## players.janet
(defn next-player
  [id players &opt out-of]
  
  (var ind (find-index |(and (= ($0 :id) id)) players))
  (let [f (fiber/new (fn []
                       (while true
                         (do
                           (set ind (mod (inc ind) (length players)))
                           (yield ind)))))]
    (var found nil)
    (while (not found)
      (let [new-ind (resume f)
            new-id ((players new-ind) :id)]
        (if (or (nil? out-of) (in out-of (keyword new-id)))
          (set found new-id))))
    found))

(defn of-team [players team] (->> players
                                  (filter |(= ($0 :team) team))
                                  (map |($0 :id))))