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 class TypeNode extends PatternNode {
32 String fact_type = null;
33
34 TypeNode(ReteEngine engine, String fact_type) {
35 super(engine);
36 this.fact_type = fact_type;
37 }
38 void evaluate(String path, int tag, int type, Vector input, Bindings b) {
39 // System.out.println("evaluating Type " + path);
40 Assert.notFalse(path == null);
41 Assert.notFalse(type == SINGLE);
42 Assert.notFalse(input.size() == 1);
43 Fact f = (Fact)input.elementAt(0);
44
45 // if ( fact_type.equals(f.getType()) )
46 // System.out.println(f.getType()+ " == " + fact_type);
47 if ( f.isa (fact_type)) // change !
48 propagate(path,tag,input,b);
49 }
50
51
52 void propagate(String path, int tag, Vector input, Bindings b) {
53 Core.DEBUG(5,"\nPropagate: " + path + " " + this);
54 Successor s;
55 Enumeration keys = successors.keys();
56 while( keys.hasMoreElements() ) {
57 path = (String)keys.nextElement();
58 s = (Successor)successors.get(path);
59 s.node.evaluate(path,tag,s.type,input,new Bindings(b));
60 }
61 }
62
63
64 public boolean equals(Object any) {
65 if ( any instanceof TypeNode ) {
66 TypeNode node = (TypeNode)any;
67 return fact_type.equals(node.fact_type);
68 }
69 return false;
70 }
71 public String toString() {
72 return "TypeNode(" + fact_type + ")";
73 }
74 }