content: package org.apache.lucene.search.payloads;
  /**
   * 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.
   */
  
  import java.io.Serializable;
  import org.apache.lucene.search.Explanation;
  
  /**
   * An abstract class that defines a way for Payload*Query instances to transform
   * the cumulative effects of payload scores for a document.
   * 
   * @see org.apache.lucene.search.payloads.PayloadTermQuery for more information
   * 
   * @lucene.experimental This class and its derivations are experimental and subject to
   *               change
   * 
   **/
  public abstract class PayloadFunction implements Serializable {
  
    /**
     * Calculate the score up to this point for this doc and field
     * @param docId The current doc
     * @param field The field
     * @param start The start position of the matching Span
     * @param end The end position of the matching Span
     * @param numPayloadsSeen The number of payloads seen so far
     * @param currentScore The current score so far
     * @param currentPayloadScore The score for the current payload
     * @return The new current Score
     *
     * @see org.apache.lucene.search.spans.Spans
     */
    public abstract float currentScore(int docId, String field, int start, int end, int numPayloadsSeen, float currentScore, float currentPayloadScore);
  
    /**
     * Calculate the final score for all the payloads seen so far for this doc/field
     * @param docId The current doc
     * @param field The current field
     * @param numPayloadsSeen The total number of payloads seen on this document
     * @param payloadScore The raw score for those payloads
     * @return The final score for the payloads
     */
    public abstract float docScore(int docId, String field, int numPayloadsSeen, float payloadScore);
    
    public Explanation explain(int docId, int numPayloadsSeen, float payloadScore){
  	  Explanation result = new Explanation();
  	  result.setDescription("Unimpl Payload Function Explain");
  	  result.setValue(1);
  	  return result;
    };
    
    @Override
    public abstract int hashCode();
    
    @Override
    public abstract boolean equals(Object o);
  
  }
  