(* TEST
 * expect
*)
(** Test the error message for existential types apparearing
    in unexpected position *)
type any = Any: 'a -> any
[%%expect {|
type any = Any : 'a -> any
|}]

let Any x = Any ()
[%%expect {|
Line 1, characters 4-9:
1 | let Any x = Any ()
        ^^^^^
Error: Existential types are not allowed in toplevel bindings,
       but this pattern introduces the existential type $Any_'a.
|}]

let () =
  let Any x = Any () and () = () in
  ()
[%%expect {|
Line 2, characters 6-11:
2 |   let Any x = Any () and () = () in
          ^^^^^
Error: Existential types are not allowed in "let ... and ..." bindings,
       but this pattern introduces the existential type $Any_'a.
|}]


let () =
  let rec Any x = Any () in
  ()
[%%expect {|
Line 2, characters 10-15:
2 |   let rec Any x = Any () in
              ^^^^^
Error: Existential types are not allowed in recursive bindings,
       but this pattern introduces the existential type $Any_'a.
|}]


let () =
  let[@attribute] Any x = Any () in
  ()
[%%expect {|
Line 2, characters 18-23:
2 |   let[@attribute] Any x = Any () in
                      ^^^^^
Error: Existential types are not allowed in presence of attributes,
       but this pattern introduces the existential type $Any_'a.
|}]


class c (Any x) = object end
[%%expect {|
Line 1, characters 8-15:
1 | class c (Any x) = object end
            ^^^^^^^
Error: Existential types are not allowed in class arguments,
       but this pattern introduces the existential type $Any_'a.
|}]

class c = object(Any x)end
[%%expect {|
Line 1, characters 16-23:
1 | class c = object(Any x)end
                    ^^^^^^^
Error: Existential types are not allowed in self patterns,
       but this pattern introduces the existential type $Any_'a.
|}]

type other = Any: _ -> other
[%%expect {|
type other = Any : 'a -> other
|}]

let Any x = Any ()
[%%expect {|
Line 1, characters 4-9:
1 | let Any x = Any ()
        ^^^^^
Error: Existential types are not allowed in toplevel bindings,
       but the constructor Any introduces existential types.
|}]


class c = let Any _x = () in object end
[%%expect {|
Line 1, characters 14-20:
1 | class c = let Any _x = () in object end
                  ^^^^^^
Error: Existential types are not allowed in bindings inside class definition,
       but the constructor Any introduces existential types.
|}]

let () =
  let Any x = Any () and () = () in
  ()
[%%expect {|
Line 2, characters 6-11:
2 |   let Any x = Any () and () = () in
          ^^^^^
Error: Existential types are not allowed in "let ... and ..." bindings,
       but the constructor Any introduces existential types.
|}]


let () =
  let rec Any x = Any () in
  ()
[%%expect {|
Line 2, characters 10-15:
2 |   let rec Any x = Any () in
              ^^^^^
Error: Existential types are not allowed in recursive bindings,
       but the constructor Any introduces existential types.
|}]


let () =
  let[@attribute] Any x = Any () in
  ()
[%%expect {|
Line 2, characters 18-23:
2 |   let[@attribute] Any x = Any () in
                      ^^^^^
Error: Existential types are not allowed in presence of attributes,
       but the constructor Any introduces existential types.
|}]

class c (Any x) = object end
[%%expect {|
Line 1, characters 8-15:
1 | class c (Any x) = object end
            ^^^^^^^
Error: Existential types are not allowed in class arguments,
       but the constructor Any introduces existential types.
|}]

class c = object(Any x) end
[%%expect {|
Line 1, characters 16-23:
1 | class c = object(Any x) end
                    ^^^^^^^
Error: Existential types are not allowed in self patterns,
       but the constructor Any introduces existential types.
|}]

class c = let Any _x = () in object end
[%%expect {|
Line 1, characters 14-20:
1 | class c = let Any _x = () in object end
                  ^^^^^^
Error: Existential types are not allowed in bindings inside class definition,
       but the constructor Any introduces existential types.
|}]