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Java > Open Source Codes > JFlex > LexicalStates


1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
2  * JFlex 1.4.1 *
3  * Copyright (C) 1998-2004 Gerwin Klein <lsf@jflex.de> *
4  * All rights reserved. *
5  * *
6  * This program is free software; you can redistribute it and/or modify *
7  * it under the terms of the GNU General Public License. See the file *
8  * COPYRIGHT for more information. *
9  * *
10  * This program is distributed in the hope that it will be useful, *
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13  * GNU General Public License for more details. *
14  * *
15  * You should have received a copy of the GNU General Public License along *
16  * with this program; if not, write to the Free Software Foundation, Inc., *
17  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *
18  * *
19  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
20
21 package JFlex;
22
23 import java.util.*;
24
25
26 /**
27  * Simple symbol table, mapping lexical state names to integers.
28  *
29  * @author Gerwin Klein
30  * @version JFlex 1.4.1, $Revision: 2.2 $, $Date: 2004/11/06 23:03:32 $
31  */
32 public class LexicalStates {
33   
34   /** maps state name to state number */
35   Hashtable states;
36
37   /** codes of inclusive states (subset of states) */
38   Vector inclusive;
39
40   /** number of declared states */
41   int numStates;
42
43
44   /**
45    * constructs a new lexical state symbol table
46    */
47   public LexicalStates() {
48     states = new Hashtable();
49     inclusive = new Vector();
50   }
51
52   
53   /**
54    * insert a new state declaration
55    */
56   public void insert(String JavaDoc name, boolean is_inclusive) {
57     if ( states.containsKey(name) ) return;
58
59     Integer JavaDoc code = new Integer JavaDoc(numStates++);
60     states.put(name, code);
61
62     if (is_inclusive)
63       inclusive.addElement(code);
64   }
65
66
67   /**
68    * returns the number (code) of a declared state,
69    * <code>null</code> if no such state has been declared.
70    */
71   public Integer JavaDoc getNumber(String JavaDoc name) {
72     return (Integer JavaDoc) states.get(name);
73   }
74
75   
76   /**
77    * returns the number of declared states
78    */
79   public int number() {
80     return numStates;
81   }
82
83   
84   /**
85    * returns the names of all states
86    */
87   public Enumeration names() {
88     return states.keys();
89   }
90
91   /**
92    * returns the code of all inclusive states
93    */
94   public Enumeration getInclusiveStates() {
95     return inclusive.elements();
96   }
97 }
98
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