Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!gatech!bloom-beacon!eru!hagbard!sunic!mcsun!cernvax!chx400!chx400!sicsun!disuns2!/!baechler From: baechler@disuns2.epfl.ch (Emmanuel Baechler) Newsgroups: comp.lang.lisp Subject: Re: So who's really using LISP? Message-ID: <1991Mar20.110700@disuns2.epfl.ch> Date: 20 Mar 91 10:07:00 GMT References: <1227@culhua.prg.ox.ac.uk> <1991Feb18.082559@disuns2.epfl.ch> <25595@neptune.inf.ethz.ch> <4330@skye.ed.ac.uk> Sender: news@disuns2.epfl.ch Reply-To: baechler@disuns2.epfl.ch (Emmanuel Baechler) Organization: Ecole Polytechnique Federale de Lausanne Lines: 53 In article <4330@skye.ed.ac.uk>, jeff@aiai.ed.ac.uk (Jeff Dalton) writes: > In article <25595@neptune.inf.ethz.ch> marti@mint.inf.ethz.ch (Robert > Marti) writes: > >> but I am convinced that without lisp our programs would be > unmanageable. > > > >What evidence do you have to support the above statement? Have you > >actually compared at least one nontrivial Lisp application (say > >10000 > >lines of code) with the same application written in another > language? > >(You may want to look at "C++ versus Lisp: A Case Study", by H. > Trickey, > >SIGPLAN Notices Vol.23, No.2, February 1988, pp.9-18. Note that I > do > >not claim that Trickey's findings generalize to _all_ applications, > >though.) > > But you think they're true of _his_ application? That is, if someone > else performed the same experiment they'd get the same result? > What I am doing is qualitavite reasoning applied to mechanism kinematics. My code is bigger than 1 Meg. It was (and is) difficult to develop. However Lisp proved to be *VERY* helpful to do it. I still claim than doing it with a "classical" (i.e. imperative (and even with an object-oriented extension, C++ remains imperative)) would have been several orders of magnitude more difficult. Common Lisp is not only, functional, object-oriented, and so on, it is EXTENSIBLE, wich allows to describe something in a way corresponding to the problem. As all programming languages have a THEORETICALLY equivalent expressive power, experience showed me that there is a strong difference between theory and prectice, in the sense that some languages allow to express thing more easily than other. This is where Lisp definitely wins. As this difference between theory and prectice has already been discussed a lot, I won't go into it any more. I have read than some people are extemely happy to build AI programs in C or whatever else. In a sense, they could also do it in assembly language, which wouldn't be very different. In my opinion this is like people spending their time writing huge programs in assembly langage, because it can be done ansd because one can win 1 femtosecond on a loop wich might be never executed. This is simply not the thing to do, because things are not described at the proper level. E. Baechler AI Lab Ecole Polytechnique Federale de Lausanne MA - Ecublens 1015 Lausanne Switzerland