001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.text.diff;
019
020import java.util.List;
021
022/**
023 * Handles synchronized replacement sequences.
024 *
025 * @param <T> object type
026 * @see ReplacementsFinder
027 * @since 1.0
028 */
029public interface ReplacementsHandler<T> {
030
031    /**
032     * Handle two synchronized sequences.
033     * <p>
034     * This method is called by a {@link ReplacementsFinder ReplacementsFinder} instance when it has synchronized two sub-sequences of object arrays being
035     * compared, and at least one of the sequences is non-empty. Since the sequences are synchronized, the objects before the two sub-sequences are equals (if
036     * they exist). This property also holds for the objects after the two sub-sequences.
037     * </p>
038     * <p>
039     * The replacement is defined as replacing the {@code from} sub-sequence into the {@code to} sub-sequence.
040     * </p>
041     *
042     * @param skipped number of tokens skipped since the last call (i.e. number of tokens that were in both sequences), this number should be strictly positive
043     *                except on the very first call where it can be zero (if the first object of the two sequences are different).
044     * @param from    sub-sequence of objects coming from the first sequence.
045     * @param to      sub-sequence of objects coming from the second sequence.
046     */
047    void handleReplacement(int skipped, List<T> from, List<T> to);
048}