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From: chouc@mist.cs.orst.edu (Chou Chung-Di)
Newsgroups: comp.lang.smalltalk
Subject: Class deletion in Digitalk's Smalltalk/V
Message-ID: <15859@orstcs.CS.ORST.EDU>
Date: 15 Feb 90 07:00:45 GMT
Sender: usenet@orstcs.CS.ORST.EDU
Reply-To: chouc@mist.CS.ORST.EDU (Chou Chung-Di)
Distribution: comp.lang.smalltalk
Organization: Oregon State Univ. -- Computer Science
Lines: 22


Could anyone help me on this problem?

Digitalk's Smalltalk/V supports a funtion to remove global variables using
the following expression:

    Smalltalk removeKey: #AGlobalVariable.

Or, I can inspect the dictionary and explicit remove the key associated with
the object. But I encountered a problem - how do I delete a class?

If SomeClass exists and I want to delete it from the system, I can remove it
and it seems that SomeClass is no longer defined in Smalltalk. But when I go
to my class hierarch browser, I'll still see it there, but with class 
definition same as that of an UndefinedObject. Later, when I retrieve the
class definition file of SomeClass, I'll find two entries in my class 
hierarchy browser for SomeClass - with the same new definition.

I notice there is a way in Smalltalk/V 286 that you can delete a class. 
Actually its name will still be posted in the class hierarchy browser, but
you cannot access it - it becomes an instance of non-existent class. 
What's wrong with this?