class List
  attr_reader :list

  def initialize *args
    args.each do |a|
      if a.kind_of? Range
        @list = parse(args, args.index(a))
      end
    end
  end

  def parse args, index
    r = args[index]
    Array.new(r.max) do |i|
      x = args.dup
      x[index] = i
      x
    end
  end
end

a = List.new (1..10), 2, 3, 4
puts a.list.inspect