org.jaxen.function.RoundFunction Maven / Gradle / Ivy
/*
* $Header$
* $Revision$
* $Date$
*
* ====================================================================
*
* Copyright 2000-2002 bob mcwhirter & James Strachan.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of the Jaxen Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ====================================================================
* This software consists of voluntary contributions made by many
* individuals on behalf of the Jaxen Project and was originally
* created by bob mcwhirter and
* James Strachan . For more information on the
* Jaxen Project, please see 4.4 number round(number)
*
*
*
* The round function returns the number that is closest to the argument and that is an integer.
* If there are two such numbers, then the one that is closest to positive infinity is returned.
* If the argument is NaN, then NaN is returned. If the argument is positive infinity, then positive infinity is returned.
* If the argument is negative infinity, then negative infinity is returned.
* If the argument is positive zero, then positive zero is returned.
* If the argument is negative zero, then negative zero is returned.
* If the argument is less than zero, but greater than or equal to -0.5, then negative zero is returned.
*
*
* @author bob mcwhirter (bob @ werken.com)
*
* @see Section 4.4 of the XPath Specification
*/
@SuppressWarnings({"rawtypes"})
public class RoundFunction implements Function
{
/**
* Create a new RoundFunction object.
*/
public RoundFunction() {}
/** Returns the nearest integer to the number.
*
* @param context the context at the point in the
* expression when the function is called
* @param args a list with exactly one item which will be converted to a
* Double as if by the XPath number() function
*
* @return a Double containing the integer nearest to
* args.get(0)
*
* @ if args has more or less than one item
*/
public Object call(Context context,
List args)
{
if (args.size() == 1)
{
return evaluate( args.get(0),
context.getNavigator() );
}
throw new RuntimeException( "round() requires one argument." );
}
/**
* Returns the integer nearest to the argument.
* If necessary, the argument is first converted to a Double
* as if by the XPath number() function.
*
* @param obj the object to be rounded
* @param nav ignored
*
* @return the integer nearest to obj
*/
public static Double evaluate(Object obj,
Navigator nav)
{
Double d = NumberFunction.evaluate( obj,
nav );
if (d.isNaN() || d.isInfinite())
{
return d;
}
double value = d.doubleValue();
return Double.valueOf( Math.round( value ) );
}
}