From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15354 invoked by alias); 5 Jan 2003 11:19:32 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 15338 invoked from network); 5 Jan 2003 11:19:29 -0000 Received: from unknown (HELO executor.cambridge.redhat.com) (195.224.55.237) by 209.249.29.67 with SMTP; 5 Jan 2003 11:19:29 -0000 Received: from cuddles.cambridge.redhat.com (vpn50-2.rdu.redhat.com [172.16.50.2]) by executor.cambridge.redhat.com (Postfix) with ESMTP id D7B1DABB11; Sun, 5 Jan 2003 11:19:15 +0000 (GMT) Received: (from aph@localhost) by cuddles.cambridge.redhat.com (8.11.6/8.11.0) id h05BJbc10402; Sun, 5 Jan 2003 11:19:37 GMT From: Andrew Haley MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15896.5319.39142.29263@cuddles.cambridge.redhat.com> Date: Sun, 05 Jan 2003 11:33:00 -0000 To: dewar@gnat.com (Robert Dewar) Cc: gcc@gcc.gnu.org Subject: Re: c++ "with" keyword In-Reply-To: <20030104162506.E11CFF2D4F@nile.gnat.com> References: <20030104162506.E11CFF2D4F@nile.gnat.com> X-SW-Source: 2003-01/txt/msg00199.txt.bz2 Robert Dewar writes: > > See Algol 68 for what happens if you do it the other way... > > I am willing to bet that this comment is made with *ZERO* knowledge > about Algol-68. Believe that if you wish. I'm not a betting man. The Algol 68 language had no implementations when it was standardized -- AFAIK the first delivery was 1977! > In fact the Algol-68 standard was remarkably complete and > successful, and in environments where full Algol-69 compilers > became available (notably on the ICL-9000 and CDC-6000 series > machines it was widely used). The issue of why it was not more > successful is a commercial/marketing one, which had very little if > anything to do with the way the standard was produced. To quote Lindsey's official history: "...why it did not come into more widespread use, and the answer here is simple enough: because it was not implemented widely enough, or soon enough. And the reason for that is that implementation was too hard..." This would not have been the case if implementations had existed at the time of standardization. > Another danger of course is that if a half baked feature is > implemented, then it gets stuck and never removed (we will in > fact remove the "WITH TYPE" feature in GNAT when a better > substitute comes along, even though it will discombobulate > people). It is too easy to argue for keeping junk stuff around > for compatibility reasons (witness recent thread here in which > some argued that junk illegal semicolons should be accepted in > C++ due to the existence of incorrect code :-) Yes, but it's a lot easier to remove a feature from a compiler than from a standard. Andrew.