use strict;
use warnings;
-our $VERSION = '0.13';
+our $VERSION = '0.45';
+our $AUTHORITY = 'cpan:STEVAN';
use Scalar::Util 'blessed', 'reftype';
-use Carp 'confess';
-use Sub::Name 'subname';
-use B 'svref_2object';
+use Carp 'confess', 'croak', 'cluck';
-use UNIVERSAL::require;
use Sub::Exporter;
-use Class::MOP;
+use Class::MOP 0.56;
use Moose::Meta::Class;
use Moose::Meta::TypeConstraint;
use Moose::Meta::Attribute;
use Moose::Meta::Instance;
+use Moose::Meta::Role;
+
use Moose::Object;
use Moose::Util::TypeConstraints;
+use Moose::Util ();
{
my $CALLER;
- sub _init_meta {
- my $class = $CALLER;
+ sub init_meta {
+ my ( $class, $base_class, $metaclass ) = @_;
+ $base_class = 'Moose::Object' unless defined $base_class;
+ $metaclass = 'Moose::Meta::Class' unless defined $metaclass;
+
+ confess
+ "The Metaclass $metaclass must be a subclass of Moose::Meta::Class."
+ unless $metaclass->isa('Moose::Meta::Class');
# make a subtype for each Moose class
- subtype $class
- => as 'Object'
- => where { $_->isa($class) }
- unless find_type_constraint($class);
+ class_type($class)
+ unless find_type_constraint($class);
my $meta;
- if ($class->can('meta')) {
+ if ( $class->can('meta') ) {
# NOTE:
- # this is the case where the metaclass pragma
- # was used before the 'use Moose' statement to
+ # this is the case where the metaclass pragma
+ # was used before the 'use Moose' statement to
# override a specific class
$meta = $class->meta();
- (blessed($meta) && $meta->isa('Moose::Meta::Class'))
- || confess "You already have a &meta function, but it does not return a Moose::Meta::Class";
+ ( blessed($meta) && $meta->isa('Moose::Meta::Class') )
+ || confess "You already have a &meta function, but it does not return a Moose::Meta::Class";
}
else {
# NOTE:
- # this is broken currently, we actually need
- # to allow the possiblity of an inherited
- # meta, which will not be visible until the
- # user 'extends' first. This needs to have
- # more intelligence to it
- $meta = Moose::Meta::Class->initialize($class);
- $meta->add_method('meta' => sub {
- # re-initialize so it inherits properly
- Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]);
- })
+ # this is broken currently, we actually need
+ # to allow the possiblity of an inherited
+ # meta, which will not be visible until the
+ # user 'extends' first. This needs to have
+ # more intelligence to it
+ $meta = $metaclass->initialize($class);
+ $meta->add_method(
+ 'meta' => sub {
+ # re-initialize so it inherits properly
+ $metaclass->initialize( blessed( $_[0] ) || $_[0] );
+ }
+ );
}
# make sure they inherit from Moose::Object
- $meta->superclasses('Moose::Object')
- unless $meta->superclasses();
+ $meta->superclasses($base_class)
+ unless $meta->superclasses();
+
+ return $meta;
}
my %exports = (
extends => sub {
my $class = $CALLER;
- return subname 'Moose::extends' => sub (@) {
+ return Class::MOP::subname('Moose::extends' => sub (@) {
confess "Must derive at least one class" unless @_;
- _load_all_classes(@_);
- # this checks the metaclass to make sure
- # it is correct, sometimes it can get out
+
+ my @supers = @_;
+ foreach my $super (@supers) {
+ Class::MOP::load_class($super);
+ }
+
+ # this checks the metaclass to make sure
+ # it is correct, sometimes it can get out
# of sync when the classes are being built
- my $meta = $class->meta->_fix_metaclass_incompatability(@_);
- $meta->superclasses(@_);
- };
+ my $meta = $class->meta->_fix_metaclass_incompatability(@supers);
+ $meta->superclasses(@supers);
+ });
},
with => sub {
my $class = $CALLER;
- return subname 'Moose::with' => sub (@) {
- my (@roles) = @_;
- confess "Must specify at least one role" unless @roles;
- _load_all_classes(@roles);
- $class->meta->_apply_all_roles(@roles);
- };
+ return Class::MOP::subname('Moose::with' => sub (@) {
+ Moose::Util::apply_all_roles($class->meta, @_)
+ });
},
has => sub {
my $class = $CALLER;
- return subname 'Moose::has' => sub ($;%) {
- my ($name, %options) = @_;
- $class->meta->_process_attribute($name, %options);
- };
+ return Class::MOP::subname('Moose::has' => sub ($;%) {
+ my $name = shift;
+ croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1;
+ my %options = @_;
+ my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ];
+ $class->meta->add_attribute( $_, %options ) for @$attrs;
+ });
},
before => sub {
my $class = $CALLER;
- return subname 'Moose::before' => sub (@&) {
+ return Class::MOP::subname('Moose::before' => sub (@&) {
my $code = pop @_;
my $meta = $class->meta;
- $meta->add_before_method_modifier($_, $code) for @_;
- };
+ $meta->add_before_method_modifier( $_, $code ) for @_;
+ });
},
after => sub {
my $class = $CALLER;
- return subname 'Moose::after' => sub (@&) {
+ return Class::MOP::subname('Moose::after' => sub (@&) {
