good science and lisp->C case histories

[Fred Lakin <lakin@CSLI.STANFORD.EDU>]

   Date: Mon, 16 Oct 89 17:18 EDT
   From: David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>
   Subject: lisp->C case histories
   To: Fred Lakin <lakin@csli.Stanford.EDU>

       Date: Mon, 16 Oct 89 10:44:10 PDT
       From: lakin@csli.Stanford.EDU (Fred Lakin)

       I am compiling case histories of large lisp programs that were
       translated into C.

   To make this good science, you should try to separate the effects
   of rewriting in C from rewriting period.  For example, if a program
   was first written in Lisp, then rewritten in C, and got faster as
   a result, some of the speedup can be attributed to C, some might be
   attributable to faster hardware made accessible by the use of C, and
   some can be attributed to what one learns from rewriting a program.
   I doubt that any controlled experiments have been conducted where
   two teams competed to rewrite a program, one using Lisp and the other
   using C, but the results of such an experiment would certainly be
   interesting.

I agree completely. Especially, controlling for the "second time you
write a program effect" would be crucial. Your experiment sounds
interesting.

But on the other hand, until there is time and money to do good
science, I thought it would be interesting to get a list of programs
that were translated from lisp to C. Certainly one hears on the street
that such translation is being done all the time (there are only two
kinds of lisp applications, those already translated into C and those
that are going to be, etc). So i wondered how much of this is actually
going on. Of course, any *interpretation* of the cases should be
subject to the caveats you mention above.


   Personally I believe that one ought to use C for what C is good for
   and Lisp for what Lisp is good for, and dispense with the religious
   wars.

Yes.