Multiple Language Support

[Harvey J. Stein]

Tim Pierce writes:
 > > >You'd still have problems
 > > >dealing with all of those CL functions that return nil for false.
 > > >That's a much, much harder problem to deal with.
 > > 
 > > Yeah I forgot about that. A good argument for writing the system in
 > > Scheme and putting Lisp as an extra language on top :-)
 > 
 > For a long discussion about the difficulty (but tractability) of
 > implementing Lisp on top of Scheme, see the Guile mailing list
 > archives at <URL: http://www.cyclic.com/guile/>.

Being on the guile mailing list, and having followed the discussion, I
believe the final conclusion was that it's really not *that*
difficult.

I think the thing is that it's mostly just frustrating that the
languages are so similar, but you still have to actually go and do
alot of translation.

The initial requirement of making #f eq to nil was dropped.  The
ultimate conclusion of that particular battle was that it's not going
to cause much of a performance hit to allow #f to be different from
nil.

So, I think it turns out that regardless of which one is on the
bottom, it still takes a significant implementation effort to put the
other on top.

-- 
Harvey J. Stein
Berger Financial Research
abel@netvision.net.il