Implementation Limits

[Scott E. Fahlman <Fahlman@CMU-CS-C>]

I tried sending this earlier, but the mail came bouncing back.

Just for the record, our Spice/PERQ implementation puts no limit on the
number of args to an apply or to any &rest arg, unless you run out of
virtual memory or disk -- this will happen before you get into bignums
for the argument count.

We currently cut off the number of symbols and constants in a function
at 32K, locals at 2K, and non-rest arguments at 255.  Our branch offsets
are only 16 bits, so function objects cannot be longer than 64K bytes.
If any of this ever gets in the way, we'll fix it, but I think it is
safe to say that any program that violates these limits would also
violate good coding style in Lisp.  The only real worry is that
program-generating programs might produce some bizarre giant-sized
function.

I believe that the Vax Common Lisp implementation has less stringent
limits.

-- Scott