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authorLorry Tar Creator <lorry-tar-importer@lorry>2015-06-06 17:50:16 +0000
committerLorry Tar Creator <lorry-tar-importer@lorry>2015-06-06 17:50:16 +0000
commit5ac2026f7eed78958d69d051e7a8e993dcf51205 (patch)
tree298c3d2f08bdfe5689998b11892d72a897985be1 /lib/Moose.pm
downloadMoose-tarball-5ac2026f7eed78958d69d051e7a8e993dcf51205.tar.gz
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+use strict;
+use warnings;
+package Moose; # git description: 2.1404-10-gfb25585
+our $VERSION = '2.1405';
+our $AUTHORITY = 'cpan:STEVAN';
+
+use 5.008003;
+
+use Scalar::Util ();
+use Carp 'carp';
+use Module::Runtime 'module_notional_filename';
+use Class::Load 'is_class_loaded';
+
+use Moose::Deprecated;
+use Moose::Exporter;
+
+use Class::MOP;
+
+BEGIN {
+ die "Class::MOP version $Moose::VERSION required--this is version $Class::MOP::VERSION"
+ if $Moose::VERSION && $Class::MOP::VERSION ne $Moose::VERSION;
+}
+
+use Moose::Meta::Class;
+use Moose::Meta::TypeConstraint;
+use Moose::Meta::TypeCoercion;
+use Moose::Meta::Attribute;
+use Moose::Meta::Instance;
+
+use Moose::Object;
+
+use Moose::Meta::Role;
+use Moose::Meta::Role::Composite;
+use Moose::Meta::Role::Application;
+use Moose::Meta::Role::Application::RoleSummation;
+use Moose::Meta::Role::Application::ToClass;
+use Moose::Meta::Role::Application::ToRole;
+use Moose::Meta::Role::Application::ToInstance;
+
+use Moose::Util::TypeConstraints;
+use Moose::Util 'throw_exception';
+
+use Moose::Meta::Attribute::Native;
+
+sub extends {
+ my $meta = shift;
+
+ unless ( @_ )
+ {
+ throw_exception( ExtendsMissingArgs => class_name => $meta->name );
+ }
+ # this checks the metaclass to make sure
+ # it is correct, sometimes it can get out
+ # of sync when the classes are being built
+ $meta->superclasses(@_);
+}
+
+sub with {
+ Moose::Util::apply_all_roles(shift, @_);
+}
+
+sub throw_error {
+ shift;
+ Class::MOP::Object->throw_error(@_);
+}
+
+sub has {
+ my $meta = shift;
+ my $name = shift;
+
+ my %context = Moose::Util::_caller_info;
+ $context{context} = 'has declaration';
+ $context{type} = 'class';
+ my @options = ( definition_context => \%context, @_ );
+ my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ];
+ $meta->add_attribute( $_, @options ) for @$attrs;
+}
+
+sub before {
+ Moose::Util::add_method_modifier(shift, 'before', \@_);
+}
+
+sub after {
+ Moose::Util::add_method_modifier(shift, 'after', \@_);
+}
+
+sub around {
+ Moose::Util::add_method_modifier(shift, 'around', \@_);
+}
+
+our $SUPER_PACKAGE;
+our $SUPER_BODY;
+our @SUPER_ARGS;
+
+sub super {
+ if (@_) {
+ carp 'Arguments passed to super() are ignored';
+ }
+
+ # This check avoids a recursion loop - see
+ # t/bugs/super_recursion.t
+ return if defined $SUPER_PACKAGE && $SUPER_PACKAGE ne caller();
+ return unless $SUPER_BODY; $SUPER_BODY->(@SUPER_ARGS);
+}
+
+sub override {
+ my $meta = shift;
+ my ( $name, $method ) = @_;
+ $meta->add_override_method_modifier( $name => $method );
+}
+
+sub inner {
+ 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;
+ }
+}
+
+sub augment {
+ my $meta = shift;