my $code = pop @_;
my $meta = $class->meta;
- $meta->add_after_method_modifier($_, $code) for @_;
- };
+ $meta->add_after_method_modifier( $_, $code ) for @_;
+ });
},
around => sub {
- my $class = $CALLER;
- return subname 'Moose::around' => sub (@&) {
+ my $class = $CALLER;
+ return Class::MOP::subname('Moose::around' => sub (@&) {
my $code = pop @_;
my $meta = $class->meta;
- $meta->add_around_method_modifier($_, $code) for @_;
- };
+ $meta->add_around_method_modifier( $_, $code ) for @_;
+ });
},
super => sub {
- return subname 'Moose::super' => sub {};
+ # FIXME can be made into goto, might break caller() for existing code
+ return Class::MOP::subname('Moose::super' => sub { return unless our $SUPER_BODY; $SUPER_BODY->(our @SUPER_ARGS) })
},
+ #next => sub {
+ # return subname 'Moose::next' => sub { @_ = our @SUPER_ARGS; goto \&next::method };
+ #},
override => sub {
my $class = $CALLER;
- return subname 'Moose::override' => sub ($&) {
- my ($name, $method) = @_;
- $class->meta->add_override_method_modifier($name => $method);
- };
+ return Class::MOP::subname('Moose::override' => sub ($&) {
+ my ( $name, $method ) = @_;
+ $class->meta->add_override_method_modifier( $name => $method );
+ });
},
inner => sub {
- return subname 'Moose::inner' => sub {};
+ return Class::MOP::subname('Moose::inner' => sub {
+ my $pkg = caller();
+ our ( %INNER_BODY, %INNER_ARGS );
+
+ if ( my $body = $INNER_BODY{$pkg} ) {
+ my @args = @{ $INNER_ARGS{$pkg} };
+ local $INNER_ARGS{$pkg};
+ local $INNER_BODY{$pkg};
+ return $body->(@args);
+ } else {
+ return;
+ }
+ });
},
augment => sub {
my $class = $CALLER;
- return subname 'Moose::augment' => sub (@&) {
- my ($name, $method) = @_;
- $class->meta->add_augment_method_modifier($name => $method);
- };
+ return Class::MOP::subname('Moose::augment' => sub (@&) {
+ my ( $name, $method ) = @_;
+ $class->meta->add_augment_method_modifier( $name => $method );
+ });
},
-
- # NOTE:
- # this is experimental for now ...
- self => sub {
- return subname 'Moose::self' => sub {};
- },
- method => sub {
+ make_immutable => sub {
my $class = $CALLER;
- return subname 'Moose::method' => sub {
- my ($name, $method) = @_;
- $class->meta->add_method($name, sub {
- my $self = shift;
- no strict 'refs';
- no warnings 'redefine';
- local *{$class->meta->name . '::self'} = sub { $self };
- $method->(@_);
- });
- };
- },
-
+ return Class::MOP::subname('Moose::make_immutable' => sub {
+ cluck "The make_immutable keyword has been deprecated, " .
+ "please go back to __PACKAGE__->meta->make_immutable\n";
+ $class->meta->make_immutable(@_);
+ });
+ },
confess => sub {
return \&Carp::confess;
},
},
);
- my $exporter = Sub::Exporter::build_exporter({
- exports => \%exports,
- groups => {
- default => [':all']
+ my $exporter = Sub::Exporter::build_exporter(
+ {
+ exports => \%exports,
+ groups => { default => [':all'] }
}
- });
-
- sub import {
- $CALLER = caller();
-
+ );
+
+ # 1 extra level because it's called by import so there's a layer of indirection
+ sub _get_caller{
+ my $offset = 1;
+ return
+ ref $_[1] && defined $_[1]->{into}
+ ? $_[1]->{into}
+ : ref $_[1] && defined $_[1]->{into_level}
+ ? caller($offset + $_[1]->{into_level})
+ : caller($offset);
+ }
+
+ sub import {
+ $CALLER = _get_caller(@_);
+
+ # this works because both pragmas set $^H (see perldoc perlvar)
+ # which affects the current compilation - i.e. the file who use'd
+ # us - which is why we don't need to do anything special to make
+ # it affect that file rather than this one (which is already compiled)
+
strict->import;
- warnings->import;
+ warnings->import;
# we should never export to main
return if $CALLER eq 'main';
-
- _init_meta();
-
+
+ init_meta( $CALLER, 'Moose::Object' );
+
goto $exporter;
}
-
+
sub unimport {
- no strict 'refs';
- my $class = caller();
+ no strict 'refs';
+ my $class = _get_caller(@_);
+
# loop through the exports ...
- foreach my $name (keys %exports) {
- next if $name =~ /inner|super|self/;
-
+ foreach my $name ( keys %exports ) {
+
# if we find one ...
- if (defined &{$class . '::' . $name}) {
- my $keyword = \&{$class . '::' . $name};
-
+ if ( defined &{ $class . '::' . $name } ) {
+ my $keyword = \&{ $class . '::' . $name };
+
# make sure it is from Moose
- my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
- next if $@;
+ my ($pkg_name) = Class::MOP::get_code_info($keyword);
next if $pkg_name ne 'Moose';
-
+
# and if it is from Moose then undef the slot
- delete ${$class . '::'}{$name};
+ delete ${ $class . '::' }{$name};
}
}
}
-}
-## Utility functions
-
-sub _load_all_classes {
- foreach my $super (@_) {
- # see if this is already
- # loaded in the symbol table
- next if _is_class_already_loaded($super);
- # otherwise require it ...
