package # hide the package from PAUSE
Perl6Attribute;
use strict;
use warnings;
our $VERSION = '0.02';
use parent 'Class::MOP::Attribute';
Perl6Attribute->meta->add_around_method_modifier('new' => sub {
my $cont = shift;
my ($class, $attribute_name, %options) = @_;
# extract the sigil and accessor name
my ($sigil, $accessor_name) = ($attribute_name =~ /^([\$\@\%])\.(.*)$/);
# pass the accessor name
$options{accessor} = $accessor_name;
# create a default value based on the sigil
$options{default} = sub { [] } if ($sigil eq '@');
$options{default} = sub { {} } if ($sigil eq '%');
$cont->($class, $attribute_name, %options);
});
1;
__END__
=pod
=head1 NAME
Perl6Attribute - An example attribute metaclass for Perl 6 style attributes
=head1 SYNOPSIS
package Foo;
Foo->meta->add_attribute(Perl6Attribute->new('$.foo'));
Foo->meta->add_attribute(Perl6Attribute->new('@.bar'));
Foo->meta->add_attribute(Perl6Attribute->new('%.baz'));
sub new {
my $class = shift;
$class->meta->new_object(@_);
}
=head1 DESCRIPTION
This is an attribute metaclass which implements Perl 6 style
attributes, including the auto-generating accessors.
This code is very simple, we only need to subclass
C<Class::MOP::Attribute> and override C<&new>. Then we just
pre-process the attribute name, and create the accessor name
and default value based on it.
More advanced features like the C<handles> trait (see
L<Perl6::Bible/A12>) can be accomplished as well doing the
same pre-processing approach. This is left as an exercise to
the reader though (if you do it, please send me a patch
though, and will update this).
=head1 AUTHORS
Stevan Little E<lt>stevan@iinteractive.comE<gt>
Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
=cut