Sha256: 8c1779111f714cb79811ec62990b3aab8c6144d7514bc13b76300a832d280511
Contents?: true
Size: 1.41 KB
Versions: 396
Compression:
Stored size: 1.41 KB
Contents
(ns robot-simulator)
(def directions [:north :east :south :west])
(defn robot [coordinates bearing]
{:coordinates coordinates :bearing bearing})
(defn turn [bearing direction-list]
(let [dir-stream (drop-while #(not (= bearing %1)) (cycle direction-list))]
(nth dir-stream 1)))
(defn turn-right [bearing]
(turn bearing directions))
(defn turn-left [bearing]
(turn bearing (reverse directions)))
(defn advance [coordinates bearing]
(let [x (:x coordinates)
y (:y coordinates)]
(cond
(= :north bearing) {:x x :y (inc y)}
(= :south bearing) {:x x :y (dec y)}
(= :east bearing) {:x (inc x) :y y}
(= :west bearing) {:x (dec x) :y y})))
(defn simulate [instructions current-state]
(loop [instructions instructions
current-state current-state]
(let [instruction (first instructions)
remainder (rest instructions)
coordinates (:coordinates current-state)
bearing (:bearing current-state)
next-state (cond
(= \L instruction)
(robot coordinates (turn-left bearing))
(= \R instruction)
(robot coordinates (turn-right bearing))
:else
(robot (advance coordinates bearing) bearing))]
(if (seq remainder)
(recur remainder next-state)
next-state))))
Version data entries
396 entries across 396 versions & 1 rubygems