🚀 go-pugleaf

>Talk about LISP (one person mentioned Prolog).  What about
>Smalltalk-80(tm)?  Simula-67?  Other declarative functional languages?
>Backus is working on an interesting new language named FL.  VAL/ID/SISAL

>Talk to me about classes of languages.  Post the follow up.

One of the classes of languages that has received little attention is the class
of concurrent languages, VAL and SISAL are mentioned above and come under the
general class of data flow languages.  One of the aspects of the single
assignment data flow language (re SISAL) is that it appears to be functional
in nature, is this a fact of life, do all data flow languages need to be
functional ?  I would say no, it is not but is in fact
a product of our up-bringing with von-Neumann machines, iterative programming
structures etc.  The Single Assignment Rule (SAR) appears to be an attempt to
control the chaos of the iterative programming language construct, if we accept
that iteration and recursion are equivalent why not then just stick to
recursion, sure make it look iterative (so that we all don't get technology 
shock :-)) but remove iteration from the program model (we could talk about
GOTOs if you like :-) :-)).  The actor model and continuations have a solution
to distributing recursion, why not use it.

Anyway, back to the subject, I feel that few modern languages can afford
to ignore the problem of concurrency ( be it parallelism or distribution) and
that the determination of that concurrency should be implicit (ie tasks
etc. are right out).  Those interested in implicit concurrency should
look at languages such as Ether (an actor language), SISAL (data flow)
or get my forthcoming internal report (ah ha you say, all is revealed) on the 
implicitly parallel, non-single assignemnt (more not very many assignemnts)
data flow language (AARC - Implicitly parallel Data Flow Language, internal
report LG-02-88, available end of Feb 1988). All reports are free
from the University of Lancaster at the address given below (or via e-mail
to me).


Craig.

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