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|
(* TEST
expect;
*)
module M : sig
type t = private [ `Bar of 'a | `Foo ] as 'a
val bar : t
end = struct
type t = [ `Bar of 'a | `Foo ] as 'a
let bar = `Bar `Foo
end;;
[%%expect{|
module M : sig type t = private [ `Bar of 'a | `Foo ] as 'a val bar : t end
|}]
let y =
match (M.bar :> [ `Bar of 'a | `Foo ] as 'a) with
| `Bar x -> x
| `Foo -> assert false
;;
[%%expect{|
val y : [ `Bar of 'a | `Foo ] as 'a = `Foo
|}]
let y =
match (M.bar :> [ `Bar of M.t | `Foo ]) with
| `Bar x -> x
| `Foo -> assert false
;;
[%%expect{|
Line 2, characters 8-41:
2 | match (M.bar :> [ `Bar of M.t | `Foo ]) with
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Type M.t is not a subtype of [ `Bar of M.t | `Foo ]
Type M.t = [ `Bar of M.t | `Foo ] is not a subtype of M.t
|}]
module F(X : sig end) : sig
type s = private [ `Bar of 'a | `Foo ] as 'a
val from : M.t -> s
val to_ : s -> M.t
end = struct
type s = M.t
let from x = x
let to_ x = x
end;;
[%%expect{|
module F :
functor (X : sig end) ->
sig
type s = private [ `Bar of 'a | `Foo ] as 'a
val from : M.t -> s
val to_ : s -> M.t
end
|}]
module N = F(struct end);;
[%%expect{|
module N :
sig
type s = private [ `Bar of 'a | `Foo ] as 'a
val from : M.t -> s
val to_ : s -> M.t
end
|}]
let y =
match (N.from M.bar :> [ `Bar of N.s | `Foo ]) with
| `Bar x -> N.to_ x
| `Foo -> assert false
;;
[%%expect{|
Line 2, characters 8-48:
2 | match (N.from M.bar :> [ `Bar of N.s | `Foo ]) with
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Type N.s is not a subtype of [ `Bar of N.s | `Foo ]
Type N.s = [ `Bar of N.s | `Foo ] is not a subtype of N.s
|}]
|
