add linting (and some initial fixes)

author: Florian Dold <florian.dold@gmail.com> 2017-05-28 00:38:50 +0200
committer: Florian Dold <florian.dold@gmail.com> 2017-05-28 00:40:43 +0200
commit: 7fff4499fd915bcea3fa93b1aa8b35f4fe7a6027 (patch)
tree: 6de9a1aebd150a23b7f8c273ec657a5d0a18fe3e /node_modules/diff-match-patch
parent: 963b7a41feb29cc4be090a2446bdfe0c1f1bcd81 (diff)
7 files changed, 3295 insertions, 0 deletions
diff --git a/node_modules/diff-match-patch/.npmignore b/node_modules/diff-match-patch/.npmignore
new file mode 100644
index 000000000..b83202d05
--- /dev/null
+++ b/node_modules/diff-match-patch/.npmignore
@@ -0,0 +1,13 @@
+lib-cov
+*.seed
+*.log
+*.csv
+*.dat
+*.out
+*.pid
+*.gz
+pids
+logs
+results
+npm-debug.log
+node_modules
diff --git a/node_modules/diff-match-patch/.travis.yml b/node_modules/diff-match-patch/.travis.yml
new file mode 100644
index 000000000..87f8cd91a
--- /dev/null
+++ b/node_modules/diff-match-patch/.travis.yml
@@ -0,0 +1,3 @@
+language: node_js
+node_js:
+  - "0.10"
+\ No newline at end of file
diff --git a/node_modules/diff-match-patch/LICENSE b/node_modules/diff-match-patch/LICENSE
new file mode 100644
index 000000000..fe52cb6d5
--- /dev/null
+++ b/node_modules/diff-match-patch/LICENSE
@@ -0,0 +1,14 @@
+Copyright 2006 Google Inc.
+http://code.google.com/p/google-diff-match-patch/
+
+Licensed 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.
+\ No newline at end of file
diff --git a/node_modules/diff-match-patch/README.md b/node_modules/diff-match-patch/README.md
new file mode 100644
index 000000000..f8b98e929
--- /dev/null
+++ b/node_modules/diff-match-patch/README.md
@@ -0,0 +1,32 @@
+# diff-match-patch
+
+npm package for https://code.google.com/p/google-diff-match-patch/
+
+[![Build Status](https://travis-ci.org/ForbesLindesay/diff-match-patch.png?branch=master)](https://travis-ci.org/ForbesLindesay/diff-match-patch)
+[![Dependency Status](https://gemnasium.com/ForbesLindesay/diff-match-patch.png)](https://gemnasium.com/ForbesLindesay/diff-match-patch)
+[![NPM version](https://badge.fury.io/js/diff-match-patch.png)](http://badge.fury.io/js/diff-match-patch)
+
+## Installation
+
+    npm install diff-match-patch
+
+## API
+
+https://code.google.com/p/google-diff-match-patch/wiki/API
+
+```javascript
+var DiffMatchPatch = require('diff-match-patch');
+var dmp = new DiffMatchPatch();
+//use the methods that dmp has
+//see: https://code.google.com/p/google-diff-match-patch/wiki/API
+
+//You can also use the following properties:
+
+DiffMatchPatch.DIFF_DELETE = -1;
+DiffMatchPatch.DIFF_INSERT = 1;
+DiffMatchPatch.DIFF_EQUAL = 0;
+```
+
+## License
+
+  http://www.apache.org/licenses/LICENSE-2.0
+\ No newline at end of file
diff --git a/node_modules/diff-match-patch/index.js b/node_modules/diff-match-patch/index.js
new file mode 100644
index 000000000..95f7324fc
--- /dev/null
+++ b/node_modules/diff-match-patch/index.js
@@ -0,0 +1,2193 @@
+'use strict'
+
+/**
+ * Diff Match and Patch
+ *
+ * Copyright 2006 Google Inc.
+ * http://code.google.com/p/google-diff-match-patch/
+ *
+ * Licensed 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.
+ */
+
+/**
+ * @fileoverview Computes the difference between two texts to create a patch.
+ * Applies the patch onto another text, allowing for errors.
+ * @author fraser@google.com (Neil Fraser)
+ */
+
+/**
+ * Class containing the diff, match and patch methods.
+ * @constructor
+ */
+function diff_match_patch() {
+
+  // Defaults.
+  // Redefine these in your program to override the defaults.
+
+  // Number of seconds to map a diff before giving up (0 for infinity).
+  this.Diff_Timeout = 1.0;
+  // Cost of an empty edit operation in terms of edit characters.
+  this.Diff_EditCost = 4;
+  // At what point is no match declared (0.0 = perfection, 1.0 = very loose).
+  this.Match_Threshold = 0.5;
+  // How far to search for a match (0 = exact location, 1000+ = broad match).
+  // A match this many characters away from the expected location will add
+  // 1.0 to the score (0.0 is a perfect match).
