KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > JFlex > StatePairList


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 /**
24  * A list of pairs of states. Used in DFA minimization.
25  *
26  * @author Gerwin Klein
27  * @version JFlex 1.4.1, $Revision: 2.4 $, $Date: 2004/11/06 23:03:30 $
28  */
29 final public class StatePairList {
30
31   // implemented as two arrays of integers.
32 // java.util classes proved too inefficient.
33
34   int p [];
35   int q [];
36   
37   int num;
38
39   public StatePairList() {
40     p = new int [8];
41     q = new int [8];
42     num = 0;
43   }
44
45   public void addPair(int i, int j) {
46     for (int x = 0; x < num; x++)
47       if (p[x] == i && q[x] == j) return;
48
49     if (num >= p.length) increaseSize(num);
50
51     p[num] = i;
52     q[num] = j;
53     
54     num++;
55   }
56
57   public void markAll(StatePairList [] [] list, boolean [] [] equiv) {
58     for (int x = 0; x < num; x++) {
59       int i = p[x];
60       int j = q[x];
61       
62       if (equiv[i][j]) {
63         equiv[i][j] = false;
64         if (list[i][j] != null)
65           list[i][j].markAll(list, equiv);
66       }
67     }
68   }
69
70   private void increaseSize(int length) {
71     length = Math.max(length+1, 4*p.length);
72     Out.debug("increasing length to "+length); //$NON-NLS-1$
73
74     int pn [] = new int[length];
75     int qn [] = new int[length];
76
77     System.arraycopy(p, 0, pn, 0, p.length);
78     System.arraycopy(q, 0, qn, 0, q.length);
79
80     p = pn;
81     q = qn;
82   }
83 }
84
Popular Tags