Hi Carl
Yes, I have always felt that you got nowhere near the coverage and recognition
you deserved for PLANNER (the whole enchilada) -- to me it was a real landmark
of a set of very powerful insights and perspectives. Definitely one of the very
top gems of the late 60s!
I recall there was lots of good wine at that Pajaro Dunes meeting! (And Jeff
Rulifson helped me pull off that Beef Wellington with the three must have
sauces). That was also a great group. Cordell Green was there, Richard
Waldinger, Rulifson, (Bob Yates?), Bob Balzer, etc. Can you remember any of the
others? That one must have been in 1970.
And it was indeed the second -- and sequential -- evaluator (from the Lisp
1.5 manual) that I had in mind when I did the ST-72 eval. Another influence on
that scheme was the tiny Meta II parser-compiler that Val Shorre did at UCLA in
1963 (for an 8K byte 1401!). I loved that little system. This led to the ST-72
eval really being a kind of cascaded apply ...
And there's no question that once
you aim at real objects a distributed eval makes great sense.
Cheers,
Alan
From: Carl Hewitt hew...@concurrency.biz
To: Alan Kay alan.n...@yahoo.com
Cc: Programming Language Design pi...@googlegroups.com; Dale Schumacher
dale.schumac...@gmail.com; The Friday Morning Applied Complexity Coffee
Group fr...@redfish.com; computational-actors-gu...@googlegroups.com
computational-actors-gu...@googlegroups.com; Fundamentals of New Computing
fonc@vpri.org
Sent: Saturday, November 26, 2011 9:24 AM
Subject: RE: [CAG] Re: [fonc] Fexpr the Ultimate Lambda
Hi Alan,
Yes, Smalltalk-71 had lots of potential! Unfortunately, the way it developed
was that Kowalski picked up a subset of micro-Planner (backward chaining only
along with backtracking only control structure) and PROLOG was made into
something of an ideology. I have published a history in ArXiv titled “Middle
History of Logic Programming: Resolution, Planner, Edinburgh LCF, Prolog, and
the Japanese Fifth Generation Project” at
http://arxiv.org/abs/0904.3036
I have fond memories of the Beef Wellington that you prepared at one of the
Pajaro Dunes meetings of the “DARPA Junior Over-achievers” society! Before
McCarthy developed his meta-circular definition, the developers of Lisp 1 took
a similar approach to yours by developing a looped sequential program that
mimicked their assembly language implementation.
Using “eval” as a message instead of the Lisp procedure is an interesting way
to do language extension. For example lambda notation could be added to
ActorScript as follows:
”lambda” “(“ id|-Identifier “)” body|-Expression ~~ eval(env) --
(argument) -- body.eval(Environment(id,argument, env))
where
Environment(iden, value, enviro) ~~ lookup(iden2) --
iden2=iden ?~ true -- value ?? false -- enviro.lookup(iden2) ~?
Cheers,
Carl
From:Alan Kay [mailto:alan.n...@yahoo.com]
Sent: Friday, November 25, 2011 15:37
To: Carl Hewitt; Dale Schumacher
Cc: Programming Language Design; The Friday Morning Applied Complexity Coffee
Group; computational-actors-gu...@googlegroups.com; Fundamentals of New
Computing
Subject: Re: [CAG] Re: [fonc] Fexpr the Ultimate Lambda
Hi Carl
I've always wished that we had gotten around to doing Smalltalk-71 -- which in
many ways was a more interesting approach because it was heavily influenced by
Planner -- kind of a Planner Logo with objects -- it was more aimed at the
child users we were thinking about. ST-72 did the job at a more primitive
level.
P.S. The characterizations of ST-71 and ST-72 in your paper are not quite
accurate -- but this doesn't matter -- but it is certainly true that we did
not put concurrency in at the lowest level, nor did we have a truly formal
model (I wrote the first interpreter scheme using a McCarthy-like approach --
it was a short one-pager -- but I wrote it as a looped sequential program
rather than metacircularly because I wanted to show how it could be
implemented).
Cheers,
Alan
From:Carl Hewitt hew...@concurrency.biz
To: Dale Schumacher dale.schumac...@gmail.com
Cc: Programming Language Design pi...@googlegroups.com; The Friday Morning
Applied Complexity Coffee Group fr...@redfish.com;
computational-actors-gu...@googlegroups.com
computational-actors-gu...@googlegroups.com; Alan Kay
alan.n...@yahoo.com; Fundamentals of New Computing fonc@vpri.org
Sent: Friday, November 25, 2011 12:11 PM
Subject: RE: [CAG] Re: [fonc] Fexpr the Ultimate Lambda
I have started a discussion topic on Lambda the Ultimate so that others can
participate here: Actors all the way down
How SmallTalk-72 influenced the development of Actors is discussed in Actor
Model of Computation: Scalable Robust Information Systems.
Cheers,
Carl
PS. Kristen Nygaard and I had some fascinating late night discussions over
such matters in Aarhus lubricated with Linie
