KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > antlr > works > visualization > fa > FAAnalysis


1 /*
2
3 [The "BSD licence"]
4 Copyright (c) 2005 Jean Bovet
5 All rights reserved.
6
7 Redistribution and use in source and binary forms, with or without
8 modification, are permitted provided that the following conditions
9 are met:
10
11 1. Redistributions of source code must retain the above copyright
12 notice, this list of conditions and the following disclaimer.
13 2. Redistributions in binary form must reproduce the above copyright
14 notice, this list of conditions and the following disclaimer in the
15 documentation and/or other materials provided with the distribution.
16 3. The name of the author may not be used to endorse or promote products
17 derived from this software without specific prior written permission.
18
19 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30 */
31
32 package org.antlr.works.visualization.fa;
33
34 import org.antlr.analysis.NFAState;
35 import org.antlr.analysis.Transition;
36
37 import java.util.*;
38
39 /** This class computes the number of incoming transition for each state.
40  *
41  *
42  */
43
44 public class FAAnalysis {
45
46     private Set processedStates = new HashSet();
47     private Map stateIncomingTransitionCount = new HashMap();
48
49     public FAAnalysis() {
50     }
51
52     public void reset() {
53         processedStates.clear();
54         stateIncomingTransitionCount.clear();
55     }
56
57     /** Compute for an ANTLR NFA
58      *
59      */
60
61     public void analyze(FAState state) {
62         reset();
63         recursiveAnalysis(state);
64     }
65
66     /** Compute for an GUI Editor NFA
67      *
68      */
69
70     public void analyze(NFAState state) {
71         reset();
72         recursiveAnalysis(state);
73     }
74
75     public void recursiveAnalysis(NFAState state) {
76         if(processedStates.contains(state))
77             return;
78         processedStates.add(state);
79
80         for(int t=0; t<state.getNumberOfTransitions(); t++) {
81             Transition transition = state.transition(t);
82             addIncomingTransitionToState((NFAState)transition.target);
83             recursiveAnalysis((NFAState)transition.target);
84         }
85     }
86
87     public void recursiveAnalysis(FAState state) {
88         if(processedStates.contains(state))
89             return;
90         processedStates.add(state);
91
92         for(int t=0; t<state.getNumberOfTransitions(); t++) {
93             FATransition transition = state.transition(t);
94             addIncomingTransitionToState(transition.target);
95             recursiveAnalysis(transition.target);
96         }
97     }
98
99     public void addIncomingTransitionToState(Object JavaDoc state) {
100         Integer JavaDoc i = (Integer JavaDoc)stateIncomingTransitionCount.get(state);
101         int count = 0;
102         if(i != null)
103             count = i.intValue();
104         stateIncomingTransitionCount.put(state, new Integer JavaDoc(count+1));
105     }
106
107     public int numberOfIncomingTransition(Object JavaDoc state) {
108         Integer JavaDoc i = (Integer JavaDoc)stateIncomingTransitionCount.get(state);
109         if(i == null)
110             return 0;
111         else
112             return i.intValue();
113     }
114     
115     public String JavaDoc toString() {
116         StringBuffer JavaDoc s = new StringBuffer JavaDoc();
117         Iterator iterator = stateIncomingTransitionCount.keySet().iterator();
118         while(iterator.hasNext()) {
119             NFAState key = (NFAState)iterator.next();
120             Integer JavaDoc count = (Integer JavaDoc)stateIncomingTransitionCount.get(key);
121             s.append(key.stateNumber+" = "+count.intValue()+"\n");
122         }
123         return s.toString();
124     }
125 }
126
Popular Tags