From owner-sc22wg5+sc22wg5-dom8=www.open-std.org@open-std.org Fri Feb 20 19:38:33 2015 Return-Path: X-Original-To: sc22wg5-dom8 Delivered-To: sc22wg5-dom8@www.open-std.org Received: by www.open-std.org (Postfix, from userid 521) id CBDAC3585FC; Fri, 20 Feb 2015 19:38:33 +0100 (CET) Delivered-To: sc22wg5@open-std.org Received: from ppsw-50.csi.cam.ac.uk (ppsw-50.csi.cam.ac.uk [131.111.8.150]) by www.open-std.org (Postfix) with ESMTP id 8B0E035730E for ; Fri, 20 Feb 2015 19:38:30 +0100 (CET) X-Cam-AntiVirus: no malware found X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Received: from hermes-1.csi.cam.ac.uk ([131.111.8.51]:52999) by ppsw-50.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.158]:25) with esmtpa (EXTERNAL:nmm1) id 1YOsT3-0004nU-s7 (Exim 4.82_3-c0e5623) (return-path ); Fri, 20 Feb 2015 18:38:25 +0000 Received: from prayer by hermes-1.csi.cam.ac.uk (hermes.cam.ac.uk) with local (PRAYER:nmm1) id 1YOsT3-0003TB-M9 (Exim 4.72) (return-path ); Fri, 20 Feb 2015 18:38:25 +0000 Received: from [87.115.68.93] by old-webmail.hermes.cam.ac.uk with HTTP (Prayer-1.3.5); 20 Feb 2015 18:38:25 +0000 Date: 20 Feb 2015 18:38:25 +0000 From: "N.M. Maclaren" To: Bill Long Cc: fortran standards email list for J3 , WG5 Subject: Re: [ukfortran] (SC22WG5.5451) (j3.2006) Response to TS ballot Message-ID: In-Reply-To: <20150220165455.076C4358262@www.open-std.org> References: <20150219231019.EF7E83570D2@www.open-std.org> <20150220114055.4BF3C358556@www.open-std.org> <20150220165455.076C4358262@www.open-std.org> X-Mailer: Prayer v1.3.5 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Sender: owner-sc22wg5@open-std.org Precedence: bulk On Feb 20 2015, Bill Long wrote: >>> >>> No, for the reasons given in N2038, N2013 and other votes. I need to >>> reiterate that neither response in N2039 even addresses my comments. I >>> believe that incorporating the TS into the main standard will cause >>> serious harm to Fortran, because the (semantic) difficulties cannot be >>> resolved (let alone specified unambiguously) in the time available. >>> Indeed, it is not clear even that they ARE soluble, because this TS is >>> specifying a feature that is beyond the state of the art, and has been >>> for half a century. I would be prepared to change my vote to abstain if >>> the decision to incorporate it were reversed. >>> >>> Response >>> It is our belief that agreeing to delay to a later revision of the >>> Fortran standard would lead to several "no" votes. Failure to >>> standardize a resilience capability before compilers implement F2015 >>> would lead to vendors implementing incompatible schemes, hurting the >>> goal of code portability. >> >> Whether or not the second statement is true, and it is extremely >> unclear whether it is, it is not a response to my objections. I am >> asserting that the task is infeasible, for the reasons I gave. > > There are differing opinions on whether "the task is infeasible". I tend > to weight higher the opinions of the guys who will end up writing the > compiler and runtime code. Firstly, as I have told you before, I have written run-time systems that allowed recovery, call back to user code and continuation. I have met (or even heard of) very, very few other people that have. And, based on that and experience with projects that have tried to specify such recovery, I can tell you that writing a run-time system that recovers when possible is TRIVIAL by comparison to specifying the circumstances when recovery is possible and the state of the program following such recovery - let alone doing that in a system-indepdent fashion! It is the task that WG5 is faced with that I regard as infeasible, and (as evidence) point out that it has been an important but unachievable requirement for half a century. As I hope that we all know, specifying the syntax for a facility but leaving its semantics unclear does NOT help portability, as each system behaves differently. For example, following a failure, exactly WHICH objects are: Defined In an unspecified but valid state Undefined but definable Undefined and not definable Please will you stop misrepresenting me? Regards, Nick.