- # NOTE:
- # just in case the class we are
- # loading has a locally defined
- # &require, we make sure that we
- # use the on in UNIVERSAL
- ($super->UNIVERSAL::require)
- || confess "Could not load module '$super' because : " . $UNIVERSAL::require::ERROR;
- }
}
-sub _is_class_already_loaded {
- my $name = shift;
- no strict 'refs';
- return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
- foreach (keys %{"${name}::"}) {
- next if substr($_, -2, 2) eq '::';
- return 1 if defined &{"${name}::$_"};
- }
- return 0;
-}
+## make 'em all immutable
+
+$_->meta->make_immutable(
+ inline_constructor => 0,
+ inline_accessors => 1, # these are Class::MOP accessors, so they need inlining
+ )
+ for (
+ 'Moose::Meta::Attribute',
+ 'Moose::Meta::Class',
+ 'Moose::Meta::Instance',
+
+ 'Moose::Meta::TypeConstraint',
+ 'Moose::Meta::TypeConstraint::Union',
+ 'Moose::Meta::TypeConstraint::Parameterized',
+ 'Moose::Meta::TypeCoercion',
+
+ 'Moose::Meta::Method',
+ 'Moose::Meta::Method::Accessor',
+ 'Moose::Meta::Method::Constructor',
+ 'Moose::Meta::Method::Destructor',
+ 'Moose::Meta::Method::Overriden',
+
+ 'Moose::Meta::Role',
+ 'Moose::Meta::Role::Method',
+ 'Moose::Meta::Role::Method::Required',
+ );
1;
=head1 NAME
-Moose - A complete modern object system for Perl 5
+Moose - A postmodern object system for Perl 5
=head1 SYNOPSIS
package Point;
- use strict;
- use warnings;
- use Moose;
-
+ use Moose; # automatically turns on strict and warnings
+
has 'x' => (is => 'rw', isa => 'Int');
has 'y' => (is => 'rw', isa => 'Int');
-
+
sub clear {
my $self = shift;
$self->x(0);
- $self->y(0);
+ $self->y(0);
}
-
+
package Point3D;
- use strict;
- use warnings;
use Moose;
-
+
extends 'Point';
-
+
has 'z' => (is => 'rw', isa => 'Int');
-
+
after 'clear' => sub {
my $self = shift;
$self->z(0);
};
-
-=head1 CAVEAT
-
-Moose is a rapidly maturing module, and is already being used by
-a number of people. It's test suite is growing larger by the day,
-and the docs should soon follow.
-
-This said, Moose is not yet finished, and should still be considered
-to be evolving. Much of the outer API is stable, but the internals
-are still subject to change (although not without serious thought
-given to it).
-
-For more details, please refer to the L<FUTURE PLANS> section of
-this document.
=head1 DESCRIPTION
-Moose is an extension of the Perl 5 object system.
+Moose is an extension of the Perl 5 object system.
-=head2 Another object system!?!?
+The main goal of Moose is to make Perl 5 Object Oriented programming
+easier, more consistent and less tedious. With Moose you can to think
+more about what you want to do and less about the mechanics of OOP.
-Yes, I know there has been an explosion recently of new ways to
-build object's in Perl 5, most of them based on inside-out objects
-and other such things. Moose is different because it is not a new
-object system for Perl 5, but instead an extension of the existing
-object system.
+Additionally, Moose is built on top of L<Class::MOP>, which is a
+metaclass system for Perl 5. This means that Moose not only makes
+building normal Perl 5 objects better, but it provides the power of
+metaclass programming as well.
-Moose is built on top of L<Class::MOP>, which is a metaclass system
-for Perl 5. This means that Moose not only makes building normal
-Perl 5 objects better, but it also provides the power of metaclass
-programming.
-
-=head2 Can I use this in production? Or is this just an experiment?
+=head2 Moose Extensions
-Moose is I<based> on the prototypes and experiments I did for the Perl 6
-meta-model; however Moose is B<NOT> an experiment/prototype, it is
-for B<real>. I will be deploying Moose into production environments later
-this year, and I have every intentions of using it as my de facto class
-builder from now on.
-
-=head2 Is Moose just Perl 6 in Perl 5?
-
-No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
-Instead, it is an OO system for Perl 5. I built Moose because I was tired or
-writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
-instead of switching to Ruby, I wrote Moose :)
+The L<MooseX::> namespace is the official place to find Moose extensions.
+There are a number of these modules out on CPAN right now the best way to
+find them is to search for MooseX:: on search.cpan.org or to look at the
+latest version of L<Task::Moose> which aims to keep an up to date, easily
+installable list of these extensions.
