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"
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COPYRIGHT (c) 1989 by Claus Gittinger
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All Rights Reserved
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This software is furnished under a license and may be used
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only in accordance with the terms of that license and with the
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inclusion of the above copyright notice. This software may not
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be provided or otherwise made available to, or used by, any
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other person. No title to or ownership of the software is
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hereby transferred.
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"
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WriteStream subclass:#ReadWriteStream
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instanceVariableNames:''
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classVariableNames:''
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poolDictionaries:''
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category:'Streams'
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1
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!
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611
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!ReadWriteStream class methodsFor:'documentation'!
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88
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copyright
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"
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COPYRIGHT (c) 1989 by Claus Gittinger
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329
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All Rights Reserved
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88
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This software is furnished under a license and may be used
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only in accordance with the terms of that license and with the
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inclusion of the above copyright notice. This software may not
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be provided or otherwise made available to, or used by, any
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other person. No title to or ownership of the software is
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hereby transferred.
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"
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!
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documentation
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"
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ReadWriteStreams allow both read- and write-access to some collection.
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To allow this, they reenable some methods blocked in WriteStream.
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(being one of the seldom places, where multiple inheritance could be
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of good use in smalltalk).
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329
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Claus:
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I personally find the ReadStream - WriteStream - ReadWriteStream
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organization brain-damaged. It would be better to have an attribute
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(such as readOnly / writeOnly / readWrite) in an InternalStream subclass
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of Stream ...
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"
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!
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345
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version
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^ '$Header: /cvs/stx/stx/libbasic/ReadWriteStream.st,v 1.13 1995-11-23 01:31:50 cg Exp $'
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! !
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!ReadWriteStream methodsFor:'access-reading'!
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next
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"return the next element; advance read position.
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If there are no more elements, nil is returned."
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|element|
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(position > readLimit) ifTrue:[^ nil].
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element := collection at:position.
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position := position + 1.
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^ element
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!
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peek
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"return the element to be read next without advancing read position.
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If there are no more elements, nil is returned."
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(position > readLimit) ifTrue:[^ nil].
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^ collection at:position
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! !
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611
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!ReadWriteStream methodsFor:'positioning'!
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reset
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"re-redefine to not clobber the collection"
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position := "0" 1
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! !
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!ReadWriteStream methodsFor:'queries'!
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isReadable
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^ true
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! !
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