"======================================================================
|
|   UndefinedObject Method Definitions
|
 ======================================================================"


"======================================================================
|
| Copyright (C) 1988, 1989, 1990 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

!!