DistanceX.java

package pingus;

import ca.uqac.lif.cep.Context;
import ca.uqac.lif.cep.functions.FunctionTree;
import ca.uqac.lif.cep.util.Numbers;
import ca.uqac.lif.cep.xml.XPathFunctionGetNumber;

/**
 * Function |x<sub>1</sub>-x<sub>2</sub>|
 */
public class DistanceX extends FunctionTree
{
  public static final transient DistanceX instance = new DistanceX();
  
  ///
    protected DistanceX()
    {
        super(Numbers.absoluteValue);
        FunctionTree minus = new FunctionTree(Numbers.subtraction);
        minus.setChild(0, new XPathFunctionGetNumber("message/characters/character[id=$p1]/position/x/text()"));
        minus.setChild(1, new XPathFunctionGetNumber("message/characters/character[id=$p2]/position/x/text()"));
        setChild(0, minus);
    }
    ///
    
    @Override
    public DistanceX clone()
    {
        DistanceX dx = new DistanceX();
        return dx;
    }
    
    @Override
    public DistanceX duplicate(boolean with_state)
    {
        return this;
    }
    
    @Override
    public void evaluate(Object[] inputs, Object[] outputs, Context context)
    {
        super.evaluate(inputs, outputs, context);
    }
}