=head1 BUILDING CLASSES WITH MOOSE
class construction/definition, but still stay out of your way if you want it
to. Here are a few items to note when building classes with Moose.
-Unless specified with C<extends>, any class which uses Moose will
+Unless specified with C<extends>, any class which uses Moose will
inherit from L<Moose::Object>.
-Moose will also manage all attributes (including inherited ones) that
-are defined with C<has>. And assuming that you call C<new>, which is
-inherited from L<Moose::Object>, then this includes properly initializing
-all instance slots, setting defaults where appropriate, and performing any
-type constraint checking or coercion.
+Moose will also manage all attributes (including inherited ones) that are
+defined with C<has>. And (assuming you call C<new>, which is inherited from
+L<Moose::Object>) this includes properly initializing all instance slots,
+setting defaults where appropriate, and performing any type constraint checking
+or coercion.
-=head1 EXPORTED FUNCTIONS
+=head1 PROVIDED METHODS
-Moose will export a number of functions into the class's namespace which
-can then be used to set up the class. These functions all work directly
-on the current class.
+Moose provides a number of methods to all your classes, mostly through the
+inheritance of L<Moose::Object>. There is however, one exception.
=over 4
This is a method which provides access to the current class's metaclass.
+=back
+
+=head1 EXPORTED FUNCTIONS
+
+Moose will export a number of functions into the class's namespace which
+may then be used to set up the class. These functions all work directly
+on the current class.
+
+=over 4
+
=item B<extends (@superclasses)>
This function will set the superclass(es) for the current class.
-This approach is recommended instead of C<use base>, because C<use base>
-actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
-replace it. This is important to ensure that classes which do not have
+This approach is recommended instead of C<use base>, because C<use base>
+actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
+replace it. This is important to ensure that classes which do not have
superclasses still properly inherit from L<Moose::Object>.
=item B<with (@roles)>
-This will apply a given set of C<@roles> to the local class. Role support
-is currently under heavy development; see L<Moose::Role> for more details.
+This will apply a given set of C<@roles> to the local class.
-=item B<has ($name, %options)>
+=item B<has $name =E<gt> %options>
-This will install an attribute of a given C<$name> into the current class.
-The list of C<%options> are the same as those provided by
-L<Class::MOP::Attribute>, in addition to the list below which are provided
+This will install an attribute of a given C<$name> into the current class.
+The C<%options> are the same as those provided by
+L<Class::MOP::Attribute>, in addition to the list below which are provided
by Moose (L<Moose::Meta::Attribute> to be more specific):
=over 4
=item I<is =E<gt> 'rw'|'ro'>
-The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
-only). These will create either a read/write accessor or a read-only
+The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
+only). These will create either a read/write accessor or a read-only
accessor respectively, using the same name as the C<$name> of the attribute.
-If you need more control over how your accessors are named, you can use the
-I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
+If you need more control over how your accessors are named, you can use the
+I<reader>, I<writer> and I<accessor> options inherited from
+L<Class::MOP::Attribute>, however if you use those, you won't need the I<is>
+option.
=item I<isa =E<gt> $type_name>
-The I<isa> option uses Moose's type constraint facilities to set up runtime
-type checking for this attribute. Moose will perform the checks during class
-construction, and within any accessors. The C<$type_name> argument must be a
-string. The string can be either a class name or a type defined using
-Moose's type definition features.
+The I<isa> option uses Moose's type constraint facilities to set up runtime
+type checking for this attribute. Moose will perform the checks during class
+construction, and within any accessors. The C<$type_name> argument must be a
+string. The string may be either a class name or a type defined using
+Moose's type definition features. (Refer to L<Moose::Util::TypeConstraints>
+for information on how to define a new type, and how to retrieve type meta-data).
=item I<coerce =E<gt> (1|0)>
-This will attempt to use coercion with the supplied type constraint to change
-the value passed into any accessors or constructors. You B<must> have supplied
+This will attempt to use coercion with the supplied type constraint to change
+the value passed into any accessors or constructors. You B<must> have supplied
a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
-for an example usage.
+for an example.
=item I<does =E<gt> $role_name>
-This will accept the name of a role which the value stored in this attribute
+This will accept the name of a role which the value stored in this attribute
is expected to have consumed.
=item I<required =E<gt> (1|0)>
-This marks the attribute as being required. This means a value must be supplied
-during class construction, and the attribute can never be set to C<undef> with
-an accessor.
+This marks the attribute as being required. This means a I<defined> value must be
+supplied during class construction, and the attribute may never be set to
+C<undef> with an accessor.
=item I<weak_ref =E<gt> (1|0)>
=item I<lazy =E<gt> (1|0)>
-This will tell the class to not create this slot until absolutely necessary.
+This will tell the class to not create this slot until absolutely necessary.
If an attribute is marked as lazy it B<must> have a default supplied.
=item I<auto_deref =E<gt> (1|0)>
-This tells the accessor whether to automatically dereference the value returned.
-This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
+This tells the accessor whether to automatically dereference the value returned.
+This is only legal if your C<isa> option is either C<ArrayRef> or C<HashRef>.
