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Common Lisp implementation running on the JVM
/*
* BroadcastStream.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 BroadcastStream extends Stream
{
final Stream[] streams;
BroadcastStream(Stream[] streams)
{
super(Symbol.BROADCAST_STREAM);
this.streams = streams;
isOutputStream = true;
if (streams.length == 0) {
elementType = T;
isBinaryStream = true;
isCharacterStream = true;
} else {
elementType = streams[streams.length-1].getElementType();
if (elementType == Symbol.CHARACTER || elementType == Symbol.BASE_CHAR)
isCharacterStream = true;
else
isBinaryStream = true;
}
}
public Stream[] getStreams()
{
return streams;
}
@Override
public LispObject typeOf()
{
return Symbol.BROADCAST_STREAM;
}
@Override
public LispObject classOf()
{
return BuiltInClass.BROADCAST_STREAM;
}
@Override
public LispObject typep(LispObject typeSpecifier)
{
if (typeSpecifier == Symbol.BROADCAST_STREAM)
return T;
if (typeSpecifier == BuiltInClass.BROADCAST_STREAM)
return T;
return super.typep(typeSpecifier);
}
@Override
public LispObject listen()
{
notSupported();
// Not reached.
return NIL;
}
@Override
public LispObject fileLength()
{
if (streams.length > 0)
return streams[streams.length - 1].fileLength();
else
return Fixnum.ZERO;
}
@Override
public LispObject fileStringLength(LispObject arg)
{
if (streams.length > 0)
return streams[streams.length - 1].fileStringLength(arg);
else
return Fixnum.ONE;
}
// Returns -1 at end of file.
@Override
protected int _readChar()
{
notSupported();
// Not reached.
return -1;
}
@Override
protected void _unreadChar(int n)
{
notSupported();
}
@Override
protected boolean _charReady()
{
notSupported();
// Not reached.
return false;
}
@Override
public void _writeChar(char c)
{
for (int i = 0; i < streams.length; i++)
streams[i]._writeChar(c);
}
@Override
public void _writeChars(char[] chars, int start, int end)
{
for (int i = 0; i < streams.length; i++)
streams[i]._writeChars(chars, start, end);
}
@Override
public void _writeString(String s)
{
for (int i = 0; i < streams.length; i++)
streams[i]._writeString(s);
}
@Override
public void _writeLine(String s)
{
for (int i = 0; i < streams.length; i++)
streams[i]._writeLine(s);
}
// Reads an 8-bit byte.
@Override
public int _readByte()
{
notSupported();
// Not reached.
return -1;
}
// Writes an 8-bit byte.
@Override
public void _writeByte(int n)
{
for (int i = 0; i < streams.length; i++)
streams[i]._writeByte(n);
}
@Override
public void _finishOutput()
{
for (int i = 0; i < streams.length; i++)
streams[i]._finishOutput();
}
@Override
public void _clearInput()
{
notSupported();
}
@Override
protected long _getFilePosition()
{
if (streams.length == 0)
return 0;
else
return streams[streams.length-1]._getFilePosition();
}
@Override
protected boolean _setFilePosition(LispObject arg)
{
return false;
}
@Override
public void _close()
{
setOpen(false);
}
private void notSupported()
{
error(new TypeError("Operation is not supported for streams of type BROADCAST-STREAM."));
}
@Override
public String printObject()
{
return unreadableString("BROADCAST-STREAM");
}
// ### make-broadcast-stream &rest streams => broadcast-stream
private static final Primitive MAKE_BROADCAST_STREAM =
new Primitive("make-broadcast-stream", "&rest streams")
{
@Override
public LispObject execute()
{
return new BroadcastStream(new Stream[0]);
}
@Override
public LispObject execute(LispObject[] args)
{
Stream[] streams = new Stream[args.length];
for (int i = 0; i < args.length; i++) {
if (args[i] instanceof Stream) {
if (((Stream)args[i]).isOutputStream()) {
streams[i] = (Stream) args[i];
continue;
} else
return type_error(args[i],
list(Symbol.SATISFIES, Symbol.OUTPUT_STREAM_P));
} else
return type_error(args[i], Symbol.STREAM);
}
// All is well.
return new BroadcastStream(streams);
}
};
// ### broadcast-stream-streams broadcast-stream => streams
private static final Primitive BROADCAST_STREAM_STREAMS =
new Primitive("broadcast-stream-streams", "broadcast-stream")
{
@Override
public LispObject execute(LispObject arg)
{
if (arg instanceof BroadcastStream) {
BroadcastStream stream = (BroadcastStream) arg;
Stream[] streams = stream.streams;
LispObject result = NIL;
for (int i = streams.length; i-- > 0;)
result = new Cons(streams[i], result);
return result;
}
return type_error(arg, Symbol.BROADCAST_STREAM);
}
};
}