TVar is of type U.t

parser/ast.ml

@@ -105,7 +105,7 @@ and branches = (ppat * pexpr) list
 
 and ppat = ppat' located
 and ppat' =
-  | TVar of string (** polymorphic type variables *)
+  | TVar of U.t (** polymorphic type variables *)
   | PatVar of U.t list
   | Cst of pexpr
   | NsT of U.t

parser/parser.ml

@@ -606,7 +606,7 @@ EXTEND Gram
     | "no_arrow" [ x = pat; "|"; y = pat -> mk _loc (Or (x,y)) ]
     | "simple" [ x = pat; "&"; y = pat -> mk _loc (And (x,y))
 	       | x = pat; "\\"; y = pat -> mk _loc (Diff (x,y)) ]
-    | "var_typ" [ x = PTYPE -> mk _loc (TVar x) ]
+    | "var_typ" [ x = PTYPE -> mk _loc (TVar (ident x)) ]
     |
       [ "{"; r = record_spec; "}" -> r
       | "ref"; p = pat ->
@@ -621,7 +621,7 @@ EXTEND Gram
       | "!"; a = IDENT ->
 	  mk _loc (Internal (Types.abstract (Types.Abstracts.atom a)))
       | ids = LIST1 ident_or_keyword SEP "." ->
-	  let ids = List.map (fun x -> ident x) ids in
+	  let ids = List.map ident ids in
 	  mk _loc (PatVar ids)
       | i = INT ; "--"; j = INT ->
           let i =  Intervals.V.mk i

typing/typer.ml

@@ -325,9 +325,10 @@ module IType = struct
     all_delayed := [];
     List.iter check_one_delayed l
 
+  (* Ast -> symbolic type *)
   let rec derecurs env p =
     match p.descr with
-    | TVar s -> mk_type (Types.var (Var.mk s))
+    | TVar s -> mk_type (Types.var (Var.mk (U.to_string s)))
     | PatVar ids -> derecurs_var env p.loc ids
     | Recurs (p,b) -> derecurs (fst (derecurs_def env b)) p
     | Internal t -> mk_type t
@@ -478,7 +479,10 @@ type branch = Branch of Typed.branch * branch list
 let cur_branch : branch list ref = ref []
 
 let exp' loc e =
-  { Typed.exp_loc = loc; Typed.exp_typ = Types.empty; Typed.exp_descr = e }
+  { Typed.exp_loc = loc;
+    Typed.exp_typ = Types.empty;
+    Typed.exp_descr = e
+  }
 
 let exp loc fv e = fv, exp' loc e