unique_names_in_unification.ml

type t = A
let x = A
module M = struct
  type t = B
  let f: t -> t = fun B -> x
end;;

[%%expect{|
type t = A
val x : t = A
Line _, characters 27-28:
Error: This expression has type t/2 but an expression was expected of type
         t/1
file "", line 4, characters 2-12:
  Definition of type t/1
file "", line 1, characters 0-10:
  Definition of type t/2
|}]

module M = struct type t = B end
let y = M.B
module N = struct
  module M = struct
     type t = C
  end
  let f : M.t -> M.t = fun M.C -> y
end;;

[%%expect{|
module M : sig type t = B end
val y : M.t = M.B
Line _, characters 34-35:
Error: This expression has type M/2.t but an expression was expected of type
         M/1.t
file "", line 4, characters 2-41:
  Definition of module M/1
file "", line 1, characters 0-32:
  Definition of module M/2
|}]

type t = D
let f: t -> t = fun D -> x;;


[%%expect{|
type t = D
Line _, characters 25-26:
Error: This expression has type t/1 but an expression was expected of type
         t/2
file "", line 1, characters 0-10:
  Definition of type t/1
file "", line 1, characters 0-10:
  Definition of type t/2
|}]