1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
(************************************************************************)
(* v * The Coq Proof Assistant / The Coq Development Team *)
(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
(* \VV/ **************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(************************************************************************)
(* $Id$ *)
(* Maps using the generic comparison function of ocaml. Code borrowed from
the ocaml standard library. *)
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 = match l with Empty -> 0 | Node(_,_,_,_,h) -> h in
let hr = match r with Empty -> 0 | Node(_,_,_,_,h) -> h in
if hl > hr + 2 then begin
match l with
Empty -> invalid_arg "Map.bal"
| Node(ll, lv, ld, lr, _) ->
if height ll >= height lr then
create ll lv ld (create lr x d r)
else begin
match lr with
Empty -> invalid_arg "Map.bal"
| Node(lrl, lrv, lrd, lrr, _)->
create (create ll lv ld lrl) lrv lrd (create lrr x d r)
end
end else if hr > hl + 2 then begin
match r with
Empty -> invalid_arg "Map.bal"
| Node(rl, rv, rd, rr, _) ->
if height rr >= height rl then
create (create l x d rl) rv rd rr
else begin
match rl with
Empty -> invalid_arg "Map.bal"
| Node(rll, rlv, rld, rlr, _) ->
create (create l x d rll) rlv rld (create rlr rv rd rr)
end
end else
Node(l, x, d, r, (if hl >= hr then hl + 1 else hr + 1))
let rec add x data = function
Empty ->
Node(Empty, x, data, Empty, 1)
| Node(l, v, d, r, h) ->
let c = Pervasives.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 = Pervasives.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 = Pervasives.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 = Pervasives.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 d, map f r, h)
let rec fold f m accu =
match m with
Empty -> accu
| Node(l, v, d, r, _) ->
fold f l (f v d (fold f r accu))
(* Added with respect to ocaml standard library. *)
let dom m = fold (fun x _ acc -> x::acc) m []
let rng m = fold (fun _ y acc -> y::acc) m []
let to_list m = fold (fun x y acc -> (x,y)::acc) m []
|