+  this.Match_Distance = 1000;
+  // When deleting a large block of text (over ~64 characters), how close do
+  // the contents have to be to match the expected contents. (0.0 = perfection,
+  // 1.0 = very loose).  Note that Match_Threshold controls how closely the
+  // end points of a delete need to match.
+  this.Patch_DeleteThreshold = 0.5;
+  // Chunk size for context length.
+  this.Patch_Margin = 4;
+
+  // The number of bits in an int.
+  this.Match_MaxBits = 32;
+}
+
+
+//  DIFF FUNCTIONS
+
+
+/**
+ * The data structure representing a diff is an array of tuples:
+ * [[DIFF_DELETE, 'Hello'], [DIFF_INSERT, 'Goodbye'], [DIFF_EQUAL, ' world.']]
+ * which means: delete 'Hello', add 'Goodbye' and keep ' world.'
+ */
+var DIFF_DELETE = -1;
+var DIFF_INSERT = 1;
+var DIFF_EQUAL = 0;
+
+/** @typedef {{0: number, 1: string}} */
+diff_match_patch.Diff;
+
+
+/**
+ * Find the differences between two texts.  Simplifies the problem by stripping
+ * any common prefix or suffix off the texts before diffing.
+ * @param {string} text1 Old string to be diffed.
+ * @param {string} text2 New string to be diffed.
+ * @param {boolean=} opt_checklines Optional speedup flag. If present and false,
+ *     then don't run a line-level diff first to identify the changed areas.
+ *     Defaults to true, which does a faster, slightly less optimal diff.
+ * @param {number} opt_deadline Optional time when the diff should be complete
+ *     by.  Used internally for recursive calls.  Users should set DiffTimeout
+ *     instead.
+ * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+ */
+diff_match_patch.prototype.diff_main = function(text1, text2, opt_checklines,
+    opt_deadline) {
+  // Set a deadline by which time the diff must be complete.
+  if (typeof opt_deadline == 'undefined') {
+    if (this.Diff_Timeout <= 0) {
+      opt_deadline = Number.MAX_VALUE;
+    } else {
+      opt_deadline = (new Date).getTime() + this.Diff_Timeout * 1000;
+    }
+  }
+  var deadline = opt_deadline;
+
+  // Check for null inputs.
+  if (text1 == null || text2 == null) {
+    throw new Error('Null input. (diff_main)');
+  }
+
+  // Check for equality (speedup).
+  if (text1 == text2) {
+    if (text1) {
+      return [[DIFF_EQUAL, text1]];
+    }
+    return [];
+  }
+
+  if (typeof opt_checklines == 'undefined') {
+    opt_checklines = true;
+  }
+  var checklines = opt_checklines;
+
+  // Trim off common prefix (speedup).
+  var commonlength = this.diff_commonPrefix(text1, text2);
+  var commonprefix = text1.substring(0, commonlength);
+  text1 = text1.substring(commonlength);
+  text2 = text2.substring(commonlength);
+
+  // Trim off common suffix (speedup).
+  commonlength = this.diff_commonSuffix(text1, text2);
+  var commonsuffix = text1.substring(text1.length - commonlength);
+  text1 = text1.substring(0, text1.length - commonlength);
+  text2 = text2.substring(0, text2.length - commonlength);
+
+  // Compute the diff on the middle block.
+  var diffs = this.diff_compute_(text1, text2, checklines, deadline);
+
+  // Restore the prefix and suffix.
+  if (commonprefix) {
+    diffs.unshift([DIFF_EQUAL, commonprefix]);
+  }
+  if (commonsuffix) {
+    diffs.push([DIFF_EQUAL, commonsuffix]);
+  }
+  this.diff_cleanupMerge(diffs);
+  return diffs;
+};
+
+
+/**
+ * Find the differences between two texts.  Assumes that the texts do not
+ * have any common prefix or suffix.
+ * @param {string} text1 Old string to be diffed.
+ * @param {string} text2 New string to be diffed.
+ * @param {boolean} checklines Speedup flag.  If false, then don't run a
+ *     line-level diff first to identify the changed areas.
+ *     If true, then run a faster, slightly less optimal diff.
+ * @param {number} deadline Time when the diff should be complete by.
+ * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+ * @private
+ */
+diff_match_patch.prototype.diff_compute_ = function(text1, text2, checklines,
+    deadline) {
+  var diffs;
+
+  if (!text1) {
+    // Just add some text (speedup).
+    return [[DIFF_INSERT, text2]];
+  }
+
+  if (!text2) {
+    // Just delete some text (speedup).
+    return [[DIFF_DELETE, text1]];
+  }
+
+  var longtext = text1.length > text2.length ? text1 : text2;
+  var shorttext = text1.length > text2.length ? text2 : text1;
+  var i = longtext.indexOf(shorttext);
+  if (i != -1) {
+    // Shorter text is inside the longer text (speedup).
