Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!uunet!munnari.oz.au!goanna!ok From: ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) Newsgroups: comp.lang.scheme Subject: Re: Named constants in Scheme Message-ID: <5941@goanna.cs.rmit.oz.au> Date: 24 May 91 04:05:12 GMT Article-I.D.: goanna.5941 References: <1991May15.172635.18635@Think.COM> Organization: Comp Sci, RMIT, Melbourne, Australia Lines: 43 In article , jinx@zurich.ai.mit.edu (Guillermo J. Rozas) writes: > Perhaps I should restate the goals of MIT Scheme and of the original > reports. > > RnRS Scheme was a common dialect agreed upon by various people working > with dialects of Scheme so that they could read each other's code, not > so that they could run it verbatim. As such, clarity in the semantics > (rather than performance) was paramount. I believe this to still be > the goal of the reports, and as such, efficiency-related issues > are not terribly important to the authors. Nor is the intent of the > reports to describe a complete implementation. > > The only purpose of IEEE Scheme, as far as I know, was to legitimize > the choice of Scheme by some commercial ventures that were having a > hard time justifying the choice of a non-standard educational > language, since the reports did not carry the weight of a standards > body. If implementations do not conform to the standard, the usefulness of Scheme as an educational language is greatly diminished. I want to give my students examples that they can _use_. I want to write tools for them that will run on the Schemes they have access to. We have here TI PC Scheme, MacScheme, Elk, OakLisp, T, Gambit (on Macs), and when I can find some time we'll have MIT Scheme. Now, () -vs- #f is something I can live with. The widely varying ways of defining macros is something I've sorted out for TI PC Scheme, Elk, OakLisp, and T, and don't expect any difficulty with for the others. But there are limits to what I have time for. There are other people writing educational stuff that I would like to be able to use, and I'd rather not have to spend a lot of time porting it. I don't _expect_ to run MIT Scheme code using bitstrings. But I shouldn't have to put a lot of effort into porting code that uses only standard data types. Recently I received a program which I would like to consider using, but I'm afraid that if RnRS Scheme was "so they could read each other's code" then it has already failed; the program is in Chez Scheme and it looks as though it'll be easier to translate some Miranda code than to figure out what the Chez Scheme stuff is up to. (If I had a Chez Scheme manual, that would be a different story, but I haven't.) -- I rejoiced that at least So-and-So could spell "hierarchical", but the _real_ explanation was that he couldn't spell "heir". -me