+ my ( $name, $method ) = @_;
+ $meta->add_augment_method_modifier( $name => $method );
+}
+
+Moose::Exporter->setup_import_methods(
+ with_meta => [
+ qw( extends with has before after around override augment )
+ ],
+ as_is => [
+ qw( super inner ),
+ 'Carp::confess',
+ 'Scalar::Util::blessed',
+ ],
+);
+
+sub init_meta {
+ shift;
+ my %args = @_;
+
+ my $class = $args{for_class}
+ or throw_exception( InitMetaRequiresClass => params => \%args );
+
+ my $base_class = $args{base_class} || 'Moose::Object';
+ my $metaclass = $args{metaclass} || 'Moose::Meta::Class';
+ my $meta_name = exists $args{meta_name} ? $args{meta_name} : 'meta';
+
+ throw_exception( MetaclassNotLoaded => class_name => $metaclass )
+ unless is_class_loaded($metaclass);
+
+ throw_exception( MetaclassMustBeASubclassOfMooseMetaClass => class_name => $metaclass )
+ unless $metaclass->isa('Moose::Meta::Class');
+
+ # make a subtype for each Moose class
+ class_type($class)
+ unless find_type_constraint($class);
+
+ my $meta;
+
+ if ( $meta = Class::MOP::get_metaclass_by_name($class) ) {
+ unless ( $meta->isa("Moose::Meta::Class") ) {
+ if ( $meta->isa('Moose::Meta::Role') ) {
+ throw_exception( MetaclassIsARoleNotASubclassOfGivenMetaclass => role_name => $class,
+ metaclass => $metaclass,
+ role => $meta
+ );
+ } else {
+ throw_exception( MetaclassIsNotASubclassOfGivenMetaclass => class_name => $class,
+ metaclass => $metaclass,
+ class => $meta
+ );
+ }
+ }
+ } else {
+ # no metaclass
+
+ # now we check whether our ancestors have metaclass, and if so borrow that
+ my ( undef, @isa ) = @{ mro::get_linear_isa($class) };
+
+ foreach my $ancestor ( @isa ) {
+ my $ancestor_meta = Class::MOP::get_metaclass_by_name($ancestor) || next;
+
+ my $ancestor_meta_class = $ancestor_meta->_real_ref_name;
+
+ # if we have an ancestor metaclass that inherits $metaclass, we use
+ # that. This is like _fix_metaclass_incompatibility, but we can do it now.
+
+ # the case of having an ancestry is not very common, but arises in
+ # e.g. Reaction
+ unless ( $metaclass->isa( $ancestor_meta_class ) ) {
+ if ( $ancestor_meta_class->isa($metaclass) ) {
+ $metaclass = $ancestor_meta_class;
+ }
+ }
+ }
+
+ $meta = $metaclass->initialize($class);
+ my $filename = module_notional_filename($meta->name);
+ $INC{$filename} = '(set by Moose)'
+ unless exists $INC{$filename};
+ }
+
+ if (defined $meta_name) {
+ # also check for inherited non moose 'meta' method?
+ my $existing = $meta->get_method($meta_name);
+ if ($existing && !$existing->isa('Class::MOP::Method::Meta')) {
+ Carp::cluck "Moose is overwriting an existing method named "
+ . "$meta_name in class $class with a method "
+ . "which returns the class's metaclass. If this is "
+ . "actually what you want, you should remove the "
+ . "existing method, otherwise, you should rename or "
+ . "disable this generated method using the "
+ . "'-meta_name' option to 'use Moose'.";
+ }
+ $meta->_add_meta_method($meta_name);
+ }
+
+ # make sure they inherit from Moose::Object
+ $meta->superclasses($base_class)
+ unless $meta->superclasses();
+
+ return $meta;
+}
+
+# This may be used in some older MooseX extensions.