+    diffs = [[DIFF_INSERT, longtext.substring(0, i)],
+             [DIFF_EQUAL, shorttext],
+             [DIFF_INSERT, longtext.substring(i + shorttext.length)]];
+    // Swap insertions for deletions if diff is reversed.
+    if (text1.length > text2.length) {
+      diffs[0][0] = diffs[2][0] = DIFF_DELETE;
+    }
+    return diffs;
+  }
+
+  if (shorttext.length == 1) {
+    // Single character string.
+    // After the previous speedup, the character can't be an equality.
+    return [[DIFF_DELETE, text1], [DIFF_INSERT, text2]];
+  }
+
+  // Check to see if the problem can be split in two.
+  var hm = this.diff_halfMatch_(text1, text2);
+  if (hm) {
+    // A half-match was found, sort out the return data.
+    var text1_a = hm[0];
+    var text1_b = hm[1];
+    var text2_a = hm[2];
+    var text2_b = hm[3];
+    var mid_common = hm[4];
+    // Send both pairs off for separate processing.
+    var diffs_a = this.diff_main(text1_a, text2_a, checklines, deadline);
+    var diffs_b = this.diff_main(text1_b, text2_b, checklines, deadline);
+    // Merge the results.
+    return diffs_a.concat([[DIFF_EQUAL, mid_common]], diffs_b);
+  }
+
+  if (checklines && text1.length > 100 && text2.length > 100) {
+    return this.diff_lineMode_(text1, text2, deadline);
+  }
+
+  return this.diff_bisect_(text1, text2, deadline);
+};
+
+
+/**
+ * Do a quick line-level diff on both strings, then rediff the parts for
+ * greater accuracy.
+ * This speedup can produce non-minimal diffs.
+ * @param {string} text1 Old string to be diffed.
+ * @param {string} text2 New string to be diffed.
+ * @param {number} deadline Time when the diff should be complete by.
+ * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+ * @private
+ */
+diff_match_patch.prototype.diff_lineMode_ = function(text1, text2, deadline) {
+  // Scan the text on a line-by-line basis first.
+  var a = this.diff_linesToChars_(text1, text2);
+  text1 = a.chars1;
+  text2 = a.chars2;
+  var linearray = a.lineArray;
+
+  var diffs = this.diff_main(text1, text2, false, deadline);
+
+  // Convert the diff back to original text.
+  this.diff_charsToLines_(diffs, linearray);
+  // Eliminate freak matches (e.g. blank lines)
+  this.diff_cleanupSemantic(diffs);
+
+  // Rediff any replacement blocks, this time character-by-character.
+  // Add a dummy entry at the end.
+  diffs.push([DIFF_EQUAL, '']);
+  var pointer = 0;
+  var count_delete = 0;
+  var count_insert = 0;
+  var text_delete = '';
+  var text_insert = '';
+  while (pointer < diffs.length) {
+    switch (diffs[pointer][0]) {
+      case DIFF_INSERT:
+        count_insert++;
+        text_insert += diffs[pointer][1];
+        break;
+      case DIFF_DELETE:
+        count_delete++;
+        text_delete += diffs[pointer][1];
+        break;
+      case DIFF_EQUAL:
+        // Upon reaching an equality, check for prior redundancies.
+        if (count_delete >= 1 && count_insert >= 1) {
+          // Delete the offending records and add the merged ones.
+          diffs.splice(pointer - count_delete - count_insert,
+                       count_delete + count_insert);
+          pointer = pointer - count_delete - count_insert;
+          var a = this.diff_main(text_delete, text_insert, false, deadline);
+          for (var j = a.length - 1; j >= 0; j--) {
+            diffs.splice(pointer, 0, a[j]);
+          }
+          pointer = pointer + a.length;
+        }
+        count_insert = 0;
+        count_delete = 0;
+        text_delete = '';
+        text_insert = '';
+        break;
+    }
+    pointer++;
+  }
+  diffs.pop();  // Remove the dummy entry at the end.
+
+  return diffs;
+};
+
+
+/**
+ * Find the 'middle snake' of a diff, split the problem in two
+ * and return the recursively constructed diff.
+ * See Myers 1986 paper: An O(ND) Difference Algorithm and Its Variations.
+ * @param {string} text1 Old string to be diffed.
+ * @param {string} text2 New string to be diffed.
+ * @param {number} deadline Time at which to bail if not yet complete.
+ * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+ * @private
+ */
+diff_match_patch.prototype.diff_bisect_ = function(text1, text2, deadline) {
+  // Cache the text lengths to prevent multiple calls.
+  var text1_length = text1.length;
+  var text2_length = text2.length;
+  var max_d = Math.ceil((text1_length + text2_length) / 2);
+  var v_offset = max_d;
+  var v_length = 2 * max_d;
+  var v1 = new Array(v_length);
+  var v2 = new Array(v_length);
+  // Setting all elements to -1 is faster in Chrome & Firefox than mixing
+  // integers and undefined.
