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Common Lisp implementation running on the JVM
/*
* ConcatenatedStream.java
*
* Copyright (C) 2004-2005 Peter Graves
* $Id$
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* As a special exception, the copyright holders of this library give you
* permission to link this library with independent modules to produce an
* executable, regardless of the license terms of these independent
* modules, and to copy and distribute the resulting executable under
* terms of your choice, provided that you also meet, for each linked
* independent module, the terms and conditions of the license of that
* module. An independent module is a module which is not derived from
* or based on this library. If you modify this library, you may extend
* this exception to your version of the library, but you are not
* obligated to do so. If you do not wish to do so, delete this
* exception statement from your version.
*/
package org.armedbear.lisp;
import static org.armedbear.lisp.Lisp.*;
public final class ConcatenatedStream extends Stream
{
LispObject streams;
ConcatenatedStream(LispObject streams)
{
super(Symbol.CONCATENATED_STREAM);
this.streams = streams;
isInputStream = true;
}
@Override
public boolean isCharacterInputStream()
{
if (streams == NIL)
return true;
return ((Stream)streams.car()).isCharacterInputStream();
}
@Override
public boolean isBinaryInputStream()
{
if (streams == NIL)
return true;
return ((Stream)streams.car()).isBinaryInputStream();
}
@Override
public boolean isCharacterOutputStream()
{
return false;
}
@Override
public boolean isBinaryOutputStream()
{
return false;
}
@Override
public LispObject typeOf()
{
return Symbol.CONCATENATED_STREAM;
}
@Override
public LispObject classOf()
{
return BuiltInClass.CONCATENATED_STREAM;
}
@Override
public LispObject typep(LispObject typeSpecifier)
{
if (typeSpecifier == Symbol.CONCATENATED_STREAM)
return T;
if (typeSpecifier == BuiltInClass.CONCATENATED_STREAM)
return T;
return super.typep(typeSpecifier);
}
@Override
public LispObject getElementType()
{
if (streams == NIL)
return NIL;
return ((Stream)streams.car()).getElementType();
}
@Override
public LispObject readCharNoHang(boolean eofError, LispObject eofValue)
{
if (streams == NIL) {
if (eofError)
return error(new EndOfFile(this));
else
return eofValue;
}
try
{
return _charReady() ? readChar(eofError, eofValue) : NIL;
}
catch (java.io.IOException e)
{
return error(new StreamError(this, e));
}
}
@Override
public LispObject listen()
{
if (streams == NIL)
return NIL;
Stream stream = (Stream)streams.car();
if (stream.listen() == NIL) {
streams = streams.cdr();
return listen();
}
return T;
}
// Returns -1 at end of file.
@Override
protected int _readChar() throws java.io.IOException
{
int n;
if (streams == NIL)
return -1;
Stream stream = (Stream) streams.car();
n = stream._readChar();
if (n >= 0)
return n;
streams = streams.cdr();
return _readChar();
}
@Override
protected void _unreadChar(int n) throws java.io.IOException
{
if (streams == NIL)
error(new StreamError(this, "UNREAD-CHAR was invoked without a stream to unread into."));
Stream stream = (Stream)streams.car();
stream._unreadChar(n);
}
@Override
protected boolean _charReady() throws java.io.IOException
{
if (streams == NIL)
return false;
Stream stream = (Stream) streams.car();
if (stream._charReady())
return true;
LispObject remainingStreams = streams.cdr();
while (remainingStreams != NIL) {
stream = (Stream) remainingStreams.car();
if (stream._charReady())
return true;
remainingStreams = remainingStreams.cdr();
}
return false;
}
@Override
public void _writeChar(char c)
{
outputStreamError();
}
@Override
public void _writeChars(char[] chars, int start, int end)
{
outputStreamError();
}
@Override
public void _writeString(String s)
{
outputStreamError();
}
@Override
public void _writeLine(String s)
{
outputStreamError();
}
// Reads an 8-bit byte.
@Override
public int _readByte()
{
if (streams == NIL)
return -1;
Stream stream = (Stream) streams.car();
int n = stream._readByte();
if (n >= 0)
return n;
streams = streams.cdr();
return _readByte();
}
// Writes an 8-bit byte.
@Override
public void _writeByte(int n)
{
outputStreamError();
}
@Override
public void _finishOutput()
{
outputStreamError();
}
@Override
public void _clearInput()
{
// FIXME
}
private void outputStreamError()
{
error(new StreamError(this,
String.valueOf(this) + " is not an output stream."));
}
// ### make-concatenated-stream &rest streams => concatenated-stream
private static final Primitive MAKE_CONCATENATED_STREAM =
new Primitive("make-concatenated-stream", "&rest streams")
{
@Override
public LispObject execute(LispObject[] args)
{
LispObject streams = NIL;
for (int i = 0; i < args.length; i++) {
if (args[i] instanceof Stream) {
Stream stream = (Stream) args[i];
if (stream.isInputStream()) {
// streams[i] = (Stream) args[i];
streams = new Cons(stream, streams);
continue;
}
}
error(new TypeError(String.valueOf(args[i]) +
" is not an input stream."));
}
return new ConcatenatedStream(streams.nreverse());
}
};
// ### concatenated-stream-streams concatenated-stream => streams
private static final Primitive CONCATENATED_STREAM_STREAMS =
new Primitive("concatenated-stream-streams", "concatenated-stream")
{
@Override
public LispObject execute(LispObject arg)
{
if (arg instanceof ConcatenatedStream)
return ((ConcatenatedStream)arg).streams;
return type_error(arg, Symbol.CONCATENATED_STREAM);
}
};
}