Uses std library instead of implementing it

lib/syntax/check.ml

@@ -1,51 +1,14 @@
-(** This module provide a way to create new Id dynamically in the runtime,
-    and some fonctions for comparing them. *)
-module Id : sig
-  type 'a typeid
-  (** The type created on-the-fly. *)
-
-  val newtype : unit -> 'a typeid
-  (** Create a new instance of a dynamic type *)
-
-  type ('a, 'b) eq = Eq : ('a, 'a) eq
-
-  val try_cast : 'a typeid -> 'b typeid -> ('a, 'b) eq option
-  (** Compare two types using the Eq pattern *)
-end = struct
-  type 'a witness = ..
-
-  module type Witness = sig
-    type t
-    type _ witness += Id : t witness
-  end
-
-  type 'a typeid = (module Witness with type t = 'a)
-  type ('a, 'b) eq = Eq : ('a, 'a) eq
-
-  let try_cast : type a b. a typeid -> b typeid -> (a, b) eq option =
-   fun x y ->
-    let module X : Witness with type t = a = (val x) in
-    let module Y : Witness with type t = b = (val y) in
-    match X.Id with Y.Id -> Some Eq | _ -> None
-
-  let newtype (type u) () =
-    (* The extensible type need to be extended in a module, it is not possible
-       to declare a type in a function. That’s why we need to pack a module
-       here *)
-    let module Witness = struct
-      type t = u
-      type _ witness += Id : t witness
-    end in
-    (module Witness : Witness with type t = u)
-end
+module Id = Type.Id
 
 (** The the Id module, wrap a value in an existencial type with a witness
     associate with. *)
-type result = R : { value : 'a; witness : 'a Id.typeid } -> result
+type result = R : { value : 'a; witness : 'a Id.t } -> result
 
-let get : type a. a Id.typeid -> result -> a option =
+let get : type a. a Id.t -> result -> a option =
  fun typeid (R { value; witness }) ->
-  match Id.try_cast typeid witness with Some Eq -> Some value | None -> None
+  match Id.provably_equal typeid witness with
+  | Some Type.Equal -> Some value
+  | None -> None
 
 type t =
   | E : {
@@ -57,12 +20,12 @@ type t =
             and type Instruction.t' = 'd
             and type Location.t = 'e
             and type context = 'f);
-      expr_witness : 'a Id.typeid;
-      expr' : 'b Id.typeid;
-      instr_witness : 'c Id.typeid;
-      instr' : 'd Id.typeid;
-      location_witness : 'e Id.typeid;
-      context : 'f Id.typeid;
+      expr_witness : 'a Id.t;
+      expr' : 'b Id.t;
+      instr_witness : 'c Id.t;
+      instr' : 'd Id.t;
+      location_witness : 'e Id.t;
+      context : 'f Id.t;
     }
       -> t
 
@@ -74,14 +37,14 @@ let build :
         and type Instruction.t' = _
         and type Location.t = 'a
         and type context = _) ->
-    'a Id.typeid * t =
+    'a Id.t * t =
  fun module_ ->
-  let expr_witness = Id.newtype ()
-  and expr' = Id.newtype ()
-  and instr_witness = Id.newtype ()
-  and instr' = Id.newtype ()
-  and location_witness = Id.newtype ()
-  and context = Id.newtype () in
+  let expr_witness = Id.make ()
+  and expr' = Id.make ()
+  and instr_witness = Id.make ()
+  and instr' = Id.make ()
+  and location_witness = Id.make ()
+  and context = Id.make () in
   let t =
     E
       {
@@ -106,9 +69,9 @@ end
 open StdLabels
 
 module Helper = struct
-  type 'a expr_list = { witness : 'a Id.typeid; values : 'a list }
+  type 'a expr_list = { witness : 'a Id.t; values : 'a list }
 
-  let expr_i : result array list -> 'a Id.typeid -> int -> 'a expr_list =
+  let expr_i : result array list -> 'a Id.t -> int -> 'a expr_list =
    fun args witness i ->
     let result =
       List.fold_left args ~init:{ values = []; witness }
@@ -355,8 +318,8 @@ module Make (A : App) = struct
     let rebuild_clause :
         type a b.
         int ->
-        a Id.typeid ->
-        b Id.typeid ->
+        a Id.t ->
+        b Id.t ->
         S.pos * result array * result array list ->
         (b, a) S.clause =
      fun i instr_witness expr' clause ->

lib/syntax/check.mli

@@ -15,7 +15,7 @@
 *)
 
 module Id : sig
-  type 'a typeid
+  type 'a t
   (** The type created on-the-fly. *)
 end
 
@@ -30,9 +30,9 @@ val build :
       and type Instruction.t' = _
       and type Location.t = 'a
       and type context = _) ->
-  'a Id.typeid * t
+  'a Id.t * t
 (** Build a new check from a module following S.Analyzer signature. 
-
+ypeid 
     Return the result type which hold the final result value, and checker
     itself. *)
 
@@ -40,7 +40,7 @@ val get_module : t -> (module S.Analyzer)
 
 type result
 
-val get : 'a Id.typeid -> result -> 'a option
+val get : 'a Id.t -> result -> 'a option
 (** The method [get] can be used to get the internal value for one of the
     checker used.
  *)