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-Thread: 103376,b8b8a54001adc4d2 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!news.glorb.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local1.nntp.dca.giganews.com!nntp.megapath.net!news.megapath.net.POSTED!not-for-mail NNTP-Posting-Date: Mon, 10 Jan 2005 14:31:22 -0600 From: "Randy Brukardt" Newsgroups: comp.lang.ada References: <1104516913.718856.94090@z14g2000cwz.googlegroups.com> <1105290947.422412.195950@c13g2000cwb.googlegroups.com> <1105327132.335673.73950@c13g2000cwb.googlegroups.com> Subject: Re: Possible Ada deficiency? Date: Mon, 10 Jan 2005 14:32:59 -0600 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4910.0300 Message-ID: NNTP-Posting-Host: 64.32.209.38 X-Trace: sv3-VBg801RAVS9Dl/WwQi170tAIXAmqpC49aBnaf1MzMKi1JXjNH4gUM1b9tvALkemA/pogCiaFR0xTWEq!aGRyTgd2t5fbYMmBIsdcyblwXtYSMEzlR67G7Pm0a8da+1d1ZhcR8M5PPEfx/tpdokkys2A5rsov X-Complaints-To: abuse@megapath.net X-DMCA-Complaints-To: abuse@megapath.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.22 Xref: g2news1.google.com comp.lang.ada:7618 Date: 2005-01-10T14:32:59-06:00 List-Id: wrote in message news:1105327132.335673.73950@c13g2000cwb.googlegroups.com... > I don't think it needs to be this complicated an issue. The only > mechanism I'm proposing is that a parent package can choose to hide > detail(s) from child packages. There would be 3 areas of visibilty: > public, private, & concealed. There are already three areas of visibility: public/private/body, and you're suggesting to add a fourth (not third). And, as I previously indicated, the three existing areas of visibility have caused no end of problems, both at the language definition level, and in implementations. Moreover, this idea would require a large number of additional rules to explain, and almost certainly would introduce lots of new bugs. "I don't think is needs to be this complicated an issue." Visibility is an extremely complicated issue; changes to it have to be made with extreme care. Limited with proved to be very, very difficult to get right (mostly because of obscure issues with use clauses and renames of child packages that no one would ever try to do in practice). Your suggestion would be much worse. It also would make Ada programs harder to read and write, because you'd have to declare things out of the usual order to put them into the right "part". In any case, infinite repetition that your solution is "simple" is not going to make it so. Putting private types in the body is the right solution, because it hides the information without adding new visibility. But that too is too big a leap for right now. Randy.