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From: rees@parc.xerox.COM
Newsgroups: comp.lang.scheme
Subject: what is lisp, instead?
Message-ID: <9008141823.AA08641@satchmo>
Date: 14 Aug 90 18:03:10 GMT
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   Date: Mon, 13 Aug 90 12:30:00 EDT
   From: gjc@mitech.com

   What is one requirement for living well with C? That if you
   have a lisp-level call to a procedure like (equal (f x) (g y)) that
   you must be able to call it at C-level as equal(f(x),g(y));

This is a tall order; the only solution of which I'm aware is a
conservative GC, and I didn't think siod had one of those (I deduce
this from the presence in slib.c of a function called "gc_protect").
Or do you have some other way of dealing with the situation where
(assuming left-to-right argument evaluation in C)

  - the result of f is consed
  - the only pointer to this result while in g is on the C stack
  - invoking g triggers a GC
  - after the gc g does more allocation, thereby overwriting the
    result of the call to f?