class ConsumerList inherits System {
	item: IStringConsumer;
	next: ConsumerList;

	init(value: IStringConsumer, tail: Object) : ConsumerList {{
		assert(not (isvoid value), "init", "value argument cannot be void!");
		assert(isvoid item, "init", "List has already been initialised!");

		item <- value;
		if isvoid tail then
			void
		else
			case tail of
				cl: ConsumerList => next <- cl;
				o: Object => assert(false, "init", "tail argument can be either a ConsumerList or void!");
			esac
		fi;

		self;
	}};

	push(value: IStringConsumer) : ConsumerList {{
		assert(not (isvoid value), "push", "value argument cannot be void!");

		if isvoid item
		then
			item <- value
		else if isvoid next
		then
			next <- (new ConsumerList).init(value, void)
		else
			next.push(value)
		fi
		fi;
		self;
	}};

	find(s: String) : Object {{
		assert(not (isvoid item), "find", "list isn't initialised!");

		if 0 < item.consume(s)
		then
			item
		else if isvoid next
		then
			void
		else
			next.find(s)
		fi
		fi;
	}};
};