src/test/java/com/googlecode/aviator/example/AddFunctionExample.java

package com.googlecode.aviator.example;

import java.util.Map;

import com.googlecode.aviator.AviatorEvaluator;
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.AviatorObject;


public class AddFunctionExample {
    private static class AddFunction extends AbstractFunction {

        @Override
        public AviatorObject call(Map<String, Object> env, AviatorObject arg1, AviatorObject arg2) {
            Number left = FunctionUtils.getNumberValue(arg1, env);
            Number right = FunctionUtils.getNumberValue(arg2, env);
            return new AviatorDouble(left.doubleValue() + right.doubleValue());
        }


        public String getName() {
            return "add";
        }

    }


    public static void main(String[] args) {
        AviatorEvaluator.addFunction(new AddFunction());
        System.out.println(AviatorEvaluator.execute("add(1,2)"));
        System.out.println(AviatorEvaluator.execute("add(add(1,2),100)"));
    }
}