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 * 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
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.lucene.search.highlight;

import java.io.IOException;

import org.apache.lucene.analysis.TokenStream;

A Scorer is responsible for scoring a stream of tokens. These token scores can then be used to compute TextFragment scores.
/** * A Scorer is responsible for scoring a stream of tokens. These token scores * can then be used to compute {@link TextFragment} scores. */
public interface Scorer {
Called to init the Scorer with a TokenStream. You can grab references to the attributes you are interested in here and access them from getTokenScore().
Params:
Throws:
Returns:either a TokenStream that the Highlighter should continue using (eg if you read the tokenSream in this method) or null to continue using the same TokenStream that was passed in.
/** * Called to init the Scorer with a {@link TokenStream}. You can grab references to * the attributes you are interested in here and access them from {@link #getTokenScore()}. * * @param tokenStream the {@link TokenStream} that will be scored. * @return either a {@link TokenStream} that the Highlighter should continue using (eg * if you read the tokenSream in this method) or null to continue * using the same {@link TokenStream} that was passed in. * @throws IOException If there is a low-level I/O error */
public TokenStream init(TokenStream tokenStream) throws IOException;
Called when a new fragment is started for consideration.
Params:
  • newFragment – the fragment that will be scored next
/** * Called when a new fragment is started for consideration. * * @param newFragment the fragment that will be scored next */
public void startFragment(TextFragment newFragment);
Called for each token in the current fragment. The Highlighter will increment the TokenStream passed to init on every call.
Returns:a score which is passed to the Highlighter class to influence the mark-up of the text (this return value is NOT used to score the fragment)
/** * Called for each token in the current fragment. The {@link Highlighter} will * increment the {@link TokenStream} passed to init on every call. * * @return a score which is passed to the {@link Highlighter} class to influence the * mark-up of the text (this return value is NOT used to score the * fragment) */
public float getTokenScore();
Called when the Highlighter has no more tokens for the current fragment - the Scorer returns the weighting it has derived for the most recent fragment, typically based on the results of getTokenScore().
/** * Called when the {@link Highlighter} has no more tokens for the current fragment - * the Scorer returns the weighting it has derived for the most recent * fragment, typically based on the results of {@link #getTokenScore()}. * */
public float getFragmentScore(); }