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1   /*
2   * The contents of this file are subject to the BT "ZEUS" Open Source 
3   * Licence (L77741), Version 1.0 (the "Licence"); you may not use this file 
4   * except in compliance with the Licence. You may obtain a copy of the Licence
5   * from $ZEUS_INSTALL/licence.html or alternatively from
6   * http://www.labs.bt.com/projects/agents/zeus/licence.htm
7   * 
8   * Except as stated in Clause 7 of the Licence, software distributed under the
9   * Licence is distributed WITHOUT WARRANTY OF ANY KIND, either express or 
10  * implied. See the Licence for the specific language governing rights and 
11  * limitations under the Licence.
12  * 
13  * The Original Code is within the package zeus.*.
14  * The Initial Developer of the Original Code is British Telecommunications
15  * public limited company, whose registered office is at 81 Newgate Street, 
16  * London, EC1A 7AJ, England. Portions created by British Telecommunications 
17  * public limited company are Copyright 1996-9. All Rights Reserved.
18  * 
19  * THIS NOTICE MUST BE INCLUDED ON ANY COPY OF THIS FILE
20  */
21  
22  
23  
24  package zeus.rete;
25  
26  import java.util.*;
27  import zeus.util.*;
28  import zeus.concepts.*;
29  
30  
31  public abstract class Node {
32     public static final int ADD = 0;
33     public static final int REMOVE = 1;
34  
35     static final int SINGLE = 0;
36     static final int ACTION = 1;
37     static final int LEFT   = 2;
38     static final int RIGHT  = 3;
39  
40     Hashtable  successors = new Hashtable();
41     ReteEngine engine = null;
42     int use_count = 0;
43  
44     Node(ReteEngine engine) {
45        this.engine = engine;
46     }
47  
48     void addSuccessor(String path, Node node, int type) {
49        Assert.notFalse(successors.put(path,new Successor(node,type)) == null);
50     }
51  
52     void propagate(String path, int tag, Vector input, Bindings b) {
53        Core.DEBUG(5,"\nPropagate: " + path + " " + this);
54        Successor s = (Successor)successors.get(path);
55        s.node.evaluate(path,tag,s.type,input,b);
56     }
57  
58     abstract void evaluate(String path, int tag, int type,
59                            Vector input, Bindings b);
60  }