if-vs-cond.clj

(defn branch-off
  "Draws the game tree from an initial node and rules of the game."
  [rules {:keys [pid id] :as node}]
  (cond
    (node/terminal? node) node
    (nil? pid) (branch-off rules (assoc node :pid -1 :id 0))
    :else (assoc node
            :actions (map-vals (partial branch-off rules)
                       (add-ids id (map-actions rules node))))))

;; vs.

(defn branch-off
  "Draws the game tree from an initial node and rules of the game."
  [rules {:keys [pid id] :as node}]
  (if (node/terminal? node)
    node
    (if (nil? pid)
      (branch-off rules (assoc node :pid -1 :id 0))
      (assoc node
        :actions (map-vals (partial branch-off rules)
                   (map-actions rules node))))))