Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!snorkelwacker.mit.edu!bloom-beacon!eru!hagbard!sunic!mcsun!ukc!edcastle!aiai!jeff From: jeff@aiai.ed.ac.uk (Jeff Dalton) Newsgroups: comp.lang.lisp Subject: Re: So who's really using LISP? Message-ID: <4330@skye.ed.ac.uk> Date: 18 Mar 91 15:19:47 GMT References: <1227@culhua.prg.ox.ac.uk> <1991Feb18.082559@disuns2.epfl.ch> <25595@neptune.inf.ethz.ch> Reply-To: jeff@aiai.UUCP (Jeff Dalton) Organization: AIAI, University of Edinburgh, Scotland Lines: 44 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? Indeed, when someone says "our programs would be unmanageable" you need some evidence that those very programs would be manageable, not that someone once found that they preffered C++ for some other programs. What Trickey says is extremely misleading as a guide to what's true, as opposed to how things appear to someone who prefers C++ to Lisp. As far as Dickey was concerned compile-time type checking was the most important difference, and it appears that he would decide against Lisp no matter what Lisp implementations do so long as that difference remained. A common pattern in his observations is to say Lisp has feature X, but he could code up something in C++ that was nearly as good and after this initial effort the advantage to Lisp was essentially removed. Ok, so in his view print functions are just as good as an inspector, but this is hardly something with which everyone will agree. Moreover, he is strongly influenced by problems with particular implementations of Lisp (eg, the (real) superiority of dbx over the Lisp debugger). He tried to gain a measure of objectivity by trying two implementations, but he was nonetheless comparing implementations rather than languages. I have no objection to people preferring one language over another, and Trickey has good reasons (from his point of view) for preferring C++. What I do object to is the attempt to universalize this judgement. Trickey doesn't do this explicitly, but his article is easily used to that end and goes some way to encourage it.