From: Frederic Tronel <Frederic.Tronel@inrialpes.fr>
To: caml-list@inria.fr
Subject: [Caml-list] Polymorphic methods
Date: Fri, 23 Aug 2002 17:46:24 +0200 [thread overview]
Message-ID: <3D6658D0.F18A453D@inrialpes.fr> (raw)
Hello list,
I've just compiled the new 3.05 version (I will change for 3.06
tomorrow),
and start playing a little bit with polymorphic methods.
But this small piece of code does not compile:
class node =
object
val mutable t = None
method set_t: 'a. 'a -> unit = fun nt -> t <- Some nt
end
File "essai.ml", line 4, characters 31-53:
This method has type 'a -> unit which is less general than 'b. 'b ->
unit
while this one is OK (useless).
class node =
object
val mutable t = None
method set_t: 'a. 'a -> unit = fun nt -> ()
end
class node : object val mutable t : 'a option method set_t : 'b -> unit
end
Where am I going wrong ??
Best regards,
Frederic.
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next reply other threads:[~2002-08-23 15:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-08-23 15:46 Frederic Tronel [this message]
2002-08-23 17:32 ` Fred Smith
2002-08-23 18:21 ` Remi VANICAT
-- strict thread matches above, loose matches on Subject: below --
2015-12-18 9:18 [Caml-list] polymorphic methods Christoph Höger
2015-12-18 10:07 ` Leo White
2003-03-12 23:07 Damien
2003-03-13 0:56 ` brogoff
2003-03-13 1:56 ` Jacques Garrigue
2003-03-13 9:04 ` Damien
2003-03-13 9:27 ` Jacques Garrigue
2003-03-13 14:49 ` Damien
2003-03-13 9:41 ` Olivier Andrieu
2002-07-14 23:16 nadji
2002-07-15 1:05 ` Jacques Garrigue
2002-07-15 2:08 ` Brian Smith
2002-07-15 16:24 ` nadji
2001-11-19 15:29 [Caml-list] Polymorphic methods Alain Frisch
2001-11-20 0:29 ` Jacques Garrigue
2001-11-20 9:33 ` Alain Frisch
2001-11-20 20:55 ` Xavier Leroy
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