Received: from leopard.cs.byu.edu (leopard.cs.byu.edu [128.187.2.182]) by ra.abo.fi (8.6.10/8.6.10) with ESMTP id LAA28495; Tue, 21 Nov 1995 11:28:57 +0200 Received: by leopard.cs.byu.edu (1.37.109.15/16.2) id AA145733134; Tue, 21 Nov 1995 01:38:54 -0700 Sender: info-hol-request@leopard.cs.byu.edu Errors-To: info-hol-request@leopard.cs.byu.edu Precedence: list Received: from iraun1.ira.uka.de by leopard.cs.byu.edu with SMTP (1.37.109.15/16.2) id AA145703129; Tue, 21 Nov 1995 01:38:49 -0700 Received: from ira.uka.de (actually i80s16.ira.uka.de) by iraun1.ira.uka.de with SMTP (PP); Tue, 21 Nov 1995 09:35:45 +0100 X-Mailer: exmh version 1.5.3 12/28/94 To: Donald Syme Subject: Re: better error messages in hol90? Cc: info-hol@leopard.cs.byu.edu In-Reply-To: Your message of "Mon, 20 Nov 1995 16:34:25 +0100." <"swan.cl.cam.:242190:951120163440"@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 21 Nov 1995 09:35:13 +0100 From: reetz Message-Id: <"iraun1.ira.878:21.11.95.08.35.46"@ira.uka.de> Having print out the whole exception hierarchy would be very comfortable for debugging. I think it would ease finding bugs. But I wonder about memory consumption. How much memory do we need for that? Consider a deep calling sequence (which may happen often as e.g. with (DEPTH_CONV my_buggy_one_I_want_to_test_CONV)). I just don't know. As memory consumption is critical for hol90, we should be careful with that and first try out these several alternatives. I would strongly recommend not to depend on a however ``hacked'' version of nj/sml for printing exceptions. The already existing dependency of hol90 on nj/sml only is painful enough. Considering non-compatible changes, you almost always don't get something for nothing. I personally feel that getting much better error messages is worth changing the code. But that's how I see it. Maybe other people around here do not agree? :-) Ralf (*******************************************************************) (* *) (* Ralf Reetz *) (* Research Assistent *) (* University of Karlsruhe *) (* Institut fuer Rechnerentwurf und Fehlertoleranz *) (* 76128 Karlsruhe, Zirkel 2, Postfach 6980, Germany *) (* *) (* e-mail: reetz@informatik.uni-karlsruhe.de or reetz@ira.uka.de *) (* WWW: http://goethe.ira.uka.de/people/reetz/reetz.html *) (* fax: +49 721 370455 *) (* tel: +49 721 6084220 *) (* *) (*******************************************************************)