=item I<trigger =E<gt> $code>
-The trigger option is a CODE reference which will be called after the value of
-the attribute is set. The CODE ref will be passed the instance itself, the
+The I<trigger> option is a CODE reference which will be called after the value of
+the attribute is set. The CODE ref will be passed the instance itself, the
updated value and the attribute meta-object (this is for more advanced fiddling
-and can typically be ignored in most cases). You B<cannot> have a trigger on
-a read-only attribute.
+and can typically be ignored). You B<cannot> have a trigger on a read-only
+attribute.
+
+=item I<handles =E<gt> ARRAY | HASH | REGEXP | ROLE | CODE>
+
+The I<handles> option provides Moose classes with automated delegation features.
+This is a pretty complex and powerful option. It accepts many different option
+formats, each with its own benefits and drawbacks.
+
+B<NOTE:> The class being delegated to does not need to be a Moose based class,
+which is why this feature is especially useful when wrapping non-Moose classes.
+
+All I<handles> option formats share the following traits:
+
+You cannot override a locally defined method with a delegated method; an
+exception will be thrown if you try. That is to say, if you define C<foo> in
+your class, you cannot override it with a delegated C<foo>. This is almost never
+something you would want to do, and if it is, you should do it by hand and not
+use Moose.
+
+You cannot override any of the methods found in Moose::Object, or the C<BUILD>
+and C<DEMOLISH> methods. These will not throw an exception, but will silently
+move on to the next method in the list. My reasoning for this is that you would
+almost never want to do this, since it usually breaks your class. As with
+overriding locally defined methods, if you do want to do this, you should do it
+manually, not with Moose.
+
+You do not I<need> to have a reader (or accessor) for the attribute in order
+to delegate to it. Moose will create a means of accessing the value for you,
+however this will be several times B<less> efficient then if you had given
+the attribute a reader (or accessor) to use.
+
+Below is the documentation for each option format:
+
+=over 4
+
+=item C<ARRAY>
+
+This is the most common usage for I<handles>. You basically pass a list of
+method names to be delegated, and Moose will install a delegation method
+for each one.
+
+=item C<HASH>
+
+This is the second most common usage for I<handles>. Instead of a list of
+method names, you pass a HASH ref where each key is the method name you
+want installed locally, and its value is the name of the original method
+in the class being delegated to.
+
+This can be very useful for recursive classes like trees. Here is a
+quick example (soon to be expanded into a Moose::Cookbook::Recipe):
+
+ package Tree;
+ use Moose;
+
+ has 'node' => (is => 'rw', isa => 'Any');
+
+ has 'children' => (
+ is => 'ro',
+ isa => 'ArrayRef',
+ default => sub { [] }
+ );
+
+ has 'parent' => (
+ is => 'rw',
+ isa => 'Tree',
+ weak_ref => 1,
+ handles => {
+ parent_node => 'node',
+ siblings => 'children',
+ }
+ );
+
+In this example, the Tree package gets C<parent_node> and C<siblings> methods,
+which delegate to the C<node> and C<children> methods (respectively) of the Tree
+instance stored in the C<parent> slot.
+
+=item C<REGEXP>
+
+The regexp option works very similar to the ARRAY option, except that it builds
+the list of methods for you. It starts by collecting all possible methods of the
+class being delegated to, then filters that list using the regexp supplied here.
+
+B<NOTE:> An I<isa> option is required when using the regexp option format. This
+is so that we can determine (at compile time) the method list from the class.
+Without an I<isa> this is just not possible.
+
+=item C<ROLE>
+
+With the role option, you specify the name of a role whose "interface" then
+becomes the list of methods to handle. The "interface" can be defined as; the
+methods of the role and any required methods of the role. It should be noted
+that this does B<not> include any method modifiers or generated attribute
+methods (which is consistent with role composition).
+
+=item C<CODE>
+
+This is the option to use when you really want to do something funky. You should
+only use it if you really know what you are doing, as it involves manual
+metaclass twiddling.
+
+This takes a code reference, which should expect two arguments. The first is the
+attribute meta-object this I<handles> is attached to. The second is the
+metaclass of the class being delegated to. It expects you to return a hash (not
+a HASH ref) of the methods you want mapped.
+
+=back
+
+=item I<metaclass =E<gt> $metaclass_name>
+
+This tells the class to use a custom attribute metaclass for this particular
+attribute. Custom attribute metaclasses are useful for extending the
+capabilities of the I<has> keyword: they are the simplest way to extend the MOP,
+but they are still a fairly advanced topic and too much to cover here, see
+L<Moose::Cookbook::Recipe11> for more information.
+
+The default behavior here is to just load C<$metaclass_name>; however, we also
+have a way to alias to a shorter name. This will first look to see if
+B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose
+will then check to see if that has the method C<register_implementation>, which
+should return the actual name of the custom attribute metaclass. If there is no
+C<register_implementation> method, it will fall back to using
+B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name.
+
+=item I<traits =E<gt> [ @role_names ]>
+
+This tells Moose to take the list of C<@role_names> and apply them to the
+attribute meta-object. This is very similar to the I<metaclass> option, but
+allows you to use more than one extension at a time. This too is an advanced
+topic, we don't yet have a cookbook for it though.
