source: branches/streams/abcl/src/org/armedbear/lisp/BroadcastStream.java

Last change on this file was 14466, checked in by rschlatte, 12 years ago

call type_error when possible

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 7.2 KB
Line 
1/*
2 * BroadcastStream.java
3 *
4 * Copyright (C) 2004-2005 Peter Graves
5 * $Id: BroadcastStream.java 14466 2013-04-24 12:50:40Z rschlatte $
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
20 *
21 * As a special exception, the copyright holders of this library give you
22 * permission to link this library with independent modules to produce an
23 * executable, regardless of the license terms of these independent
24 * modules, and to copy and distribute the resulting executable under
25 * terms of your choice, provided that you also meet, for each linked
26 * independent module, the terms and conditions of the license of that
27 * module.  An independent module is a module which is not derived from
28 * or based on this library.  If you modify this library, you may extend
29 * this exception to your version of the library, but you are not
30 * obligated to do so.  If you do not wish to do so, delete this
31 * exception statement from your version.
32 */
33
34package org.armedbear.lisp;
35
36import static org.armedbear.lisp.Lisp.*;
37
38public final class BroadcastStream extends Stream
39{
40    final Stream[] streams;
41
42    BroadcastStream(Stream[] streams)
43    {
44        super(Symbol.BROADCAST_STREAM);
45        this.streams = streams;
46        isOutputStream = true;
47        if (streams.length == 0) {
48            elementType = T;
49            isBinaryStream = true;
50            isCharacterStream = true;
51        } else {
52            elementType = streams[streams.length-1].getElementType();
53            if (elementType == Symbol.CHARACTER || elementType == Symbol.BASE_CHAR)
54                isCharacterStream = true;
55            else
56                isBinaryStream = true;
57        }
58    }
59
60    public Stream[] getStreams()
61    {
62        return streams;
63    }
64
65    @Override
66    public LispObject typeOf()
67    {
68        return Symbol.BROADCAST_STREAM;
69    }
70
71    @Override
72    public LispObject classOf()
73    {
74        return BuiltInClass.BROADCAST_STREAM;
75    }
76
77    @Override
78    public LispObject typep(LispObject typeSpecifier)
79    {
80        if (typeSpecifier == Symbol.BROADCAST_STREAM)
81            return T;
82        if (typeSpecifier == BuiltInClass.BROADCAST_STREAM)
83            return T;
84        return super.typep(typeSpecifier);
85    }
86
87    @Override
88    public LispObject listen()
89    {
90        notSupported();
91        // Not reached.
92        return NIL;
93    }
94
95    @Override
96    public LispObject fileLength()
97    {
98        if (streams.length > 0)
99            return streams[streams.length - 1].fileLength();
100        else
101            return Fixnum.ZERO;
102    }
103
104    @Override
105    public LispObject fileStringLength(LispObject arg)
106    {
107        if (streams.length > 0)
108            return streams[streams.length - 1].fileStringLength(arg);
109        else
110            return Fixnum.ONE;
111    }
112
113    // Returns -1 at end of file.
114    @Override
115    protected int _readChar()
116    {
117        notSupported();
118        // Not reached.
119        return -1;
120    }
121
122    @Override
123    protected void _unreadChar(int n)
124    {
125        notSupported();
126    }
127
128    @Override
129    protected boolean _charReady()
130    {
131        notSupported();
132        // Not reached.
133        return false;
134    }
135
136    @Override
137    public void _writeChar(char c)
138    {
139        for (int i = 0; i < streams.length; i++)
140            streams[i]._writeChar(c);
141    }
142
143    @Override
144    public void _writeChars(char[] chars, int start, int end)
145
146    {
147        for (int i = 0; i < streams.length; i++)
148            streams[i]._writeChars(chars, start, end);
149    }
150
151    @Override
152    public void _writeString(String s)
153    {
154        for (int i = 0; i < streams.length; i++)
155            streams[i]._writeString(s);
156    }
157
158    @Override
159    public void _writeLine(String s)
160    {
161        for (int i = 0; i < streams.length; i++)
162            streams[i]._writeLine(s);
163    }
164
165    // Reads an 8-bit byte.
166    @Override
167    public int _readByte()
168    {
169        notSupported();
170        // Not reached.
171        return -1;
172    }
173
174    // Writes an 8-bit byte.
175    @Override
176    public void _writeByte(int n)
177    {
178        for (int i = 0; i < streams.length; i++)
179            streams[i]._writeByte(n);
180    }
181
182    @Override
183    public void _finishOutput()
184    {
185        for (int i = 0; i < streams.length; i++)
186            streams[i]._finishOutput();
187    }
188
189    @Override
190    public void _clearInput()
191    {
192        notSupported();
193    }
194
195    @Override
196    protected long _getFilePosition()
197    {
198        if (streams.length == 0)
199            return 0;
200        else
201            return streams[streams.length-1]._getFilePosition();
202    }
203
204    @Override
205    protected boolean _setFilePosition(LispObject arg)
206    {
207        return false;
208    }
209
210    @Override
211    public void _close()
212    {
213        setOpen(false);
214    }
215
216    private void notSupported()
217    {
218        error(new TypeError("Operation is not supported for streams of type BROADCAST-STREAM."));
219    }
220
221    @Override
222    public String printObject()
223    {
224        return unreadableString("BROADCAST-STREAM");
225    }
226
227    // ### make-broadcast-stream &rest streams => broadcast-stream
228    private static final Primitive MAKE_BROADCAST_STREAM =
229        new Primitive("make-broadcast-stream", "&rest streams")
230    {
231        @Override
232        public LispObject execute()
233        {
234            return new BroadcastStream(new Stream[0]);
235        }
236        @Override
237        public LispObject execute(LispObject[] args)
238        {
239            Stream[] streams = new Stream[args.length];
240            for (int i = 0; i < args.length; i++) {
241                if (args[i] instanceof Stream) {
242                    if (((Stream)args[i]).isOutputStream()) {
243                        streams[i] = (Stream) args[i];
244                        continue;
245                    } else
246                        return type_error(args[i],
247                                          list(Symbol.SATISFIES, Symbol.OUTPUT_STREAM_P));
248                } else
249                    return type_error(args[i], Symbol.STREAM);
250            }
251            // All is well.
252            return new BroadcastStream(streams);
253        }
254    };
255
256    // ### broadcast-stream-streams broadcast-stream => streams
257    private static final Primitive BROADCAST_STREAM_STREAMS =
258        new Primitive("broadcast-stream-streams", "broadcast-stream")
259    {
260        @Override
261        public LispObject execute(LispObject arg)
262        {
263            if (arg instanceof BroadcastStream) {
264                BroadcastStream stream = (BroadcastStream) arg;
265                Stream[] streams = stream.streams;
266                LispObject result = NIL;
267                for (int i = streams.length; i-- > 0;)
268                    result = new Cons(streams[i], result);
269                return result;
270            }
271            return type_error(arg, Symbol.BROADCAST_STREAM);
272        }
273    };
274}
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