package Mouse;
use strict;
use warnings;
use 5.006;
use base 'Exporter';
our $VERSION = '0.17';
BEGIN {
if ($ENV{MOUSE_DEBUG}) {
*DEBUG = sub (){ 1 };
} else {
*DEBUG = sub (){ 0 };
}
}
use Carp 'confess';
use Scalar::Util 'blessed';
use Mouse::Util;
use Mouse::Meta::Attribute;
use Mouse::Meta::Class;
use Mouse::Object;
use Mouse::Util::TypeConstraints;
our @EXPORT = qw(extends has before after around override super blessed confess with);
sub extends { Mouse::Meta::Class->initialize(caller)->superclasses(@_) }
sub has {
my $meta = Mouse::Meta::Class->initialize(caller);
my $names = shift;
$names = [$names] if !ref($names);
for my $name (@$names) {
if ($name =~ s/^\+//) {
Mouse::Meta::Attribute->clone_parent($meta, $name, @_);
}
else {
Mouse::Meta::Attribute->create($meta, $name, @_);
}
}
}
sub before {
my $meta = Mouse::Meta::Class->initialize(caller);
my $code = pop;
for (@_) {
$meta->add_before_method_modifier($_ => $code);
}
}
sub after {
my $meta = Mouse::Meta::Class->initialize(caller);
my $code = pop;
for (@_) {
$meta->add_after_method_modifier($_ => $code);
}
}
sub around {
my $meta = Mouse::Meta::Class->initialize(caller);
my $code = pop;
for (@_) {
$meta->add_around_method_modifier($_ => $code);
}
}
sub with {
Mouse::Util::apply_all_roles((caller)[0], @_);
}
our $SUPER_PACKAGE;
our $SUPER_BODY;
our @SUPER_ARGS;
sub super {
# This check avoids a recursion loop - see
# t/100_bugs/020_super_recursion.t
return if defined $SUPER_PACKAGE && $SUPER_PACKAGE ne caller();
return unless $SUPER_BODY; $SUPER_BODY->(@SUPER_ARGS);
}
sub override {
my $meta = Mouse::Meta::Class->initialize(caller);
my $pkg = $meta->name;
my $name = shift;
my $code = shift;
my $body = $pkg->can($name)
or confess "You cannot override '$name' because it has no super method";
$meta->add_method($name => sub {
local $SUPER_PACKAGE = $pkg;
local @SUPER_ARGS = @_;
local $SUPER_BODY = $body;
$code->(@_);
});
}
sub import {
my $class = shift;
strict->import;
warnings->import;
my $caller = caller;
# we should never export to main
if ($caller eq 'main') {
warn qq{$class does not export its sugar to the 'main' package.\n};
return;
}
my $meta = Mouse::Meta::Class->initialize($caller);
$meta->superclasses('Mouse::Object')
unless $meta->superclasses;
no strict 'refs';
no warnings 'redefine';
*{$caller.'::meta'} = sub { $meta };
if (@_) {
__PACKAGE__->export_to_level( 1, $class, @_);
} else {
# shortcut for the common case of no type character
no strict 'refs';
for my $keyword (@EXPORT) {
*{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
}
}
}
sub unimport {
my $caller = caller;
no strict 'refs';
for my $keyword (@EXPORT) {
delete ${ $caller . '::' }{$keyword};
}
}
sub load_class {
my $class = shift;
if (ref($class) || !defined($class) || !length($class)) {
my $display = defined($class) ? $class : 'undef';
confess "Invalid class name ($display)";
}
return 1 if $class eq 'Mouse::Object';
return 1 if is_class_loaded($class);
(my $file = "$class.pm") =~ s{::}{/}g;
eval { CORE::require($file) };
confess "Could not load class ($class) because : $@" if $@;
return 1;
}
sub is_class_loaded {
my $class = shift;
return 0 if ref($class) || !defined($class) || !length($class);
# walk the symbol table tree to avoid autovififying
# \*{${main::}{"Foo::"}} == \*main::Foo::
my $pack = \*::;
foreach my $part (split('::', $class)) {
return 0 unless exists ${$$pack}{"${part}::"};
$pack = \*{${$$pack}{"${part}::"}};
}
# check for $VERSION or @ISA
return 1 if exists ${$$pack}{VERSION}
&& defined *{${$$pack}{VERSION}}{SCALAR};
return 1 if exists ${$$pack}{ISA}
&& defined *{${$$pack}{ISA}}{ARRAY};
# check for any method
foreach ( keys %{$$pack} ) {
next if substr($_, -2, 2) eq '::';
return 1 if defined *{${$$pack}{$_}}{CODE};
}
# fail
return 0;
}
1;
__END__
=head1 NAME
Mouse - Moose minus the antlers
=head1 SYNOPSIS
package Point;
use Mouse; # 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 Mouse;
extends 'Point';
has 'z' => (is => 'rw', isa => 'Int');
after 'clear' => sub {
my $self = shift;
$self->z(0);
};
=head1 DESCRIPTION
L<Moose> is wonderful.
Unfortunately, it's a little slow. Though significant progress has been made
over the years, the compile time penalty is a non-starter for some
applications.
Mouse aims to alleviate this by providing a subset of Moose's
functionality, faster. In particular, L<Moose/has> is missing only a few
expert-level features.
We're also going as light on dependencies as possible.
L<Class::Method::Modifiers> or L<Data::Util> is required if you want support
for L</before>, L</after>, and L</around>.
