clojure.core.async/sub

View this page on ClojureDocs

Type: function Added: Clojure unknown Examples: 2 Runnable: 0

([p topic ch] [p topic ch close?])

Subscribes a channel to a topic of a pub.

By default the channel will be closed when the source closes, but can be determined by the close? parameter.

Examples

by runexec on 2014-10-01 . May have evaluation errors. ▶

(def c (chan 1)) #'user/c (def sub-c (pub c :route)) #'user/sub-c (def cx (chan 1)) #'user/cx (sub sub-c :up-stream cx) #<ManyToManyChannel clojure.core.async.impl.channels.ManyToManyChannel@526eb67f> (def cy (chan 1)) #'user/cy (sub sub-c :down-stream cy) #<ManyToManyChannel clojure.core.async.impl.channels.ManyToManyChannel@777692ac> (go-loop [_ (<! cx)] (println "Got something coming up!")) #<ManyToManyChannel clojure.core.async.impl.channels.ManyToManyChannel@49e2e0f9> (go-loop [_ (<! cy)] (println "Got something going down!")) #<ManyToManyChannel clojure.core.async.impl.channels.ManyToManyChannel@33498147> (put! c {:route :up-stream :data 123}) true Got something coming up! (put! c {:route :down-stream :data 123}) Got something going down! true

by milelo on 2020-10-24 . May have evaluation errors. ▶

(defn monitor! [publisher topic] (let [<listen (chan 1)] (async/sub publisher topic <listen) (go-loop [] (when-let [{:keys [message]} (<! <listen)] (println topic \- message) (recur))))) (defn start [] (let [<publish (chan 1) publisher (async/pub <publish :source) ] (monitor! publisher :alice) (monitor! publisher :bob) (put! <publish {:source :alice :message "Alice says Hi!"}) (put! <publish {:source :bob :message "Bob says Hi!"}) (put! <publish {:source :john :message "John says Hi!"}) (put! <publish {:source :alice :message "Alice says Hi again"}) (close! <publish) )) (start) => nil :alice - Alice says Hi! :bob - Bob says Hi! :alice - Alice says Hi again

See also

• clojure.core.async/pub (0)

---

Content from the matching ClojureDocs page, with authors credited on each contribution.