collection-type

; This works
(defn collection-type [col]
  (cond
    (= clojure.lang.PersistentList (class col)) :list
    (= clojure.lang.PersistentMap (class col)) :map
    (= clojure.lang.PersistentVector (class col)) :vector))

; IllegalArgumentException No matching clause: class clojure.lang.PersistentVector  user/collection-type (NO_SOURCE_FILE:2)
(defn collection-type [col]
  (case (class col)
    clojure.lang.PersistentList :list
    clojure.lang.PersistentMap :map
    clojure.lang.PersistentVector :vector))