Rock Paper Sissors

rps.clj

(defn draw?
  [machine-choice player-choice]
  (= machine-choice player-choice))

(defn player-win?
  [machine-choice player-choice]
  (case machine-choice
    "rock"    (= player-choice "paper")
    "paper"   (= player-choice "sissors")
    "sissors" (= player-choice "rock")))

(defn play-game
  [rounds]
  (loop [round 1
         machine-points 0
         player-points  0]
    (if (> round rounds) ; Game Over
      (do (println "Machine score:" machine-points)
          (println "Player score:" player-points))
      (do (println "Round" round ": choose either rock, paper, or sissors.")
          (let [player-choice (read-line)
                machine-choice (rand-nth ["rock" "paper" "sissors"])]
            (cond
              (draw? machine-choice player-choice)
              (do (println "It was a draw! Try again.")
                  (recur round machine-points player-points))

              (player-win? machine-choice player-choice)
              (do (println "Machine chose" machine-choice ", you won!")
                  (recur (inc round) machine-points (inc player-points)))

              :else
              (do (println "Machine chose" machine-choice ", machine won!")
                  (recur (inc round) (inc machine-points) player-points))))))))