Bowling Kata in Clojure

bowling.clj

(def STRIKE_SCORE 10)
(def SPARE_SCORE 10)
(def MAX_FRAMES 10)

(defn- max-frames? [frames]
  (>= (count frames) MAX_FRAMES)
  )

(defn- strike? [roll]
  (= STRIKE_SCORE roll)
  )

(defn- spare? [frame-score]
  (= SPARE_SCORE frame-score)
  )

(defn- second-roll [rolls]
  (if-let [second-roll (second rolls)]
    second-roll
    0
    )
  )
(defn- first-roll [rolls]
  (if-let [first-roll (first rolls)]
    first-roll
    0
    )
  )

(defn- next-two-rolls [rolls]
  (+ (first-roll rolls) (second-roll rolls))
  )

(defn- get-spare-frame-score [remaining-frames]
  (+ SPARE_SCORE (first-roll remaining-frames))
  )

(defn- get-strike-frame-score [remaining-frames]
  (+ STRIKE_SCORE (next-two-rolls remaining-frames))
  )

(defn rolls-to-frames [rolls]
  (loop [rolls rolls frames []]
    (if (or (empty? rolls) (max-frames? frames))
      frames
      (let [frame-score (next-two-rolls rolls)]
        (cond
          (strike? (first-roll rolls))
          (let [remaining-rolls (rest rolls)]
            (recur remaining-rolls (conj frames (get-strike-frame-score remaining-rolls))) 
            )
          (spare? frame-score)
          (let [remaining-rolls (rest (rest rolls))]
            (recur remaining-rolls (conj frames (get-spare-frame-score remaining-rolls)))
            )
          :else
          (let [remaining-rolls (rest (rest rolls))]
            (recur remaining-rolls (conj frames frame-score))
            )
          )
        )
      )
    )
  )

(defn get-score [rolls]
  (apply + (rolls-to-frames rolls)) 
  )