+sub _get_caller {
+ goto &Moose::Exporter::_get_caller;
+}
+
+## make 'em all immutable
+
+$_->make_immutable(
+ inline_constructor => 1,
+ constructor_name => "_new",
+ # these are Class::MOP accessors, so they need inlining
+ inline_accessors => 1
+ ) for grep { $_->is_mutable }
+ map { $_->meta }
+ qw(
+ Moose::Meta::Attribute
+ Moose::Meta::Class
+ Moose::Meta::Instance
+
+ Moose::Meta::TypeCoercion
+ Moose::Meta::TypeCoercion::Union
+
+ Moose::Meta::Method
+ Moose::Meta::Method::Constructor
+ Moose::Meta::Method::Destructor
+ Moose::Meta::Method::Overridden
+ Moose::Meta::Method::Augmented
+
+ Moose::Meta::Role
+ Moose::Meta::Role::Attribute
+ Moose::Meta::Role::Method
+ Moose::Meta::Role::Method::Required
+ Moose::Meta::Role::Method::Conflicting
+
+ Moose::Meta::Role::Composite
+
+ Moose::Meta::Role::Application
+ Moose::Meta::Role::Application::RoleSummation
+ Moose::Meta::Role::Application::ToClass
+ Moose::Meta::Role::Application::ToRole
+ Moose::Meta::Role::Application::ToInstance
+);
+
+$_->make_immutable(
+ inline_constructor => 0,
+ constructor_name => undef,
+ # these are Class::MOP accessors, so they need inlining
+ inline_accessors => 1
+ ) for grep { $_->is_mutable }
+ map { $_->meta }
+ qw(
+ Moose::Meta::Method::Accessor
+ Moose::Meta::Method::Delegation
+ Moose::Meta::Mixin::AttributeCore
+);
+
+1;
+
+# ABSTRACT: A postmodern object system for Perl 5
+
+__END__
+
+=pod
+
+=encoding UTF-8
+
+=head1 NAME
+
+Moose - A postmodern object system for Perl 5
+
+=head1 VERSION
+
+version 2.1405
+
+=head1 SYNOPSIS
+
+ package Point;
+ 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);
+ }
+
+ package Point3D;
+ use Moose;
+
+ extends 'Point';
+
+ has 'z' => (is => 'rw', isa => 'Int');
+
+ after 'clear' => sub {
+ my $self = shift;
+ $self->z(0);
+ };
+
+=head1 DESCRIPTION
+
+Moose is an extension of the Perl 5 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 think
+more about what you want to do and less about the mechanics of OOP.
+
+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.
+
+=head2 New to Moose?
+
+If you're new to Moose, the best place to start is the
+L<Moose::Manual> docs, followed by the L<Moose::Cookbook>. The intro
+will show you what Moose is, and how it makes Perl 5 OO better.
+
+The cookbook recipes on Moose basics will get you up to speed with
+many of Moose's features quickly. Once you have an idea of what Moose
+can do, you can use the API documentation to get more detail on
+features which interest you.
+
+=head2 Moose Extensions
+
+The C<MooseX::> namespace is the official place to find Moose extensions.
+These extensions can be found on the CPAN. The easiest way to find them
+is to search for them (L<https://metacpan.org/search?q=MooseX::>),
+or to examine L<Task::Moose> which aims to keep an up-to-date, easily
+installable list of Moose extensions.
+
+=head1 TRANSLATIONS
+
+Much of the Moose documentation has been translated into other languages.
+
+=over 4
+
+=item Japanese
+
+Japanese docs can be found at
+L<http://perldoc.perlassociation.org/pod/Moose-Doc-JA/index.html>. The
+source POD files can be found in GitHub:
+L<http://github.com/jpa/Moose-Doc-JA>
+
+=back
+
+=head1 BUILDING CLASSES WITH MOOSE
+
+Moose makes every attempt to provide as much convenience as possible during
+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.
+
+When you C<use Moose>, Moose will set the class's parent class to
+L<Moose::Object>, I<unless> the class using Moose already has a parent
+class. In addition, specifying a parent with C<extends> will change the parent
+class.
+
+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 PROVIDED METHODS
+
+Moose provides a number of methods to all your classes, mostly through the
+inheritance of L<Moose::Object>. There is however, one exception. By default,
+Moose will install a method named C<meta> in any class which uses
+C<Moose>. This method returns the current class's metaclass.
