A small ring buffer implementation in Ruby

ring.rb

# A ring buffer enumerable object
class Ring
  include Enumerable
  
  def initialize(size)
    @array = Array.new(size)
    @pos = 0
  end

  def pos
    @pos
  end

  def each
    previous_pos = @pos
    @array.length.times { yield(self.next) }
    self
  ensure
    @pos = previous_pos
  end

  def <<(value)
    @array[@pos] = value
    @pos = (@pos + 1) % @array.length
    self
  end

  def next
    @array[@pos].tap do
      @pos = (@pos + 1) % @array.length
    end
  end
end