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Languguage OS II Version 10-94 (Knowledge Media)(1994).ISO
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smaltalk.lha
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smalltalk-1.1.1
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UndefinedObject.st
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1991-09-12
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"======================================================================
|
| UndefinedObject Method Definitions
|
======================================================================"
"======================================================================
|
| Copyright (C) 1990, 1991 Free Software Foundation, Inc.
| Written by Steve Byrne.
|
| This file is part of GNU Smalltalk.
|
| GNU Smalltalk is free software; you can redistribute it and/or modify it
| under the terms of the GNU General Public License as published by the Free
| Software Foundation; either version 1, or (at your option) any later version.
|
| GNU Smalltalk is distributed in the hope that it will be useful, but WITHOUT
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
| FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
| details.
|
| You should have received a copy of the GNU General Public License along with
| GNU Smalltalk; see the file COPYING. If not, write to the Free Software
| Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|
======================================================================"
"
| Change Log
| ============================================================================
| Author Date Change
| sbyrne 19 Sep 89 Changed to use real method categories.
|
| sbyrne 25 Apr 89 created.
|
"
Object subclass: #UndefinedObject
instanceVariableNames: ''
classVariableNames: ''
poolDictionaries: ''
category: nil.
UndefinedObject comment:
'I have the questionable distinction of being a class with only one
instance, which is the object "nil". I suspect that I should be sent
messages when errors occur, but currently I am not.' !
!UndefinedObject methodsFor: 'testing'!
isNil
^true
!
notNil
^false
!!
!UndefinedObject methodsFor: 'printing'!
printOn: aStream
'nil' printOn: aStream
!!
!UndefinedObject methodsFor: 'storing'!
storeOn: aStream
'nil' printOn: aStream
!!