From jkr@jkr.cc.rl.ac.uk Mon Jun 29 16:12:26 1998 Received: from nameserv.rl.ac.uk (nameserv.rl.ac.uk [130.246.132.17]) by dkuug.dk (8.6.12/8.6.12) with ESMTP id QAA16245 for ; Mon, 29 Jun 1998 16:12:24 +0200 Received: from jkr.cc.rl.ac.uk (jkr.cc.rl.ac.uk [130.246.8.20]) by nameserv.rl.ac.uk (8.8.8/8.8.8) with ESMTP id PAA06312 for ; Mon, 29 Jun 1998 15:12:16 +0100 Received: (from jkr@localhost) by jkr.cc.rl.ac.uk (8.8.8/8.8.8) id PAA18555 for SC22WG5@dkuug.dk; Mon, 29 Jun 1998 15:12:57 +0100 (BST) Date: Mon, 29 Jun 1998 15:12:57 +0100 (BST) From: John Reid Message-Id: <199806291412.PAA18555@jkr.cc.rl.ac.uk> To: SC22WG5@dkuug.dk Subject: ISO/IEC 1539-2: Varying Length Character Strings X-Sun-Charset: US-ASCII I have prepared a new draft of the revised ISO/IEC 1539-2, with the changes agreed in Trollhatten (see N1319). Lawrie and Steve have seen a draft and I have accommodated their comments except for the treatment of REPEAT and LEN. Lawrie is opposed to our decision to make REPEAT elemental. As defined in the standard NCOPIES must not be negative. The sample module STOPs with a message on the default I/O unit if NCOPIES is negative. This has to be removed if REPEAT is to be elemental. My view is that this is OK - the philosophy of the intrinsics is that the compiler is not rwquired to check for error conditions. Lawrie also points out that the existing REPEAT is not elemental. He says" The intrinsic language and procedures set the basis. Extending these to a derived type should retain as much of the characteristics of the intrinsic as possible. If the behaviour for an extended type is significantly different it should be provided by a different procedure not by an overload to the intrinsic. This is just adding complexity for the user. As a general principle I think it is bad design to have procedures that are elemental for one overload and transformational for another, particularly when they overload an intrinsic. pureness and elementalness should be a characteristic of a whole generic set not just some specific mebers of the set." A similar argument holds for LEN. I would be most grateful for your opinion on this. Please comment by the end of this week (i.e. by July 5th) or let me know that you wish to comment, but need more time. I will set the ball rolling by saying that I can accept either way, but would prefer to stay with our Trollhatten decision. The development body consists of me, Lawrie, Steve, Lars, someone to be nominated by DIN. If you would like to join, please tell me. I am sending uuencoded and gzipped Postscript in a separate message. I have also put gzipped Postscript in my ftp server: jkr.cc.rl.ac.uk in the file pub/wg5 Best wishes, John.