(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 1996 Institut National de Recherche en Informatique et   *)
(*  Automatique.  Distributed only by permission.                      *)
(*                                                                     *)
(***********************************************************************)

(* $Id$ *)

(function "quick" (lo: int hi: int a: addr)
  (if (< lo hi)
      (let (i lo
            j hi
            pivot (addraref a (>>s hi 1)))
        (while (< i j)
          (catch
              (while 1
                (if (>= i hi) exit [])
                (if (> (addraref a (>>s i 1)) pivot) exit [])
                (assign i (+ i 2)))
           with [])
          (catch
              (while 1
                (if (<= j lo) exit [])
                (if (< (addraref a (>>s j 1)) pivot) exit [])
                (assign j (- j 2)))
           with [])
          (if (< i j)
              (let temp (addraref a (>>s i 1))
                   (addraset a (>>s i 1) (addraref a (>>s j 1)))
                   (addraset a (>>s j 1) temp))
            []))
        (let temp (addraref a (>>s i 1))
             (addraset a (>>s i 1) (addraref a (>>s hi 1)))
             (addraset a (>>s hi 1) temp))
        (app "quick" [lo (- i 2) a] unit)
        (app "quick" [(+ i 2) hi a] unit))
    []))

(function "quicksort" (lo: int hi: int a: addr)
   (app "quick" [(+ (<< lo 1) 1) (+ (<< hi 1) 1) a] unit))