+  for (var x = 0; x < v_length; x++) {
+    v1[x] = -1;
+    v2[x] = -1;
+  }
+  v1[v_offset + 1] = 0;
+  v2[v_offset + 1] = 0;
+  var delta = text1_length - text2_length;
+  // If the total number of characters is odd, then the front path will collide
+  // with the reverse path.
+  var front = (delta % 2 != 0);
+  // Offsets for start and end of k loop.
+  // Prevents mapping of space beyond the grid.
+  var k1start = 0;
+  var k1end = 0;
+  var k2start = 0;
+  var k2end = 0;
+  for (var d = 0; d < max_d; d++) {
+    // Bail out if deadline is reached.
+    if ((new Date()).getTime() > deadline) {
+      break;
+    }
+
+    // Walk the front path one step.
+    for (var k1 = -d + k1start; k1 <= d - k1end; k1 += 2) {
+      var k1_offset = v_offset + k1;
+      var x1;
+      if (k1 == -d || (k1 != d && v1[k1_offset - 1] < v1[k1_offset + 1])) {
+        x1 = v1[k1_offset + 1];
+      } else {
+        x1 = v1[k1_offset - 1] + 1;
+      }
+      var y1 = x1 - k1;
+      while (x1 < text1_length && y1 < text2_length &&
+             text1.charAt(x1) == text2.charAt(y1)) {
+        x1++;
+        y1++;
+      }
+      v1[k1_offset] = x1;
+      if (x1 > text1_length) {
+        // Ran off the right of the graph.
+        k1end += 2;
+      } else if (y1 > text2_length) {
+        // Ran off the bottom of the graph.
+        k1start += 2;
+      } else if (front) {
+        var k2_offset = v_offset + delta - k1;
+        if (k2_offset >= 0 && k2_offset < v_length && v2[k2_offset] != -1) {
+          // Mirror x2 onto top-left coordinate system.
+          var x2 = text1_length - v2[k2_offset];
+          if (x1 >= x2) {
+            // Overlap detected.
+            return this.diff_bisectSplit_(text1, text2, x1, y1, deadline);
+          }
+        }
+      }
+    }
+
+    // Walk the reverse path one step.
+    for (var k2 = -d + k2start; k2 <= d - k2end; k2 += 2) {
+      var k2_offset = v_offset + k2;
+      var x2;
+      if (k2 == -d || (k2 != d && v2[k2_offset - 1] < v2[k2_offset + 1])) {
+        x2 = v2[k2_offset + 1];
+      } else {
+        x2 = v2[k2_offset - 1] + 1;
+      }
+      var y2 = x2 - k2;
+      while (x2 < text1_length && y2 < text2_length &&
+             text1.charAt(text1_length - x2 - 1) ==
+             text2.charAt(text2_length - y2 - 1)) {
+        x2++;
+        y2++;
+      }
+      v2[k2_offset] = x2;
+      if (x2 > text1_length) {
+        // Ran off the left of the graph.
+        k2end += 2;
+      } else if (y2 > text2_length) {
+        // Ran off the top of the graph.
+        k2start += 2;
+      } else if (!front) {
+        var k1_offset = v_offset + delta - k2;
+        if (k1_offset >= 0 && k1_offset < v_length && v1[k1_offset] != -1) {
+          var x1 = v1[k1_offset];
+          var y1 = v_offset + x1 - k1_offset;
+          // Mirror x2 onto top-left coordinate system.
+          x2 = text1_length - x2;
+          if (x1 >= x2) {
+            // Overlap detected.
+            return this.diff_bisectSplit_(text1, text2, x1, y1, deadline);
+          }
+        }
+      }
+    }
+  }
+  // Diff took too long and hit the deadline or
+  // number of diffs equals number of characters, no commonality at all.
+  return [[DIFF_DELETE, text1], [DIFF_INSERT, text2]];
+};
+
+
+/**
+ * Given the location of the 'middle snake', split the diff in two parts
+ * and recurse.
+ * @param {string} text1 Old string to be diffed.
+ * @param {string} text2 New string to be diffed.
+ * @param {number} x Index of split point in text1.
+ * @param {number} y Index of split point in text2.
+ * @param {number} deadline Time at which to bail if not yet complete.
+ * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+ * @private
+ */
+diff_match_patch.prototype.diff_bisectSplit_ = function(text1, text2, x, y,
+    deadline) {
+  var text1a = text1.substring(0, x);
+  var text2a = text2.substring(0, y);
+  var text1b = text1.substring(x);
+  var text2b = text2.substring(y);
+
+  // Compute both diffs serially.
+  var diffs = this.diff_main(text1a, text2a, false, deadline);
+  var diffsb = this.diff_main(text1b, text2b, false, deadline);
+
+  return diffs.concat(diffsb);
+};
+
+
+/**
+ * Split two texts into an array of strings.  Reduce the texts to a string of
+ * hashes where each Unicode character represents one line.
+ * @param {string} text1 First string.
+ * @param {string} text2 Second string.
