7 our $VERSION = '0.009_017'; # 0.9.17
8 $VERSION = eval $VERSION;
10 require Moo::sification;
18 return if $MAKERS{$target}; # already exported into this package
19 _install_coderef "${target}::extends" => sub {
20 _load_module($_) for @_;
21 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
22 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
23 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
24 delete _getstash($target)->{new};
25 Moo->_constructor_maker_for($target)
26 ->register_attribute_specs(%{$old->all_attribute_specs});
29 _install_coderef "${target}::with" => sub {
31 Moo::Role->apply_roles_to_package($target, $_[0]);
33 $MAKERS{$target} = {};
34 _install_coderef "${target}::has" => sub {
35 my ($name, %spec) = @_;
36 ($MAKERS{$target}{accessor} ||= do {
37 require Method::Generate::Accessor;
38 Method::Generate::Accessor->new
39 })->generate_method($target, $name, \%spec);
40 $class->_constructor_maker_for($target)
41 ->register_attribute_specs($name, \%spec);
43 foreach my $type (qw(before after around)) {
44 _install_coderef "${target}::${type}" => sub {
45 require Class::Method::Modifiers;
46 _install_modifier($target, $type, @_);
51 @{"${target}::ISA"} = do {
52 require Moo::Object; ('Moo::Object');
53 } unless @{"${target}::ISA"};
55 if ($INC{'Moo/HandleMoose.pm'}) {
56 Moo::HandleMoose::inject_fake_metaclass_for($target);
60 sub _constructor_maker_for {
61 my ($class, $target, $select_super) = @_;
62 return unless $MAKERS{$target};
63 $MAKERS{$target}{constructor} ||= do {
64 require Method::Generate::Constructor;
66 my ($moo_constructor, $con);
68 if ($select_super && $MAKERS{$select_super}) {
70 $con = $MAKERS{$select_super}{constructor};
72 my $t_new = $target->can('new');
74 if ($t_new == Moo::Object->can('new')) {
76 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
77 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
80 $con = $MAKERS{$pkg}{constructor};
84 $moo_constructor = 1; # no other constructor, make a Moo one
87 Method::Generate::Constructor
90 accessor_generator => do {
91 require Method::Generate::Accessor;
92 Method::Generate::Accessor->new;
94 construction_string => (
96 ? ($con ? $con->construction_string : undef)
97 : ('$class->'.$target.'::SUPER::new(@_)')
99 subconstructor_handler => (
100 ' if ($Moo::MAKERS{$class}) {'."\n"
101 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
102 .' return $class->new(@_)'.";\n"
107 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
118 Moo - Minimalist Object Orientation (with Moose compatiblity)
129 my $amount = shift || 1;
131 $self->pounds( $self->pounds - $amount );
141 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
147 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
154 my $full = Cat::Food->new(
155 taste => 'DELICIOUS.',
156 brand => 'SWEET-TREATZ',
166 This module is an extremely light-weight, high-performance L<Moose> replacement.
167 It also avoids depending on any XS modules to allow simple deployments. The
168 name C<Moo> is based on the idea that it provides almost -but not quite- two
171 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
172 L</INCOMPATIBILITIES> for more details.
174 =head1 WHY MOO EXISTS
176 If you want a full object system with a rich Metaprotocol, L<Moose> is
179 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
180 takes longer to load than most of my Moo based CGI scripts take to run.
182 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
183 you want "as little as possible" - which means "no metaprotocol", which is
186 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
187 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
190 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
191 to make it smooth to upgrade to L<Moose> when you need more than minimal
194 =head1 IMPORTED METHODS
198 Foo::Bar->new( attr1 => 3 );
202 Foo::Bar->new({ attr1 => 3 });
206 around BUILDARGS => sub {
208 my ( $class, @args ) = @_;
210 unshift @args, "attr1" if @args % 2 == 1;
212 return $class->$orig(@args);
217 The default implementation of this method accepts a hash or hash reference of
218 named parameters. If it receives a single argument that isn't a hash reference
221 You can override this method in your class to handle other types of options
222 passed to the constructor.
224 This method should always return a hash reference of named options.
228 Define a C<BUILD> method on your class and the constructor will automatically
229 call the C<BUILD> method from parent down to child after the object has
230 been instantiated. Typically this is used for object validation or possibly
235 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
236 a C<DESTROY> method is created on first object construction which will call
237 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
238 method from child upwards to parents.
240 Note that the C<DESTROY> method is created on first construction of an object
241 of your class in order to not add overhead to classes without C<DEMOLISH>
242 methods; this may prove slightly surprising if you try and define your own.
246 if ($foo->does('Some::Role1')) {
250 Returns true if the object composes in the passed role.
252 =head1 IMPORTED SUBROUTINES
256 extends 'Parent::Class';
258 Declares base class. Multiple superclasses can be passed for multiple
259 inheritance (but please use roles instead).
261 Calling extends more than once will REPLACE your superclasses, not add to
262 them like 'use base' would.
269 Composes a L<Role::Tiny> into current class. Only one role may be composed in
270 at a time to allow the code to remain as simple as possible.
278 Declares an attribute for the class.
280 The options for C<has> are as follows:
286 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
287 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
288 will create a perlish getter/setter.