+
+As with I<metaclass>, the default behavior is to just load C<$role_name>; however,
+we also have a way to alias to a shorter name. This will first look to see if
+B<Moose::Meta::Attribute::Custom::Trait::$role_name> exists. If it does, Moose
+will then check to see if that has the method C<register_implementation>, which
+should return the actual name of the custom attribute trait. If there is no
+C<register_implementation> method, it will fall back to using
+B<Moose::Meta::Attribute::Custom::Trait::$metaclass_name> as the trait name.
+
+=back
+
+=item B<has +$name =E<gt> %options>
+
+This is variation on the normal attibute creator C<has> which allows you to
+clone and extend an attribute from a superclass or from a role. Here is an
+example of the superclass usage:
+
+ package Foo;
+ use Moose;
+
+ has 'message' => (
+ is => 'rw',
+ isa => 'Str',
+ default => 'Hello, I am a Foo'
+ );
+
+ package My::Foo;
+ use Moose;
+
+ extends 'Foo';
+
+ has '+message' => (default => 'Hello I am My::Foo');
-=item I<handles =E<gt> [ @handles ]>
+What is happening here is that B<My::Foo> is cloning the C<message> attribute
+from its parent class B<Foo>, retaining the C<is =E<gt> 'rw'> and C<isa =E<gt>
+'Str'> characteristics, but changing the value in C<default>.
-There is experimental support for attribute delegation using the C<handles>
-option. More docs to come later.
+Here is another example, but within the context of a role:
+
+ package Foo::Role;
+ use Moose::Role;
+
+ has 'message' => (
+ is => 'rw',
+ isa => 'Str',
+ default => 'Hello, I am a Foo'
+ );
+
+ package My::Foo;
+ use Moose;
+
+ with 'Foo::Role';
+
+ has '+message' => (default => 'Hello I am My::Foo');
+
+In this case, we are basically taking the attribute which the role supplied
+and altering it within the bounds of this feature.
+
+Aside from where the attributes come from (one from superclass, the other
+from a role), this feature works exactly the same. This feature is restricted
+somewhat, so as to try and force at least I<some> sanity into it. You are only
+allowed to change the following attributes:
+
+=over 4
+
+=item I<default>
+
+Change the default value of an attribute.
+
+=item I<coerce>
+
+Change whether the attribute attempts to coerce a value passed to it.
+
+=item I<required>
+
+Change if the attribute is required to have a value.
+
+=item I<documentation>
+
+Change the documentation string associated with the attribute.
+
+=item I<lazy>
+
+Change if the attribute lazily initializes the slot.
+
+=item I<isa>
+
+You I<are> allowed to change the type without restriction.
+
+It is recommended that you use this freedom with caution. We used to
+only allow for extension only if the type was a subtype of the parent's
+type, but we felt that was too restrictive and is better left as a
+policy descision.
+
+=item I<handles>
+
+You are allowed to B<add> a new C<handles> definition, but you are B<not>
+allowed to I<change> one.
+
+=item I<builder>
+
+You are allowed to B<add> a new C<builder> definition, but you are B<not>
+allowed to I<change> one.
+
+=item I<metaclass>
+
+You are allowed to B<add> a new C<metaclass> definition, but you are
+B<not> allowed to I<change> one.
+
+=item I<traits>
+
+You are allowed to B<add> additional traits to the C<traits> definition.
+These traits will be composed into the attribute, but pre-existing traits
+B<are not> overridden, or removed.
=back
=item B<around $name|@names =E<gt> sub { ... }>
-This three items are syntactic sugar for the before, after, and around method
-modifier features that L<Class::MOP> provides. More information on these can
-be found in the L<Class::MOP> documentation for now.
+This three items are syntactic sugar for the before, after, and around method
+modifier features that L<Class::MOP> provides. More information on these may be
+found in the L<Class::MOP::Class documentation|Class::MOP::Class/"Method
+Modifiers"> for now.
=item B<super>
-The keyword C<super> is a no-op when called outside of an C<override> method. In
-the context of an C<override> method, it will call the next most appropriate
+The keyword C<super> is a no-op when called outside of an C<override> method. In
+the context of an C<override> method, it will call the next most appropriate
superclass method with the same arguments as the original method.
=item B<override ($name, &sub)>
-An C<override> method is a way of explicitly saying "I am overriding this
-method from my superclass". You can call C<super> within this method, and
-it will work as expected. The same thing I<can> be accomplished with a normal
-method call and the C<SUPER::> pseudo-package; it is really your choice.
+An C<override> method is a way of explicitly saying "I am overriding this
+method from my superclass". You can call C<super> within this method, and
+it will work as expected. The same thing I<can> be accomplished with a normal
+method call and the C<SUPER::> pseudo-package; it is really your choice.
=item B<inner>
-The keyword C<inner>, much like C<super>, is a no-op outside of the context of
-an C<augment> method. You can think of C<inner> as being the inverse of
+The keyword C<inner>, much like C<super>, is a no-op outside of the context of
+an C<augment> method. You can think of C<inner> as being the inverse of
C<super>; the details of how C<inner> and C<augment> work is best described in
-the L<Moose::Cookbook>.
+the L<Moose::Cookbook::Recipe6>.
