Just messing around with the bowling kata

gistfile1.rb

class BowlingScorer

  def initialize
    @score = 0
    @rolls = []
    @frame_index = 0
  end

  def roll(n)
    @rolls << n
  end

  def score
    10.times do
      if strike?
        score_strike_bonus
      elsif spare?
        score_spare_bonus
      else
        score_standard_frame
      end

      advance_frame
    end

    @score
  end

  private

  def strike?
    @rolls[@frame_index] == 10
  end

  def score_strike_bonus
    @score += 10 + @rolls[@frame_index + 1] + @rolls[@frame_index + 2]
  end

  def spare?
    @rolls[@frame_index] + @rolls[@frame_index + 1] == 10
  end

  def score_spare_bonus
    @score += 10 + @rolls[@frame_index + 2]
  end

  def score_standard_frame
    @score += @rolls[@frame_index] + @rolls[@frame_index + 1]
  end

  def advance_frame
    strike? ? @frame_index += 1 : @frame_index += 2
  end
end