292 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
293 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
297 die "$_[0] is not a number!" unless looks_like_number $_[0]
300 L<Sub::Quote aware|/SUB QUOTE AWARE>
304 Takes a coderef which is meant to coerce the attribute. The basic idea is to
305 do something like the following:
307 coerce => quote_sub q{
308 $_[0] + 1 unless $_[0] % 2
311 Coerce does not require C<isa> to be defined.
313 L<Sub::Quote aware|/SUB QUOTE AWARE>
319 handles => 'RobotRole'
321 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
322 becomes the list of methods to handle.
324 Takes a list of methods
326 handles => [ qw( one two ) ]
336 Takes a coderef which will get called any time the attribute is set. This
337 includes the constructor. Coderef will be invoked against the object with the
338 new value as an argument.
340 Note that Moose also passes the old value, if any; this feature is not yet
343 L<Sub::Quote aware|/SUB QUOTE AWARE>
347 Takes a coderef which will get called with $self as its only argument
348 to populate an attribute if no value is supplied to the constructor - or
349 if the attribute is lazy, when the attribute is first retrieved if no
350 value has yet been provided.
352 Note that if your default is fired during new() there is no guarantee that
353 other attributes have been populated yet so you should not rely on their
356 L<Sub::Quote aware|/SUB QUOTE AWARE>
360 Takes a method name which will return true if an attribute has a value.
362 A common example of this would be to call it C<has_$foo>, implying that the
363 object has a C<$foo> set.
367 Takes a method name which will be called to create the attribute - functions
368 exactly like default except that instead of calling
378 Takes a method name which will clear the attribute.
382 B<Boolean>. Set this if you want values for the attribute to be grabbed
383 lazily. This is usually a good idea if you have a L</builder> which requires
384 another attribute to be set.
388 B<Boolean>. Set this if the attribute must be passed on instantiation.
392 The value of this attribute will be the name of the method to get the value of
393 the attribute. If you like Java style methods, you might set this to
398 The value of this attribute will be the name of the method to set the value of
399 the attribute. If you like Java style methods, you might set this to
404 B<Boolean>. Set this if you want the reference that the attribute contains to
405 be weakened; use this when circular references are possible, which will cause
410 Takes the name of the key to look for at instantiation time of the object. A
411 common use of this is to make an underscored attribute have a non-underscored
412 initialization name. C<undef> means that passing the value in on instantiation
418 before foo => sub { ... };
420 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
425 around foo => sub { ... };
427 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
432 after foo => sub { ... };
434 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
437 =head1 SUB QUOTE AWARE
439 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
440 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
441 aware can take advantage of this.
443 =head1 INCOMPATIBILITIES WITH MOOSE
445 You can only compose one role at a time. If your application is large or
446 complex enough to warrant complex composition, you wanted L<Moose>. Note that
447 this does not mean you can only compose one role per class -
452 is absolutely fine, there's just currently no equivalent of Moose's
454 with 'FirstRole', 'SecondRole';
456 which composes the two roles together, and then applies them.
458 There is no built in type system. C<isa> is verified with a coderef, if you
459 need complex types, just make a library of coderefs, or better yet, functions
460 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
461 to L<MooseX::Types::Moose> so that you can write
463 has days_to_live => (is => 'ro', isa => Int);
465 and have it work with both; it is hoped that providing only subrefs as an
466 API will encourage the use of other type systems as well, since it's
467 probably the weakest part of Moose design-wise.
469 C<initializer> is not supported in core since the author considers it to be a
470 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
471 C<coerce> are more likely to be able to fulfill your needs.
473 There is no meta object. If you need this level of complexity you wanted
474 L<Moose> - Moo succeeds at being small because it explicitly does not
475 provide a metaprotocol.
477 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
478 be handled by around albeit with a little more typing, and the author considers
479 augment to be a bad idea.
481 The C<dump> method is not provided by default. The author suggests loading
482 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
483 using C<$obj-E<gt>$::Dwarn()> instead.
485 L</default> only supports coderefs, because doing otherwise is usually a
488 C<lazy_build> is not supported per se, but of course it will work if you
489 manually set all the options it implies.
491 C<auto_deref> is not supported since the author considers it a bad idea.
493 C<documentation> is not supported since it's a very poor replacement for POD.
495 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
496 similar invocation for L<Moose> would be:
499 use warnings FATAL => "all";
501 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
502 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
503 module L<MooseX::AttributeShortcuts>. So if you:
508 The nearest L<Moose> invocation would be:
513 use warnings FATAL => "all";
514 use MooseX::AttributeShortcuts;
516 or, if you're inheriting from a non-Moose class,
521 use MooseX::NonMoose;
522 use warnings FATAL => "all";
523 use MooseX::AttributeShortcuts;
525 Finally, Moose requires you to call
527 __PACKAGE__->meta->make_immutable;
529 at the end of your class to get an inlined (i.e. not horribly slow)
530 constructor. Moo does it automatically the first time ->new is called
535 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
539 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
541 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
543 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
545 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
547 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
549 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
551 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
553 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
555 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
559 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
564 This library is free software and may be distributed under the same terms