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|
"======================================================================
|
| ReadStream Method Definitions
|
|
======================================================================"
"======================================================================
|
| Copyright 1988,92,94,95,99,2000,2001,2006
| 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.LIB.
| If not, write to the Free Software Foundation, 59 Temple Place - Suite
| 330, Boston, MA 02110-1301, USA.
|
======================================================================"
PositionableStream subclass: ReadStream [
<category: 'Streams-Collections'>
<comment: 'I implement the set of read-only stream objects. You may read from
my objects, but you may not write to them.'>
ReadStream class >> on: aCollection [
"Answer a new stream working on aCollection from its start."
<category: 'instance creation'>
^(self basicNew initCollection: aCollection limit: aCollection size)
beReadOnly
]
ReadStream class >> on: aCollection from: firstIndex to: lastIndex [
"Answer an instance of the receiver streaming from
the firstIndex-th item of aCollection to the lastIndex-th"
<category: 'instance creation'>
firstIndex = 1
ifFalse:
[^super
on: aCollection
from: firstIndex
to: lastIndex].
lastIndex > aCollection size
ifTrue:
[^SystemExceptions.IndexOutOfRange signalOn: self withIndex: lastIndex].
^(self basicNew initCollection: aCollection limit: lastIndex) beReadOnly
]
initCollection: aCollection limit: anInteger [
<category: 'private methods'>
collection := aCollection.
ptr := 1.
endPtr := anInteger
]
]
|
