clojure.core.async/take!

View this page on ClojureDocs

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

([port fn1] [port fn1 on-caller?])

Asynchronously takes a val from port, passing to fn1. Will pass nil if closed. If on-caller? (default true) is true, and value is immediately available, will call fn1 on calling thread.

fn1 may be run in a fixed-size dispatch thread pool and should not perform blocking IO, including core.async blocking ops (those that end in !!).

Returns nil.

Examples

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

(def c (chan 1)) #'user/c (take! c (fn [x] (println "Clojure callback value " x))) nil (put! c "XYZ") Clojure callback value XYZ true (put! c "XYZ") true

by jayzawrotny on 2018-01-19 . May have evaluation errors. ▶

(require '[clojure.core.async :refer [chan take! put!]]) (def input-channel (chan 1)) ;; Take the first message from a channel and print it (take! input-channel println) (put! input-channel "A") ;; => "A" (put! input-channel "B") ;; Does not output anything because take only takes the first message

See also

• clojure.core.async/put! (0)
• clojure.core.async/<! (0)
• clojure.core.async/<!!

---

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