RosettaCodeData/Task/Queue-Definition/Sidef/queue-definition.sidef

class FIFO(*array) {
    method pop {
        array.is_empty && die "underflow";
        array.shift;
    }
    method push(*items) {
        array += items;
        self;
    }
    method empty {
        array.len == 0;
    }
}