From: Josh Berdine <jjb@microsoft.com>
To: "caml-list@yquem.inria.fr" <caml-list@yquem.inria.fr>
Subject: typing difference (bug?) between 3.10.2 and 3.11(.1?)
Date: Sun, 7 Jun 2009 14:28:16 +0100 [thread overview]
Message-ID: <857DD0FDAC042B4485F9F5F4EA6751042D82FC23A5@EA-EXMSG-C332.europe.corp.microsoft.com> (raw)
Hi,
I'm observing a difference in typing-checking of private types between 3.10.2 and 3.11.1+rc1 (I haven't checked 3.11.0).
Consider the following code:
module M : sig
type t = private T of int
val mk : int -> t
end = struct
type t = T of int
let mk x = T(x)
end
module M' = M
let x = M'.mk 42
let y = M'.T(42)
With 3.10.2, the let binding for y fails to type-check:
Objective Caml version 3.10.2
[snip]
# let y = M'.T(42);;
Characters 8-16:
let y = M'.T(42);;
^^^^^^^^
Cannot create values of the private type M'.t
With 3.11.1+rc1, however, it type-checks:
Objective Caml version 3.11.1+rc1
[snip]
# let y = M'.T(42);;
val y : M'.t = M'.T 42
#
Am I misunderstanding the type system, or is this not intended?
If I change the code to declare t private in the struct, or if I do not use the alias for M, type-checking fails as expected.
Cheers, Josh
reply other threads:[~2009-06-07 13:28 UTC|newest]
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