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authorGravatar Stephane Glondu <steph@glondu.net>2012-01-12 16:04:54 +0100
committerGravatar Stephane Glondu <steph@glondu.net>2012-01-12 16:04:54 +0100
commit39efc41237ec906226a3a53d7396d51173495204 (patch)
tree87cd58d72d43469d2a2a0a127c1060d7c9e0206b /lib/store.ml
parent5fe4ac437bed43547b3695664974f492b55cb553 (diff)
parent97fefe1fcca363a1317e066e7f4b99b9c1e9987b (diff)
Remove non-DFSG contentsupstream/8.4_beta+dfsg
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+(***********************************************************************)
+(* v * The Coq Proof Assistant / The Coq Development Team *)
+(* <O___,, * INRIA-Rocquencourt & LRI-CNRS-Orsay *)
+(* \VV/ *************************************************************)
+(* // * This file is distributed under the terms of the *)
+(* * GNU Lesser General Public License Version 2.1 *)
+(***********************************************************************)
+
+(*** This module implements an "untyped store", in this particular case we
+ see it as an extensible record whose fields are left unspecified. ***)
+
+(* We give a short implementation of a universal type. This is mostly equivalent
+ to what is proposed by module Dyn.ml, except that it requires no explicit tag. *)
+module type Universal = sig
+ type t
+
+ type 'a etype = {
+ put : 'a -> t ;
+ get : t -> 'a option
+ }
+
+ val embed : unit -> 'a etype
+end
+
+(* We use a dynamic "name" allocator. But if we needed to serialise stores, we
+might want something static to avoid troubles with plugins order. *)
+
+let next =
+ let count = ref 0 in fun () ->
+ let n = !count in
+ incr count;
+ n
+
+type t = Obj.t Util.Intmap.t
+
+module Field = struct
+ type 'a field = {
+ set : 'a -> t -> t ;
+ get : t -> 'a option ;
+ remove : t -> t
+ }
+ type 'a t = 'a field
+end
+
+open Field
+
+let empty = Util.Intmap.empty
+
+let field () =
+ let fid = next () in
+ let set a s =
+ Util.Intmap.add fid (Obj.repr a) s
+ in
+ let get s =
+ try Some (Obj.obj (Util.Intmap.find fid s))
+ with _ -> None
+ in
+ let remove s =
+ Util.Intmap.remove fid s
+ in
+ { set = set ; get = get ; remove = remove }