# Each reduce action has its own class, this one is the root of the hierarchy.
private abstract class ReduceAction
	fun action(p: Parser) is abstract
	fun concat(l1, l2 : Array[Object]): Array[Object]
	do
		if l1.is_empty then return l2
		l1.append(l2)
		return l1
	end
	var goto: Int
end