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
|
(************************************************************************)
(* * The Coq Proof Assistant / The Coq Development Team *)
(* v * INRIA, CNRS and contributors - Copyright 1999-2018 *)
(* <O___,, * (see CREDITS file for the list of authors) *)
(* \VV/ **************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(* * (see LICENSE file for the text of the license) *)
(************************************************************************)
module type TParam =
sig
type 'a t
end
module type MapS =
sig
type t
type 'a obj
type 'a key
val empty : t
val add : 'a key -> 'a obj -> t -> t
val remove : 'a key -> t -> t
val find : 'a key -> t -> 'a obj
val mem : 'a key -> t -> bool
type any = Any : 'a key * 'a obj -> any
type map = { map : 'a. 'a key -> 'a obj -> 'a obj }
val map : map -> t -> t
val iter : (any -> unit) -> t -> unit
val fold : (any -> 'r -> 'r) -> t -> 'r -> 'r
end
module type PreS =
sig
type 'a tag
type t = Dyn : 'a tag * 'a -> t
val create : string -> 'a tag
val eq : 'a tag -> 'b tag -> ('a, 'b) CSig.eq option
val repr : 'a tag -> string
type any = Any : 'a tag -> any
val name : string -> any option
module Map(M : TParam) : MapS with type 'a obj = 'a M.t with type 'a key = 'a tag
val dump : unit -> (int * string) list
end
module type S =
sig
include PreS
module Easy : sig
val make_dyn_tag : string -> ('a -> t) * (t -> 'a) * 'a tag
val make_dyn : string -> ('a -> t) * (t -> 'a)
val inj : 'a -> 'a tag -> t
val prj : t -> 'a tag -> 'a option
end
end
module Make () = struct
module Self : PreS = struct
(* Dynamics, programmed with DANGER !!! *)
type 'a tag = int
type t = Dyn : 'a tag * 'a -> t
type any = Any : 'a tag -> any
let dyntab = ref (Int.Map.empty : string Int.Map.t)
(** Instead of working with tags as strings, which are costly, we use their
hash. We ensure unicity of the hash in the [create] function. If ever a
collision occurs, which is unlikely, it is sufficient to tweak the offending
dynamic tag. *)
let create (s : string) =
let hash = Hashtbl.hash s in
let () =
if Int.Map.mem hash !dyntab then
let old = Int.Map.find hash !dyntab in
let () = Printf.eprintf "Dynamic tag collision: %s vs. %s\n%!" s old in
assert false
in
let () = dyntab := Int.Map.add hash s !dyntab in
hash
let eq : 'a 'b. 'a tag -> 'b tag -> ('a, 'b) CSig.eq option =
fun h1 h2 -> if Int.equal h1 h2 then Some (Obj.magic CSig.Refl) else None
let repr s =
try Int.Map.find s !dyntab
with Not_found ->
let () = Printf.eprintf "Unknown dynamic tag %i\n%!" s in
assert false
let name s =
let hash = Hashtbl.hash s in
if Int.Map.mem hash !dyntab then Some (Any hash) else None
let dump () = Int.Map.bindings !dyntab
module Map(M : TParam) =
struct
type t = Obj.t M.t Int.Map.t
type 'a obj = 'a M.t
type 'a key = 'a tag
let cast : 'a M.t -> 'b M.t = Obj.magic
let empty = Int.Map.empty
let add tag v m = Int.Map.add tag (cast v) m
let remove tag m = Int.Map.remove tag m
let find tag m = cast (Int.Map.find tag m)
let mem = Int.Map.mem
type any = Any : 'a tag * 'a M.t -> any
type map = { map : 'a. 'a tag -> 'a M.t -> 'a M.t }
let map f m = Int.Map.mapi f.map m
let iter f m = Int.Map.iter (fun k v -> f (Any (k, v))) m
let fold f m accu = Int.Map.fold (fun k v accu -> f (Any (k, v)) accu) m accu
end
end
include Self
module Easy = struct
(* now tags are opaque, we can do the trick *)
let make_dyn_tag (s : string) =
(fun (type a) (tag : a tag) ->
let infun : (a -> t) = fun x -> Dyn (tag, x) in
let outfun : (t -> a) = fun (Dyn (t, x)) ->
match eq tag t with
| None -> assert false
| Some CSig.Refl -> x
in
infun, outfun, tag)
(create s)
let make_dyn (s : string) =
let inf, outf, _ = make_dyn_tag s in inf, outf
let inj x tag = Dyn(tag,x)
let prj : type a. t -> a tag -> a option =
fun (Dyn(tag',x)) tag ->
match eq tag tag' with
| None -> None
| Some CSig.Refl -> Some x
end
end
|
