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,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.236.231.137 with SMTP id l9mr16310677yhq.41.1432992061435; Sat, 30 May 2015 06:21:01 -0700 (PDT) X-Received: by 10.140.29.119 with SMTP id a110mr180635qga.20.1432992061419; Sat, 30 May 2015 06:21:01 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!news.glorb.com!z60no4661562qgd.1!news-out.google.com!4ni109qgh.1!nntp.google.com!z60no4662402qgd.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Sat, 30 May 2015 06:21:01 -0700 (PDT) In-Reply-To: <1dmgofrqo3xn5$.1p4241xr4z92p.dlg@40tude.net> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=105.237.62.132; posting-account=orbgeAkAAADzWCTlruxuX_Ts4lIq8C5J NNTP-Posting-Host: 105.237.62.132 References: <59a4ee45-23fb-4b0e-905c-cc16ce46b5f6@googlegroups.com> <46b2dce1-2a1c-455d-b041-3a9d217e2c3f@googlegroups.com> <3277d769-6503-4c7f-885f-3a730762b620@googlegroups.com> <9fa68fb7-89f0-42b3-8f25-20e70cb34d63@googlegroups.com> <87egm3u662.fsf@adaheads.sparre-andersen.dk> <20c56bea-2803-4aa9-a626-2d25e480df20@googlegroups.com> <1dmgofrqo3xn5$.1p4241xr4z92p.dlg@40tude.net> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: Build language with weak typing, then add scaffolding later to strengthen it? From: jan.de.kruyf@gmail.com Injection-Date: Sat, 30 May 2015 13:21:01 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Xref: news.eternal-september.org comp.lang.ada:26095 Date: 2015-05-30T06:21:01-07:00 List-Id: On Saturday, May 30, 2015 at 1:12:20 PM UTC+2, Dmitry A. Kazakov wrote: > BNF describes the language syntax or a formal language. Formal language <= << > programming language. Since 60's there is nothing interesting you could > describe in BNF or in any other syntactic formalism. We do know how "good= " > syntax looks like. yes we do know that. But you did not address what I said yet.=20 I am trying to stress this here: "The mathematical aspect dictates that the language be elegant, but simple = to describe mathematically. Lisp-like languages are an example of languages= for which this aspect is especially noticeable. Other ways to describe this aspect are to say that the language should have= an inherent simplicity and be easy to learn, expressive and orthogonal. Ex= pressiveness is the power of a language to solve problems. Orthogonality re= quires combinations of legal constructs to be themselves legal constructs."= =20 (fom http://web.cs.wpi.edu/~kal/courses/cs4533/module2/grammars.html) And please save me your comment about lisp, I do not know it, and it is imm= aterial in this discussion. > You mean IF-THEN-ELSE, did he? (:-)) It is funny that I dont recall ever having a problem with it. I do recall b= eing caught for a sucker because I did not forsee the consequences of my ow= n doings. Unless you talk of an issue before my time? . . >=20 > BTW, in all Wirth books I ever read he used directed graphs for syntax > definitions instead of BNF. Did not see any lately but I vaguely remember the Apple Pascal book had the= m. >=20 > > So if you want to do any cleaning up I would say lets start with drawin= g > > up a EBNF of Ada. >=20 > ARM Annex P. Thank you! I missed that. The question to be resolved next is whether I can use it in day to day codi= ng practice. > =20 > That is less than 0.1% of what constitutes a programming language. No it is not, unless you call the library the other 99.9 %. In other words I suspect we are arguing about semantics here. >=20 > > It will explain the critique from Dijkstra and Wirth, >=20 > It wasn't for Ada syntax AFAIK. No I did not hear or see that either. It was much rougher than that, in goo= d swiss (and dutch) fashion. :) >=20 > > And the biggest bonus will be that we will be able to work faster, once= we > > have a good understanding of the mathematical underpinnings of the > > language. >=20 > Which ones? There is no problem parsing Ada. It is trivial, in fact.=20 Yes it _is_ trivial . . . for a computer or a highly trained person like yo= u. But we are talking here about the class of programmers you refer to in your= next paragraph.=20 >=20 > And this is not a problem people have with Ada. Even those, who dearly wa= nt > curly brackets and =3D for assignment, should understand that grammatical= ly > there would be absolutely NO difference. Whether the end token is "end" o= r > "}" matters only aesthetically. So now we could argue that it will be good to have both ways in the languag= e. I mean it will be trivial to put into the ebnf and trivial to parse. And= that specific group of programmers will like it, etc, etc. Or we can argue that they need to be educated in the syntax of Ada, as you = say. Because clearly from other fields of human experience we know that it will = only cause confusion. So similarly I argue ---Not that this language or that language is Better--= - but that there is room for improvement in Ada, And where this improvement= can be made will follow from the reading and trying to understand appendix= P as the core document of the language. But the crowd likes to turn this into a language war around every corner, p= erhaps because from other fields of human experience it is also known that = it is very difficult to do self refection. > Few syntax problems Ada has come straight from Wirth himself. E.g. > different syntax for declarations of subprogram types and values (bodies) > from other types and values. Wirth seems never cared much about types. >=20 Believe it or not he did, but he has never been known to be paranoid.=20 Dmitry, when I first got to know Ada I jumped on it specially for the nice = multitude of types (since that is what I learned from the old man, to be ty= pesafe) But after a few years of experience I find that I have often confus= ed myself plainly with having too many types.=20 So you could perhaps say that that was for lack of solid design. Could be. = But then I find the same multitude of unchecked conversions back in gnat. S= o apparently it is not only me.=20 By the way the other day I looked at your website and I stood in awe of the= artworks you display there. Thank you. j.