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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!gegeweb.org!news.ecp.fr!news.jacob-sparre.dk!loke.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: Ada package registry? Date: Mon, 8 Feb 2016 16:54:51 -0600 Organization: JSA Research & Innovation Message-ID: References: <02241ec4-0f95-4f63-9abc-092f167eb59e@googlegroups.com> NNTP-Posting-Host: rrsoftware.com X-Trace: loke.gir.dk 1454972092 16299 24.196.82.226 (8 Feb 2016 22:54:52 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Mon, 8 Feb 2016 22:54:52 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Xref: news.eternal-september.org comp.lang.ada:29445 Date: 2016-02-08T16:54:51-06:00 List-Id: "Jeffrey R. Carter" wrote in message news:n942ha$bks$1@dont-email.me... > On 02/05/2016 06:25 PM, Randy Brukardt wrote: >> >> [What I mean by expressing assumptions is that it's unlikely that any >> real >> Ada code would really run anywhere. I've been having fun with Gautier >> over >> his "unconditional portability" claim, as one only needs a single >> counter-example to disprove the claim. After a few obvious problems with >> the >> choices of Janus/Ada were worked out, I pointed out that his types >> wouldn't >> work on our old U2200 compiler (as that was a 1's completement, 36-bit >> machine). He decided quite reasonably not to worry about that, but that >> means in his case, that means his code is "unconditionally portable" so >> long >> as your target supports 32-bit integers and is 2's complement. That might >> be >> 99% of machines, but its not quite unconditional.] > > Wasn't that an Ada-83 compiler? And isn't he trying for portability across > Ada-95 compilers? No, it was Ada 95 (we worked on it roughly 1995-8). > If you had an Ada-95 compiler for that machine, what would be the problem > with > > type U is mod 2 ** 32; > for U'Size use 32; > > type S is range -(2 ** 31) .. (2 ** 31) - 1; > for S'Size use 32; > ? Those would work, but the data would still be stored in 36-bits. Since he uses streaming to get data in and out, the 9-bit stream-elements on that machine would get him. It *might* even have worked on that machine, but the .jpg files still wouldn't be portable to/from more normal machines. So it still would have been pointless. Randy.