1 /*
2 * $Header$
3 * $Revision$
4 * $Date$
5 *
6 * ====================================================================
7 *
8 * Copyright 2000-2002 bob mcwhirter & James Strachan.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions are
13 * met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * * Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * * Neither the name of the Jaxen Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * ====================================================================
39 * This software consists of voluntary contributions made by many
40 * individuals on behalf of the Jaxen Project and was originally
41 * created by bob mcwhirter <bob@werken.com> and
42 * James Strachan <jstrachan@apache.org>. For more information on the
43 * Jaxen Project, please see <http://www.jaxen.org/>.
44 *
45 * $Id$
46 */
47
48
49 package org.jaxen.function;
50
51 import java.util.List;
52
53 import org.jaxen.Context;
54 import org.jaxen.Function;
55 import org.jaxen.FunctionCallException;
56 import org.jaxen.Navigator;
57
58 /**
59 * <p><b>4.4</b> <code><i>number</i> ceiling(<i>number</i>)</code></p>
60 * <blockquote cite="http://www.w3.org/TR/xpath">
61 *
62 * <p>The ceiling function returns the smallest
63 * (closest to negative infinity) number that is not less
64 * than the argument and that is an integer....If the argument
65 * is NaN, then NaN is returned. If the argument is positive infinity,
66 * then positive infinity is returned. If the argument is negative infinity,
67 * then negative infinity is returned. If the argument is positive zero,
68 * then positive zero is returned.
69 * If the argument is negative zero, then negative zero is returned.
70 * If the argument is less than zero, but greater than -1,
71 * then negative zero is returned.
72 * </p></blockquote>
73 *
74 * @author bob mcwhirter (bob @ werken.com)
75 *
76 * @see <a href="https://www.w3.org/TR/xpath#function-ceiling">Section 4.4 of the XPath Specification</a>
77 * @see <a href="https://www.w3.org/1999/11/REC-xpath-19991116-errata/">XPath Specification Errata</a>
78 *
79 */
80 public class CeilingFunction implements Function
81 {
82
83 /**
84 * Create a new <code>CeilingFunction</code> object.
85 */
86 public CeilingFunction() {}
87
88 /** Returns the smallest integer greater than or equal to a number.
89 *
90 * @param context the context at the point in the
91 * expression when the function is called
92 * @param args a list with exactly one item which will be converted to a
93 * <code>Double</code> as if by the XPath <code>number()</code> function
94 *
95 * @return a <code>Double</code> containing the smallest integer greater than or equal
96 * <code>args.get(0)</code>
97 *
98 * @throws FunctionCallException if <code>args</code> has more or less than one item
99 */
100 public Object call(Context context,
101 List args) throws FunctionCallException
102 {
103 if (args.size() == 1)
104 {
105 return evaluate( args.get(0),
106 context.getNavigator() );
107 }
108
109 throw new FunctionCallException("ceiling() requires one argument.");
110 }
111
112 /** Returns the smallest integer greater than or equal to the argument.
113 * If necessary, the argument is first converted to a <code>Double</code>
114 * as if by the XPath <code>number()</code> function.
115 *
116 * @param obj the object whose ceiling is returned
117 * @param nav ignored
118 *
119 * @return a <code>Double</code> containing the smallest integer
120 * greater than or equal to <code>obj</code>
121 */
122 public static Double evaluate(Object obj,
123 Navigator nav)
124 {
125 Double value = NumberFunction.evaluate( obj,
126 nav );
127
128 return new Double( Math.ceil( value.doubleValue() ) );
129 }
130 }