code: /***************************************************************************
   *   Copyright (C) 2009-2016 by Fabrizio Montesi <famontesi@gmail.com>     *
   *                                                                         *
   *   This program is free software; you can redistribute it and/or modify  *
   *   it under the terms of the GNU Library General Public License as       *
   *   published by the Free Software Foundation; either version 2 of the    *
   *   License, or (at your option) any later version.                       *
   *                                                                         *
   *   This program is distributed in the hope that it will be useful,       *
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
   *   GNU General Public License for more details.                          *
   *                                                                         *
   *   You should have received a copy of the GNU Library General Public     *
   *   License along with this program; if not, write to the                 *
   *   Free Software Foundation, Inc.,                                       *
   *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
   *                                                                         *
   *   For details about the authors of this software, see the AUTHORS file. *
   ***************************************************************************/
  
  package joliex.util;
  
  import java.math.BigDecimal;
  import jolie.runtime.JavaService;
  import jolie.runtime.Value;
  
  /**
   * JavaService offering various math related functionalities.
   * @author Fabrizio Montesi
   */
  public class MathService extends JavaService
  {
  	public Double pi()
  	{
  		return Math.PI;
  	}
  	
  	public Double random()
  	{
  		return Math.random();
  	}
  
  	public Integer abs( Integer i )
  	{
  		return Math.abs( i );
  	}
  
  	public Double pow( Value request )
  	{
  		return Math.pow( request.getFirstChild( "base" ).doubleValue(), request.getFirstChild( "exponent" ).doubleValue() );
  	}
  
  	public Integer summation( Value request )
  	{
  		int from = request.getFirstChild( "from" ).intValue();
  		int to = request.getFirstChild( "to" ).intValue();
  		int result = 0;
  		while( from <= to ) {
  			result += from;
  			from++;
  		}
  		return result;
  	}
  
  	/**
  	 * @author Claudio Guidi
  	 * @author Fabrizio Montesi
  	 * @param v
  	 * @return 
  	 */
  	public Double round( Value v )
  	{
  		int decimals = 0;
  		if ( v.hasChildren( "decimals" ) ) {
  			decimals = v.getFirstChild( "decimals" ).intValue();
  		}
  		double orig = v.doubleValue();
  		double power = Math.pow( 10, decimals );
  		double ret = orig * power;
  		if ( ret == Double.POSITIVE_INFINITY ) {
  			BigDecimal b = new BigDecimal( orig );
  			b = b.setScale( decimals, BigDecimal.ROUND_HALF_UP );
  			ret = b.doubleValue();
  		} else {
  			ret = Math.round( ret ) / power;
  		}
  		
  		return ret;
  	}
  }
  