Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!ncar!noao!arizona!gudeman From: gudeman@cs.arizona.edu (David Gudeman) Newsgroups: comp.lang.misc Subject: Re: Run-time Type Errors in Smalltalk Message-ID: <2110@optima.cs.arizona.edu> Date: 18 Apr 91 18:12:46 GMT Sender: news@cs.arizona.edu Lines: 45 In article Jim Showalter writes: ]% ]%>... If they ]%>hadn't caught those errors by static typing they would have caught ]%>them by testing -- the same way the found the other 90% of the errors. ]Bzzzzzzt. Thank you for playing. Bzzzzzzt. Thank you for being obnoxious. That might have been funny the first time it was done, but it is getting really old. Especially as it is usually done by people who demonstrably know no more than the person they are replying to. ]Testing is NOT guaranteed to catch these errors, whereas static typing ]is, by its nature, guaranteed to do so. No, it isn't guaranteed. But it will catch most of them, and I claim that the tradeoff (static typing _causes_ some errors that aren't caught) is in favor of dynamic typing. ]I defy you to come up with a ]way to ensure that you have traversed all possible paths through a ]dynamically-typed program that could conceivably send the wrong message ]to the wrong recipient. Ooh. I've been defied. Well lets see, this should take about 3 seconds... OK, write a type inferencer. (Not that I think this is obviously worth doing.) ]Nobody is claiming that there are not ways to go bump in statically-typed ]languages, only that the number of ways you can go bump is REDUCED. People aren't just claiming that, they are assuming it. I think they need to question their assumptions. ]... Why anybody would deliberately ]choose to code in a language that is guaranteed to permit MORE errors ]than another language is beyond me. See what I mean? Assuming that dynamic typing has more errors. Completely without evidence, I might add (or repeat actually). -- David Gudeman gudeman@cs.arizona.edu noao!arizona!gudeman