For memory efficiency, we don’t need sub-java-array, but we can use reduce-subarray. Efficiency is equivalent to manipulating data on the Subarray view.
(defn reduce-subarray [f xs start end]
(->> (range start end)
(reduce #(->> (aget xs %2) f (conj %1 ,)) [] ,)
doall))
(def xs (int-array [0 1 2 3 4 5 6 7 8 9]))
(reduce-subarray str xs 2 7)
;=> ["2" "3" "4" "5" "6"]