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'rapiddweller Script' is an open source software library for resolving Java-like script expressions, forked from Databene Scripts written by Volker Bergmann.

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/*
 * Copyright (C) 2011-2014 Volker Bergmann ([email protected]).
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.rapiddweller.script.expression;

import com.rapiddweller.commons.Context;
import com.rapiddweller.script.Expression;

/**
 * Expression which evaluates a list of expressions and returns the first result which is not null.


 * Created: 16.06.2010 07:39:20
 * @since 0.5.3
 * @author Volker Bergmann
 */
public class FallbackExpression extends CompositeExpression {

    public FallbackExpression(Expression... terms) {
	    super(terms);
    }

    @Override
	public E evaluate(Context context) {
    	for (Expression term : terms) {
        	E result = (term != null ? term.evaluate(context) : null);
        	if (result != null)
        		return result;
    	}
	    return null;
    }

}