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package Moose::Meta::TypeConstraint::DuckType;
our $VERSION = '2.4000';
use strict;
use warnings;
use metaclass;
use B;
use Scalar::Util 'blessed';
use List::Util 1.33 qw(all);
use Moose::Util 'english_list';
use Moose::Util::TypeConstraints ();
use parent 'Moose::Meta::TypeConstraint';
__PACKAGE__->meta->add_attribute('methods' => (
accessor => 'methods',
Class::MOP::_definition_context(),
));
my $inliner = sub {
my $self = shift;
my $val = shift;
return $self->parent->_inline_check($val)
. ' && do {' . "\n"
. 'my $val = ' . $val . ';' . "\n"
. '&List::Util::all(' . "\n"
. 'sub { $val->can($_) },' . "\n"
. join(', ', map { B::perlstring($_) } @{ $self->methods })
. ');' . "\n"
. '}';
};
sub new {
my ( $class, %args ) = @_;
$args{parent}
= Moose::Util::TypeConstraints::find_type_constraint('Object');
my @methods = @{ $args{methods} };
$args{constraint} = sub {
my $val = $_[0];
return all { $val->can($_) } @methods;
};
$args{inlined} = $inliner;
my $self = $class->SUPER::new(\%args);
$self->compile_type_constraint()
unless $self->_has_compiled_type_constraint;
return $self;
}
sub equals {
my ( $self, $type_or_name ) = @_;
my $other = Moose::Util::TypeConstraints::find_type_constraint($type_or_name);
return unless $other->isa(__PACKAGE__);
my @self_methods = sort @{ $self->methods };
my @other_methods = sort @{ $other->methods };
return unless @self_methods == @other_methods;
while ( @self_methods ) {
my $method = shift @self_methods;
my $other_method = shift @other_methods;
return unless $method eq $other_method;
}
return 1;
}
sub create_child_type {
my ($self, @args) = @_;
return Moose::Meta::TypeConstraint->new(@args, parent => $self);
}
sub get_message {
my $self = shift;
my ($value) = @_;
if ($self->has_message) {
return $self->SUPER::get_message(@_);
}
return $self->SUPER::get_message($value) unless blessed($value);
my @methods = grep { !$value->can($_) } @{ $self->methods };
my $class = blessed $value;
$class ||= $value;
return $class
. " is missing methods "
. english_list(map { "'$_'" } @methods);
}
1;
# ABSTRACT: Type constraint for duck typing
__END__
=pod
=encoding UTF-8
=head1 NAME
Moose::Meta::TypeConstraint::DuckType - Type constraint for duck typing
=head1 VERSION
version 2.4000
=head1 DESCRIPTION
This class represents type constraints based on an enumerated list of
required methods.
=head1 INHERITANCE
C<Moose::Meta::TypeConstraint::DuckType> is a subclass of
L<Moose::Meta::TypeConstraint>.
=head1 METHODS
=head2 Moose::Meta::TypeConstraint::DuckType->new(%options)
This creates a new duck type constraint based on the given
C<%options>.
It takes the same options as its parent, with several
exceptions. First, it requires an additional option, C<methods>. This
should be an array reference containing a list of required method
names. Second, it automatically sets the parent to the C<Object> type.
Finally, it ignores any provided C<constraint> option. The constraint
is generated automatically based on the provided C<methods>.
=head2 $constraint->methods
Returns the array reference of required methods provided to the
constructor.
=head2 $constraint->create_child_type
This returns a new L<Moose::Meta::TypeConstraint> object with the type
as its parent.
Note that it does I<not> return a C<Moose::Meta::TypeConstraint::DuckType>
object!
=head1 BUGS
See L<Moose/BUGS> for details on reporting bugs.
=head1 AUTHORS
=over 4
=item *
Stevan Little <stevan@cpan.org>
=item *
Dave Rolsky <autarch@urth.org>
=item *
Jesse Luehrs <doy@cpan.org>
=item *
Shawn M Moore <sartak@cpan.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@cpan.org>
=item *
Chris Prather <chris@prather.org>
=item *
Matt S Trout <mstrout@cpan.org>
=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
|
