ibid clojure - from Gene Kim's interview on the Functional Geekery podcast.

ibid.clj

;; couldn't resist after hearing the podcast...

(defn ibid [coll]
 (reduce (fn [res cur] 
           (if (= cur "ibid")
             (conj res (last res))
             (conj res cur)))
  [(first coll)]
  (rest coll)))

 (clojure.test/is 
   (= (ibid ["foo" "ibid" "ibid" "bar" "meh" "ibid" "yay"])
            ["foo" "foo" "foo" "bar" "meh" "meh" "yay"]))