/*
 * 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
 *
 *      https://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.commons.text.diff;

import java.util.List;

/**
 * Handles synchronized replacement sequences.
 *
 * @param <T> object type
 * @see ReplacementsFinder
 * @since 1.0
 */
public interface ReplacementsHandler<T> {

    /**
     * Handle two synchronized sequences.
     * <p>
     * This method is called by a {@link ReplacementsFinder ReplacementsFinder} instance when it has synchronized two sub-sequences of object arrays being
     * 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
     * they exist). This property also holds for the objects after the two sub-sequences.
     * </p>
     * <p>
     * The replacement is defined as replacing the {@code from} sub-sequence into the {@code to} sub-sequence.
     * </p>
     *
     * @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
     *                except on the very first call where it can be zero (if the first object of the two sequences are different).
     * @param from    sub-sequence of objects coming from the first sequence.
     * @param to      sub-sequence of objects coming from the second sequence.
     */
    void handleReplacement(int skipped, List<T> from, List<T> to);
}