+ * @return {{chars1: string, chars2: string, lineArray: !Array.<string>}}
+ *     An object containing the encoded text1, the encoded text2 and
+ *     the array of unique strings.
+ *     The zeroth element of the array of unique strings is intentionally blank.
+ * @private
+ */
+diff_match_patch.prototype.diff_linesToChars_ = function(text1, text2) {
+  var lineArray = [];  // e.g. lineArray[4] == 'Hello\n'
+  var lineHash = {};   // e.g. lineHash['Hello\n'] == 4
+
+  // '\x00' is a valid character, but various debuggers don't like it.
+  // So we'll insert a junk entry to avoid generating a null character.
+  lineArray[0] = '';
+
+  /**
+   * Split a text into an array of strings.  Reduce the texts to a string of
+   * hashes where each Unicode character represents one line.
+   * Modifies linearray and linehash through being a closure.
+   * @param {string} text String to encode.
+   * @return {string} Encoded string.
+   * @private
+   */
+  function diff_linesToCharsMunge_(text) {
+    var chars = '';
+    // Walk the text, pulling out a substring for each line.
+    // text.split('\n') would would temporarily double our memory footprint.
+    // Modifying text would create many large strings to garbage collect.
+    var lineStart = 0;
+    var lineEnd = -1;
+    // Keeping our own length variable is faster than looking it up.
+    var lineArrayLength = lineArray.length;
+    while (lineEnd < text.length - 1) {
+      lineEnd = text.indexOf('\n', lineStart);
+      if (lineEnd == -1) {
+        lineEnd = text.length - 1;
+      }
+      var line = text.substring(lineStart, lineEnd + 1);
+      lineStart = lineEnd + 1;
+
+      if (lineHash.hasOwnProperty ? lineHash.hasOwnProperty(line) :
+          (lineHash[line] !== undefined)) {
+        chars += String.fromCharCode(lineHash[line]);
+      } else {
+        chars += String.fromCharCode(lineArrayLength);
+        lineHash[line] = lineArrayLength;
+        lineArray[lineArrayLength++] = line;
+      }
+    }
+    return chars;
+  }
+
+  var chars1 = diff_linesToCharsMunge_(text1);
+  var chars2 = diff_linesToCharsMunge_(text2);
+  return {chars1: chars1, chars2: chars2, lineArray: lineArray};
+};
+
+
+/**
+ * Rehydrate the text in a diff from a string of line hashes to real lines of
+ * text.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @param {!Array.<string>} lineArray Array of unique strings.
+ * @private
+ */
+diff_match_patch.prototype.diff_charsToLines_ = function(diffs, lineArray) {
+  for (var x = 0; x < diffs.length; x++) {
+    var chars = diffs[x][1];
+    var text = [];
+    for (var y = 0; y < chars.length; y++) {
+      text[y] = lineArray[chars.charCodeAt(y)];
+    }
+    diffs[x][1] = text.join('');
+  }
+};
+
+
+/**
+ * Determine the common prefix of two strings.
+ * @param {string} text1 First string.
+ * @param {string} text2 Second string.
+ * @return {number} The number of characters common to the start of each
+ *     string.
+ */
+diff_match_patch.prototype.diff_commonPrefix = function(text1, text2) {
+  // Quick check for common null cases.
+  if (!text1 || !text2 || text1.charAt(0) != text2.charAt(0)) {
+    return 0;
+  }
+  // Binary search.
+  // Performance analysis: http://neil.fraser.name/news/2007/10/09/
+  var pointermin = 0;
+  var pointermax = Math.min(text1.length, text2.length);
+  var pointermid = pointermax;
+  var pointerstart = 0;
+  while (pointermin < pointermid) {
+    if (text1.substring(pointerstart, pointermid) ==
+        text2.substring(pointerstart, pointermid)) {
+      pointermin = pointermid;
+      pointerstart = pointermin;
+    } else {
+      pointermax = pointermid;
+    }
+    pointermid = Math.floor((pointermax - pointermin) / 2 + pointermin);
+  }
+  return pointermid;
+};
+
+
+/**
+ * Determine the common suffix of two strings.
+ * @param {string} text1 First string.
+ * @param {string} text2 Second string.
+ * @return {number} The number of characters common to the end of each string.
+ */
+diff_match_patch.prototype.diff_commonSuffix = function(text1, text2) {
+  // Quick check for common null cases.
+  if (!text1 || !text2 ||
+      text1.charAt(text1.length - 1) != text2.charAt(text2.length - 1)) {
+    return 0;
+  }
+  // Binary search.
+  // Performance analysis: http://neil.fraser.name/news/2007/10/09/
+  var pointermin = 0;
+  var pointermax = Math.min(text1.length, text2.length);
+  var pointermid = pointermax;
+  var pointerend = 0;
+  while (pointermin < pointermid) {
+    if (text1.substring(text1.length - pointermid, text1.length - pointerend) ==
+        text2.substring(text2.length - pointermid, text2.length - pointerend)) {
+      pointermin = pointermid;
+      pointerend = pointermin;
+    } else {
+      pointermax = pointermid;
+    }
+    pointermid = Math.floor((pointermax - pointermin) / 2 + pointermin);
+  }
+  return pointermid;
+};
+
+
+/**
+ * Determine if the suffix of one string is the prefix of another.
