Xref: utzoo comp.lang.scheme:1412 comp.sys.mac.programmer:15821 Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!decwrl!argosy!freeman From: freeman@argosy.UUCP (Jay R. Freeman) Newsgroups: comp.lang.scheme,comp.sys.mac.programmer Subject: Re: Free Macintosh Scheme Message-ID: <606@argosy.UUCP> Date: 8 Jul 90 04:52:19 GMT References: <601@argosy.UUCP> <12383@yunexus.YorkU.CA> Sender: news@argosy.UUCP Reply-To: freeman@cleo.UUCP (Jay R. Freeman) Organization: MasPar Computer Corporation, Sunnyvale, CA Lines: 61 In article <12383@yunexus.YorkU.CA> you write: >In article <601@argosy.UUCP> freeman@MasPar.COM (Jay Reynolds Freeman) writes: >> >> I have written a shareware Scheme implementation for the Apple >>Macintosh. > >You realise of course that there is a *very inexpensive* and very well >implemented scheme for Macintosh: Scheme Express or MacScheme Student >editions, and the latter comes in a book. I didn't know LightShip Software (I think that is what they are called now) had released a student edition: I am a registered user of MacScheme/Toolsmith, and I am surprised they haven't mailed me any advertising on it. Perhaps I have moved too often and have fallen off a mailing list. Where is it advertised and how much does it cost? Is "Scheme Express" the same as "MacScheme Student Edition"? > Why should anyone be interested >in "yet another" implementation ?? Well, I don't know if anyone is. I shall have to wait and see. > What is it that makes your implementation >special? [I am not trying to be cynical... I am just curious] I wrote my implementation, "Pixie Scheme", because I like Scheme and wanted one to play with, that I could modify to suit myself. That takes source, and I thought the best way to get source I understood (?) was to write it. So I coded and coded. Part way through, it occured to me that if I got the program into reasonable shape, it might be a useful public service to make it available as shareware, or perhaps to put it in public domain. (The least expensive MacScheme at that time was $125, I think, which might set some folks back a bit.) I decided on shareware because I was curious to see who (if anyone) used it: I thought more people would be willing to send me a dollar (my suggested shareware donation) than a post card or a letter. I will be flabbergasted if I gross more than the price of an occasional cup of coffee from the program. Anyhow, Pixie Scheme is a nearly complete "R3" Scheme. The most notable lacks are: No support for complex numbers, no support for rationals with numerator and denominator stored as separate integers, "mutation" procedures (set-car!, etc.) are not prevented from altering constants, and decimal numeric printing and scanning is only IEEE, not the much tougher standard specified by the R3 report. My implementation is (essentially) interpreted: It is *much* slower than (e. g.) MacScheme's compiled code, possibly excepting programs that make heavy use of the 68881. I may release a compiler some day. What you get on your 800K disk is two versions of the program -- one that runs on a Mac Plus or better, one that requires a 68020-or-better and a 68881-or-better, a couple of saved worlds, a HyperCard stack that describes the implementation, and a few other things. -- Jay Freeman