1 files changed, 97 insertions, 5 deletions

diff --git a/lib/dyn.ml b/lib/dyn.ml
index 826cfaf8db..65d1442ac6 100644
--- a/lib/dyn.ml
+++ b/lib/dyn.ml
@@ -1,12 +1,17 @@
 (************************************************************************)
 (*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
-(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2015     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016     *)
 (*   \VV/  **************************************************************)
 (*    //   *      This file is distributed under the terms of the       *)
 (*         *       GNU Lesser General Public License Version 2.1        *)
 (************************************************************************)
 
-module type S =
+module type TParam =
+sig
+  type 'a t
+end
+
+module type PreS =
 sig
 type 'a tag
 type t = Dyn : 'a tag * 'a -> t
@@ -14,17 +19,56 @@ 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) :
+sig
+  type t
+  val empty : t
+  val add : 'a tag -> 'a M.t -> t -> t
+  val remove : 'a tag -> t -> t
+  val find : 'a tag -> t -> 'a M.t
+  val mem : 'a tag -> t -> bool
+
+  type any = Any : 'a tag * 'a M.t -> any
+
+  type map = { map : 'a. 'a tag -> 'a M.t -> 'a M.t }
+  val map : map -> t -> t
+
+  val iter : (any -> unit) -> t -> unit
+  val fold : (any -> 'r -> 'r) -> t -> 'r -> 'r
+
+end
+
 val dump : unit -> (int * string) list
+
 end
 
-module Make(M : CSig.EmptyS) =
-struct
+module type S =
+sig
+  include PreS
+
+  module Easy : sig
+    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(M : CSig.EmptyS) = 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
@@ -51,6 +95,54 @@ let repr s =
     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
 
-end
\ No newline at end of file
+module Map(M : TParam) =
+struct
+type t = Obj.t M.t Int.Map.t
+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 (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))
+ (create s)
+
+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
+