+ * @param {string} text1 First string.
+ * @param {string} text2 Second string.
+ * @return {number} The number of characters common to the end of the first
+ *     string and the start of the second string.
+ * @private
+ */
+diff_match_patch.prototype.diff_commonOverlap_ = function(text1, text2) {
+  // Cache the text lengths to prevent multiple calls.
+  var text1_length = text1.length;
+  var text2_length = text2.length;
+  // Eliminate the null case.
+  if (text1_length == 0 || text2_length == 0) {
+    return 0;
+  }
+  // Truncate the longer string.
+  if (text1_length > text2_length) {
+    text1 = text1.substring(text1_length - text2_length);
+  } else if (text1_length < text2_length) {
+    text2 = text2.substring(0, text1_length);
+  }
+  var text_length = Math.min(text1_length, text2_length);
+  // Quick check for the worst case.
+  if (text1 == text2) {
+    return text_length;
+  }
+
+  // Start by looking for a single character match
+  // and increase length until no match is found.
+  // Performance analysis: http://neil.fraser.name/news/2010/11/04/
+  var best = 0;
+  var length = 1;
+  while (true) {
+    var pattern = text1.substring(text_length - length);
+    var found = text2.indexOf(pattern);
+    if (found == -1) {
+      return best;
+    }
+    length += found;
+    if (found == 0 || text1.substring(text_length - length) ==
+        text2.substring(0, length)) {
+      best = length;
+      length++;
+    }
+  }
+};
+
+
+/**
+ * Do the two texts share a substring which is at least half the length of the
+ * longer text?
+ * This speedup can produce non-minimal diffs.
+ * @param {string} text1 First string.
+ * @param {string} text2 Second string.
+ * @return {Array.<string>} Five element Array, containing the prefix of
+ *     text1, the suffix of text1, the prefix of text2, the suffix of
+ *     text2 and the common middle.  Or null if there was no match.
+ * @private
+ */
+diff_match_patch.prototype.diff_halfMatch_ = function(text1, text2) {
+  if (this.Diff_Timeout <= 0) {
+    // Don't risk returning a non-optimal diff if we have unlimited time.
+    return null;
+  }
+  var longtext = text1.length > text2.length ? text1 : text2;
+  var shorttext = text1.length > text2.length ? text2 : text1;
+  if (longtext.length < 4 || shorttext.length * 2 < longtext.length) {
+    return null;  // Pointless.
+  }
+  var dmp = this;  // 'this' becomes 'window' in a closure.
+
+  /**
+   * Does a substring of shorttext exist within longtext such that the substring
+   * is at least half the length of longtext?
+   * Closure, but does not reference any external variables.
+   * @param {string} longtext Longer string.
+   * @param {string} shorttext Shorter string.
+   * @param {number} i Start index of quarter length substring within longtext.
+   * @return {Array.<string>} Five element Array, containing the prefix of
+   *     longtext, the suffix of longtext, the prefix of shorttext, the suffix
+   *     of shorttext and the common middle.  Or null if there was no match.
+   * @private
+   */
+  function diff_halfMatchI_(longtext, shorttext, i) {
+    // Start with a 1/4 length substring at position i as a seed.
+    var seed = longtext.substring(i, i + Math.floor(longtext.length / 4));
+    var j = -1;
+    var best_common = '';
+    var best_longtext_a, best_longtext_b, best_shorttext_a, best_shorttext_b;
+    while ((j = shorttext.indexOf(seed, j + 1)) != -1) {
+      var prefixLength = dmp.diff_commonPrefix(longtext.substring(i),
+                                               shorttext.substring(j));
+      var suffixLength = dmp.diff_commonSuffix(longtext.substring(0, i),
+                                               shorttext.substring(0, j));
+      if (best_common.length < suffixLength + prefixLength) {
+        best_common = shorttext.substring(j - suffixLength, j) +
+            shorttext.substring(j, j + prefixLength);
+        best_longtext_a = longtext.substring(0, i - suffixLength);
+        best_longtext_b = longtext.substring(i + prefixLength);
+        best_shorttext_a = shorttext.substring(0, j - suffixLength);
+        best_shorttext_b = shorttext.substring(j + prefixLength);
+      }
+    }
+    if (best_common.length * 2 >= longtext.length) {
+      return [best_longtext_a, best_longtext_b,
+              best_shorttext_a, best_shorttext_b, best_common];
+    } else {
+      return null;
+    }
+  }
+
+  // First check if the second quarter is the seed for a half-match.
+  var hm1 = diff_halfMatchI_(longtext, shorttext,
+                             Math.ceil(longtext.length / 4));
+  // Check again based on the third quarter.