+
+If you'd like to rename this method, you can do so by passing the
+C<-meta_name> option when using Moose:
+
+ use Moose -meta_name => 'my_meta';
+
+However, the L<Moose::Object> class I<also> provides a method named C<meta>
+which does the same thing. If your class inherits from L<Moose::Object> (which
+is the default), then you will still have a C<meta> method. However, if your
+class inherits from a parent which provides a C<meta> method of its own, your
+class will inherit that instead.
+
+If you'd like for Moose to not install a meta method at all, you can pass
+C<undef> as the C<-meta_name> option:
+
+ use Moose -meta_name => undef;
+
+Again, you will still inherit C<meta> from L<Moose::Object> in this case.
+
+=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. If the parent
+classes are not yet loaded, then C<extends> tries to load them.
+
+This approach is recommended instead of C<use L<base>>/C<use L<parent>>, 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>.
+
+Each superclass can be followed by a hash reference with options. Currently,
+only L<-version|Class::MOP/Class Loading Options> is recognized:
+
+ extends 'My::Parent' => { -version => 0.01 },
+ 'My::OtherParent' => { -version => 0.03 };
+
+An exception will be thrown if the version requirements are not
+satisfied.
+
+=item B<with (@roles)>
+
+This will apply a given set of C<@roles> to the local class.
+
+Like with C<extends>, each specified role can be followed by a hash
+reference with a L<-version|Class::MOP/Class Loading Options> option:
+
+ with 'My::Role' => { -version => 0.32 },
+ 'My::Otherrole' => { -version => 0.23 };
+
+The specified version requirements must be satisfied, otherwise an
+exception will be thrown.
+
+If your role takes options or arguments, they can be passed along in the
+hash reference as well.
+
+=item B<has $name|@$names =E<gt> %options>
+
+This will install an attribute of a given C<$name> into the current class. If
+the first parameter is an array reference, it will create an attribute for
+every C<$name> in the list. The C<%options> will be passed to the constructor
+for L<Moose::Meta::Attribute> (which inherits from L<Class::MOP::Attribute>),
+so the full documentation for the valid options can be found there. These are
+the most commonly used options:
+
+=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
+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 L<reader|Class::MOP::Attribute/reader>,
+L<writer|Class::MOP::Attribute/writer> and
+L<accessor|Class::MOP::Attribute/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 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> supply a type
+constraint, and that type constraint B<must> define a coercion. See
+L<Moose::Cookbook::Basics::HTTP_SubtypesAndCoercion> 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
+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, I<or> the attribute must be lazy
+and have either a default or a builder. Note that c<required> does not
+say anything about the attribute's value, which can be C<undef>.
+
+=item I<weak_ref =E<gt> (1|0)>
+
+This will tell the class to store the value of this attribute as a weakened
+reference. If an attribute is a weakened reference, it B<cannot> also be
+coerced. Note that when a weak ref expires, the attribute's value becomes
+undefined, and is still considered to be set for purposes of predicate,
+default, etc.
+
+=item I<lazy =E<gt> (1|0)>
+
+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 or builder
+supplied.
+
+=item I<trigger =E<gt> $code>
+
+The I<trigger> option is a CODE reference which will be called after
+the value of the attribute is set. The CODE ref is passed the
+instance itself, the updated value, and the original value if the
+attribute was already set.
+
+You B<can> have a trigger on a read-only attribute.
+
+B<NOTE:> Triggers will only fire when you B<assign> to the attribute,
+either in the constructor, or using the writer. Default and built values will
+B<not> cause the trigger to be fired.
+
+=item I<handles =E<gt> ARRAY | HASH | REGEXP | ROLE | ROLETYPE | DUCKTYPE | 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.
+
+You may also use an array reference to curry arguments to the original method.
+
+ has 'thing' => (
+ ...
+ handles => { set_foo => [ set => 'foo' ] },
+ );
+
+ # $self->set_foo(...) calls $self->thing->set('foo', ...)
+
+The first element of the array reference is the original method name, and the
+rest is a list of curried arguments.
