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Java > Open Source Codes > JFlex > EOFActions


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  * A simple table to store EOF actions for each lexical state.
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 EOFActions {
33
34   /** maps lexical states to actions */
35   private Hashtable /* Integer -> Action */ actions = new Hashtable();
36   private Action defaultAction;
37   private int numLexStates;
38
39   public void setNumLexStates(int num) {
40     numLexStates = num;
41   }
42
43   public void add(Vector stateList, Action action) {
44
45     if (stateList != null && stateList.size() > 0) {
46       Enumeration states = stateList.elements();
47       
48       while (states.hasMoreElements())
49         add( (Integer JavaDoc) states.nextElement(), action );
50     }
51     else {
52       defaultAction = action.getHigherPriority(defaultAction);
53       
54       for (int i = 0; i < numLexStates; i++) {
55         Integer JavaDoc state = new Integer JavaDoc(i);
56         if ( actions.get(state) != null ) {
57           Action oldAction = (Action) actions.get(state);
58           actions.put(state, oldAction.getHigherPriority(action));
59         }
60       }
61     }
62   }
63
64   public void add(Integer JavaDoc state, Action action) {
65     if ( actions.get(state) == null )
66       actions.put(state, action);
67     else {
68       Action oldAction = (Action) actions.get(state);
69       actions.put(state, oldAction.getHigherPriority(action));
70     }
71   }
72
73   public boolean isEOFAction(Object JavaDoc a) {
74     if (a == defaultAction) return true;
75
76     Enumeration e = actions.elements();
77     while ( e.hasMoreElements() )
78       if (a == e.nextElement()) return true;
79
80     return false;
81   }
82
83   public Action getAction(int state) {
84     return (Action) actions.get(new Integer JavaDoc(state));
85   }
86
87   public Action getDefault() {
88     return defaultAction;
89   }
90
91   public int numActions() {
92     return actions.size();
93   }
94 }
95
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