lucene/queryparser/src/java/org/apache/lucene/queryparser/surround/query/DistanceSubQuery.java

/*
 * 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.lucene.queryparser.surround.query;

import java.io.IOException;

/** Interface for queries that can be nested as subqueries into a span near. */
public interface DistanceSubQuery {
  /**
   * When distanceSubQueryNotAllowed() returns non null, the reason why the subquery is not allowed
   * as a distance subquery is returned. <br>
   * When distanceSubQueryNotAllowed() returns null addSpanNearQueries() can be used in the creation
   * of the span near clause for the subquery.
   */
  String distanceSubQueryNotAllowed();

  void addSpanQueries(SpanNearClauseFactory sncf) throws IOException;
}