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,fa2cc518ef3b992c X-Google-Attributes: gid103376,public From: "Samuel T. Harris" Subject: Re: scripting/extension language for Ada (we have an opportunity here) Date: 2000/02/17 Message-ID: <38ABF54E.6EBB34B3@Raytheon.com>#1/1 X-Deja-AN: 586907181 Content-Transfer-Encoding: 7bit References: <389207CC.C16D80E8@averstar.com> <38971028.BB16D8A2@earthlink.net> <3899F757.FAE131B3@free.fr> <389D43A6.786C7B79@free.fr> <880gpk$fv04@ftp.kvaerner.com> <38A47E5A42406034@earthlink.net> <38A53714.3EBC10C3@online.no> <38A5E4FC.9C20A0E4@Raytheon.com> <38A9A7D4.5331F2C3@Raytheon.com> <38AAF0C1.C3F82C40@Raytheon.com> X-Accept-Language: en Content-Type: text/plain; charset=us-ascii Organization: Raytheon Aerospace Engineering Services Mime-Version: 1.0 Newsgroups: comp.lang.ada Date: 2000-02-17T00:00:00+00:00 List-Id: Robert A Duff wrote: > > "Samuel T. Harris" writes: > > >... So I don't need syntax non-terminals > > such as function_call_or_array_index_or_qualified_aggregate > > with all the complexity involved. The semantics > > still have to verify the appropriate nature of > > the element. > > > > Given this, I believe you would agree that the substitution > > of () for [] and {} would now be trivial. > > Yes. > > But the simplification of the grammar is fairly minor, when compared > with the complexity of overload resolution. I feel the simplification of the grammar is much more than minor. I get much closer to being able to apply the Ada syntax directly to aflex/ayacc with these special substitutions. I suppose we place a different priority on the ease of syntax translation. However, I do agree with you on the semantics. They are just as hard with or without special delimiters. > > There may be good and bad things about "[", but I wouldn't say "[" > greatly simplifies the compiler/interpreter, as you've defined it. > > By the way, aggregates (qualified or not) can be syntactically > distinguished from function calls and whatnot. The aggregate issue is > the potential confusion between a parenthesized expression and a > one-element positional aggregate. (I consider it a design flaw in Ada > that there are no one-element and zero-element positional aggregates. > But with you're "trivial substitution" model, you can't solve that > problem.) Yes, that is a stickler with me as well. All in all, when my short list of Ada peeves contains these kinds of things, I thinks that speaks very highly of the quality of the language. > > - Bob -- Samuel T. Harris, Principal Engineer Raytheon, Aerospace Engineering Services "If you can make it, We can fake it!"