Return-Path: Delivery-Date: Received: from leopard.cs.byu.edu (no rfc931) by swan.cl.cam.ac.uk with SMTP (PP-6.5) outside ac.uk; Tue, 14 Jun 1994 15:12:38 +0100 Received: by leopard.cs.byu.edu (1.37.109.8/16.2) id AA01416; Tue, 14 Jun 1994 08:08:39 -0600 Sender: hol2000-request@lal.cs.byu.edu Errors-To: hol2000-request@lal.cs.byu.edu Precedence: bulk Received: from swan.cl.cam.ac.uk by leopard.cs.byu.edu with SMTP (1.37.109.8/16.2) id AA01412; Tue, 14 Jun 1994 08:08:30 -0600 Received: from puffin.cl.cam.ac.uk (user btg (rfc931)) by swan.cl.cam.ac.uk with SMTP (PP-6.5) to cl; Tue, 14 Jun 1994 15:06:55 +0100 To: hol2000@leopard.cs.byu.edu Cc: leonard@ricks.enet.dec.com Subject: Re: Improved error messages In-Reply-To: Your message of "Tue, 14 Jun 94 09:43:42 EDT." <9406141343.AA01592@easynet.crl.dec.com> Date: Tue, 14 Jun 94 15:06:48 +0100 From: Brian Graham Message-Id: <"swan.cl.cam.:149770:940614140705"@cl.cam.ac.uk> When I was porting the conversions for the revised list theory from hol88 to hol90, I looked at the exception handling in a few other places, and generally thought that it didn't provide much helpful information. (Note: not yet released.) I attempted to provide a trace in the exception by concatenating the origin function to the front of the message of the exception, so that as the exception gets passed from handler to handler you end up with a path of function names. It may be primitive, but it seemed more helpful to give some indication of the origin of possibly obscure exceptions. I think there should be a documented standard procedure for the handling of exceptions in HOL90, so that we might get a more uniform treatment in the system. Perhaps Konrad could tell us what scheme he used to organize exception handling; there are significant differences in exception handling between classic ml and sml, so I doubt it was a simple carryover of existing code. ------------------------------------------------------------------------------ Brian Graham | Tel: +44-223-334688 University of Cambridge | Fax: +44-223-334678 Computer Laboratory | Pembroke Street | Email: btg@cl.cam.ac.uk Cambridge, U.K. CB2 3QG |