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: 115aec,f41f1f25333fa601 X-Google-Attributes: gid115aec,public X-Google-Thread: 103376,a3ca574fc2007430 X-Google-Attributes: gid103376,public From: dewar@merv.cs.nyu.edu (Robert Dewar) Subject: Re: Ada and Automotive Industry Date: 1996/11/11 Message-ID: #1/1 X-Deja-AN: 195839505 references: <55ea3g$m1j@newsbf02.news.aol.com> <3280DA96.15FB@hso.link.com> <1996Nov6.210957.3070@ole.cdac.com> <32812D6B.ABD@hso.link.com> organization: New York University newsgroups: comp.lang.ada,comp.realtime Date: 1996-11-11T00:00:00+00:00 List-Id: Ken Tindall says There's quite a lot in Ada that does indeed imply bad performance. Quite a few optimization techniques are disallowed because of the elaboration and evaluation rules (see papers by Mike Kamrad for examples). General claims like this are often bogus, and this one is. Please state one specific claim, it is impossible to refute incorrect generalities! You still miss the point. If Ada implementations costs 20% more code space then that's a few cents per unit. But a few cents per unit added up over millions of units adds up to a lot of money. Please prove your point that Ada implementations cost 20% mode code space. Some Ada implementations may be more expensive than some C implementations, and the converse is also true (for example there are lots of C compilers for the PC that generate far worse code than GNAT). But there is no basis at all for such general claims. It's not a red herring. Ada is hugely complex, and not well understood. If you think that Ada is elegant and consistent then you don't understand it very well. You only have to look at the "Dear Ada" column in ACM Ada Letters to see this (I really recommend you do read the column!). Almost any language has complex edges in it. But one interesting thing about Ada is that these usually take the form of whether some marginal diction is or is not legal, NOT, as in C, the case where something that looks obvious is legal but does something quite different. Also remember that complexity in terms of features in a language can result in improved simplicity in a program. This general claim of excessive complexity in Ada is almost always made by those who do not know Ada very well. Parnas publically made these claims, and I challenged him to a debate on the issue, which he accepted, but unfortunately backed out due to ill health at the last moment, and despite my invitation, never rescheduled. A pity ... Tony Hoare once said that one of the keys to success in language design was to make it so simple that there are obviously no deficiencies. The other way is to make it so complicated that there are no obvious deficiencies. Be careful using Tony Hoare as your ally, check what he would think of your proposed alternatives to Ada before assuming that he would agree with your position! In fact he considers Ada to be considerably superior to much of the competition. It is impossible. Ada 83 tasking cannot be used reliably for real-time (as the Boeing people above mentioned). Ada 95 tasking still leaves a big efficiency problem, which is crucial to the automotive industry, where a few cents on a control unit add up to millions over a product life. Again, unsubstantiated general claims. It must almost certainly be the case that the writer does NOT know Ada very well. If I am wrong on this, then Ken, make some specific technical points that we can address instead of unsubstantiated generalities.