ocaml/utils/tbl.ml

116 lines
3.6 KiB
OCaml

(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. *)
(* *)
(* All rights reserved. This file is distributed under the terms of *)
(* the GNU Lesser General Public License version 2.1, with the *)
(* special exception on linking described in the file LICENSE. *)
(* *)
(**************************************************************************)
type ('a, 'b) t =
Empty
| Node of ('a, 'b) t * 'a * 'b * ('a, 'b) t * int
let empty = Empty
let height = function
Empty -> 0
| Node(_,_,_,_,h) -> h
let create l x d r =
let hl = height l and hr = height r in
Node(l, x, d, r, (if hl >= hr then hl + 1 else hr + 1))
let bal l x d r =
let hl = height l and hr = height r in
if hl > hr + 1 then
match l with
| Node (ll, lv, ld, lr, _) when height ll >= height lr ->
create ll lv ld (create lr x d r)
| Node (ll, lv, ld, Node (lrl, lrv, lrd, lrr, _), _) ->
create (create ll lv ld lrl) lrv lrd (create lrr x d r)
| _ -> assert false
else if hr > hl + 1 then
match r with
| Node (rl, rv, rd, rr, _) when height rr >= height rl ->
create (create l x d rl) rv rd rr
| Node (Node (rll, rlv, rld, rlr, _), rv, rd, rr, _) ->
create (create l x d rll) rlv rld (create rlr rv rd rr)
| _ -> assert false
else
create l x d r
let rec add x data = function
Empty ->
Node(Empty, x, data, Empty, 1)
| Node(l, v, d, r, h) ->
let c = compare x v in
if c = 0 then
Node(l, x, data, r, h)
else if c < 0 then
bal (add x data l) v d r
else
bal l v d (add x data r)
let rec find x = function
Empty ->
raise Not_found
| Node(l, v, d, r, _) ->
let c = compare x v in
if c = 0 then d
else find x (if c < 0 then l else r)
let rec mem x = function
Empty -> false
| Node(l, v, _d, r, _) ->
let c = compare x v in
c = 0 || mem x (if c < 0 then l else r)
let rec merge t1 t2 =
match (t1, t2) with
(Empty, t) -> t
| (t, Empty) -> t
| (Node(l1, v1, d1, r1, _h1), Node(l2, v2, d2, r2, _h2)) ->
bal l1 v1 d1 (bal (merge r1 l2) v2 d2 r2)
let rec remove x = function
Empty ->
Empty
| Node(l, v, d, r, _h) ->
let c = compare x v in
if c = 0 then
merge l r
else if c < 0 then
bal (remove x l) v d r
else
bal l v d (remove x r)
let rec iter f = function
Empty -> ()
| Node(l, v, d, r, _) ->
iter f l; f v d; iter f r
let rec map f = function
Empty -> Empty
| Node(l, v, d, r, h) -> Node(map f l, v, f v d, map f r, h)
let rec fold f m accu =
match m with
| Empty -> accu
| Node(l, v, d, r, _) ->
fold f r (f v d (fold f l accu))
open Format
let print print_key print_data ppf tbl =
let print_tbl ppf tbl =
iter (fun k d -> fprintf ppf "@[<2>%a ->@ %a;@]@ " print_key k print_data d)
tbl in
fprintf ppf "@[<hv 2>[[%a]]@]" print_tbl tbl