/**
* 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.analysis;
import java.io.Reader;
/**
* CharStream adds {@link #correctOffset}
* functionality over {@link Reader}. All Tokenizers accept a
* CharStream instead of {@link Reader} as input, which enables
* arbitrary character based filtering before tokenization.
* The {@link #correctOffset} method fixed offsets to account for
* removal or insertion of characters, so that the offsets
* reported in the tokens match the character offsets of the
* original Reader.
*/
public abstract class CharStream extends Reader {
/**
* Called by CharFilter(s) and Tokenizer to correct token offset.
*
* @param currentOff offset as seen in the output
* @return corrected offset based on the input
*/
public abstract int correctOffset(int currentOff);
}