+
+=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> or C<ROLETYPE>
+
+With the role option, you specify the name of a role or a
+L<role type|Moose::Meta::TypeConstraint::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<DUCKTYPE>
+
+With the duck type option, you pass a duck type object whose "interface" then
+becomes the list of methods to handle. The "interface" can be defined as the
+list of methods passed to C<duck_type> to create a duck type object. For more
+information on C<duck_type> please check
+L<Moose::Util::TypeConstraints>.
+
+=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<traits =E<gt> [ @role_names ]>
+
+This tells Moose to take the list of C<@role_names> and apply them to the
+attribute meta-object. Custom attribute metaclass traits 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<Metaclass and Trait Name Resolution> for details on how a trait name is
+resolved to a role name.
+
+Also see L<Moose::Cookbook::Meta::Labeled_AttributeTrait> for a metaclass
+trait example.
+
+=item I<builder> => Str
+
+The value of this key is the name of the method that will be called to obtain
+the value used to initialize the attribute. See the L<builder option docs in
+Class::MOP::Attribute|Class::MOP::Attribute/builder> and/or
+L<Moose::Cookbook::Basics::BinaryTree_BuilderAndLazyBuild> for more
+information.
+
+=item I<default> => SCALAR | CODE
+
+The value of this key is the default value which will initialize the attribute.
+
+NOTE: If the value is a simple scalar (string or number), then it can
+be just passed as is. However, if you wish to initialize it with a
+HASH or ARRAY ref, then you need to wrap that inside a CODE reference.
+See the L<default option docs in
+Class::MOP::Attribute|Class::MOP::Attribute/default> for more
+information.
+
+=item I<clearer> => Str
+
+Creates a method allowing you to clear the value. See the L<clearer option
+docs in Class::MOP::Attribute|Class::MOP::Attribute/clearer> for more
+information.
+
+=item I<predicate> => Str
+
+Creates a method to perform a basic test to see if a value has been set in the
+attribute. See the L<predicate option docs in
+Class::MOP::Attribute|Class::MOP::Attribute/predicate> for more information.
+
+Note that the predicate will return true even for a C<weak_ref> attribute
+whose value has expired.
+
+=item I<documentation> => $string
+
+An arbitrary string that can be retrieved later by calling C<<
+$attr->documentation >>.
+
+=back
+
+=item B<has +$name =E<gt> %options>
+
+This is variation on the normal attribute 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');
+
+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>.
+
+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.
+
+Note that you can only extend an attribute from either a superclass or a role,
+you cannot extend an attribute in a role that composes over an attribute from
+another role.
+
+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. Most options work the same, but there are some exceptions:
+
+=over 4
+
+=item I<reader>
+
+=item I<writer>
+
+=item I<accessor>
+
+=item I<clearer>
+
+=item I<predicate>
+
+These options can be added, but cannot override a superclass definition.
+
+=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 preexisting traits
+B<are not> overridden, or removed.
+
+=back
+
+=item B<before $name|@names|\@names|qr/.../ =E<gt> sub { ... }>
+
+=item B<after $name|@names|\@names|qr/.../ =E<gt> sub { ... }>
+
+=item B<around $name|@names|\@names|qr/.../ =E<gt> sub { ... }>
+
+These three items are syntactic sugar for the before, after, and around method
+modifier features that L<Class::MOP> provides. More information on these may be
+found in L<Moose::Manual::MethodModifiers> and the
+L<Class::MOP::Class documentation|Class::MOP::Class/"Method Modifiers">.
+
+=item B<override ($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.
+
+=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
+superclass method with the same arguments as the original method.
+
+=item B<augment ($name, &sub)>
+
+An C<augment> method, is a way of explicitly saying "I am augmenting this
+method from my superclass". Once again, the details of how C<inner> and
+C<augment> work is best described in the
+L<Moose::Cookbook::Basics::Document_AugmentAndInner>.
