Typecheck x |> f y as (f y x), not ((f y) x)

Author: stedolan

testsuite/tests/typing-misc/printing.ml

@@ -110,9 +110,9 @@ and bar () =
   let x = foo () in
   x |> List.fold_left max 0 x
 [%%expect {|
-Line 4, characters 7-29:
+Line 4, characters 26-27:
 4 |   x |> List.fold_left max 0 x
-           ^^^^^^^^^^^^^^^^^^^^^^
-Error: This expression has type int
-       This is not a function; it cannot be applied.
+                              ^
+Error: This expression has type int but an expression was expected of type
+         'a -> 'b
 |}]

typing/typecore.ml

@@ -3498,18 +3498,25 @@ and type_expect_
         wrap_trace_gadt_instances env (lower_args []) ty;
         funct
       in
+      let type_sfunct_args sfunct extra_args =
+        match sfunct.pexp_desc with
+        | Pexp_apply (sfunct, args) ->
+           type_sfunct sfunct, args @ extra_args
+        | _ ->
+           type_sfunct sfunct, extra_args
+      in
       let funct, sargs =
         let funct = type_sfunct sfunct in
         match funct.exp_desc, sargs with
         | Texp_ident (_, _, {val_kind = Val_prim {prim_name = "%revapply"}},
                       Id_prim _),
           [Nolabel, sarg; Nolabel, actual_sfunct]
           when is_inferred actual_sfunct ->
-            type_sfunct actual_sfunct, [Nolabel, sarg]
+            type_sfunct_args actual_sfunct [Nolabel, sarg]
         | Texp_ident (_, _, {val_kind = Val_prim {prim_name = "%apply"}},
                       Id_prim _),
           [Nolabel, actual_sfunct; Nolabel, sarg] ->
-            type_sfunct actual_sfunct, [Nolabel, sarg]
+            type_sfunct_args actual_sfunct [Nolabel, sarg]
         | _ ->
             funct, sargs
       in