Reduce with multiple accumulators

multi-acc-reduce.clj

(reduce
 (fn [{:keys [odd even]} datum]
   (if (odd? datum)
     {:odd (conj odd datum)
      :even even}
     {:odd odd
      :even (conj even datum)}))
 {:odd []
  :even []}
 (range 20))

;;{:odd [1 3 5 7 9 11 13 15 17 19], :even [0 2 4 6 8 10 12 14 16 18]}

(defn sieve [pred coll]
  (reduce
   (fn [[acc rej] x]
     (if (pred x)
       [(conj acc x) rej]
       [acc (conj rej x)]))
   [[] []] coll))

;;user> (sieve odd? (range 20))
;; [[1 3 5 7 9 11 13 15 17 19] [0 2 4 6 8 10 12 14 16 18]]