difflib.myers
Class MyersDiff

java.lang.Object
  difflib.myers.MyersDiff

All Implemented Interfaces:

DiffAlgorithm

public class MyersDiff
extends Object
implements DiffAlgorithm

A clean-room implementation of Eugene Myers differencing algorithm.

See the paper at http://www.cs.arizona.edu/people/gene/PAPERS/diff.ps

Author:

Juanco Anez

Constructor Summary

MyersDiff()
Constructs an instance of the Myers differencing algorithm.

Method Summary

static PathNode	buildPath(Object[] orig, Object[] rev) Computes the minimum diffpath that expresses de differences between the original and revised sequences, according to Gene Myers differencing algorithm.
static Patch	buildRevision(PathNode path, Object[] orig, Object[] rev) Constructs a Patch from a difference path.
static <T> T[]	copyOfRange(T[] original, int from, int to) Copied here from JDK 1.6
static <T,U> T[]	copyOfRange(U[] original, int from, int to, Class<? extends T[]> newType) Copied here from JDK 1.6
Patch	diff(List<?> original, List<?> revised) Computes the difference between the original sequence and the revised sequence and returns it as a Patch object.
Patch	diff(Object[] orig, Object[] rev) Computes the difference between the original sequence and the revised sequence and returns it as a Patch object.

Methods inherited from class java.lang.Object

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

Constructor Detail

MyersDiff

public MyersDiff()

Constructs an instance of the Myers differencing algorithm.

Method Detail

diff

public Patch diff(List<?> original,
                  List<?> revised)

Computes the difference between the original sequence and the revised sequence and returns it as a Patch object. Return empty diff if get the error while procession the difference.

Specified by:

diff in interface DiffAlgorithm

Parameters:

original - the original text

revised - the revised text

Returns:

the patch

diff

public Patch diff(Object[] orig,
                  Object[] rev)

Computes the difference between the original sequence and the revised sequence and returns it as a Patch object. Return empty diff if get the error while procession the difference.

Specified by:

diff in interface DiffAlgorithm

Parameters:

orig - the original text

rev - the revised text

Returns:

the patch

buildPath

public static PathNode buildPath(Object[] orig,
                                 Object[] rev)
                          throws DifferentiationFailedException

Computes the minimum diffpath that expresses de differences between the original and revised sequences, according to Gene Myers differencing algorithm.

Parameters:

orig - The original sequence.

rev - The revised sequence.

Returns:

A minimum Path accross the differences graph.

Throws:

DifferentiationFailedException - if a diff path could not be found.

buildRevision

public static Patch buildRevision(PathNode path,
                                  Object[] orig,
                                  Object[] rev)

Constructs a Patch from a difference path.

Parameters:

path - The path.

orig - The original sequence.

rev - The revised sequence.

Returns:

A Patch script corresponding to the path.

Throws:

DifferentiationFailedException - if a Patch could not be built from the given path.

copyOfRange

public static <T> T[] copyOfRange(T[] original,
                                  int from,
                                  int to)

Copied here from JDK 1.6

copyOfRange

public static <T,U> T[] copyOfRange(U[] original,
                                    int from,
                                    int to,
                                    Class<? extends T[]> newType)

Copied here from JDK 1.6