package Add;

use strict;
use warnings;

sub new {
	my $class = shift;
	my $self = {
		ACC => undef,
	};
	my $closure = sub {
		my $field = shift;
		if (@_) { $self->{$field} = shift; }
		return $self->{$field};
	};
	bless ($closure,$class);
	return $closure;
}

sub acc { &{ $_[0] }("ACC", @_[1 .. $#_]) }

sub add {
	acc( $_[0],acc( $_[0] )+@_[1 .. $#_] );
}

1;

##</code><code>##


use strict;
use warnings;

use Test::More tests => 7;

BEGIN {
	use_ok('Add');
}

ok(my $a = Add->new(),"creation of accumulator");
ok($a->acc(3),"accumulator set to 3");
isnt($a->acc,0,"check if accumulator isn't zero");
is($a->acc,3,"check accumulator equals 3");
ok($a->add(3),"add 3 to accumulator");
is($a->acc,6,"check if add equals 6");