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1
4 package gnu.expr;
5 import java.util.*;
6 import gnu.kawa.util.GeneralHashTable;
7 import gnu.kawa.util.HashNode;
8
9
10
11 public class NameLookup extends GeneralHashTable
12 {
13 Language language;
14
15 public NameLookup (Language language)
16 {
17 this.language = language;
18 }
19
20 public void push (Declaration decl)
21 {
22 Object  symbol = decl.getSymbol();
23 if (symbol == null)
24 return;
25 if (++num_bindings >= table.length)
26 rehash();
27 int hash = hash(symbol);
28 HashNode node = makeEntry(symbol, hash, decl);
29 int index = hash & mask;
30 node.next = table[index];
31 table[index] = node;
32 }
33
34 public boolean pop (Declaration decl)
35 {
36 Object symbol = decl.getSymbol();
37 if (symbol == null)
38 return false;
39 int hash = hash(symbol);
40 HashNode prev = null;
41 int index = hash & this.mask;
42 HashNode node = table[index];
43 while (node != null)
44 {
45 HashNode next = node.next;
46 if (node.getValue() == decl)
47 {
48 if (prev == null)
49 table[index] = next;
50 else
51 prev.next = next;
52 num_bindings--;
53 return true;
54 }
55 prev = node;
56 node = next;
57 }
58 return false;
59 }
60
61 public void push (ScopeExp exp)
62 {
63 for (Declaration decl = exp.firstDecl();
64 decl != null; decl = decl.nextDecl())
65 push(decl);
66 }
67
68 public void pop (ScopeExp exp)
69 {
70 for (Declaration decl = exp.firstDecl();
71 decl != null; decl = decl.nextDecl())
72 pop(decl);
73 }
74
75 public Declaration lookup (Object symbol, int namespace)
76 {
77 int hash = hash(symbol);
78 int index = hash & this.mask;
79 for (HashNode node = table[index];
80 node != null; node = node.next)
81 {
82 Declaration decl = (Declaration) node.getValue();
83 if (symbol.equals(decl.getSymbol())
84 && language.hasNamespace(decl, namespace))
85 return decl;
86 }
87 return null;
88 }
89
90 public Declaration lookup (Object symbol, boolean function)
91 {
92 return lookup(symbol, (function ? Language.FUNCTION_NAMESPACE
93 : Language.VALUE_NAMESPACE));
94 }
95 }
96 |
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