Clojurians Log v2
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missionary 2026-02-11
flowthing 2026-02-11T20:23:09.332689Z
The wiki https://github.com/leonoel/missionary/wiki/Task-interop#turn-a-blocking-call-into-a-task this approach to converting a core.async channel to a task:
(defn <!
[c] (doto (m/dfv) (->> (async/take! c))))(<! (async/chan))
Execution error (ClassCastException) at clojure.core.async/on-caller (async.clj:60).
class missionary.impl.Dataflow$Port cannot be cast to class clojure.lang.IObj (missionary.impl.Dataflow$Port and clojure.lang.IObj are in unnamed module of loader 'app')
leonoel 2026-02-11T20:46:33.323699Z
Interesting. core.async expects the callback function to support metadata, but the dfv object does not. As a workaround we can pass a wrapper function :
(defn <! [c]
(let [v (m/dfv)]
(async/take! c #(v %))
v))👍 1
leonoel 2026-02-11T20:48:39.387019Z
The right fix is probably to implement metadata support