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,f34f1a1939dc0c40 X-Google-Attributes: gid103376,public From: Robert A Duff Subject: Re: conditional compilation Date: 2000/08/03 Message-ID: #1/1 X-Deja-AN: 654024566 Sender: bobduff@world.std.com (Robert A Duff) References: <87d7jvp3qq.fsf@chiark.greenend.org.uk> <39857E5F.33C40014@acm.com> <3985FB16.82D140BB@below.for.email.address> <8m6log$r3a$1@nnrp1.deja.com> <398749EF.15829554@below.for.email.address> Organization: The World Public Access UNIX, Brookline, MA Newsgroups: comp.lang.ada Date: 2000-08-03T00:00:00+00:00 List-Id: Brian Rogoff writes: > On Wed, 2 Aug 2000, Robert A Duff wrote: > > In any case, from a language design point of view, if you think the > > compiler should see things in a different order or different > > organization than human beings, then clearly the programming language is > > poorly designed. > > That isn't so clear to me. I don't think Common Lisp, Scheme and Dylan are > poorly designed because they include powerful macro systems. I completely agree with you, so if you think we disagree, I think you misunderstand what I mean. I have nothing against Lisp macros -- they are quite powerful and useful. Note that one feeds them directly to the compiler, and also reads them as is. What I object to, is using Literate Programming to stir the code around in an obfuscatory manner. In cases where Literate Programming improves the structure of the code, that indicates a flaw in the underlying programming language. In cases where it damages the structure of the code (see my previous post about loop exits), well, that's not a good thing. Note that Lisp macros operate at a completely different level than text-based macros. Lisp macros don't stir the code around in ways that totally violates the language rules. Text-based macros are evil. >... I believe > their designers feel that syntactic abstraction is important enough to > include facilities in the language for extensible syntax. That may > conflict with some of the design goals of Ada, but I don't thnk it > clearly indicates poor design. > > > Macros can be used to get around poor language > > designs. > > They can also be used to change the syntax of the language so that it is > more suitable for a particular problem. There are lots of things I don't > like about Lisp, but the inclusion of a powerful macro system is not among > them. > > -- Brian - Bob