change to use Ppat_type as transfer mechanism for variant spreads ins…

…tead of Ppat_var

jscomp/ml/typecore.ml

@@ -596,7 +596,7 @@ let build_or_pat env loc lid =
           pat pats in
       (path, rp { r with pat_loc = loc },ty)
 
-let extract_type_from_pat_variant_spread env loc lid expected_ty =
+let extract_type_from_pat_variant_spread env lid expected_ty =
   let path, decl = Typetexp.find_type env lid.loc lid.txt in
   match decl with
   | {type_kind = Type_variant constructors; type_params} -> (
@@ -606,29 +606,27 @@ let extract_type_from_pat_variant_spread env loc lid expected_ty =
         Ctype.subtype env ty expected_ty () 
       with 
         Ctype.Subtype (tr1, tr2) -> 
-          raise(Error(loc, env, Not_subtype(tr1, tr2)))
+          raise(Error(lid.loc, env, Not_subtype(tr1, tr2)))
       );
     (path, decl, constructors, ty))
   | _ -> raise (Error (lid.loc, env, Not_a_variant_type lid.txt))
 
 let build_ppat_or_for_variant_spread pat env expected_ty =
   match pat with
-  | {ppat_desc = Ppat_var {txt; loc = var_loc}; ppat_attributes}
+  | {ppat_desc = Ppat_type lident; ppat_attributes}
     when Variant_coercion.has_res_pat_variant_spread_attribute ppat_attributes
     ->
     let _, _, constructors, ty =
-      extract_type_from_pat_variant_spread !env var_loc
-        (Location.mkloc (Longident.parse txt) var_loc)
-        expected_ty
+      extract_type_from_pat_variant_spread !env lident expected_ty
     in
     let synthetic_or_patterns =
       constructors
       |> List.map (fun (c : Types.constructor_declaration) ->
-              Ast_helper.Pat.mk ~attrs:[Variant_type_spread.mk_pat_from_variant_spread_attr ()] ~loc:var_loc
+              Ast_helper.Pat.mk ~attrs:[Variant_type_spread.mk_pat_from_variant_spread_attr ()] ~loc:lident.loc
                 (Ppat_construct
                   ( Location.mkloc
                       (Longident.Lident (Ident.name c.cd_id))
-                      var_loc,
+                      lident.loc,
                     match c.cd_args with
                     | Cstr_tuple [] -> None
                     | _ -> Some (Ast_helper.Pat.any ()) )))
@@ -645,11 +643,11 @@ let build_ppat_or_for_variant_spread pat env expected_ty =
 
 let maybe_expand_variant_spread_in_pattern pattern env expected_ty =
   match pattern.Parsetree.ppat_desc with
-  | Ppat_var _
+  | Ppat_type _
     when Variant_coercion.has_res_pat_variant_spread_attribute
             pattern.ppat_attributes -> (
     match build_ppat_or_for_variant_spread pattern env expected_ty with
-    | None -> assert false
+    | None -> assert false (* TODO: Fix. *)
     | Some (pattern, _) -> pattern)
   | _ -> pattern
 
@@ -1186,7 +1184,7 @@ and type_pat_aux ~constrs ~labels ~no_existentials ~mode ~explode ~env
   | Ppat_alias(sq, name) ->
       let as_type, sq =
         match sq with
-        | {ppat_desc = Ppat_var _; ppat_attributes}
+        | {ppat_desc = Ppat_type _; ppat_attributes}
           when Variant_coercion.has_res_pat_variant_spread_attribute ppat_attributes
           -> (
           match build_ppat_or_for_variant_spread sq env expected_ty with

jscomp/syntax/src/res_core.ml

@@ -1082,11 +1082,10 @@ let rec parse_pattern ?(alias = true) ?(or_ = true) p =
     | DotDotDot ->
       Parser.next p;
       let ident = parse_value_path p in
-      let var_name = ident.txt |> Longident.flatten |> String.concat "." in
       let loc = mk_loc start_pos ident.loc.loc_end in
-      Ast_helper.Pat.var ~loc
+      Ast_helper.Pat.type_ ~loc
         ~attrs:(make_pat_variant_spread_attr :: attrs)
-        (Location.mkloc var_name ident.loc)
+        ident
     | Hash -> (
       Parser.next p;
       if p.Parser.token == DotDotDot then (

jscomp/syntax/src/res_printer.ml

@@ -2203,10 +2203,6 @@ and print_pattern ~state (p : Parsetree.pattern) cmt_tbl =
   let pattern_without_attributes =
     match p.ppat_desc with
     | Ppat_any -> Doc.text "_"
-    | Ppat_var var
-      when ParsetreeViewer.has_res_pat_variant_spread_attribute
-             p.ppat_attributes ->
-      Doc.concat [Doc.text "..."; print_ident_like var.txt]
     | Ppat_var var -> print_ident_like var.txt
     | Ppat_constant c ->
       let template_literal =
@@ -2408,6 +2404,10 @@ and print_pattern ~state (p : Parsetree.pattern) cmt_tbl =
             ]
       in
       Doc.group (Doc.concat [variant_name; args_doc])
+    | Ppat_type ident
+      when ParsetreeViewer.has_res_pat_variant_spread_attribute
+             p.ppat_attributes ->
+      Doc.concat [Doc.text "..."; print_ident_path ident cmt_tbl]
     | Ppat_type ident ->
       Doc.concat [Doc.text "#..."; print_ident_path ident cmt_tbl]
     | Ppat_record (rows, open_flag) ->