map-progress.clj

(defn dot-points
  "Return a seq of points that would be good places to print a progress dot when doing n things"
  [n]
  (map first
       (partition (inc (int (/ n 10)))
		  (range n))))

(defn map-progress
  [f coll]
  (let [n (count coll)
	dot-set (set (dot-points n))
	progress (atom 0)]
    (map
     (fn [x]
       (when (dot-set @progress)
	 (print ".")
	 (.flush *out*))
       (swap! progress inc)
       ;; and finally
       (f x))
     coll)))