:excess throws on a java.util.Map

Mon, 26 Oct 2026 09:18:11 +0000

(def m (java.util.HashMap. {:a 1 :b 2}))

(def select-a (selector {:keys [a] :select s}))
(def excess-a (selector {:keys [a] :excess e}))

(select-a m)
;; => {:a 1}

(excess-a m)
;; => ClassCastException: class java.util.HashMap cannot be cast to class clojure.lang.IPersistentMap
;; Expected `{:b 2}`.

Reproduced on Clojure 1.13.0-alpha10.

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:excess throws on a java.util.Map