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    1   /*
    2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/CeilingFunction.java,v 1.10 2005/06/28 13:44:45 elharo Exp $
    3    * $Revision: 1.10 $
    4    * $Date: 2005/06/28 13:44:45 $
    5    *
    6    * ====================================================================
    7    *
    8    * Copyright (C) 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
    13   * are met:
    14   *
    15   * 1. Redistributions of source code must retain the above copyright
    16   *    notice, this list of conditions, and the following disclaimer.
    17   *
    18   * 2. Redistributions in binary form must reproduce the above copyright
    19   *    notice, this list of conditions, and the disclaimer that follows
    20   *    these conditions in the documentation and/or other materials
    21   *    provided with the distribution.
    22   *
    23   * 3. The name "Jaxen" must not be used to endorse or promote products
    24   *    derived from this software without prior written permission.  For
    25   *    written permission, please contact license@jaxen.org.
    26   *
    27   * 4. Products derived from this software may not be called "Jaxen", nor
    28   *    may "Jaxen" appear in their name, without prior written permission
    29   *    from the Jaxen Project Management (pm@jaxen.org).
    30   *
    31   * In addition, we request (but do not require) that you include in the
    32   * end-user documentation provided with the redistribution and/or in the
    33   * software itself an acknowledgement equivalent to the following:
    34   *     "This product includes software developed by the
    35   *      Jaxen Project <http://www.jaxen.org/>."
    36   * Alternatively, the acknowledgment may be graphical using the logos
    37   * available at http://www.jaxen.org/
    38   *
    39   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
    40   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    41   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    42   * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
    43   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    44   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    45   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
    46   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    47   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    48   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    49   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    50   * SUCH DAMAGE.
    51   *
    52   * ====================================================================
    53   * This software consists of voluntary contributions made by many
    54   * individuals on behalf of the Jaxen Project and was originally
    55   * created by bob mcwhirter <bob@werken.com> and
    56   * James Strachan <jstrachan@apache.org>.  For more information on the
    57   * Jaxen Project, please see <http://www.jaxen.org/>.
    58   *
    59   * $Id: CeilingFunction.java,v 1.10 2005/06/28 13:44:45 elharo Exp $
    60   */
    61
    62
    63  package org.jaxen.function;
    64
    65  import java.util.List;
    66
    67  import org.jaxen.Context;
    68  import org.jaxen.Function;
    69  import org.jaxen.FunctionCallException;
    70  import org.jaxen.Navigator;
    71
    72  /***
    73   *  <p><b>4.4</b> <code><i>number</i> ceiling(<i>number</i>)</code>
    74   * <blockquote src="http://www.w3.org/TR/xpath">
    75   * <p>
    76   *
    77   * <p><q>The ceiling function returns the smallest
    78   *   (closest to negative infinity) number that is not less
    79   *   than the argument and that is an integer....If the argument
    80   *   is NaN, then NaN is returned. If the argument is positive infinity,
    81   *   then positive infinity is returned. If the argument is negative infinity,
    82   *   then negative infinity is returned. If the argument is positive zero,
    83   *   then positive zero is returned.
    84   *   If the argument is negative zero, then negative zero is returned.
    85   *   If the argument is less than zero, but greater than -1,
    86   *   then negative zero is returned.</q>
    87   * </p>
    88   *
    89   *  @author bob mcwhirter (bob @ werken.com)
    90   *
    91   *  @see <a href="http://www.w3.org/TR/xpath#function-ceiling">Section 4.4 of the XPath Specification</a>
    92   *  @see <a href="http://www.w3.org/1999/11/REC-xpath-19991116-errata/">XPath Specification Errata</a>
    93   *
    94   */
    95  public class CeilingFunction implements Function
    96  {
    97
    98      /***
    99       * Create a new <code>CeilingFunction</code> object.
    100      */
    101     public CeilingFunction() {}
    102
    103     /*** Returns the smallest integer greater than or equal to a number.
    104      *
    105      * @param context the context at the point in the
    106      *         expression when the function is called
    107      * @param args a list with exactly one item which will be converted to a
    108      *     <code>Double</code> as if by the XPath <code>number()</code> function
    109      *
    110      * @return a <code>Double</code> containing the smallest integer greater than or equal
    111      *     <code>args.get(0)</code>
    112      *
    113      * @throws FunctionCallException if <code>args</code> has more or less than one item
    114      */
    115     public Object call(Context context,
    116                        List args) throws FunctionCallException
    117     {
    118         if (args.size() == 1)
    119         {
    120             return evaluate( args.get(0),
    121                              context.getNavigator() );
    122         }
    123
    124         throw new FunctionCallException("ceiling() requires one argument.");
    125     }
    126
    127     /*** Returns the smallest integer greater than or equal to the argument.
    128      * If necessary, the argument is first converted to a <code>Double</code>
    129      * as if by the XPath <code>number()</code> function.
    130      *
    131      * @param obj the object whose ceiling is returned
    132      * @param nav ignored
    133      *
    134      * @return a <code>Double</code> containing the smallest integer
    135      *     greater than or equal to <code>obj</code>
    136      */
    137     public static Double evaluate(Object obj,
    138                                   Navigator nav)
    139     {
    140         Double value = NumberFunction.evaluate( obj,
    141                                                 nav );
    142
    143         return new Double( Math.ceil( value.doubleValue() ) );
    144     }
    145 }