Diff-Match-Patch

The Diff Match and Patch libraries offer robust algorithms to perform the operations required for synchronizing plain text:

• computes character-based diff of two texts
• performs fuzzy match of given string
• applies a list of patches.

This is the port of Google's diff-match-patch library to PHP.

Diff

Compare two plain text and efficiently return a array of differences. It works with characters, but if you want to compute word-based or line-based diff — you can easily tune it for your needs.

Usage:

<?php

use DiffMatchPatch\DiffMatchPatch;

$text1 = "The quick brown fox jumps over the lazy dog.";
$text2 = "That quick brown fox jumped over a lazy dog.";
$dmp = new DiffMatchPatch();
$diffs = $dmp->diff_main($text1, $text2, false);
var_dump($diffs);

Returns:

array(
    array(DiffMatchPatch::DIFF_EQUAL, "Th"),
    array(DiffMatchPatch::DIFF_DELETE, "e"),
    array(DiffMatchPatch::DIFF_INSERT, "at"),
    array(DiffMatchPatch::DIFF_EQUAL, " quick brown fox jump"),
    array(DiffMatchPatch::DIFF_DELETE, "s"),
    array(DiffMatchPatch::DIFF_INSERT, "ed"),
    array(DiffMatchPatch::DIFF_EQUAL, " over "),
    array(DiffMatchPatch::DIFF_DELETE, "the"),
    array(DiffMatchPatch::DIFF_INSERT, "a"),
    array(DiffMatchPatch::DIFF_EQUAL, " lazy dog."),
)

Demo

Match

Given a search string, find its best fuzzy match in a plain text near the given location. Weighted for both accuracy and location.

Usage:

<?php

use DiffMatchPatch\DiffMatchPatch;

$dmp = new DiffMatchPatch();
$text = "The quick brown fox jumps over the lazy fox.";
$pos = $dmp->match_main($text, "fox", 0); // Returns 16
$pos = $dmp->match_main($text, "fox", 40); // Returns 40
$pos = $dmp->match_main($text, "jmps"); // Returns 20
$pos = $dmp->match_main($text, "jmped"); // Returns -1
$pos = $dmp->Match_Threshold = 0.7;
$pos = $dmp->match_main($text, "jmped"); // Returns 20

Demo

Patch

Apply a list of patches in Unidiff-like format onto plain text. Use best-effort to apply patch even when the underlying text doesn't match.

Usage:

<?php

use DiffMatchPatch\DiffMatchPatch;

$dmp = new DiffMatchPatch();
$patches = $dmp->patch_make("The quick brown fox jumps over the lazy dog.", "That quick brown fox jumped over a lazy dog.");
// @@ -1,11 +1,12 @@
//  Th
// -e
// +at
//   quick b
// @@ -22,18 +22,17 @@
//  jump
// -s
// +ed
//   over
// -the
// +a
//   laz
$result = $dmp->patch_apply($patches, "The quick red rabbit jumps over the tired tiger.");
var_dump($result);

Returns:

array(
    "That quick red rabbit jumped over a tired tiger.",
    array (
        true,
        true,
    ),
);

Demo

API

Currently this library available in:

• PHP
• C++
• C#
• Dart
• Java
• JavaScript
• Lua
• Objective-C
• Python

Regardless of language, each library uses the same API and the same functionality.

Algorithms

This library implements Myer's diff algorithm which is generally considered to be the best general-purpose diff. A layer of pre-diff speedups and post-diff cleanups surround the diff algorithm, improving both performance and output quality.

This library also implements a Bitap matching algorithm at the heart of a flexible matching and patching strategy.

Requirements

• PHP 5.3+
• Composer

License

Diff-Match-Patch is licensed under the Apache License 2.0 - see the LICENSE file for details