itr.rb

itr.rb

class Metaclass
  include Enumerable

  def initialize obj
    @obj = obj
  end

  def each
    return enum_for(:each) unless block_given?
    x = meta_for @obj
    loop do
      yield x
      x = meta_for x
    end
  end

  private
  def meta_for o
    class << o; self; end
  end
end

x = Metaclass.new Object.new
p x.first(10) # first 10 metaclasses
itr = x.each
10.times do
  p itr.next
end