+
+=item B<inner>
+
+The keyword C<inner>, much like C<super>, is a no-op outside of the context of
+an C<augment> method. You can think of C<inner> as being the inverse of
+C<super>; the details of how C<inner> and C<augment> work is best described in
+the L<Moose::Cookbook::Basics::Document_AugmentAndInner>.
+
+=item B<blessed>
+
+This is the C<Scalar::Util::blessed> function. It is highly recommended that
+this is used instead of C<ref> anywhere you need to test for an object's class
+name.
+
+=item B<confess>
+
+This is the C<Carp::confess> function, and exported here for historical
+reasons.
+
+=back
+
+=head1 METACLASS
+
+When you use Moose, you can specify traits which will be applied to your
+metaclass:
+
+ use Moose -traits => 'My::Trait';
+
+This is very similar to the attribute traits feature. When you do
+this, your class's C<meta> object will have the specified traits
+applied to it. See L<Metaclass and Trait Name Resolution> for more
+details.
+
+=head2 Metaclass and Trait Name Resolution
+
+By default, when given a trait name, Moose simply tries to load a
+class of the same name. If such a class does not exist, it then looks
+for a class matching
+B<Moose::Meta::$type::Custom::Trait::$trait_name>. The C<$type>
+variable here will be one of B<Attribute> or B<Class>, depending on
+what the trait is being applied to.
+
+If a class with this long name exists, Moose checks to see if it has
+the method C<register_implementation>. This method is expected to
+return the I<real> class name of the trait. If there is no
+C<register_implementation> method, it will fall back to using
+B<Moose::Meta::$type::Custom::Trait::$trait> as the trait name.
+
+The lookup method for metaclasses is the same, except that it looks
+for a class matching B<Moose::Meta::$type::Custom::$metaclass_name>.
+
+If all this is confusing, take a look at
+L<Moose::Cookbook::Meta::Labeled_AttributeTrait>, which demonstrates how to
+create an attribute trait.
+
+=head1 UNIMPORTING FUNCTIONS
+
+=head2 B<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:
+
+ package Person;
+ use Moose;
+
+ has 'first_name' => (is => 'rw', isa => 'Str');
+ has 'last_name' => (is => 'rw', isa => 'Str');
+
+ sub full_name {
+ my $self = shift;
+ $self->first_name . ' ' . $self->last_name
+ }
+
+ no Moose; # keywords are removed from the Person package
+
+=head1 EXTENDING AND EMBEDDING MOOSE
+
+To learn more about extending Moose, we recommend checking out the
+"Extending" recipes in the L<Moose::Cookbook>, starting with
+L<Moose::Cookbook::Extending::ExtensionOverview>, which provides an overview of
+all the different ways you might extend Moose. L<Moose::Exporter> and
+L<Moose::Util::MetaRole> are the modules which provide the majority of the
+extension functionality, so reading their documentation should also be helpful.
+
+=head2 The MooseX:: namespace
+
+Generally if you're writing an extension I<for> Moose itself you'll want
+to put your extension in the C<MooseX::> namespace. This namespace is
+specifically for extensions that make Moose better or different in some
+fundamental way. It is traditionally B<not> for a package that just happens
+to use Moose. This namespace follows from the examples of the C<LWPx::>
+and C<DBIx::> namespaces that perform the same function for C<LWP> and C<DBI>
+respectively.
+
+=head1 METACLASS COMPATIBILITY AND MOOSE
+
+Metaclass compatibility is a thorny subject. You should start by
+reading the "About Metaclass compatibility" section in the
+L<Class::MOP> docs.
+
+Moose will attempt to resolve a few cases of metaclass incompatibility
+when you set the superclasses for a class, in addition to the cases that
+L<Class::MOP> handles.
+
+Moose tries to determine if the metaclasses only "differ by roles". This
+means that the parent and child's metaclass share a common ancestor in
+their respective hierarchies, and that the subclasses under the common
+ancestor are only different because of role applications. This case is
+actually fairly common when you mix and match various C<MooseX::*>
+modules, many of which apply roles to the metaclass.
