larry@Jpl-VLSI.ARPA.UUCP (01/22/87)
Scheme can be gotten for Apple Macs and IBM PCs. MacScheme is $125 and can
be gotten from Semantic Microsystems in Oregon, 503/643-4359. The Texas
Inst. version costs $95; their phone # is 800/527-3500. A review from last
Feb. is appended for those who did not see it before. Larry @ jpl-vlsi.arpa
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From: Rob Pettengill <CAD.PETTENGILL@MCC.ARPA> [69 lines]
I recently purchased an implementation of the Scheme dialect of lisp for my
PC. I am familiar with GC Lisp, IQ Lisp, and Mu Lisp for the PC. I use
Lambdas and 3600s with ZetaLisp at work.
TI PC Scheme is a very complete implementation of scheme for the IBM and TI
personal computers and compatibles. It combines high speed code execution,
a good debugging and editing environment, and very low cost.
The Language:
* Adheres faithfully to the Scheme standard.
* Has true lexical scoping.
* Prodedures and environments are first class data objects.
* Is properly tail recursive - there is no penalty compared
to iteration.
* Includes window and graphics extensions.
The Environment:
* An incremental optimizing compiler (not native 8086 code)
* Top level read-compile-print loop.
* Interactive debugger allows run time error recovery.
* A minimal Emacs-like full screen editor with a scheme mode
featuring parethesis matching and auto indenting of lisp code.
* An execute DOS command or "push" to DOS capability - this is
only practical with a hard disk because of the swap file PCS writes.
* A DOS based Fast Load file format object file conversion utility.
* A fast 2 stage garbage collector.
First Impressions:
Scheme seems to be much better sized to a PC class machine than the other
standard dialects of lisp because of its simplicity. The TI implementation
appears to be very solid and complete. The compiled code that it produces
(with debugging switches off) is 2 to 5 times faster than the other PC lisps
that I have used. With the full screen editor loaded (there is also a
structure editor) there seems to be plenty of room for my code in a 640k PC.
TI recommends 320k or 512k with the editor loaded. The documentation is of
professional quality (about 390 pages), but not tutorial. Abelson and
Sussman's "Structure and Interpretation of Computer Programs" is a very
good companion for learning scheme as well as the art and science of
cprogramming in general.
My favorite quick benchmark -
(define (test n)
(do
((i 0 (1+ i))
(r () (cons i r)))
((>= i n) r)))
runs (test 10000) in less than 10 seconds with the editor loaded - of course
it takes a couple of minutes to print out the ten thousand element list that
results.
The main lack I find is that the source code for the system is not included-
one gets used to that in good lisp environments. I have hit only a couple
of minor glitches, that are probably pilot error, so far. Since the system
is compiled with debugging switches off it is hard to get much useful
information about the system from the dubugger.
Based on my brief, but very positive experience with TI PC scheme and its
very low price of $95 - I recommend it to anyone interested in a PC based
lisp. (Standard disclaimers about personal opinions and having no
commercial interest in the product ...)