triboard.logic.next-turn-2.cljs

(defn- who-can-play
  "Given the current player and the transitions for the next turn,
   returns the next player that has at least one transition available"
  [player transitions]
  (filter                         ;; Keep only the players which
    #(contains? transitions %)    ;; have at least a valid move to play
    (player/next-three player)))  ;; from the next three players

(defn- with-next-player
  "Complete the turn to compute to find the next player than can act
   * Requires to look-ahead for the next possible transitions
   * To save computation, keep this look-ahead available"
  [{:keys [board player] :as turn}]
  (let [transitions (transition/all-transitions board)
        next-player (first (who-can-play player transitions))]
    (merge turn
      {:transitions (get transitions next-player) ;; Keep the transitions of player
       :player next-player})))                    ;; Inside the turn (caching)