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

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 { 0 },
    fallback => 1,
    nomethod => 'AUTOLOAD';

sub AUTOLOAD { return; }

1;
__END__
Commit	Line	Data
f0276afb	1	package DBM::Deep::Null;
	2
	3	use 5.006_000;
	4
	5	use strict;
	6	use warnings FATAL => 'all';
	7
	8	=head1 NAME
	9
	10	DBM::Deep::Null
	11
	12	=head1 PURPOSE
	13
1c62d370	14	This is an internal-use-only object for L<DBM::Deep>. It acts as a NULL object
1c62d370	15	in the same vein as MARCEL's L<Class::Null>. I couldn't use L<Class::Null>
f0276afb	16	because DBM::Deep needed an object that always evaluated as undef, not an
	17	implementation of the Null Class pattern.
	18
	19	=head1 OVERVIEW
	20
	21	It is used to represent null sectors in DBM::Deep.
	22
	23	=cut
	24
	25	use overload
	26	'bool' => sub { undef },
	27	'""' => sub { undef },
66285e35	28	'0+' => sub { 0 },
f0276afb	29	fallback => 1,
	30	nomethod => 'AUTOLOAD';
	31
	32	sub AUTOLOAD { return; }
	33
	34	1;
	35	__END__