turtle.cljs

(defn turtle-repeat! [[times {:keys [:instructions :index]}]]
  (doseq [x (range times)]
    (do-script! instructions (count instructions))))

(defn do-script! [script until-step]
  (doseq [step-n (range until-step)]
    (let [[instr & data] (nth script step-n)]
      (case instr
        :move (move-turtle! (first data) step-n)
        :turn-right (turn-right! (first data))
        :turn-left (turn-left! (first data))
        :repeat (turtle-repeat! data)
        :pen nil)))) ;; pen instructions are handled by (pen-down? step-n)