=item B<augment ($name, &sub)>
-An C<augment> method, is a way of explicitly saying "I am augmenting this
-method from my superclass". Once again, the details of how C<inner> and
-C<augment> work is best described in the L<Moose::Cookbook>.
+An C<augment> method, is a way of explicitly saying "I am augmenting this
+method from my superclass". Once again, the details of how C<inner> and
+C<augment> work is best described in the L<Moose::Cookbook::Recipe6>.
=item B<confess>
This is the C<Carp::confess> function, and exported here because I use it
-all the time. This feature may change in the future, so you have been warned.
+all the time.
=item B<blessed>
-This is the C<Scalar::Uti::blessed> function, it is exported here because I
-use it all the time. It is highly recommended that this is used instead of
+This is the C<Scalar::Util::blessed> function, it is exported here because I
+use it all the time. It is highly recommended that this is used instead of
C<ref> anywhere you need to test for an object's class name.
=back
-=head1 UNEXPORTING FUNCTIONS
+=head1 UNIMPORTING FUNCTIONS
=head2 B<unimport>
-Moose offers a way of removing the keywords it exports though the C<unimport>
+Moose offers a way to remove the keywords it exports, through the C<unimport>
method. You simply have to say C<no Moose> at the bottom of your code for this
to work. Here is an example:
has 'first_name' => (is => 'rw', isa => 'Str');
has 'last_name' => (is => 'rw', isa => 'Str');
-
- sub full_name {
+
+ sub full_name {
my $self = shift;
- $self->first_name . ' ' . $self->last_name
+ $self->first_name . ' ' . $self->last_name
}
-
- no Moose; # keywords are removed from the Person package
-=head1 MISC.
+ no Moose; # keywords are removed from the Person package
-=head2 What does Moose stand for??
+=head1 EXTENDING AND EMBEDDING MOOSE
-Moose doesn't stand for one thing in particular, however, if you
-want, here are a few of my favorites; feel free to contribute
-more :)
+Moose also offers some options for extending or embedding it into your own
+framework. The basic premise is to have something that sets up your class'
+metaclass and export the moose declarators (C<has>, C<with>, C<extends>,...).
+Here is an example:
-=over 4
+ package MyFramework;
+ use Moose;
-=item Make Other Object Systems Envious
+ sub import {
+ my $CALLER = caller();
-=item Makes Object Orientation So Easy
+ strict->import;
+ warnings->import;
-=item Makes Object Orientation Spiffy- Er (sorry ingy)
+ # we should never export to main
+ return if $CALLER eq 'main';
+ Moose::init_meta( $CALLER, 'MyFramework::Base' );
+ Moose->import({into => $CALLER});
-=item Most Other Object Systems Emasculate
+ # Do my custom framework stuff
-=item Moose Often Ovulate Sorta Early
+ return 1;
+ }
-=item Moose Offers Often Super Extensions
+=head2 B<import>
-=item Meta Object Orientation Syntax Extensions
+Moose's C<import> method supports the L<Sub::Exporter> form of C<{into =E<gt> $pkg}>
+and C<{into_level =E<gt> 1}>
-=back
+=head2 B<init_meta ($class, $baseclass, $metaclass)>
+
+Moose does some boot strapping: it creates a metaclass object for your class,
+and then injects a C<meta> accessor into your class to retrieve it. Then it
+sets your baseclass to Moose::Object or the value you pass in unless you already
+have one. This is all done via C<init_meta> which takes the name of your class
+and optionally a baseclass and a metaclass as arguments.
=head1 CAVEATS
=item *
-It should be noted that C<super> and C<inner> C<cannot> be used in the same
-method. However, they can be combined together with the same class hierarchy;
-see F<t/014_override_augment_inner_super.t> for an example.
+It should be noted that C<super> and C<inner> B<cannot> be used in the same
+method. However, they may be combined within the same class hierarchy; see
+F<t/014_override_augment_inner_super.t> for an example.
-The reason for this is that C<super> is only valid within a method
-with the C<override> modifier, and C<inner> will never be valid within an
-C<override> method. In fact, C<augment> will skip over any C<override> methods
+The reason for this is that C<super> is only valid within a method
+with the C<override> modifier, and C<inner> will never be valid within an
+C<override> method. In fact, C<augment> will skip over any C<override> methods
when searching for its appropriate C<inner>.
-This might seem like a restriction, but I am of the opinion that keeping these
-two features separate (but interoperable) actually makes them easy to use, since
-their behavior is then easier to predict. Time will tell if I am right or not.
+This might seem like a restriction, but I am of the opinion that keeping these
+two features separate (yet interoperable) actually makes them easy to use, since
+their behavior is then easier to predict. Time will tell whether I am right or
+not (UPDATE: so far so good).
+
+=item *
+
+It is important to note that we currently have no simple way of combining
+multiple extended versions of Moose (see L<EXTENDING AND EMBEDDING MOOSE> above),
+and that in many cases they will conflict with one another. We are working on
+developing a way around this issue, but in the meantime, you have been warned.
+
+=back
+
+=head1 JUSTIFICATION
+
+In case you are still asking yourself "Why do I need this?", then this
+section is for you. This used to be part of the main DESCRIPTION, but
+I think Moose no longer actually needs justification, so it is included
+(read: buried) here for those who are still not convinced.
