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 * 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.
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package org.apache.commons.collections4.sequence;

import java.util.ArrayList;
import java.util.List;

This class gathers all the commands needed to transform one objects sequence into another objects sequence. 
 An edit script is the most general view of the differences between two sequences. It is built as the result of the comparison between two sequences by the SequencesComparator class. The user can walk through it using the visitor design pattern.

 It is guaranteed that the objects embedded in the insert
commands come from the second sequence and that the objects embedded in either the delete commands or keep
commands come from the first sequence. This can be important if subclassing is used for some elements in the first sequence and the equals
method is specialized.

See Also:
SequencesComparator
EditCommand
CommandVisitor
ReplacementsHandler
Since:
4.0/**
 * This class gathers all the {@link EditCommand commands} needed to transform
 * one objects sequence into another objects sequence.
 * <p>
 * An edit script is the most general view of the differences between two
 * sequences. It is built as the result of the comparison between two sequences
 * by the {@link SequencesComparator SequencesComparator} class. The user can
 * walk through it using the <em>visitor</em> design pattern.
 * </p>
 * <p>
 * It is guaranteed that the objects embedded in the {@link InsertCommand insert
 * commands} come from the second sequence and that the objects embedded in
 * either the {@link DeleteCommand delete commands} or {@link KeepCommand keep
 * commands} come from the first sequence. This can be important if subclassing
 * is used for some elements in the first sequence and the <code>equals</code>
 * method is specialized.
 * </p>
 *
 * @see SequencesComparator
 * @see EditCommand
 * @see CommandVisitor
 * @see ReplacementsHandler
 *
 * @since 4.0
 */
public class EditScript<T> {

    
Container for the commands. /** Container for the commands. */
    private final List<EditCommand<T>> commands;

    
Length of the longest common subsequence. /** Length of the longest common subsequence. */
    private int lcsLength;

    
Number of modifications. /** Number of modifications. */
    private int modifications;

    
Simple constructor. Creates a new empty script.
/**
     * Simple constructor. Creates a new empty script.
     */
    public EditScript() {
        commands = new ArrayList<>();
        lcsLength = 0;
        modifications = 0;
    }

    
Add a keep command to the script.
Params:
command –  command to add/**
     * Add a keep command to the script.
     *
     * @param command  command to add
     */
    public void append(final KeepCommand<T> command) {
        commands.add(command);
        ++lcsLength;
    }

    
Add an insert command to the script.
Params:
command –  command to add/**
     * Add an insert command to the script.
     *
     * @param command  command to add
     */
    public void append(final InsertCommand<T> command) {
        commands.add(command);
        ++modifications;
    }

    
Add a delete command to the script.
Params:
command –  command to add/**
     * Add a delete command to the script.
     *
     * @param command  command to add
     */
    public void append(final DeleteCommand<T> command) {
        commands.add(command);
        ++modifications;
    }

    
Visit the script. The script implements the visitor design
pattern, this method is the entry point to which the user supplies its
own visitor, the script will be responsible to drive it through the
commands in order and call the appropriate method as each command is
encountered.
Params:
visitor –  the visitor that will visit all commands in turn/**
     * Visit the script. The script implements the <em>visitor</em> design
     * pattern, this method is the entry point to which the user supplies its
     * own visitor, the script will be responsible to drive it through the
     * commands in order and call the appropriate method as each command is
     * encountered.
     *
     * @param visitor  the visitor that will visit all commands in turn
     */
    public void visit(final CommandVisitor<T> visitor) {
        for (final EditCommand<T> command : commands) {
            command.accept(visitor);
        }
    }

    
Get the length of the Longest Common Subsequence (LCS). The length of the longest common subsequence is the number of keep
commands in the script. 
Returns:
length of the Longest Common Subsequence/**
     * Get the length of the Longest Common Subsequence (LCS). The length of the
     * longest common subsequence is the number of {@link KeepCommand keep
     * commands} in the script.
     *
     * @return length of the Longest Common Subsequence
     */
    public int getLCSLength() {
        return lcsLength;
    }

    
Get the number of effective modifications. The number of effective modification is the number of delete and insert commands in the script. 
Returns:
number of effective modifications/**
     * Get the number of effective modifications. The number of effective
     * modification is the number of {@link DeleteCommand delete} and
     * {@link InsertCommand insert} commands in the script.
     *
     * @return number of effective modifications
     */
    public int getModifications() {
        return modifications;
    }

}