gistfile1.clj

(defn format-history-lines
  [history-lines]
  ((comp
     format-history-map
     (partial take 10)
     sort-by-weight
     counts
     (partial map history-line->command))
   history-lines))

;; ... could be ...

(defn format-history-lines
  [history-lines]
  (->> (format-history-map)
       (take 10)
       (sort-by-weight)
       (frequencies) ;; (= frequencies counts) You can get rid of the counts fn above 
       (map history-line->command history-lines)))

;; Correct order ...

(defn format-history-lines
  [history-lines]
  (->> (map history-line->command history-lines)
       (frequencies)
       (sort-by-weight) 
       (take 10)
       (format-history-map)))