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2  * Version: CPL 1.0/GPL 2.0/LGPL 2.1
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11  * implied. See the License for the specific language governing
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13  *
14  * Copyright (C) 2001-2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
15  * Copyright (C) 2001-2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
16  * Copyright (C) 2002 Anders Bengtsson <ndrsbngtssn@yahoo.se>
17  * Copyright (C) 2004-2006 Thomas E Enebo <enebo@acm.org>
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31 package org.jruby.ast;
32
33 import java.io.IOException JavaDoc;
34 import java.util.List JavaDoc;
35
36 import org.jruby.ast.types.INameNode;
37 import org.jruby.ast.visitor.NodeVisitor;
38 import org.jruby.evaluator.Instruction;
39 import org.jruby.lexer.yacc.ISourcePosition;
40
41 /**
42  * Access a dynamic variable (e.g. block scope local variable).
43  */
44 public class DVarNode extends Node implements INameNode {
45     static final long serialVersionUID = -8479281167248673970L;
46
47     // The name of the variable
48 private String JavaDoc name;
49     
50     // A scoped location of this variable (high 16 bits is how many scopes down and low 16 bits
51 // is what index in the right scope to set the value.
52 private int location;
53
54     public DVarNode(ISourcePosition position, int location, String JavaDoc name) {
55         super(position, NodeTypes.DVARNODE);
56         this.location = location;
57         this.name = name.intern();
58     }
59     
60     private void readObject(java.io.ObjectInputStream JavaDoc in) throws IOException JavaDoc, ClassNotFoundException JavaDoc {
61         in.defaultReadObject();
62         
63         // deserialized strings are not interned; intern it now
64 name = name.intern();
65     }
66
67     /**
68      * Accept for the visitor pattern.
69      * @param iVisitor the visitor
70      **/
71     public Instruction accept(NodeVisitor iVisitor) {
72         return iVisitor.visitDVarNode(this);
73     }
74     
75     /**
76      * How many scopes should we burrow down to until we need to set the block variable value.
77      *
78      * @return 0 for current scope, 1 for one down, ...
79      */
80     public int getDepth() {
81         return location >> 16;
82     }
83     
84     /**
85      * Gets the index within the scope construct that actually holds the eval'd value
86      * of this local variable
87      *
88      * @return Returns an int offset into storage structure
89      */
90     public int getIndex() {
91         return location & 0xffff;
92     }
93     
94
95     /**
96      * Gets the name.
97      * @return Returns a String
98      */
99     public String JavaDoc getName() {
100         return name;
101     }
102     
103     /**
104      * Sets the name of this variable (for refactoring support)
105      * @param name to set the variable to
106      */
107     public void setName(String JavaDoc name) {
108         this.name = name;
109     }
110     
111     public List JavaDoc childNodes() {
112         return EMPTY_LIST;
113     }
114
115 }
116
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