From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,38fc011071df5a27 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-06-16 13:26:02 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.freenet.de!newsfeed.stueberl.de!newspeer1-gui.server.ntli.net!ntli.net!news-hub.cableinet.net!blueyonder!internal-news-hub.cableinet.net!news-binary.blueyonder.co.uk.POSTED!53ab2750!not-for-mail User-Agent: Microsoft-Entourage/10.1.1.2418 Subject: Re: Ideas for Ada 200X From: Bill Findlay Newsgroups: comp.lang.ada Message-ID: References: <3EE7CC70.E1FD3A67@adaworks.com> <3EECA772.4B662024@adaworks.com> Mime-version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Date: Mon, 16 Jun 2003 21:24:30 +0100 NNTP-Posting-Host: 80.195.75.181 X-Complaints-To: abuse@blueyonder.co.uk X-Trace: news-binary.blueyonder.co.uk 1055795161 80.195.75.181 (Mon, 16 Jun 2003 20:26:01 GMT) NNTP-Posting-Date: Mon, 16 Jun 2003 20:26:01 GMT Organization: blueyonder (post doesn't reflect views of blueyonder) Xref: archiver1.google.com comp.lang.ada:39272 Date: 2003-06-16T21:24:30+01:00 List-Id: On 16/6/03 20:14, in article bcl4ul$ibu$1@a1-hrz.uni-duisburg.de, "Georg Bauhaus" wrote: > Bill Findlay wrote: > : I must be mistaking your meaning. How do you obtain and use an access value > : without aliasing the object it references; and explicitly so, if it is a > : global or local object? > > What I had been thinking of was that there is no need to explicitly > introduce > bar: aliased Foo; > if bar has been allocated with new, which surely is a restriction. Oh, right. > (f being a function returning an access value to some new record > with a component c, I can write > f.c := f.c + baz; OK. But the record has to be on the heap in that case too. A major restriction. We really want to be able to refer directly to record fields and array elements as objects in their own right, not only as a components to be located within another object: prefix.c := idem + baz; ensures that the location of prefix.c is evaluated only once. This is valuable even if prefix is a function returning a (heap) pointer. -- Bill-Findlay chez blue-yonder.co.uk ("-" => "")