+
+If the parent and child do differ by roles, Moose replaces the
+metaclass in the child with a newly created metaclass. This metaclass
+is a subclass of the parent's metaclass which does all of the roles that
+the child's metaclass did before being replaced. Effectively, this
+means the new metaclass does all of the roles done by both the
+parent's and child's original metaclasses.
+
+Ultimately, this is all transparent to you except in the case of an
+unresolvable conflict.
+
+=head1 CAVEATS
+
+=over 4
+
+=item *
+
+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/basics/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
+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 (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).
+
+=back
+
+=head1 GETTING HELP
+
+We offer both a mailing list and a very active IRC channel.
+
+The mailing list is L<mailto:moose@perl.org>. You must be subscribed to send
+a message. To subscribe, send an empty message to
+L<mailto:moose-subscribe@perl.org>
+
+You can also visit us at C<#moose> on L<irc://irc.perl.org/#moose>
+This channel is quite active, and questions at all levels (on Moose-related
+topics ;) are welcome.
+
+=head1 WHAT DOES MOOSE STAND FOR?
+
+Moose doesn't stand for one thing in particular, however, if you want, here
+are a few of our favorites. Feel free to contribute more!
+
+=over 4
+
+=item * Make Other Object Systems Envious
+
+=item * Makes Object Orientation So Easy
+
+=item * Makes Object Orientation Spiffy- Er (sorry ingy)
+
+=item * Most Other Object Systems Emasculate
+
+=item * Moose Often Ovulate Sorta Early
+
+=item * Moose Offers Often Super Extensions
+
+=item * Meta Object Obligates Salivary Excitation
+
+=item * Meta Object Orientation Syntax Extensions
+
+=item * Moo, Only Overengineered, Slow, and Execrable (blame rjbs!)
+
+=item * Massive Object-Oriented Stacktrace Emitter
+
+=back
+
+=head1 ACKNOWLEDGEMENTS
+
+=over 4
+
+=item I blame Sam Vilain for introducing me to the insanity that is meta-models.
+
+=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,
+and it certainly wouldn't have this name ;P
+
+=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 posse for all the
+early ideas/feature-requests/encouragement/bug-finding.
+
+=item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes.
+
+=back
+
+=head1 SEE ALSO
+
+=over 4
+
+=item L<http://moose.perl.org/>
+
+This is the official web home of Moose. It contains links to our public git
+repository, as well as links to a number of talks and articles on Moose and
+Moose related technologies.
+
+=item the L<Moose manual|Moose::Manual>
+
+This is an introduction to Moose which covers most of the basics.
+
+=item Modern Perl, by chromatic
+
+This is an introduction to modern Perl programming, which includes a section on
+Moose. It is available in print and as a free download from
+L<http://onyxneon.com/books/modern_perl/>.
+
+=item The Moose is flying, a tutorial by Randal Schwartz
+
+Part 1 - L<http://www.stonehenge.com/merlyn/LinuxMag/col94.html>
+
+Part 2 - L<http://www.stonehenge.com/merlyn/LinuxMag/col95.html>
+
+=item Several Moose extension modules in the C<MooseX::> namespace.
+
+See L<https://metacpan.org/search?q=MooseX::> for extensions.
+
+=back
+
+=head2 Books
+
+=over 4
+
+=item The Art of the MetaObject Protocol
+
+I mention this in the L<Class::MOP> docs too, as 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<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
+exception.
+
+Please report any bugs to C<bug-moose@rt.cpan.org>, or through the web
+interface at L<http://rt.cpan.org>. You can also submit a C<TODO> test as a
+pull request at L<https://github.com/moose/Moose>.
+
+You can also discuss feature requests or possible bugs on the Moose mailing
+list (moose@perl.org) or on IRC at L<irc://irc.perl.org/#moose>.
+
+=head1 FEATURE REQUESTS
+
+We are very strict about what features we add to the Moose core, especially
+the user-visible features. Instead we have made sure that the underlying
+meta-system of Moose is as extensible as possible so that you can add your
+own features easily.
