gistfile1.clj

(defn handle-player-movement
  [key-handler]
  (let [coords (atom [0 0])]
    (.addEventListener key-handler goog.events.KEY
                       (fn [e]
                         (let [dir (case (.-keyCode e)
                                     KeyCodes.UP :up
                                     KeyCodes.DOWN :down
                                     KeyCodes.RIGHT :right
                                     KeyCodes.LEFT :left)]
                           (match [dir]
                             :up (swap! coords ...)
                             :down (swap! coords ...)
                             :right (swap! coords ...)
                             :left (swap! coords ...)))))
    coords))