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From: caroma@ai.mit.edu
Newsgroups: comp.sys.next
Subject: T, AKCL  (was Re: Needed: Lisp on NeXT for January AI course)
Message-ID: <12568@life.ai.mit.edu>
Date: 1 Jan 91 22:00:08 GMT
References: <1990Dec22.225150.20135@cs.umn.edu> <1080@toaster.SFSU.EDU> <95437@aerospace.AERO.ORG>
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In article <95437@aerospace.AERO.ORG> srt@aerospace.aero.org (Scott "TCB" Turner) writes:
>I don't know off-hand if anyone has brought AKCL up on a NeXT, but if
>they have I'd recommend it over T.  AKCL is an excellent
>implementation of Common Lisp, very correct and fast.  I've programmed
>the same large system in both T and AKCL, and I much prefer AKCL.
>There are things I like about T, particularly the object-oriented
>aspects, but it is just too slow and kludgy compared to AKCL.

Could you characterize your application and platforms a little more,
so readers can get a better idea of what your datapoint represents?

I have an application which is VERY call intensive, so I wrote some
little test programs which basically test a few calling strategies.
On these (little test) programs, T came out on top about 10 times
faster than AKCL; AKCL was at the bottom of the heap of the Lisps I
tested, including T 3.1, Lucid, IBCL, and AKCL (yes, with safety=0,
speed=3).  I tested on Sun3's, which are 68030's I believe, and
therefore might have similar performance on NeXT's.

Admittedly, these were small programs.  Also, T seemed to invoke the
GC alot, and slowed down quite a bit when it did so.  So AKCL may be
better for some systems; I'm just countering the impression that the
AKCL would be faster that T for all applications.

For the original poster's AI class, AKCL would probably be better if
it can be found just because it is Common Lisp, which is a widely
available standard so the exercises and the student's work will be
portable.  T is a dialect of Scheme, so it would take a bit of work to
convert programs to T from CL or vice versa, but it would be better
for learning Scheme (popular for CS Lisp programming courses).

Cheers,

caroma@ai.mit.edu