+
+That said, occasionally there is a feature needed in the meta-system
+to support your planned extension, in which case you should either
+email the mailing list (moose@perl.org) or join us on IRC at
+L<irc://irc.perl.org/#moose> to discuss. The
+L<Moose::Manual::Contributing> has more detail about how and when you
+can contribute.
+
+=head1 CABAL
+
+There are only a few people with the rights to release a new version
+of Moose. The Moose Cabal are the people to go to with questions regarding
+the wider purview of Moose. They help maintain not just the code
+but the community as well. See the list below under C<AUTHORS>.
+
+=head1 CONTRIBUTORS
+
+Moose is a community project, and as such, involves the work of many, many
+members of the community beyond just the members in the cabal. In particular:
+
+Dave (autarch) Rolsky wrote most of the documentation in L<Moose::Manual>.
+
+John (jgoulah) Goulah wrote L<Moose::Cookbook::Snack::Keywords>.
+
+Jess (castaway) Robinson wrote L<Moose::Cookbook::Snack::Types>.
+
+Aran (bluefeet) Clary Deltac wrote
+L<Moose::Cookbook::Basics::Genome_OverloadingSubtypesAndCoercion>.
+
+Anders (Debolaz) Nor Berle contributed L<Test::Moose> and L<Moose::Util>.
+
+Also, the code in L<Moose::Meta::Attribute::Native> is based on code from the
+L<MooseX::AttributeHelpers> distribution, which had contributions from:
+
+Chris (perigrin) Prather
+
+Cory (gphat) Watson
+
+Evan Carroll
+
+Florian (rafl) Ragwitz
+
+Jason May
+
+Jay Hannah
+
+Jesse (doy) Luehrs
+
+Paul (frodwith) Driver
+
+Robert (rlb3) Boone
+
+Robert Buels
+
+Robert (phaylon) Sedlacek
+
+Shawn (Sartak) Moore
+
+Stevan Little
+
+Tom (dec) Lanyon
+
+Yuval Kogman
+
+Finally, these people also contributed various tests, bug fixes,
+documentation, and features to the Moose codebase:
+
+Aankhen
+
+Adam (Alias) Kennedy
+
+Christian (chansen) Hansen
+
+Cory (gphat) Watson
+
+Dylan Hardison (doc fixes)
+
+Eric (ewilhelm) Wilhelm
+
+Evan Carroll
+
+Guillermo (groditi) Roditi
+
+Jason May
+
+Jay Hannah
+
+Jonathan (jrockway) Rockway
+
+Matt (mst) Trout
+
+Nathan (kolibrie) Gray
+
+Paul (frodwith) Driver
+
+Piotr (dexter) Roszatycki
+
+Robert Buels
+
+Robert (phaylon) Sedlacek
+
+Robert (rlb3) Boone
+
+Sam (mugwump) Vilain
+
+Scott (konobi) McWhirter
+
+Shlomi (rindolf) Fish
+
+Tom (dec) Lanyon
+
+Wallace (wreis) Reis
+
+... and many other #moose folks
+
+=head1 AUTHORS
+
+=over 4
+
+=item *
+
+Stevan Little <stevan.little@iinteractive.com>
+
+=item *
+
+Dave Rolsky <autarch@urth.org>
+
+=item *
+
+Jesse Luehrs <doy@tozt.net>
+
+=item *
+
+Shawn M Moore <code@sartak.org>
+
+=item *
+
+יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>
+
+=item *
+
+Karen Etheridge <ether@cpan.org>
+
+=item *
+
+Florian Ragwitz <rafl@debian.org>
+
+=item *
+
+Hans Dieter Pearcey <hdp@weftsoar.net>
+
+=item *
+
+Chris Prather <chris@prather.org>
+
+=item *
+
+Matt S Trout <mst@shadowcat.co.uk>
+
+=back
+
+=head1 COPYRIGHT AND LICENSE
+
+This software is copyright (c) 2006 by Infinity Interactive, Inc..
+
+This is free software; you can redistribute it and/or modify it under
+the same terms as the Perl 5 programming language system itself.
+
+=cut