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 import zeus.concepts.fn.*;
30
31
32 class IdNode extends PatternNode {
33 VarFn id;
34
35 IdNode(ReteEngine engine, VarFn id) {
36 super(engine);
37 this.id = id;
38 }
39 void evaluate(String path, int tag, int type, Vector input, Bindings b) {
40 // System.out.println("evaluating idnode " + toString());
41 Assert.notFalse(type == SINGLE);
42 Assert.notFalse(input.size() == 1);
43 Fact f = (Fact)input.elementAt(0);
44 if ( id.unifiesWith(f.functor(),b) != null )
45 propagate(path,tag,input,b);
46 }
47 public boolean equals(Object any) {
48 if ( any instanceof IdNode ) {
49 IdNode node = (IdNode)any;
50 return id.equals(node.id);
51 }
52 return false;
53 }
54 public String toString() {
55 return "IdNode(" + id + ")";
56 }
57 }