/**
* Copyright (C) 2010 dennis zhuang (killme2008@gmail.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
**/
package com.googlecode.aviator.runtime.function.system;
import java.security.SecureRandom;
import java.util.Map;
import java.util.Random;
import com.googlecode.aviator.runtime.function.AbstractFunction;
import com.googlecode.aviator.runtime.function.FunctionUtils;
import com.googlecode.aviator.runtime.type.AviatorDouble;
import com.googlecode.aviator.runtime.type.AviatorLong;
import com.googlecode.aviator.runtime.type.AviatorObject;
/**
* rand() function to generate random double value
*
* @author dennis
*
*/
public class RandomFunction extends AbstractFunction {
private static ThreadLocal<Random> randomLocal = new ThreadLocal<Random>() {
@Override
protected Random initialValue() {
return new SecureRandom();
}
};
@Override
public AviatorObject call(Map<String, Object> env) {
return AviatorDouble.valueOf(randomLocal.get().nextDouble());
}
@Override
public AviatorObject call(Map<String, Object> env, AviatorObject arg) {
return AviatorLong.valueOf(randomLocal.get().nextInt(FunctionUtils.getNumberValue(arg, env).intValue()));
}
public String getName() {
return "rand";
}
}