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1 /***** BEGIN LICENSE BLOCK *****
2  * Version: CPL 1.0/GPL 2.0/LGPL 2.1
3  *
4  * The contents of this file are subject to the Common Public
5  * License Version 1.0 (the "License"); you may not use this file
6  * except in compliance with the License. You may obtain a copy of
7  * the License at http://www.eclipse.org/legal/cpl-v10.html
8  *
9  * Software distributed under the License is distributed on an "AS
10  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
11  * implied. See the License for the specific language governing
12  * rights and limitations under the License.
13  *
14  * Copyright (C) 2002 Anders Bengtsson <ndrsbngtssn@yahoo.se>
15  * Copyright (C) 2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
16  * Copyright (C) 2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
17  * Copyright (C) 2004-2005 Thomas E Enebo <enebo@acm.org>
18  * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
19  *
20  * Alternatively, the contents of this file may be used under the terms of
21  * either of the GNU General Public License Version 2 or later (the "GPL"),
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31  ***** END LICENSE BLOCK *****/
32 package org.jruby.ast;
33
34 import java.util.List JavaDoc;
35
36 import org.jruby.ast.types.IArityNode;
37 import org.jruby.ast.visitor.NodeVisitor;
38 import org.jruby.evaluator.Instruction;
39 import org.jruby.lexer.yacc.ISourcePosition;
40 import org.jruby.runtime.Arity;
41
42 /** Represents a zero arg in a block.
43  * this is never visited and is used only in an instanceof check
44  * <pre>
45  * do ||
46  * end
47  * </pre>
48  *
49  * @author jpetersen
50  */
51 public class ZeroArgNode extends Node implements IArityNode {
52     static final long serialVersionUID = 6596791950608957025L;
53
54     public ZeroArgNode(ISourcePosition position) {
55         super(position, NodeTypes.ZEROARGNODE);
56     }
57
58     /**
59      * @see Node#accept(NodeVisitor)
60      */
61     public Instruction accept(NodeVisitor visitor) {
62         return null; // never visited, should be ok
63 }
64     
65     /**
66      * Zero arguments...
67      */
68     public Arity getArity() {
69         return Arity.noArguments();
70     }
71
72     public List JavaDoc childNodes() {
73         return EMPTY_LIST;
74     }
75 }
76
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