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: 103376,699cc914522aa7c4 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!wns14feed!worldnet.att.net!208.49.83.154!uns-out.usenetserver.com!news.usenetserver.com!pc02.usenetserver.com!news.flashnewsgroups.com-b7.4zTQh5tI3A!not-for-mail Newsgroups: comp.lang.ada Subject: Re: Structured exception information References: From: Stephen Leake Date: Sat, 20 Jan 2007 11:16:16 -0500 Message-ID: User-Agent: Gnus/5.1006 (Gnus v5.10.6) Emacs/21.3 (windows-nt) Cancel-Lock: sha1:3pv8A81/H1+mehdW6H+cSBoeQVE= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Complaints-To: abuse@flashnewsgroups.com Organization: FlashNewsgroups.com X-Trace: 6900545b24053759e00d428207 Xref: g2news2.google.com comp.lang.ada:8365 Date: 2007-01-20T11:16:16-05:00 List-Id: Robert A Duff writes: > Stephen Leake writes: > >> So far, you have presented no case to show I am wrong. > > By now, several cases have been presented. Are you convinced? Well, none were very detailed. But I agree there are times when some more structure is needed. I'm certainly not willing to give up any of Ada's other features to get it. > To me, it seems pretty simple: if you restrict the type of anything > (parameters, variables, exception-data) to be String, you're losing > type information. That's true. But the devil is in the details. >> If you look into the details of "structured exception handling" in >> other languages and implementations, they have bugs, and fundamental >> flaws in design. > > Please be more specific. Well, I can't. I plead guilty to arguing from authority and vague memory on this one. The memory is of discussions of problems with various exception implementations in C++ and Java, on other newsgroups. I _believe_ that if you read the discussions of attempting to add structured exceptions to Ada, you will find these arguments. Obviously, you are closer to that than I am. >> So if you find yourself fighting Ada to do something, you need to step >> back and think more carefully about _why_ you are doing it that way. >> Ada is telling you it is inherently unsafe. > > Well, I suppose I should be flattered, given that I was one of the > designers of Ada 95. But the fact is: we made mistakes. If Ada is > telling you "it is inherently unsafe", perhaps Ada is simply wrong. That's certainly possible. But I still find it a useful approach, especially since I'm stuck with today's Ada language :). I look forward to proposals for safe structured exceptions in Ada 2015 :). -- -- Stephe