[TESTS][LAMBDA] Add special variable "_"

tests/lambda/src/compute.ml

@@ -51,14 +51,18 @@ let rec _to_typed env l expr =
     env, l, { exp_loc=loc; exp_typ=type_of_string "Int";
 	      exp_descr=Op(op, 0, [e1; e2]) }
   | Var (origloc, vname) ->
+    let line = Loc.start_line origloc in
+    let cbegin = Loc.start_off origloc - Loc.start_bol origloc in
+    let cend = Loc.stop_off origloc - Loc.start_bol origloc in
     if vname = "`nil" then
       let nil_atom = Atoms.V.mk_ascii "nil" in
       env, l, { exp_loc=loc; exp_typ=(Types.atom (Atoms.atom nil_atom));
 		exp_descr=(Cst (Types.Atom nil_atom)) }
+    else if vname = "_" then
+      (Printf.eprintf
+	 "File %s, line %d, characters %d-%d:\nError: Invalid reference to special variable %s\n"
+	 (Loc.file_name origloc) line cbegin cend vname; raise Error)
     else
-      let line = Loc.start_line origloc in
-      let cbegin = Loc.start_off origloc - Loc.start_bol origloc in
-      let cend = Loc.stop_off origloc - Loc.start_bol origloc in
       let index, vtype =
         try Locals.find vname l
         with Not_found -> Printf.eprintf
@@ -221,6 +225,8 @@ and parse_match_value env l list toptype = function
       let nil_atom = Atoms.V.mk_ascii "nil" in
       let t = Types.atom (Atoms.atom nil_atom) in
       (t, Patterns.Constr(t), list, l, true)
+    else if mname = "_" then
+      (Types.any, Patterns.Constr(Types.any), list, l, true)
     else
       let lsize = Locals.cardinal l in
       let l = Locals.add mname (lsize, type_of_ptype mtype) l in