SuccProxy.rb

class SuccProxy
  attr_accessor :inner_obj, :succ_block

  def initialize(a, &b)
    @inner_obj  = a
    @succ_block = b
  end

  def succ
    SuccProxy.new(@succ_block.call(@inner_obj), &@succ_block)
  end

  def <=>(o)
    @inner_obj <=> o
  end

  include Comparable
end

hoge = SuccProxy.new(1){|x| x+=7}
(hoge..100).each do |i|
  puts i.inner_obj
end

huga = SuccProxy.new('huga'){|x| x+=x}
(huga..'hugahugahugahuga').each do |s|
  puts s.inner_obj
end