L</INCOMPATIBILITIES> for more details.
162 =head1 WHY MOO EXISTS
164 If you want a full object system with a rich Metaprotocol, L<Moose> is
167 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
168 takes longer to load than most of my Moo based CGI scripts take to run.
170 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
171 you want "as little as possible" - which means "no metaprotocol", which is
174 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
175 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
178 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
179 to make it smooth to upgrade to L<Moose> when you need more than minimal
182 =head1 IMPORTED METHODS
186 Foo::Bar->new( attr1 => 3 );
190 Foo::Bar->new({ attr1 => 3 });
194 around BUILDARGS => sub {
196 my ( $class, @args ) = @_;
198 unshift @args, "attr1" if @args % 2 == 1;
200 return $class->$orig(@args);
205 The default implementation of this method accepts a hash or hash reference of
206 named parameters. If it receives a single argument that isn't a hash reference
209 You can override this method in your class to handle other types of options
210 passed to the constructor.
212 This method should always return a hash reference of named options.
216 Define a C<BUILD> method on your class and the constructor will automatically
217 call the C<BUILD> method from parent down to child after the object has
218 been instantiated. Typically this is used for object validation or possibly
223 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
224 a C<DESTROY> method is created on first object construction which will call
225 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
226 method from child upwards to parents.
228 Note that the C<DESTROY> method is created on first construction of an object
229 of your class in order to not add overhead to classes without C<DEMOLISH>
230 methods; this may prove slightly surprising if you try and define your own.
234 if ($foo->does('Some::Role1')) {
238 Returns true if the object composes in the passed role.
240 =head1 IMPORTED SUBROUTINES
244 extends 'Parent::Class';
246 Declares base class. Multiple superclasses can be passed for multiple
247 inheritance (but please use roles instead).
249 Calling extends more than once will REPLACE your superclasses, not add to
250 them like 'use base' would.
257 Composes a L<Role::Tiny> into current class. Only one role may be composed in
258 at a time to allow the code to remain as simple as possible.
266 Declares an attribute for the class.
268 The options for C<has> are as follows:
274 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
275 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
276 will create a perlish getter/setter.
280 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
281 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
285 die "$_[0] is not a number!" unless looks_like_number $_[0]
288 L<Sub::Quote aware|/SUB QUOTE AWARE>
292 Takes a coderef which is meant to coerce the attribute. The basic idea is to
293 do something like the following:
295 coerce => quote_sub q{
296 $_[0] + 1 unless $_[0] % 2
299 Coerce does not require C<isa> to be defined.
301 L<Sub::Quote aware|/SUB QUOTE AWARE>
307 handles => 'RobotRole'
309 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
310 becomes the list of methods to handle.
312 Takes a list of methods
314 handles => [ qw( one two ) ]
324 Takes a coderef which will get called any time the attribute is set. Coderef
325 will be invoked against the object with the new value as an argument.
327 Note that Moose also passes the old value, if any; this feature is not yet
330 L<Sub::Quote aware|/SUB QUOTE AWARE>
334 Takes a coderef which will get called with $self as its only argument
335 to populate an attribute if no value is supplied to the constructor - or
336 if the attribute is lazy, when the attribute is first retrieved if no
337 value has yet been provided.
339 Note that if your default is fired during new() there is no guarantee that
340 other attributes have been populated yet so you should not rely on their
343 L<Sub::Quote aware|/SUB QUOTE AWARE>
347 Takes a method name which will return true if an attribute has a value.
349 A common example of this would be to call it C<has_$foo>, implying that the
350 object has a C<$foo> set.
354 Takes a method name which will be called to create the attribute - functions
355 exactly like default except that instead of calling
365 Takes a method name which will clear the attribute.
369 B<Boolean>. Set this if you want values for the attribute to be grabbed
370 lazily. This is usually a good idea if you have a L</builder> which requires
371 another attribute to be set.
375 B<Boolean>. Set this if the attribute must be passed on instantiation.
379 The value of this attribute will be the name of the method to get the value of
380 the attribute. If you like Java style methods, you might set this to
385 The value of this attribute will be the name of the method to set the value of
386 the attribute. If you like Java style methods, you might set this to
391 B<Boolean>. Set this if you want the reference that the attribute contains to
392 be weakened; use this when circular references are possible, which will cause
397 Takes the name of the key to look for at instantiation time of the object. A
398 common use of this is to make an underscored attribute have a non-underscored
399 initialization name. C<undef> means that passing the value in on instantiation
405 before foo => sub { ... };
407 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
412 around foo => sub { ... };
414 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
419 after foo => sub { ... };
421 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
424 =head1 SUB QUOTE AWARE
426 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
427 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
428 aware can take advantage of this.
430 =head1 INCOMPATIBILITIES WITH MOOSE
432 You can only compose one role at a time. If your application is large or
433 complex enough to warrant complex composition, you wanted L<Moose>. Note that
434 this does not mean you can only compose one role per class -
439 is absolutely fine, there's just currently no equivalent of Moose's
441 with 'FirstRole', 'SecondRole';
443 which composes the two roles together, and then applies them.
445 There is no built in type system. C<isa> is verified with a coderef, if you
446 need complex types, just make a library of coderefs, or better yet, functions
447 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
448 to L<MooseX::Types::Moose> so that you can write
450 has days_to_live => (is => 'ro', isa => Int);
452 and have it work with both; it is hoped that providing only subrefs as an
453 API will encourage the use of other type systems as well, since it's
454 probably the weakest part of Moose design-wise.
456 C<initializer> is not supported in core since the author considers it to be a
457 bad idea but may be supported by an extension in future.
459 There is no meta object. If you need this level of complexity you wanted
460 L<Moose> - Moo succeeds at being small because it explicitly does not
461 provide a metaprotocol.
463 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
464 be handled by around albeit with a little more typing, and the author considers
465 augment to be a bad idea.
467 The C<dump> method is not provided by default. The author suggests loading
468 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
469 using C<$obj-E<gt>$::Dwarn()> instead.
471 L</default> only supports coderefs, because doing otherwise is usually a
474 C<lazy_build> is not supported per se, but of course it will work if you
475 manually set all the options it implies.
477 C<auto_deref> is not supported since the author considers it a bad idea.
479 C<documentation> is not supported since it's a very poor replacement for POD.
481 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
482 similar invocation for L<Moose> would be:
485 use warnings FATAL => "all";
487 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
488 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
489 module L<MooseX::AttributeShortcuts>. So if you:
494 The nearest L<Moose> invocation would be:
499 use warnings FATAL => "all";
500 use MooseX::AttributeShortcuts;
502 or, if you're inheriting from a non-Moose class,
507 use MooseX::NonMoose;
508 use warnings FATAL => "all";
509 use MooseX::AttributeShortcuts;
511 Finally, Moose requires you to call
513 __PACKAGE__->meta->make_immutable;
515 at the end of your class to get an inlined (i.e. not horribly slow)
516 constructor. Moo does it automatically the first time ->new is called
521 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
525 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
527 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
529 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
531 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
533 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
535 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
537 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
539 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
541 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
545 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
550 This library is free software and may be distributed under the same terms