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: 103376,2907a68906511623 X-Google-Attributes: gid103376,public From: Brian Rogoff Subject: Re: Idea for Ada 200x: Arguments that are procedures Date: 1998/07/07 Message-ID: #1/1 X-Deja-AN: 369350116 References: <6nh9f0$66i@netline.jpl.nasa.gov> Content-Type: TEXT/PLAIN; charset=US-ASCII X-Trace: 899847164 23442 bpr 206.184.139.132 Mime-Version: 1.0 Newsgroups: comp.lang.ada Date: 1998-07-07T00:00:00+00:00 List-Id: On 7 Jul 1998, Robert I. Eachus wrote: > Ada 83 and Ada 95 both support downward closures through use of > generics. Don't you agree that the expression of programs which naturally use downward closures is clumsy with generics? I also question the performance impact of this "workaround". Richard O'Keefe had a very nice post last time this came up in which he benchmarked a simple numerical integration routine in Ada, Pascal, Scheme, C, and Fortran, with the Ada using generics and the Scheme (amongst others) using downward closures. The Scheme compiler was able to do some impressive optimizations and ended up performing much better; more importantly, the Scheme code was much more readable IMO than the Ada. > Since the feature is "in there" for when it > is needed, I saw no reason to continue the fight for a simpler syntax. In the context of the 9X project, this was wise. Better to have a good standard today, than a better one at some undetermined future date. But this is definitely one of those things I hope gets fixed in a future language revision. -- Brian