Core.async version of https://gist.github.com/mneedham/9990977

gistfile1.clj

(require '[clojure.core.async :refer [alt! <!! chan go-loop]])

(defn events [quit-ch {perpage :perpage offset :offset orderby :orderby}]
  (let [out-port (chan)
    (go-loop [offset offset]
      (let [res (client/get
                  (str "https://api.meetup.com/2/events?page=" perpage
                       "&offset=" offset
                       "&orderby=" orderby
                       "&status=upcoming,past&"
                       "&group_urlname=" MEETUP_NAME
                       "&key=" MEETUP_KEY)
                  {:as :json})]

        (alt!
          ;; When the producer closes quit-ch, we're done.
          quit-ch (close! out-port)
          ;; Otherwise fetch the next set of results.
          [out-port res] (recur (+ perpage offset)))))
    out-port))

(let [quit-ch (chan)
      event-ch (events quit-ch ...)]
  (loop [result-set (<!! event-ch)]
    (if (we-still-want-more-events result-set)
      (recur (<!! event-ch))
      ;; Close the quit channel, thereby halting the producer.
      (close! quit-ch))))