+  var hm2 = diff_halfMatchI_(longtext, shorttext,
+                             Math.ceil(longtext.length / 2));
+  var hm;
+  if (!hm1 && !hm2) {
+    return null;
+  } else if (!hm2) {
+    hm = hm1;
+  } else if (!hm1) {
+    hm = hm2;
+  } else {
+    // Both matched.  Select the longest.
+    hm = hm1[4].length > hm2[4].length ? hm1 : hm2;
+  }
+
+  // A half-match was found, sort out the return data.
+  var text1_a, text1_b, text2_a, text2_b;
+  if (text1.length > text2.length) {
+    text1_a = hm[0];
+    text1_b = hm[1];
+    text2_a = hm[2];
+    text2_b = hm[3];
+  } else {
+    text2_a = hm[0];
+    text2_b = hm[1];
+    text1_a = hm[2];
+    text1_b = hm[3];
+  }
+  var mid_common = hm[4];
+  return [text1_a, text1_b, text2_a, text2_b, mid_common];
+};
+
+
+/**
+ * Reduce the number of edits by eliminating semantically trivial equalities.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ */
+diff_match_patch.prototype.diff_cleanupSemantic = function(diffs) {
+  var changes = false;
+  var equalities = [];  // Stack of indices where equalities are found.
+  var equalitiesLength = 0;  // Keeping our own length var is faster in JS.
+  /** @type {?string} */
+  var lastequality = null;
+  // Always equal to diffs[equalities[equalitiesLength - 1]][1]
+  var pointer = 0;  // Index of current position.
+  // Number of characters that changed prior to the equality.
+  var length_insertions1 = 0;
+  var length_deletions1 = 0;
+  // Number of characters that changed after the equality.
+  var length_insertions2 = 0;
+  var length_deletions2 = 0;
+  while (pointer < diffs.length) {
+    if (diffs[pointer][0] == DIFF_EQUAL) {  // Equality found.
+      equalities[equalitiesLength++] = pointer;
+      length_insertions1 = length_insertions2;
+      length_deletions1 = length_deletions2;
+      length_insertions2 = 0;
+      length_deletions2 = 0;
+      lastequality = diffs[pointer][1];
+    } else {  // An insertion or deletion.
+      if (diffs[pointer][0] == DIFF_INSERT) {
+        length_insertions2 += diffs[pointer][1].length;
+      } else {
+        length_deletions2 += diffs[pointer][1].length;
+      }
+      // Eliminate an equality that is smaller or equal to the edits on both
+      // sides of it.
+      if (lastequality && (lastequality.length <=
+          Math.max(length_insertions1, length_deletions1)) &&
+          (lastequality.length <= Math.max(length_insertions2,
+                                           length_deletions2))) {
+        // Duplicate record.
+        diffs.splice(equalities[equalitiesLength - 1], 0,
+                     [DIFF_DELETE, lastequality]);
+        // Change second copy to insert.
+        diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT;
+        // Throw away the equality we just deleted.
+        equalitiesLength--;
+        // Throw away the previous equality (it needs to be reevaluated).
+        equalitiesLength--;
+        pointer = equalitiesLength > 0 ? equalities[equalitiesLength - 1] : -1;
+        length_insertions1 = 0;  // Reset the counters.
+        length_deletions1 = 0;
+        length_insertions2 = 0;
+        length_deletions2 = 0;
+        lastequality = null;
+        changes = true;
+      }
+    }
+    pointer++;
+  }
+
+  // Normalize the diff.
+  if (changes) {
+    this.diff_cleanupMerge(diffs);
+  }
+  this.diff_cleanupSemanticLossless(diffs);
+
+  // Find any overlaps between deletions and insertions.
+  // e.g: <del>abcxxx</del><ins>xxxdef</ins>
+  //   -> <del>abc</del>xxx<ins>def</ins>
+  // e.g: <del>xxxabc</del><ins>defxxx</ins>
+  //   -> <ins>def</ins>xxx<del>abc</del>
+  // Only extract an overlap if it is as big as the edit ahead or behind it.
+  pointer = 1;
+  while (pointer < diffs.length) {
+    if (diffs[pointer - 1][0] == DIFF_DELETE &&
+        diffs[pointer][0] == DIFF_INSERT) {
+      var deletion = diffs[pointer - 1][1];
+      var insertion = diffs[pointer][1];
+      var overlap_length1 = this.diff_commonOverlap_(deletion, insertion);
+      var overlap_length2 = this.diff_commonOverlap_(insertion, deletion);
+      if (overlap_length1 >= overlap_length2) {
+        if (overlap_length1 >= deletion.length / 2 ||
+            overlap_length1 >= insertion.length / 2) {
+          // Overlap found.  Insert an equality and trim the surrounding edits.
