Clojurescript core-async：go里面的异步条件

Question

I have a problem with ClojureScript Core-Async . This only happens in ClojureScript and not in Clojure.

I have the following code:

(defn cc [x]
  (go 
    (println "cc: " x)
    x))

(defn foo [x]
  (go
    (when (and (= :ok (<! (cc x)))
               (= :ok (<! (cc :ok))))
      (print "after and"))))

(foo 1)
(foo :ok)

When calling (foo :ok) , the result is as expected - the function cc is called twice, and the console shows cc: :ok cc: :ok after and . But, when running (foo 1) , the function cc is also run twice and the console shows cc: 1 cc: :ok . So, even though the first condition isn't fullfilled, the second one is still checked!

Answer 1

This is appraently a bug with the ClojureScript core.async library. I opened a Jira issue for this.

In the meantime I was able to work around this by using:

(go
  (when (= :ok (<! (cc x))
    (when (= :ok (<! (cc :ok)))
      (print "after and")))))