module Position_for_polymorphic_variant_errors = struct
  type t1 = [ `A ] [@@deriving of_sexp]
  type t2 = [ `B ] [@@deriving of_sexp]
  type t3 = A of [ t1 | t2 ] [@@deriving of_sexp]

  let (_ : t3) = t3_of_sexp (List [ Atom "A"; Atom "C" ])
end

[%%expect
  {|
Exception:
(Of_sexp_error
  "examples.mlt.Position_for_polymorphic_variant_errors.t3_of_sexp: no matching variant found"
  (invalid_sexp C))
|}]

let _ = [%sexp_of: 'a]

[%%expect
  {|
Line _, characters _-_:
Error: ppx_sexp_conv: unbound type variable 'a
|}]

let _ = [%of_sexp: 'a]

[%%expect
  {|
Line _, characters _-_:
Error: ppx_sexp_conv: unbound type variable 'a
|}]

let _ = [%sexp (() : 'a)]

[%%expect
  {|
Line _, characters _-_:
Error: ppx_sexp_conv: unbound type variable 'a
|}]

type 'a t =
  | None
  | Something_else of { value : 'a }
[@@deriving sexp]

[%%expect {| |}]

module Record_with_defaults = struct
  open Sexplib0.Sexp_conv

  let a_field = "a_field"
  let b_field = "b_field"

  type record_with_defaults =
    { a : string [@default a_field]
    ; b : string [@default b_field]
    }
  [@@deriving of_sexp]
end

[%%expect {| |}]

module Polymorphic_recursion = struct
  type 'a t = T of 'a t t [@@deriving sexp_grammar]
end

[%%expect {| |}]