From owner-sc22wg5+sc22wg5-dom8=www.open-std.org@open-std.org Mon Aug 5 10:06:02 2013 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 4736D357194; Mon, 5 Aug 2013 10:06:01 +0200 (CEST) Delivered-To: sc22wg5@open-std.org Received: from nag-j.co.jp (nag-j.co.jp [111.68.142.10]) by www.open-std.org (Postfix) with ESMTP id 9C048357178 for ; Mon, 5 Aug 2013 10:05:40 +0200 (CEST) Received: from Maru6 (218-42-159-105.cust.bit-drive.ne.jp [218.42.159.105]) (authenticated bits=0) by nag-j.co.jp (8.14.5/8.14.5) with ESMTP id r7585TOX059369 for ; Mon, 5 Aug 2013 08:05:38 GMT (envelope-from malcolm@nag-j.co.jp) Message-ID: From: "Malcolm Cohen" To: "WG5" References: <20130710091604.2E25F35700C@www.open-std.org> <20130801131842.02EE4357123@www.open-std.org> In-Reply-To: <20130801131842.02EE4357123@www.open-std.org> Subject: Re: [ukfortran] (SC22WG5.5053) WG5 vote on draft TS on further coarray features Date: Mon, 5 Aug 2013 17:05:29 +0900 Organization: =?utf-8?B?5pel5pysTkFH?= MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="utf-8"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3555.308 X-MimeOLE: Produced By Microsoft MimeOLE V15.4.3555.308 Sender: owner-sc22wg5@open-std.org Precedence: bulk Nick Maclaren writes: >Passim. The specification is messy and restrictive, and should be >changed. For example, it is not possible to reduce INTENT(IN) examples. I agree. >A far better solution would be either two procedures or a generic >interface, of the following forms (CO_REDUCE is used as an example): > > CO_REDUCE (SOURCE, OPERATOR [, STAT, ERRMSG]) > ! SOURCE would be INTENT(INOUT) > > CO_REDUCE (SOURCE, OPERATOR, RESULT [, RESULT_IMAGE, STAT, ERRMSG]) > ! SOURCE would be INTENT(IN) Unfortunately this particular scheme does not work when SOURCE is a scalar integer, because CO_REDUCE(integer,procedure,integer) is ambiguous as to whether it is the first form or the second. It would work if they had otherwise-gratuitously-different argument orderings, e.g. CO_REDUCE (SOURCE, OPERATOR [, STAT, ERRMSG]) ! SOURCE would be INTENT(INOUT) CO_REDUCE (OPERATOR, SOURCE, RESULT [, RESULT_IMAGE, STAT, ERRMSG]) ! SOURCE would be INTENT(IN) (Swapping OPERATOR and RESULT also works, but this keeps RESULT and RESULT_IMAGE together.) The same is true of CO_SUM, but there is no OPERATOR to swap so that's a bit harder to tweak. It's probably clearer to have CO_SUM and CO_SUM_SELF. Or something. Cheers, -- ................................Malcolm Cohen, Nihon NAG, Tokyo.