/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.solr.handler.dataimport;
/**
* <p>
* Pluggable functions for resolving variables
* </p>
* <p>
* Implementations of this abstract class must provide a public no-arg constructor.
* </p>
* <p>
* Refer to <a
* href="http://wiki.apache.org/solr/DataImportHandler">http://wiki.apache.org/solr/DataImportHandler</a>
* for more details.
* </p>
* <b>This API is experimental and may change in the future.</b>
*
* @version $Id: Evaluator.java 745734 2009-02-19 05:28:48Z shalin $
* @since solr 1.3
*/
public abstract class Evaluator {
/**
* Return a String after processing an expression and a VariableResolver
*
* @see org.apache.solr.handler.dataimport.VariableResolver
* @param expression string to be evaluated
* @param context instance
* @return the value of the given expression evaluated using the resolver
*/
public abstract String evaluate(String expression, Context context);
}