reduce-algebra/vsl

This is the VSL Lisp system. Its key attribute is that it is SMALL.
The source file (vsl.c) is around 3000 lines long, but despite that
the system can build and run much of Reduce. Since there is only
an interpreter it will be slow, but for teaching purposes and for
fun it may still be of interest.

There are two versions here (apologies).
vsl1.c can be compiled and is expected to run Reduce. Try "make reduce" here
and then "./vsl1 -i reduce.img" possibly followed by a file-name to read.
This is all interpreted and the bignum arithmetic is painfully slow, but all
it needs is a simple C compiler so it may be of interest as at leaset a first
test on a new and potentially tricky machine. But note that a Reduce built
that was is not only slow but it has not been seriously tested and either
bugs in vsl1 or missing features may cause problems to arise. Because vsl1.c
is so compact you are mostly expected to track those down and fix them for
yourself!

The second version is called simply vsl.c. That was being used as part of a
project to explore the bootstrapping phases of building PSL. It thus has
options to mimic the parsing regime in a raw "bpsl" Lisp (with eg "-" and "&"
treated as letters so that one can have a token &abc-def without needing
to use escape characters to spell it). There are some somewhat fragmentary
files and stages in the Makefile for starting to build a PSL kernel. The work
there got as far as "proof of concept" and so is available if anybody wants
to pick it up, but it is not complete or tidy! If you want to port PSL as a
serious task you will be better off using an existing version and running
initial bootstrap stages as cross-builds on a platform where everthing is
known to be stable.

Arthur Norman. 2012-2018, 2021