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Java > Open Source Codes > com > hp > hpl > jena > reasoner > rulesys > builtins > Unbound


1 /******************************************************************
2  * File: unbound.java
3  * Created by: Dave Reynolds
4  * Created on: 11-May-2003
5  *
6  * (c) Copyright 2003, 2004, 2005 Hewlett-Packard Development Company, LP
7  * [See end of file]
8  * $Id: Unbound.java,v 1.7 2005/02/21 12:17:34 andy_seaborne Exp $
9  *****************************************************************/
10 package com.hp.hpl.jena.reasoner.rulesys.builtins;
11
12
13 import com.hp.hpl.jena.reasoner.rulesys.*;
14 import com.hp.hpl.jena.graph.*;
15
16 /**
17  * Predicate used to check if a variable has not been bound.
18  *
19  * @author <a HREF="mailto:der@hplb.hpl.hp.com">Dave Reynolds</a>
20  * @version $Revision: 1.7 $ on $Date: 2005/02/21 12:17:34 $
21  */
22 public class Unbound extends BaseBuiltin {
23
24     /**
25      * Return a name for this builtin, normally this will be the name of the
26      * functor that will be used to invoke it.
27      */
28     public String JavaDoc getName() {
29         return "unbound";
30     }
31     
32     /**
33      * This method is invoked when the builtin is called in a rule body.
34      * @param args the array of argument values for the builtin, this is an array
35      * of Nodes, some of which may be Node_RuleVariables.
36      * @param length the length of the argument list, may be less than the length of the args array
37      * for some rule engines
38      * @param context an execution context giving access to other relevant data
39      * @return return true if the buildin predicate is deemed to have succeeded in
40      * the current environment
41      */
42     public boolean bodyCall(Node[] args, int length, RuleContext context) {
43         BindingEnvironment env = context.getEnv();
44         for (int i = 0; i < length; i++) {
45             if ( !(getArg(i, args, context) instanceof Node_RuleVariable) ) return false;
46         }
47         return true;
48     }
49
50 }
51
52
53
54
55 /*
56     (c) Copyright 2003, 2004, 2005 Hewlett-Packard Development Company, LP
57     All rights reserved.
58
59     Redistribution and use in source and binary forms, with or without
60     modification, are permitted provided that the following conditions
61     are met:
62
63     1. Redistributions of source code must retain the above copyright
64        notice, this list of conditions and the following disclaimer.
65
66     2. Redistributions in binary form must reproduce the above copyright
67        notice, this list of conditions and the following disclaimer in the
68        documentation and/or other materials provided with the distribution.
69
70     3. The name of the author may not be used to endorse or promote products
71        derived from this software without specific prior written permission.
72
73     THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
74     IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
75     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
76     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
77     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
78     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
79     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
80     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
81     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
82     THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
83 */
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