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!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Strange crash on custom iterator Date: Tue, 3 Jul 2018 18:36:08 +0200 Organization: Aioe.org NNTP Server Message-ID: References: <70c11a71-3832-4f57-8127-f3f1c48a052f@googlegroups.com> <62e38ee4-f72f-4ed8-bef1-952040fb7f8d@googlegroups.com> <64d8b4a1-a92c-4b90-b95c-e821749de969@googlegroups.com> <887212304.552080112.848502.laguest-archeia.com@nntp.aioe.org> <87muvan83x.fsf@adaheads.home> <1449870001.552246132.581310.laguest-archeia.com@nntp.aioe.org> NNTP-Posting-Host: 3CrKQyqWAJZHy6zYVP/kUg.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 Content-Language: en-US X-Notice: Filtered by postfilter v. 0.8.3 Xref: reader02.eternal-september.org comp.lang.ada:53541 Date: 2018-07-03T18:36:08+02:00 List-Id: On 2018-07-03 18:07, Lucretia wrote: > On Tuesday, 3 July 2018 16:57:07 UTC+1, Dmitry A. Kazakov wrote: >> On 2018-07-03 17:45, J-P. Rosen wrote: > >>>> 2) Ada needs a decent Unicode library not this half-arsed crap we >>>> have now. >>> This package is about encoding only. What would you expect from a >>> Unicode library? >> >> Proper typing, for a start? >> >> P.S. It is clear that no decent library may exist without fixing Ada >> type system. > > In what way is it broken? It is not broken, it misses key features like interface inheritance. E.g. UTF8_String and String must share interfaces but have different representations. Strings [and characters] is a network of related mutually and implicitly convertible types. There is no way to design that in Ada without magic. Without having types related, we get a geometric explosion of packages: character type x encoding method x fixed/bounded/unbounded. Clearly nobody would ever add UTF-8 into this mess, because this will double the number of packages where strings are used. Static polymorphism (generics/overloading) does not work here. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de