From mboxrd@z Thu Jan  1 00:00:00 1970
Received: (from weis@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id WAA08815 for caml-red; Mon, 22 Jan 2001 22:58:42 +0100 (MET)
Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id MAA29117 for <caml-list@pauillac.inria.fr>; Mon, 22 Jan 2001 12:42:07 +0100 (MET)
Received: from shiva.jussieu.fr (shiva.jussieu.fr [134.157.0.129])
	by nez-perce.inria.fr (8.11.1/8.10.0) with ESMTP id f0MBg6X05376
	for <caml-list@inria.fr>; Mon, 22 Jan 2001 12:42:06 +0100 (MET)
Received: from akasha.ijm.jussieu.fr (akasha.ijm.jussieu.fr [134.157.173.57])
          by shiva.jussieu.fr (8.10.0/jtpda-5.3.3) with ESMTP id f0MBg6q80627
          for <caml-list@inria.fr>; Mon, 22 Jan 2001 12:42:06 +0100 (CET)
Received: (from andrieu@localhost)
	by akasha.ijm.jussieu.fr (8.9.3/8.9.3) id MAA32582;
	Mon, 22 Jan 2001 12:42:03 +0100
From: Olivier Andrieu <andrieu@oxygene.ijm.jussieu.fr>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-ID: <14956.7306.706689.299369@akasha.ijm.jussieu.fr>
Date: Mon, 22 Jan 2001 12:42:02 +0100
To: caml-list@inria.fr
Subject: Floating-point classification
X-Mailer: VM 6.90 under Emacs 20.7.1
Sender: weis@pauillac.inria.fr

Hello, 

Is there a way to test whether a float has value 'nan' or 'inf' ? I
didn't find in the standard library the equivalent of libc functions
isfinite() or isnan() (those are macros I think). 

I think that in C you can test if a float is nan by comparing it
with itself. It seems to work in  OCaml too :

        Objective Caml version 3.00

# let a = 0. /. 0. ;;
val a : float = nan
# a = a ;;
- : bool = false

Is it correct ? What about 'inf' ?

   Olivier