Clojure lazy QS

Qs.clj

(defn sort-parts
  "Lazy, tail-recursive, incremental quicksort.  Works against
   and creates partitions based on the pivot, defined as 'work'."
  [work]
  (lazy-seq
   (loop [[part & parts] work]
     (if-let [[pivot & xs] (seq part)]
       (let [smaller? #(< % pivot)]
         (recur (list*
                 (filter smaller? xs)
                 pivot
                 (remove smaller? xs)
                 parts)))
       (when-let [[x & parts] parts]
         (cons x (sort-parts parts)))))))

(defn qsort [xs]
    (sort-parts (list xs)))