aboutsummaryrefslogtreecommitdiffhomepage
path: root/lib/int.ml
blob: d99176572f1c2556784d5b737dc48e39561f79f6 (plain)
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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2015     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

type t = int

external equal : int -> int -> bool = "%eq"

external compare : int -> int -> int = "caml_int_compare"

let hash i = i land 0x3FFFFFFF

module Self =
struct
  type t = int
  let compare = compare
end

module Set = Set.Make(Self)
module Map =
struct
  include CMap.Make(Self)

  type 'a map = 'a CMap.Make(Self).t

  type 'a _map =
  | MEmpty
  | MNode of 'a map * int * 'a * 'a map * int

  let map_prj : 'a map -> 'a _map = Obj.magic

  let rec find i s = match map_prj s with
  | MEmpty -> raise Not_found
  | MNode (l, k, v, r, h) ->
    if i < k then find i l
    else if i = k then v
    else find i r
end

module List = struct
  let mem = List.memq
  let assoc = List.assq
  let mem_assoc = List.mem_assq
  let remove_assoc = List.remove_assq
end

let min (i : int) j = if i < j then i else j

(** Utility function *)
let rec next from upto =
  if from < upto then next (2 * from + 1) upto
  else from


module PArray =
struct

  type 'a t = 'a data ref
  and 'a data =
  | Root of 'a option array
  | DSet of int * 'a option * 'a t

  let empty n = ref (Root (Array.make n None))

  let rec rerootk t k = match !t with
  | Root _ -> k ()
  | DSet (i, v, t') ->
    let next () = match !t' with
    | Root a as n ->
      let v' = Array.unsafe_get a i in
      let () = Array.unsafe_set a i v in
      let () = t := n in
      let () = t' := DSet (i, v', t) in
      k ()
    | DSet _ -> assert false
    in
    rerootk t' next

  let reroot t = rerootk t (fun () -> ())

  let get t i =
  let () = assert (0 <= i) in
  match !t with
  | Root a ->
    if Array.length a <= i then None
    else Array.unsafe_get a i
  | DSet _ ->
    let () = reroot t in
    match !t with
    | Root a ->
      if Array.length a <= i then None
      else Array.unsafe_get a i
    | DSet _ -> assert false

  let set t i v =
    let () = assert (0 <= i) in
    let () = reroot t in
    match !t with
    | DSet _ -> assert false
    | Root a as n ->
      let len = Array.length a in
      if i < len then
        let old = Array.unsafe_get a i in
        if old == v then t
        else
          let () = Array.unsafe_set a i v in
          let res = ref n in
          let () = t := DSet (i, old, res) in
          res
      else match v with
      | None -> t (** Nothing to do! *)
      | Some _ -> (** we must resize *)
        let nlen = next len (succ i) in
        let nlen = min nlen Sys.max_array_length in
        let () = assert (i < nlen) in
        let a' = Array.make nlen None in
        let () = Array.blit a 0 a' 0 len in
        let () = Array.unsafe_set a' i v in
        let res = ref (Root a') in
        let () = t := DSet (i, None, res) in
        res

end

module PMap =
struct

  type key = int

  (** Invariants:

    1. an empty map is always [Empty].
    2. the set of the [Map] constructor remembers the present keys.
  *)
  type 'a t = Empty | Map of Set.t * 'a PArray.t

  let empty = Empty

  let is_empty = function
  | Empty -> true
  | Map _ -> false

  let singleton k x =
    let len = next 19 (k + 1) in
    let len = min Sys.max_array_length len in
    let v = PArray.empty len in
    let v = PArray.set v k (Some x) in
    let s = Set.singleton k in
    Map (s, v)

  let add k x = function
  | Empty -> singleton k x
  | Map (s, v) ->
    let s = match PArray.get v k with
    | None -> Set.add k s
    | Some _ -> s
    in
    let v = PArray.set v k (Some x) in
    Map (s, v)

  let remove k = function
  | Empty -> Empty
  | Map (s, v) ->
    let s = Set.remove k s in
    if Set.is_empty s then Empty
    else
      let v = PArray.set v k None in
      Map (s, v)

  let mem k = function
  | Empty -> false
  | Map (_, v) ->
    match PArray.get v k with
    | None -> false
    | Some _ -> true

  let find k = function
  | Empty -> raise Not_found
  | Map (_, v) ->
    match PArray.get v k with
    | None -> raise Not_found
    | Some x -> x

  let iter f = function
  | Empty -> ()
  | Map (s, v) ->
    let iter k = match PArray.get v k with
    | None -> ()
    | Some x -> f k x
    in
    Set.iter iter s

  let fold f m accu = match m with
  | Empty -> accu
  | Map (s, v) ->
    let fold k accu = match PArray.get v k with
    | None -> accu
    | Some x -> f k x accu
    in
    Set.fold fold s accu

  let exists f m = match m with
  | Empty -> false
  | Map (s, v) ->
    let exists k = match PArray.get v k with
    | None -> false
    | Some x -> f k x
    in
    Set.exists exists s

  let for_all f m = match m with
  | Empty -> true
  | Map (s, v) ->
    let for_all k = match PArray.get v k with
    | None -> true
    | Some x -> f k x
    in
    Set.for_all for_all s

  let cast = function
  | Empty -> Map.empty
  | Map (s, v) ->
    let bind k = match PArray.get v k with
    | None -> assert false
    | Some x -> x
    in
    Map.bind bind s

  let domain = function
  | Empty -> Set.empty
  | Map (s, _) -> s

end