RewriteRuleNodeStream.java revision 324c4644fee44b9898524c09511bd33c3f12e2df 
1/*
2 [The "BSD license"]
3 Copyright (c) 2005-2009 Terence Parr
4 All rights reserved.
5
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions
8 are met:
9 1. Redistributions of source code must retain the above copyright
10     notice, this list of conditions and the following disclaimer.
11 2. Redistributions in binary form must reproduce the above copyright
12     notice, this list of conditions and the following disclaimer in the
13     documentation and/or other materials provided with the distribution.
14 3. The name of the author may not be used to endorse or promote products
15     derived from this software without specific prior written permission.
16
17 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28package org.antlr.runtime.tree;
29
30import java.util.List;
31
32/** Queues up nodes matched on left side of -> in a tree parser. This is
33 *  the analog of RewriteRuleTokenStream for normal parsers.
34 */
35public class RewriteRuleNodeStream extends RewriteRuleElementStream {
36
37	public RewriteRuleNodeStream(TreeAdaptor adaptor, String elementDescription) {
38		super(adaptor, elementDescription);
39	}
40
41	/** Create a stream with one element */
42	public RewriteRuleNodeStream(TreeAdaptor adaptor,
43								 String elementDescription,
44								 Object oneElement)
45	{
46		super(adaptor, elementDescription, oneElement);
47	}
48
49	/** Create a stream, but feed off an existing list */
50	public RewriteRuleNodeStream(TreeAdaptor adaptor,
51								 String elementDescription,
52								 List elements)
53	{
54		super(adaptor, elementDescription, elements);
55	}
56
57	public Object nextNode() {
58		return _next();
59	}
60
61	protected Object toTree(Object el) {
62		return adaptor.dupNode(el);
63	}
64
65	protected Object dup(Object el) {
66		// we dup every node, so don't have to worry about calling dup; short-
67		// circuited next() so it doesn't call.
68		throw new UnsupportedOperationException("dup can't be called for a node stream.");
69	}
70}
71