+
+=over 4
+
+=item Another object system!?!?
+
+Yes, I know there has been an explosion recently of new ways to
+build objects in Perl 5, most of them based on inside-out objects
+and other such things. Moose is different because it is not a new
+object system for Perl 5, but instead an extension of the existing
+object system.
+
+Moose is built on top of L<Class::MOP>, which is a metaclass system
+for Perl 5. This means that Moose not only makes building normal
+Perl 5 objects better, but it also provides the power of metaclass
+programming.
+
+=item Is this for real? Or is this just an experiment?
+
+Moose is I<based> on the prototypes and experiments I did for the Perl 6
+meta-model. However, Moose is B<NOT> an experiment/prototype; it is for B<real>.
+
+=item Is this ready for use in production?
+
+Yes, I believe that it is.
+
+Moose has been used successfully in production environemnts by several people
+and companies (including the one I work for). There are Moose applications
+which have been in production with little or no issue now for well over two years.
+I consider it highly stable and we are commited to keeping it stable.
+
+Of course, in the end, you need to make this call yourself. If you have
+any questions or concerns, please feel free to email me, or even the list
+or just stop by #moose and ask away.
+
+=item Is Moose just Perl 6 in Perl 5?
+
+No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
+Instead, it is an OO system for Perl 5. I built Moose because I was tired of
+writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
+instead of switching to Ruby, I wrote Moose :)
+
+=item Wait, I<post> modern, I thought it was just I<modern>?
+
+So I was reading Larry Wall's talk from the 1999 Linux World entitled
+"Perl, the first postmodern computer language" in which he talks about how
+he picked the features for Perl because he thought they were cool and he
+threw out the ones that he thought sucked. This got me thinking about how
+we have done the same thing in Moose. For Moose, we have "borrowed" features
+from Perl 6, CLOS (LISP), Smalltalk, Java, BETA, OCaml, Ruby and more, and
+the bits we didn't like (cause they sucked) we tossed aside. So for this
+reason (and a few others) I have re-dubbed Moose a I<postmodern> object system.
+
+Nuff Said.
=back
=item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
-=item Without Yuval "nothingmuch" Kogman this module would not be possible,
+=item Without Yuval "nothingmuch" Kogman this module would not be possible,
and it certainly wouldn't have this name ;P
-=item The basis of the TypeContraints module was Rob Kinyon's idea
+=item The basis of the TypeContraints module was Rob Kinyon's idea
originally, I just ran with it.
-=item Thanks to mst & chansen and the whole #moose poose for all the
-ideas/feature-requests/encouragement
+=item Thanks to mst & chansen and the whole #moose posse for all the
+early ideas/feature-requests/encouragement/bug-finding.
=item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes.
=over 4
+=item L<http://www.iinteractive.com/moose>
+
+This is the official web home of Moose, it contains links to our public SVN repo
+as well as links to a number of talks and articles on Moose and Moose related
+technologies.
+
=item L<Class::MOP> documentation
=item The #moose channel on irc.perl.org
=item The Moose mailing list - moose@perl.org
-=item L<http://forum2.org/moose/>
+=item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/moose>
+
+=item Several Moose extension modules in the L<MooseX::> namespace.
+
+=back
+
+=head2 Books
+
+=over 4
+
+=item The Art of the MetaObject Protocol
+
+I mention this in the L<Class::MOP> docs too, this book was critical in
+the development of both modules and is highly recommended.
+
+=back
+
+=head2 Papers
+
+=over 4
=item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
-This paper (suggested by lbr on #moose) was what lead to the implementation
-of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
-want to understand this feature, I suggest you read this.
+This paper (suggested by lbr on #moose) was what lead to the implementation
+of the C<super>/C<override> and C<inner>/C<augment> features. If you really
+want to understand them, I suggest you read this.
=back
=head1 BUGS
-All complex software has bugs lurking in it, and this module is no
+All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
Stevan Little E<lt>stevan@iinteractive.comE<gt>
-Christian Hansen E<lt>chansen@cpan.orgE<gt>
+B<with contributions from:>
+
+Aankhen
+
+Adam (Alias) Kennedy
+
+Anders (Debolaz) Nor Berle
+
+Nathan (kolibre) Gray
+
+Christian (chansen) Hansen
+
+Hans Dieter (confound) Pearcey
+
+Eric (ewilhelm) Wilhelm
+
+Guillermo (groditi) Roditi
+
+Jess (castaway) Robinson
+
+Matt (mst) Trout
+
+Robert (phaylon) Sedlacek
+
+Robert (rlb3) Boone
+
+Scott (konobi) McWhirter
+
+Shlomi (rindolf) Fish
+
+Yuval (nothingmuch) Kogman
+
+Chris (perigrin) Prather
+
+Jonathan (jrockway) Rockway
+
+Piotr (dexter) Roszatycki
+
+Sam (mugwump) Vilain
+
+Shawn (sartak) Moore
-Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
+... and many other #moose folks
=head1 COPYRIGHT AND LICENSE
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006-2008 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+it under the same terms as Perl itself.
=cut