good science and lisp->C case histories

["Mr. Spock" <Spock%samson.cadr.dialnet.symbolics.com@RELAY.CS.NET>]

    Date: Mon, 16 Oct 89 16:39:32 PDT
    From: lakin@csli.Stanford.EDU (Fred Lakin)

       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.

Perhaps, it would also be a good idea to find out how many of these
programs (if any) were ported to C in order to avoid lisp-vendor
"runtime" charges involved.