From owner-sc22wg5@open-std.org Thu Nov 6 08:43:29 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id 20EAECA343A; Thu, 6 Nov 2008 08:43:29 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from ppsw-7.csi.cam.ac.uk (ppsw-7.csi.cam.ac.uk [131.111.8.137]) by www2.open-std.org (Postfix) with ESMTP id 38C33CA3434 for ; Thu, 6 Nov 2008 08:43:27 +0100 (CET) X-Cam-AntiVirus: no malware found X-Cam-SpamDetails: not scanned X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Received: from hermes-1.csi.cam.ac.uk ([131.111.8.51]:59881) by ppsw-7.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.157]:25) with esmtpa (EXTERNAL:nmm1) id 1KxzWY-0002Ed-PH (Exim 4.70) for sc22wg5@open-std.org (return-path ); Thu, 06 Nov 2008 07:43:26 +0000 Received: from prayer by hermes-1.csi.cam.ac.uk (hermes.cam.ac.uk) with local (PRAYER:nmm1) id 1KxzWY-0003Tn-Qb (Exim 4.67) for sc22wg5@open-std.org (return-path ); Thu, 06 Nov 2008 07:43:26 +0000 Received: from [83.67.89.123] by webmail.hermes.cam.ac.uk with HTTP (Prayer-1.3.1); 06 Nov 2008 07:43:26 +0000 Date: 06 Nov 2008 07:43:26 +0000 From: "N.M. Maclaren" To: sc22wg5 Subject: Re: [ukfortran] (SC22WG5.3625) (j3.2006) A comment on John Wallin's comments on Nick MacLaren's comments Message-ID: In-Reply-To: <20081106000048.7DA0FCA3434@www2.open-std.org> References: <20081105225653.DCEA7CA3428@www2.open-std.org> <20081105232803.42621CA3434@www2.open-std.org> <20081106000048.7DA0FCA3434@www2.open-std.org> X-Mailer: Prayer v1.3.1 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Sender: owner-sc22wg5@open-std.org Precedence: bulk On Nov 6 2008, Van Snyder wrote: > >> Anyway, I regard the right solution to this is that every derived type >> should have code and decode primitives, and that you should transfer >> the encoded form. You need them for a great many purposes, including >> unformatted I/O, not just MPI. > >Clause 9 of the Fortran standard already does this. It makes my head >hurt to write the encode and decode primitives for every derived type, >and then rewrite them whenever a tiny detail changes. I suppose I could >use internal I/O, which on some systems many years ago was provided by >ENCODE and DECODE statements. I'd rather use coarrays, and if they're >not available I'd rather use unformatted I/O. Internal files have been provided since Fortran 77! Yes, I remember ENCODE and DECODE, in many different variants, but let's move on. Also, let's skip the unnecessary restrictions on internal file use, which are a pain. You are using coarrays to solve a problem that has nothing to do with parallelism per se. While that is a perfectly reasonable decision from a programmer's viewpoint, it is a damn bad basis for designing a standard! Also, my point is that general derived types will contain pointers - and you have no option but to encode and decode THOSE! I should prefer for a language and program design paradigm to get the general case right, rather than to have a collection of special-case hacks. Regards, Nick Maclaren, University of Cambridge Computing Service, New Museums Site, Pembroke Street, Cambridge CB2 3QH, England. Email: nmm1@cam.ac.uk Tel.: +44 1223 334761 Fax: +44 1223 334679