Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.operator;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

public class NegOperator extends AbstractUnaryOperator {

    public static final String NAME = "NEGATE";

    public NegOperator() {

        super(Function.GROUP_NUMERIC,NAME);   

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

    public Object call(Interpreter interpreter, Object arg) {

        if( !(arg instanceof Number) ) {

            throw new IllegalArgumentException("NEGATE function require a number");

        }

        if( arg instanceof Double ) {

          return -((Number)arg).doubleValue();  

        } 

        if( arg instanceof Float ) {

          return -((Number)arg).floatValue();  

        } 

        if( arg instanceof Long ) {

          return -((Number)arg).longValue();  

        } 

        if( arg instanceof Integer ) {

          return -((Number)arg).intValue();  

        } 

        return -((Number)arg).doubleValue();  

    }

}