don't accept "use export T as ..." (thanks, François)

src/parser/parser.mly

@@ -333,16 +333,17 @@ use_clone:
 ;
 
 use:
-| imp_exp tqualid
-    { { use_theory = $2; use_as = qualid_last $2; use_imp_exp = $1 } }
-| imp_exp tqualid AS uident
-    { { use_theory = $2; use_as = $4.id; use_imp_exp = $1 } }
+| opt_import tqualid
+    { { use_theory = $2; use_import = Some ($1, qualid_last $2) } }
+| opt_import tqualid AS uident
+    { { use_theory = $2; use_import = Some ($1, $4.id) } }
+| EXPORT tqualid
+    { { use_theory = $2; use_import = None } }
 ;
 
-imp_exp:
-| IMPORT        { Some true }
-| EXPORT        { None }
-| /* epsilon */ { Some false }
+opt_import:
+| /* epsilon */ { false }
+| IMPORT        { true  }
 ;
 
 clone_subst:

src/parser/ptree.ml

@@ -87,10 +87,8 @@ type plogic_type =
   | PFunction  of pty list * pty
 
 type use = {
-  use_theory  : qualid;
-  use_as      : string;
-  use_imp_exp : bool option;
-    (* None = export, Some false = default, Some true = import *)
+  use_theory : qualid;
+  use_import : (bool (* import *) * string (* as *)) option;
 }
 
 type clone_subst =

src/parser/typing.ml

@@ -1187,12 +1187,12 @@ let add_use_clone env lenv th loc (use, subst) =
     | None -> use_export th t
     | Some s -> clone_export th t (type_inst th t s)
   in
-  let use_or_clone th = match use.use_imp_exp with
-    | Some imp ->
+  let use_or_clone th = match use.use_import with
+    | Some (import, use_as) ->
         (* use T = namespace T use_export T end *)
-        let th = open_namespace th use.use_as in
+        let th = open_namespace th use_as in
         let th = use_or_clone th in
-        close_namespace th imp
+        close_namespace th import
     | None ->
         use_or_clone th
   in

src/whyml/mlw_typing.ml

@@ -1982,16 +1982,17 @@ let use_clone_pure lib mth uc loc (use,inst) =
   let path, s = Typing.split_qualid use.use_theory in
   let th = find_theory loc lib mth path s in
   (* open namespace, if any *)
-  let uc = if use.use_imp_exp = None then uc
-  else Theory.open_namespace uc use.use_as in
+  let uc = match use.use_import with
+    | Some (_, use_as) -> Theory.open_namespace uc use_as
+    | None -> uc in
   (* use or clone *)
   let uc = match inst with
     | None -> Theory.use_export uc th
     | Some inst -> Theory.clone_export uc th (Typing.type_inst uc th inst) in
   (* close namespace, if any *)
-  match use.use_imp_exp with
+  match use.use_import with
+    | Some (import, _) -> Theory.close_namespace uc import
     | None -> uc
-    | Some imp -> Theory.close_namespace uc imp
 
 let use_clone_pure lib mth uc loc use =
   if Debug.test_flag Typing.debug_parse_only then uc else
@@ -2001,8 +2002,9 @@ let use_clone lib mmd mth uc loc (use,inst) =
   let path, s = Typing.split_qualid use.use_theory in
   let mth = find_module loc lib mmd mth path s in
   (* open namespace, if any *)
-  let uc = if use.use_imp_exp = None then uc
-  else open_namespace uc use.use_as in
+  let uc = match use.use_import with
+    | Some (_, use_as) -> open_namespace uc use_as
+    | None -> uc in
   (* use or clone *)
   let uc = match mth, inst with
     | Module m, None -> use_export uc m
@@ -2012,9 +2014,9 @@ let use_clone lib mmd mth uc loc (use,inst) =
     | Theory th, Some inst ->
         clone_export_theory uc th (Typing.type_inst (get_theory uc) th inst) in
   (* close namespace, if any *)
-  match use.use_imp_exp with
+  match use.use_import with
+    | Some (import, _) -> close_namespace uc import
     | None -> uc
-    | Some imp -> close_namespace uc imp
 
 let use_clone lib mmd mth uc loc use =
   if Debug.test_flag Typing.debug_parse_only then uc else