Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!hpda!hpcuhb!hpcilzb!hpcea!hpbsla!mfox From: mfox@hpbsla.HP.COM (Martin_Fox) Newsgroups: comp.lang.smalltalk Subject: Re: Quest. on Smalltalk Message-ID: <1430005@hpbsla.HP.COM> Date: 19 Dec 88 19:42:32 GMT References: Organization: Hewlett-Packard Boise R & D Lab Lines: 19 As long as we're discussing modification of system classes.... Before compiling a new class it may be wise to check if any existing system classes have the same class name. Otherwise the system will attempt to compile the new class definition and then hunt down each and every existing instance of that class and make them conform to the new definition. If you have accidently over-written a system class, you get to watch with horror as a Smalltalk system thrashes around and eventually dies. It is not pretty. At the very least, save your code or an image before compiling new classes. (This from the mouth of a man who didn't know Switch was a system class until an ugly scene ensued). Martin Fox