fizz_buzz.rb

class FizzBuzz
  def fizz
    loop do
      ["", "", "Fizz"].each{|s| yield s}
    end
  end

  def buzz
    loop do
      ["", "", "", "", "Buzz"].each{|s| yield s}
    end
  end

  def fizzbuzz
    return to_enum(:fizzbuzz) unless block_given?
    fizz = to_enum(:fizz)
    buzz = to_enum(:buzz)
    (1..Float::INFINITY).each do |i|
      fizzbuzz = [fizz.next, buzz.next].join
      yield fizzbuzz.empty? ? i : fizzbuzz
    end
  end
end

puts FizzBuzz.new.fizzbuzz.take(100)