[dbsrgits/DBM-Deep.git] / lib / DBM / Deep / Null.pm

# This was copied from MARCEL's Class::Null. However, I couldn't use it because
# I need an undef value, not an implementation of the Null Class pattern.
package DBM::Deep::Null;

use 5.006_000;

use strict;
use warnings FATAL => 'all';

=head1 NAME

DBM::Deep::Null

=head1 PURPOSE

This is an internal-use-only object for L<DBM::Deep/>. It acts as a NULL object
in the same vein as MARCEL's L<Class::Null/>. I couldn't use L<Class::Null/>
because DBM::Deep needed an object that always evaluated as undef, not an
implementation of the Null Class pattern.

=head1 OVERVIEW

It is used to represent null sectors in DBM::Deep.

=cut

use overload
    'bool'   => sub { undef },
    '""'     => sub { undef },
    '0+'     => sub { undef },
    fallback => 1,
    nomethod => 'AUTOLOAD';

sub AUTOLOAD { return; }

1;
__END__
Commit	Line	Data
f0276afb	1	# This was copied from MARCEL's Class::Null. However, I couldn't use it because
	2	# I need an undef value, not an implementation of the Null Class pattern.
	3	package DBM::Deep::Null;
	4
	5	use 5.006_000;
	6
	7	use strict;
	8	use warnings FATAL => 'all';
	9
	10	=head1 NAME
	11
	12	DBM::Deep::Null
	13
	14	=head1 PURPOSE
	15
	16	This is an internal-use-only object for L<DBM::Deep/>. It acts as a NULL object
	17	in the same vein as MARCEL's L<Class::Null/>. I couldn't use L<Class::Null/>
	18	because DBM::Deep needed an object that always evaluated as undef, not an
	19	implementation of the Null Class pattern.
	20
	21	=head1 OVERVIEW
	22
	23	It is used to represent null sectors in DBM::Deep.
	24
	25	=cut
	26
	27	use overload
	28	'bool' => sub { undef },
	29	'""' => sub { undef },
	30	'0+' => sub { undef },
	31	fallback => 1,
	32	nomethod => 'AUTOLOAD';
	33
	34	sub AUTOLOAD { return; }
	35
	36	1;
	37	__END__