winkler@harvard.ARPA (Dan Winkler) (06/09/85)
I saw a demo of Experlisp a few days ago. One of the developers said that they have included full support for object oriented programming, although not many classes are yet defined. They will have a complete implementation of MacApp, Apple's object oriented Macintosh development system, in their next release. It's a compiled lisp that seemed very fast in their 2 and 3 dimensional graphics demonstrations. The current version does not support stand alone applications. Their next release will be able to snapshot the entire environment to a file which can then run alone. They realize the need for the ability to remove dead code from snapshots, but did not promise to have that in the next release. They will also make their lisp more like common lisp in the next release. My impression was that this product was not intended for people who want to develop Mac applications as I do as much as for those who really want a Lisp Machine but can't afford it, but it looks like it could be great for both. They are planning to collect a small royalty on any software developed in their lisp. They are most interested in getting Lisp Machine software on the Mac right away, and they have already ported some big things easily. They noted how few Lisp Machines have ever been sold (fewer than 2,000 as I recall) and how many Macs have been sold (more than 300,000 as I recall). They say their Lisp runs on the Mac about 1/10 as fast as compiled lisp on a Lisp Machine. They plan to support 2 and 4 megabyte Macs and someone pointed out that that added memory runs 20% faster than the built in memory because it is on a separate board and is not interlaced with video refresh. (That means that if you plan to add a HyperDrive to your Mac, give GCC a 128K Mac and let them add the extra memory on their board rather than giving them a 512K Mac which has the extra memory on the main board.) Also, the new machine from Apple due next year is expected to have a 68020 which should give a speedup of at least 5 times. (It may also have a coprocessor slot meant for a floating point chip which could be used instead to speed up lisp operations like type checking.) Their hope is that they will soon have lots of great Lisp Machine software running as well or better on Macs as it currently does on Lisp Machines but for much less money. They plan to copy protect their product and may even use a keyboard attachment in the protection scheme. However, the author of MacNosy was also there demonstrating his product and I could see that the copy protection war is escalating. (Part of the MacNosy demonstration was a horrifying look at the Mac ROM. We saw, for instance, that the BlockMove trap starts off by looking 28 bytes down into the stack and dispatching on what it finds there, which is (gasp, choke, cough) the pushed return address. In other words, it checks to see who called it before deciding what it should do! I can't wait for that new ROM.) They also showed a prolog written in their lisp. They have educational discounts which will save you a lot if you buy in large quantities. Dan. (winkler@harvard)