"====================================================================== | | ReadWriteStream Method Definitions | | $Revision: 1.7.5$ | $Date: 2000/05/28 16:56:52$ | $Author: pb$ | ======================================================================" "====================================================================== | | Copyright 1988-92, 1994-95, 1999, 2000 Free Software Foundation, Inc. | Written by Steve Byrne. | | This file is part of the GNU Smalltalk class library. | | The GNU Smalltalk class library is free software; you can redistribute it | and/or modify it under the terms of the GNU Lesser General Public License | as published by the Free Software Foundation; either version 2.1, or (at | your option) any later version. | | The GNU Smalltalk class library 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 Lesser | General Public License for more details. | | You should have received a copy of the GNU Lesser General Public License | along with the GNU Smalltalk class library; see the file COPYING.LESSER. | If not, write to the Free Software Foundation, 59 Temple Place - Suite | 330, Boston, MA 02111-1307, USA. | ======================================================================" WriteStream subclass: #ReadWriteStream instanceVariableNames: '' classVariableNames: '' poolDictionaries: '' category: 'Streams-Collections' ! ReadWriteStream comment: 'I am the class of streams that may be read and written from simultaneously. In some sense, I am the best of both ReadStream and WriteStream.' ! !ReadWriteStream class methodsFor: 'instance creation'! on: aCollection "Answer a new stream working on aCollection from its start. The stream starts at the front of aCollection" ^(super on: aCollection) beReadWrite; useWholeStream ! with: aCollection "Answer a new instance of the receiver which streams from the end of aCollection." ^(super with: aCollection) beReadWrite ! ! !ReadWriteStream methodsFor: 'positioning'! position: anInteger "Unlike WriteStreams, ReadWriteStreams don't truncate the stream" self basicPosition: anInteger ! skip: anInteger "Unlike WriteStreams, ReadWriteStreams don't truncate the stream" self basicPosition: ((ptr + anInteger max: 1) min: endPtr). ! ! !ReadWriteStream methodsFor: 'private'! useWholeStream "Private - Makes sure that the contents message to this object returns the whole contents, not just that which has been written so far." endPtr := collection size ! !