org.apache.commons.text.diff

Class EditScript<T>

java.lang.Object

org.apache.commons.text.diff.EditScript<T>

Type Parameters:

T - object type

public class EditScript<T>
extends Object

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 StringsComparator 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.

Since:

1.0

See Also:

StringsComparator, EditCommand, CommandVisitor, ReplacementsHandler

Constructor Summary

Constructors

Constructor and Description
EditScript() Simple constructor.

Method Summary

Modifier and Type	Method and Description
void	append(DeleteCommand<T> command) Add a delete command to the script.
void	append(InsertCommand<T> command) Add an insert command to the script.
void	append(KeepCommand<T> command) Add a keep command to the script.
int	getLCSLength() Get the length of the Longest Common Subsequence (LCS).
int	getModifications() Get the number of effective modifications.
void	visit(CommandVisitor<T> visitor) Visit the script.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EditScript

public EditScript()

Simple constructor. Creates a new empty script.

Method Detail

append

public void append(KeepCommand<T> command)

Add a keep command to the script.

Parameters:

command - command to add

append

public void append(InsertCommand<T> command)

Add an insert command to the script.

Parameters:

command - command to add

append

public void append(DeleteCommand<T> command)

Add a delete command to the script.

Parameters:

command - command to add

visit

public void visit(CommandVisitor<T> visitor)

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.

Parameters:

visitor - the visitor that will visit all commands in turn

getLCSLength

public int getLCSLength()

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

getModifications

public int getModifications()

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