bowling-kata/src/main/java/BowlingGameCalculator.java

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class BowlingGameCalculator {

    private static final Pattern SINGLE_VALUE_PATTERN = Pattern.compile("\\d");
    private static final Pattern SPARE_PATTERN = Pattern.compile("/[ -,]*(\\d)");
    private static final int INITIAL_SCORE_VALUE = 0;

    public int score(String playerResult) {
        int playerScore = INITIAL_SCORE_VALUE;

        Matcher singleDigit = SINGLE_VALUE_PATTERN.matcher(playerResult);
        while (singleDigit.find()) {
            playerScore += Integer.parseInt(singleDigit.group());
        }

        Matcher spare = SPARE_PATTERN.matcher(playerResult);
        while (spare.find()) {
            playerScore += 10 + Integer.parseInt(spare.group(1));
        }

        return playerScore;
    }
}