01: /******************************************************************
02: * File: IsLiteral.java
03: * Created by: Dave Reynolds
04: * Created on: 15-May-2003
05: *
06: * (c) Copyright 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
07: * [See end of file]
08: * $Id: IsLiteral.java,v 1.10 2008/01/02 12:06:20 andy_seaborne Exp $
09: *****************************************************************/package com.hp.hpl.jena.reasoner.rulesys.builtins;
10:
11: import com.hp.hpl.jena.reasoner.rulesys.*;
12: import com.hp.hpl.jena.graph.*;
13:
14: /**
15: * Tests the single argument to make sure it is a literal.
16: *
17: * @author <a href="mailto:der@hplb.hpl.hp.com">Dave Reynolds</a>
18: * @version $Revision: 1.10 $ on $Date: 2008/01/02 12:06:20 $
19: */
20: public class IsLiteral extends BaseBuiltin {
21:
22: /**
23: * Return a name for this builtin, normally this will be the name of the
24: * functor that will be used to invoke it.
25: */
26: public String getName() {
27: return "isLiteral";
28: }
29:
30: /**
31: * Return the expected number of arguments for this functor or 0 if the number is flexible.
32: */
33: public int getArgLength() {
34: return 1;
35: }
36:
37: /**
38: * This method is invoked when the builtin is called in a rule body.
39: * @param args the array of argument values for the builtin, this is an array
40: * of Nodes, some of which may be Node_RuleVariables.
41: * @param length the length of the argument list, may be less than the length of the args array
42: * for some rule engines
43: * @param context an execution context giving access to other relevant data
44: * @return return true if the buildin predicate is deemed to have succeeded in
45: * the current environment
46: */
47: public boolean bodyCall(Node[] args, int length, RuleContext context) {
48: checkArgs(length, context);
49: return getArg(0, args, context).isLiteral();
50: }
51:
52: }
53:
54: /*
55: (c) Copyright 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
56: All rights reserved.
57:
58: Redistribution and use in source and binary forms, with or without
59: modification, are permitted provided that the following conditions
60: are met:
61:
62: 1. Redistributions of source code must retain the above copyright
63: notice, this list of conditions and the following disclaimer.
64:
65: 2. Redistributions in binary form must reproduce the above copyright
66: notice, this list of conditions and the following disclaimer in the
67: documentation and/or other materials provided with the distribution.
68:
69: 3. The name of the author may not be used to endorse or promote products
70: derived from this software without specific prior written permission.
71:
72: THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
73: IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
74: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
75: IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
76: INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
77: NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
78: DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
79: THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
80: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
81: THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
82: */
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