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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,d1df6bc3799debed X-Google-Attributes: gid103376,public From: "Nick Roberts" Subject: Re: Not intended for use in medical, Date: 1997/05/14 Message-ID: <01bc6004$f80bf480$LocalHost@xhv46.dial.pipex.com>#1/1 X-Deja-AN: 241469143 References: <3.0.32.19970423164855.00746db8@mail.4dcomm.com> <5kmek2$9re@bcrkh13.bnr.ca> Organization: UUNet PIPEX server (post doesn't reflect views of UUNet PIPEX) Newsgroups: comp.lang.ada Date: 1997-05-14T00:00:00+00:00 List-Id: Matthew Heaney wrote in article ... [...] > Do you disagree with the argument that a language is "bad" - specifically, > Ada - if it's difficult to implement a compiler for it? > > Do you disagree with Les Hatten who said that Ada shouldn't be used, > because it has a "large number" of interpretation requests? > > Do you disagree with Tony Hoare's assessment that Ada should not be used > for systems where high reliability is required? > > Inquiring minds want to know... Ada is a bit like the Mustang of the world of Second World War fighter planes. This aircraft was described as the 'Rolls Royce of the air'. It was a fabulous plane, and it represented (more or less) the apex of the development of that particular technology. But, then, along came jet fighters, and it was totally obsolete. In the same way, I'm sure that no 'traditional' programming language will ever be invented which is significantly better than Ada (or C++, or one of the various other languages which are at a similar level), because very soon a new generation of programming environments will become prevalent which work in a different way. [These are languages which tend (mostly) to be programmed directly by other programs, and only indirectly by humans. I could go on about this at length, but this newsgroup is probably not the right place.] The point is, there's no reason not to use Ada (et al) because there's no real alternative, and there never will be. In 300 years time from now, (the base subsystems of) spaceships will still be programmed in Ada (or C++ or whatever), because there will never have been the need to supercede the language or the software. People still use tables and chairs which were designed centuries ago; the designs are as good today as they were then: good enough. However, in 10 years time, new software will mostly be created using Super AI Intuitive Visual Java Workshop (or whatever), and actually writing source code at all will become unusual. Is Ada a bad language because it is complicated to implement? No: the goodness of a language and the ease of its implementation are two totally different things. However, a language may fail in the marketplace if it is difficult to implement. Should Ada not be used because its standard attracts a large number of implementation requests? One may be wary of the quality of implementations of the language; but this does not preclude the possibility of good implementations. The language may have benefits to offer which weigh in its favour. As for Mr. Hoare's assessment of Ada. How many (real) high-reliability systems did he write? Is he really qualified to make judgements of this kind? If software I have written in the past fails, a number of service personnel stand to lose their lives as a result. I would not have chosen Ada to write this software (and I did have the choice, then) if I had felt it would put them (and the efficacy of part our defence forces) at risk. Nick.