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Java > Open Source Codes > org > jruby > parser > LocalStaticScope


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5  * License Version 1.0 (the "License"); you may not use this file
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14  * Copyright (C) 2006 Thomas E Enebo <enebo@acm.org>
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28 package org.jruby.parser;
29
30 import org.jruby.ast.AssignableNode;
31 import org.jruby.ast.LocalAsgnNode;
32 import org.jruby.ast.LocalVarNode;
33 import org.jruby.ast.Node;
34 import org.jruby.ast.VCallNode;
35 import org.jruby.lexer.yacc.ISourcePosition;
36
37 public class LocalStaticScope extends StaticScope {
38     private static final long serialVersionUID = 2204064248888411628L;
39
40     public LocalStaticScope(StaticScope enclosingScope) {
41         super(enclosingScope);
42         
43         addVariable("$~");
44         addVariable("$_");
45     }
46
47     public StaticScope getLocalScope() {
48         return this;
49     }
50
51     public int isDefined(String JavaDoc name, int depth) {
52         return (depth << 16) | exists(name);
53     }
54
55     /**
56      * @see org.jruby.parser.StaticScope#getAllNamesInScope()
57      */
58     public String JavaDoc[] getAllNamesInScope() {
59         String JavaDoc[] variables = getVariables();
60
61         // We subtract two since we know $_ and $~ are there and they are special and not
62 // what Ruby considers a local name. BTW- We always add $~ and $_ so we know variables
63 // cannot be null.
64 int localNamesSize = variables.length - 2;
65         
66         String JavaDoc[] names = new String JavaDoc[localNamesSize];
67         System.arraycopy(variables, 2, names, 0, localNamesSize);
68         
69         return names;
70     }
71     
72     public AssignableNode assign(ISourcePosition position, String JavaDoc name, Node value,
73             StaticScope topScope, int depth) {
74         int slot = exists(name);
75         
76         // We can assign if we already have variable of that name here or we are the only
77 // scope in the chain (which Local scopes always are).
78 if (slot >= 0) {
79             //System.out.println("LASGN1: " + name + ", l: " + depth + ", i: " + slot);
80
81             return new LocalAsgnNode(position, name, ((depth << 16) | slot), value);
82         } else if (topScope == this) {
83             slot = addVariable(name);
84             //System.out.println("LASGN2: " + name + ", l: " + depth + ", i: " + slot);
85
86             return new LocalAsgnNode(position, name, slot , value);
87         }
88         
89         // We know this is a block scope because a local scope cannot be within a local scope
90 // If topScope was itself it would have created a LocalAsgnNode above.
91 return ((BlockStaticScope) topScope).addAssign(position, name, value);
92     }
93
94     public Node declare(ISourcePosition position, String JavaDoc name, int depth) {
95         int slot = exists(name);
96         
97         if (slot >= 0) {
98             //System.out.println("LVAR: " + name + ", l: " + depth + ", i: " + slot);
99 return new LocalVarNode(position, ((depth << 16) | slot), name);
100         }
101         
102         return new VCallNode(position, name);
103     }
104
105 }
106
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