mass object assignment without an array or enumerable

gistfile1.rb

class Xs # represent a string of 'x's
  include Comparable
  attr :length

  def initialize(n)
    @length = n
  end

  def succ
    Xs.new(@length + 1)
  end

  def <=>(other)
    @length <=> other.length
  end

  def to_s
    sprintf "%2d #{inspect}", @length
  end

  def inspect
    'x' * @length
  end
end

r = Xs.new(3)..Xs.new(6) #=> xxx..xxxxxx
r.to_a #=> [xxx, xxxx, xxxxx, xxxxxx]
r.member?(Xs.new(5)) #=> true