scorer.java

著名的uncle Bob的Agile software development的代码

public class Scorer
{
	public void addThrow(int pins)
	{
		itsThrows[itsCurrentThrow++] = pins;
	}

	public int scoreForFrame(int theFrame)
	{
		ball = 0;
		int score=0;
		for (int currentFrame = 0;
		     currentFrame < theFrame;
			   currentFrame++)
		{
			if (strike())
			{
				score += 10 + nextTwoBallsForStrike();
        ball++;
			}
			else if ( spare() )
			{
				score += 10 + nextBallForSpare();
				ball+=2;
			}
			else
			{
				score += twoBallsInFrame();
				ball+=2;
			}
		}

		return score;
	}

	private boolean strike()
	{
		return itsThrows[ball] == 10;
	}

	private boolean spare()
	{
		return (itsThrows[ball] + itsThrows[ball+1]) == 10;
	}

	private int nextTwoBallsForStrike()
	{
		return itsThrows[ball+1] + itsThrows[ball+2];
	}

	private int nextBallForSpare()
	{
		return itsThrows[ball+2];
	}

	private int twoBallsInFrame()
	{
		return itsThrows[ball] + itsThrows[ball+1];
	}

	private int ball;
	private int[] itsThrows = new int[21];
	private int itsCurrentThrow = 0;
}