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|
(*************************************************************************)
(* *)
(* OCaml LablTk library *)
(* *)
(* Jacques Garrigue, Kyoto University RIMS *)
(* *)
(* Copyright 1999 Institut National de Recherche en Informatique et *)
(* en Automatique and Kyoto University. All rights reserved. *)
(* This file is distributed under the terms of the GNU Library *)
(* General Public License, with the special exception on linking *)
(* described in file ../../../LICENSE. *)
(* *)
(*************************************************************************)
(* $Id$ *)
type ('a, 'b) assoc_list =
Nil
| Cons of 'a * 'b * ('a, 'b) assoc_list
let rec assq key = function
Nil -> raise Not_found
| Cons (a, b, l) ->
if key == a then b else assq key l
let fast ~f =
let memo = ref Nil in
fun key ->
try assq key !memo
with Not_found ->
let data = f key in
memo := Cons(key, data, !memo);
data
|
