Inline Ctype.path_and_expansion

typing/ctype.ml

@@ -2073,15 +2073,6 @@ let try_expand_safe_opt env ty =
   with Escape _ ->
     Btype.backtrack snap; raise Cannot_expand
 
-let path_and_expansion env ty =
-  match try_expand_safe_opt env ty with
-  | ty' ->
-    begin match get_desc ty with
-    | Tconstr (path, _, _) -> Some (path, ty')
-    | _ -> Misc.fatal_error "Ctype.path_and_expansion"
-    end
-  | exception Cannot_expand -> None
-
 let expand_head_opt env ty =
   try try_expand_head try_expand_safe_opt env ty with Cannot_expand -> ty
 

typing/ctype.mli

@@ -246,9 +246,6 @@ val apply:
 val try_expand_once_opt: Env.t -> type_expr -> type_expr
 val try_expand_safe_opt: Env.t -> type_expr -> type_expr
 
-val path_and_expansion: Env.t -> type_expr -> (Path.t * type_expr) option
-(** Return an option instead of raising, and gives the path of the input type *)
-
 val expand_head_once: Env.t -> type_expr -> type_expr
 val expand_head: Env.t -> type_expr -> type_expr
 val expand_head_opt: Env.t -> type_expr -> type_expr

typing/typedecl.ml

@@ -2093,10 +2093,16 @@ let check_unboxed_recursion ~abs_env env loc path0 ty0 to_check =
     | _ -> ()
   in
   let rec expand parents trace ty =
-    match Ctype.path_and_expansion env ty with
-    | Some (path, ty') ->
-      expand (Path.Set.add path parents) (Expands_to (ty, ty') :: trace) ty'
-    | None ->
+    match Ctype.try_expand_safe_opt env ty with
+    | ty' ->
+      begin match get_desc ty with
+      | Tconstr (path, _, _) ->
+        expand (Path.Set.add path parents) (Expands_to (ty, ty') :: trace) ty'
+      | _ ->
+        (* Only [Tconstr]s can be expanded *)
+        Misc.fatal_error "Typedecl.check_unboxed_recursion"
+      end
+    | exception Ctype.Cannot_expand ->
       parents, trace, ty
   in
   let rec visit parents trace ty =