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: a07f3367d7,f096ebb5dcac664d X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news4.google.com!proxad.net!feeder1-2.proxad.net!fdn.fr!gegeweb.org!aioe.org!nospam From: "John B. Matthews" Newsgroups: comp.lang.ada Subject: Re: Ada in teaching Date: Wed, 15 Jul 2009 11:08:54 -0400 Organization: The Wasteland Message-ID: References: <851f477d-c5a4-4c87-b930-4a47ba508579@h8g2000yqm.googlegroups.com> <4a5ce82c$0$32682$9b4e6d93@newsspool2.arcor-online.net> <4a5d17f2$0$30231$9b4e6d93@newsspool1.arcor-online.net> NNTP-Posting-Host: LQJtZWzu+iKlBROuDg+IUg.user.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org X-Notice: Filtered by postfilter v. 0.7.9 Cancel-Lock: sha1:kbmJGjqt1dkYLXhd/Kryl/WFkKY= User-Agent: MT-NewsWatcher/3.5.3b3 (Intel Mac OS X) Xref: g2news2.google.com comp.lang.ada:7071 Date: 2009-07-15T11:08:54-04:00 List-Id: In article <4a5d17f2$0$30231$9b4e6d93@newsspool1.arcor-online.net>, Georg Bauhaus wrote: > > John B. Matthews wrote: [...] > Java arrays cannot fully take advantage of Java generics, in > particular compile time checking is basically off, so the sloppy > base type system strikes again. It's an unfortunate legacy. > Another language corner case that I imagine must be explained > to students of the (Java) language at length. The usual explanation is that arrays are covariant, with type-checking enforced at runtime; Java generic types are invariant, checked only at compile-time [1]. > > and task oriented support for concurrent programming [2]. > > Yes, task *oriented*. Indeed. I think Java's original support for concurrent programming was offered at much too low a level. Ada 83's level may have been a bit too high, with protected types, for example, added in Ada 95 and enhanced in Ada 2005 [3]. In both areas, type-checking and concurrent programming, I see Ada and Java moving in similar directions, if not actually converging. I don't teach except in the sense of occasionally being asked to guide students of one language in using the other. I'd be interested to learn of any reference that outlines corresponding features of the two languages. Students (or teachers) of both languages may like to look at these simple projects done in both Ada [4, 5] and Java [6, 7], respectively. [...] [1] [2] [3] [4] [5] [6] [7] -- John B. Matthews trashgod at gmail dot com