=head2 MOOSE COMPAT
Compatibility with Moose has been the utmost concern. Fewer than 1% of the
tests fail when run against Moose instead of Mouse. Mouse code coverage is also
over 96%. Even the error messages are taken from Moose. The Mouse code just
runs the test suite 4x faster.
The idea is that, if you need the extra power, you should be able to run
C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
nothingmuch has written L<Squirrel> (part of this distribution) which will act
as Mouse unless Moose is loaded, in which case it will act as Moose.
L<Any::Moose> is a more high-tech L<Squirrel>.
=head2 MouseX
Please don't copy MooseX code to MouseX. If you need extensions, you really
should upgrade to Moose. We don't need two parallel sets of extensions!
If you really must write a Mouse extension, please contact the Moose mailing
list or #moose on IRC beforehand.
=head1 KEYWORDS
=head2 meta -> Mouse::Meta::Class
Returns this class' metaclass instance.
=head2 extends superclasses
Sets this class' superclasses.
=head2 before (method|methods) => Code
Installs a "before" method modifier. See L<Moose/before> or
L<Class::Method::Modifiers/before>.
Use of this feature requires L<Class::Method::Modifiers>!
=head2 after (method|methods) => Code
Installs an "after" method modifier. See L<Moose/after> or
L<Class::Method::Modifiers/after>.
Use of this feature requires L<Class::Method::Modifiers>!
=head2 around (method|methods) => Code
Installs an "around" method modifier. See L<Moose/around> or
L<Class::Method::Modifiers/around>.
Use of this feature requires L<Class::Method::Modifiers>!
=head2 has (name|names) => parameters
Adds an attribute (or if passed an arrayref of names, multiple attributes) to
this class. Options:
=over 4
=item is => ro|rw
If specified, inlines a read-only/read-write accessor with the same name as
the attribute.
=item isa => TypeConstraint
Provides basic type checking in the constructor and accessor. Basic types such
as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
objects).
=item required => 0|1
Whether this attribute is required to have a value. If the attribute is lazy or
has a builder, then providing a value for the attribute in the constructor is
optional.
=item init_arg => Str | Undef
Allows you to use a different key name in the constructor. If undef, the
attribue can't be passed to the constructor.
=item default => Value | CodeRef
Sets the default value of the attribute. If the default is a coderef, it will
be invoked to get the default value. Due to quirks of Perl, any bare reference
is forbidden, you must wrap the reference in a coderef. Otherwise, all
instances will share the same reference.
=item lazy => 0|1
If specified, the default is calculated on demand instead of in the
constructor.
=item predicate => Str
Lets you specify a method name for installing a predicate method, which checks
that the attribute has a value. It will not invoke a lazy default or builder
method.
=item clearer => Str
Lets you specify a method name for installing a clearer method, which clears
the attribute's value from the instance. On the next read, lazy or builder will
be invoked.
=item handles => HashRef|ArrayRef
Lets you specify methods to delegate to the attribute. ArrayRef forwards the
given method names to method calls on the attribute. HashRef maps local method
names to remote method names called on the attribute. Other forms of
L</handles>, such as regular expression and coderef, are not yet supported.
=item weak_ref => 0|1
Lets you automatically weaken any reference stored in the attribute.
Use of this feature requires L<Scalar::Util>!
=item trigger => CodeRef
Any time the attribute's value is set (either through the accessor or the constructor), the trigger is called on it. The trigger receives as arguments the instance, the new value, and the attribute instance.
Mouse 0.05 supported more complex triggers, but this behavior is now removed.
=item builder => Str
Defines a method name to be called to provide the default value of the
attribute. C<< builder => 'build_foo' >> is mostly equivalent to
C<< default => sub { $_[0]->build_foo } >>.
=item auto_deref => 0|1
Allows you to automatically dereference ArrayRef and HashRef attributes in list
context. In scalar context, the reference is returned (NOT the list length or
bucket status). You must specify an appropriate type constraint to use
auto_deref.
=item lazy_build => 0|1
Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
"clear_$attr', predicate => 'has_$attr' unless they are already defined.
=back
=head2 confess error -> BOOM
L<Carp/confess> for your convenience.
=head2 blessed value -> ClassName | undef
L<Scalar::Util/blessed> for your convenience.
=head1 MISC
=head2 import
Importing Mouse will default your class' superclass list to L<Mouse::Object>.
You may use L</extends> to replace the superclass list.
=head2 unimport
Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
keywords (such as L</extends>) it will break loudly instead breaking subtly.
=head1 FUNCTIONS
=head2 load_class Class::Name
This will load a given C<Class::Name> (or die if it's not loadable).
This function can be used in place of tricks like
C<eval "use $module"> or using C<require>.
=head2 is_class_loaded Class::Name -> Bool
Returns whether this class is actually loaded or not. It uses a heuristic which
involves checking for the existence of C<$VERSION>, C<@ISA>, and any
locally-defined method.
=head1 AUTHORS
Shawn M Moore, C<< <sartak at gmail.com> >>
Yuval Kogman, C<< <nothingmuch at woobling.org> >>
tokuhirom
Yappo
with plenty of code borrowed from L<Class::MOP> and L<Moose>
=head1 BUGS
No known bugs.
Please report any bugs through RT: email
C<bug-mouse at rt.cpan.org>, or browse
L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
=head1 COPYRIGHT AND LICENSE
Copyright 2008 Shawn M Moore.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=cut
