Coverage Report - org.jaxen.function.NumberFunction

Classes in this File Line Coverage Branch Coverage Complexity
NumberFunction
100% 
100% 
4.8

 1  
 /*
 2  
  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/NumberFunction.java,v 1.17 2005/06/28 13:44:45 elharo Exp $
 3  
  * $Revision: 1.17 $
 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: NumberFunction.java,v 1.17 2005/06/28 13:44:45 elharo Exp $
 60  
  */
 61  
 
 62  
 package org.jaxen.function;
 63  
 
 64  
 import java.util.Iterator;
 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>
 74  
  * <b>4.4</b> <code><i>number</i> number(<i>object</i>)</code>
 75  
  * 
 76  
  * 
 77  
  * <blockquote src="http://www.w3.org/TR/xpath#function-number">
 78  
  * <p>
 79  
  * The <b>number</b> function converts
 80  
  * its argument to a number as follows:
 81  
  * </p>
 82  
  * 
 83  
  * <ul>
 84  
  * 
 85  
  * <li>
 86  
  * <p>
 87  
  * a string that consists of optional whitespace followed by an optional
 88  
  * minus sign followed by a <a href="#NT-Number">Number</a> followed by
 89  
  * whitespace is converted to the IEEE 754 number that is nearest
 90  
  * (according to the IEEE 754 round-to-nearest rule) to the mathematical
 91  
  * value represented by the string; any other string is converted to NaN
 92  
  * </p>
 93  
  * </li>
 94  
  * 
 95  
  * <li>
 96  
  * <p>
 97  
  * boolean true is converted to 1; boolean false is converted to 0
 98  
  * </p>
 99  
  * </li>
 100  
  * 
 101  
  * <li>
 102  
  * 
 103  
  * <p>
 104  
  * a node-set is first converted to a string as if by a call to the <b><a
 105  
  * href="http://www.w3.org/TR/xpath#function-string" target="_top">string</a></b> function and then converted
 106  
  * in the same way as a string argument
 107  
  * </p>
 108  
  * 
 109  
  * </li>
 110  
  * 
 111  
  * <li>
 112  
  * <p>
 113  
  * an object of a type other than the four basic types is converted to a
 114  
  * number in a way that is dependent on that type
 115  
  * </p>
 116  
  * </li>
 117  
  * 
 118  
  * </ul>
 119  
  * 
 120  
  * <p>
 121  
  * If the argument is omitted, it defaults to a node-set with the
 122  
  * context node as its only member.
 123  
  * </p>
 124  
  * 
 125  
  * <blockquote> <b>NOTE: </b>The <b>number</b>
 126  
  * function should not be used for conversion of numeric data occurring
 127  
  * in an element in an XML document unless the element is of a type that
 128  
  * represents numeric data in a language-neutral format (which would
 129  
  * typically be transformed into a language-specific format for
 130  
  * presentation to a user). In addition, the <b>number</b> function cannot be used
 131  
  * unless the language-neutral format used by the element is consistent
 132  
  * with the XPath syntax for a <a href="http://www.w3.org/TR/xpath#NT-Number">Number</a>.</blockquote>
 133  
  * 
 134  
  * </blockquote>
 135  
  * 
 136  
  * @author bob mcwhirter (bob @ werken.com)
 137  
  * 
 138  
  * @see <a href="http://www.w3.org/TR/xpath#function-number"
 139  
  *      target="_top">Section 4.4 of the XPath Specification</a>
 140  
  */
 141  
 public class NumberFunction implements Function
 142  
 {
 143  
 
 144  288
     private final static Double NaN = new Double( Double.NaN );
 145  
     
 146  
     
 147  
     /**
 148  
      * Create a new <code>NumberFunction</code> object.
 149  
      */
 150  294
     public NumberFunction() {}
 151  
 
 152  
     /** 
 153  
      * Returns the number value of <code>args.get(0)</code>,
 154  
      * or the number value of the context node if <code>args</code>
 155  
      * is empty.
 156  
      *
 157  
      * @param context the context at the point in the
 158  
      *         expression when the function is called
 159  
      * @param args a list containing the single item to be converted to a 
 160  
      *     <code>Double</code>
 161  
      * 
 162  
      * @return a <code>Double</code>
 163  
      * 
 164  
      * @throws FunctionCallException if <code>args</code> has more than one item
 165  
      */
 166  
     public Object call(Context context, List args) throws FunctionCallException
 167  
     {
 168  24
         if (args.size() == 1)
 169  
         {
 170  12
             return evaluate( args.get(0), context.getNavigator() );
 171  
         }
 172  12
         else if (args.size() == 0)
 173  
         {
 174  6
             return evaluate( context.getNodeSet(), context.getNavigator() );
 175  
         }
 176  
     
 177  6
         throw new FunctionCallException( "number() takes at most one argument." );
 178  
     }
 179  
 
 180  
     /** 
 181  
      * Returns the number value of <code>obj</code>.
 182  
      *
 183  
      * @param obj the object to be converted to a number
 184  
      * @param nav the <code>Navigator</code> used to calculate the string-value
 185  
      *     of node-sets
 186  
      * 
 187  
      * @return a <code>Double</code>
 188  
      */
 189  
     public static Double evaluate(Object obj, Navigator nav)
 190  
     {
 191  13230
         if( obj instanceof Double )
 192  
         {
 193  8112
             return (Double) obj;
 194  
         }
 195  5118
         else if ( obj instanceof String )
 196  
         {
 197  2448
             String str = (String) obj;
 198  
             try
 199  
             {
 200  2448
                 Double doubleValue = new Double( str );        
 201  2442
                 return doubleValue;
 202  
             }
 203  6
             catch (NumberFormatException e)
 204  
             {
 205  6
                 return NaN;
 206  
             }
 207  
         }
 208  2670
         else if ( obj instanceof List || obj instanceof Iterator )
 209  
         {
 210  18
           return evaluate( StringFunction.evaluate( obj, nav ), nav );
 211  
         }
 212  2652
         else if ( nav.isElement( obj ) || nav.isAttribute( obj ) )
 213  
         {
 214  2424
             return evaluate( StringFunction.evaluate( obj, nav ), nav );
 215  
         }
 216  228
         else if ( obj instanceof Boolean )
 217  
           {
 218  222
           if ( obj == Boolean.TRUE )
 219  
           {
 220  174
               return new Double( 1 );
 221  
           }
 222  
           else
 223  
           {
 224  48
               return new Double( 0 );
 225  
           }
 226  
         }    
 227  6
         return NaN;
 228  
     }
 229  
   
 230  
   /**
 231  
    * Determines whether the argument is not a number (NaN) as defined
 232  
    * by IEEE 754.
 233  
    * 
 234  
    * @param val the double to test
 235  
    * @return true if the value is NaN, false otherwise
 236  
    */
 237  
     public static boolean isNaN( double val )
 238  
     {
 239  6
         return Double.isNaN(val);
 240  
     }
 241  
   
 242  
   /**
 243  
    * Determines whether the argument is not a number (NaN) as defined
 244  
    * by IEEE 754.
 245  
    * 
 246  
    * @param val the <code>Double</code> to test
 247  
    * @return true if the value is NaN, false otherwise
 248  
    */
 249  
     public static boolean isNaN( Double val )
 250  
     {
 251  4848
         return val.equals( NaN );
 252  
     }  
 253  
   
 254  
 }