Joining Transducer - PromisesPromises

(require
    '[clojure.core.async :refer [chan sliding-buffer <! go-loop onto-chan] :as async]
    '[manifold.stream :as stream]
    '[prpr.stream.cross :as stream.cross])

  (let [tick-list->macd-ch (chan (sliding-buffer 50))
        sma-list->macd-ch (chan (sliding-buffer 50))

        tick-list->MACD (->> tick-list->macd-ch
                             stream/->source
                             (stream.cross/event-source->sorted-stream :id))
        sma-list->MACD (->> sma-list->macd-ch
                            stream/->source
                            (stream.cross/event-source->sorted-stream :id))

        result (stream.cross/set-streams-union {:default-key-fn :id
                                                :skey-streams {:tick-list tick-list->MACD
                                                               :sma-list sma-list->MACD}})

        connector-ch (chan (sliding-buffer 100))]

    ;; OK
    #_(go-loop [r (<! tick-list->macd-ch)]
        (info r)
        (when r
          (recur (<! tick-list->macd-ch))))

    ;; OK
    #_(stream/map (fn [r]
                    (prn ">> " r)
                    r)
                  sma-list->MACD)

    (stream/connect @result connector-ch)
    (go-loop [{:keys [tick-list sma-list] :as r} (<! connector-ch)]
      (info "record: " r)
      (if-not r
        r
        (recur (<! connector-ch))))

    (onto-chan tick-list->macd-ch [{:id :a :val 1} {:id :b :val 2} {:id :c :val 3}])
    (onto-chan sma-list->macd-ch [{:id :a :val 2} {:id :b :val 3} {:id :c :val 4}]))

I seem to have gotten a bit further with [employeerepublic/promisespromises "0.5"], which works with [manifold "0.1.7-alpha6"].