+          diffs.splice(pointer, 0,
+              [DIFF_EQUAL, insertion.substring(0, overlap_length1)]);
+          diffs[pointer - 1][1] =
+              deletion.substring(0, deletion.length - overlap_length1);
+          diffs[pointer + 1][1] = insertion.substring(overlap_length1);
+          pointer++;
+        }
+      } else {
+        if (overlap_length2 >= deletion.length / 2 ||
+            overlap_length2 >= insertion.length / 2) {
+          // Reverse overlap found.
+          // Insert an equality and swap and trim the surrounding edits.
+          diffs.splice(pointer, 0,
+              [DIFF_EQUAL, deletion.substring(0, overlap_length2)]);
+          diffs[pointer - 1][0] = DIFF_INSERT;
+          diffs[pointer - 1][1] =
+              insertion.substring(0, insertion.length - overlap_length2);
+          diffs[pointer + 1][0] = DIFF_DELETE;
+          diffs[pointer + 1][1] =
+              deletion.substring(overlap_length2);
+          pointer++;
+        }
+      }
+      pointer++;
+    }
+    pointer++;
+  }
+};
+
+
+/**
+ * Look for single edits surrounded on both sides by equalities
+ * which can be shifted sideways to align the edit to a word boundary.
+ * e.g: The c<ins>at c</ins>ame. -> The <ins>cat </ins>came.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ */
+diff_match_patch.prototype.diff_cleanupSemanticLossless = function(diffs) {
+  /**
+   * Given two strings, compute a score representing whether the internal
+   * boundary falls on logical boundaries.
+   * Scores range from 6 (best) to 0 (worst).
+   * Closure, but does not reference any external variables.
+   * @param {string} one First string.
+   * @param {string} two Second string.
+   * @return {number} The score.
+   * @private
+   */
+  function diff_cleanupSemanticScore_(one, two) {
+    if (!one || !two) {
+      // Edges are the best.
+      return 6;
+    }
+
+    // Each port of this function behaves slightly differently due to
+    // subtle differences in each language's definition of things like
+    // 'whitespace'.  Since this function's purpose is largely cosmetic,
+    // the choice has been made to use each language's native features
+    // rather than force total conformity.
+    var char1 = one.charAt(one.length - 1);
+    var char2 = two.charAt(0);
+    var nonAlphaNumeric1 = char1.match(diff_match_patch.nonAlphaNumericRegex_);
+    var nonAlphaNumeric2 = char2.match(diff_match_patch.nonAlphaNumericRegex_);
+    var whitespace1 = nonAlphaNumeric1 &&
+        char1.match(diff_match_patch.whitespaceRegex_);
+    var whitespace2 = nonAlphaNumeric2 &&
+        char2.match(diff_match_patch.whitespaceRegex_);
+    var lineBreak1 = whitespace1 &&
+        char1.match(diff_match_patch.linebreakRegex_);
+    var lineBreak2 = whitespace2 &&
+        char2.match(diff_match_patch.linebreakRegex_);
+    var blankLine1 = lineBreak1 &&
+        one.match(diff_match_patch.blanklineEndRegex_);
+    var blankLine2 = lineBreak2 &&
+        two.match(diff_match_patch.blanklineStartRegex_);
+
+    if (blankLine1 || blankLine2) {
+      // Five points for blank lines.
+      return 5;
+    } else if (lineBreak1 || lineBreak2) {
+      // Four points for line breaks.
+      return 4;
+    } else if (nonAlphaNumeric1 && !whitespace1 && whitespace2) {
+      // Three points for end of sentences.
+      return 3;
+    } else if (whitespace1 || whitespace2) {
+      // Two points for whitespace.
+      return 2;
+    } else if (nonAlphaNumeric1 || nonAlphaNumeric2) {
+      // One point for non-alphanumeric.
+      return 1;
+    }
+    return 0;
+  }
+
+  var pointer = 1;
+  // Intentionally ignore the first and last element (don't need checking).
+  while (pointer < diffs.length - 1) {
+    if (diffs[pointer - 1][0] == DIFF_EQUAL &&
+        diffs[pointer + 1][0] == DIFF_EQUAL) {
+      // This is a single edit surrounded by equalities.
+      var equality1 = diffs[pointer - 1][1];
+      var edit = diffs[pointer][1];
+      var equality2 = diffs[pointer + 1][1];
+
+      // First, shift the edit as far left as possible.
+      var commonOffset = this.diff_commonSuffix(equality1, edit);
+      if (commonOffset) {
+        var commonString = edit.substring(edit.length - commonOffset);
+        equality1 = equality1.substring(0, equality1.length - commonOffset);
+        edit = commonString + edit.substring(0, edit.length - commonOffset);
+        equality2 = commonString + equality2;
+      }
+
+      // Second, step character by character right, looking for the best fit.
+      var bestEquality1 = equality1;
+      var bestEdit = edit;
+      var bestEquality2 = equality2;
+      var bestScore = diff_cleanupSemanticScore_(equality1, edit) +
+          diff_cleanupSemanticScore_(edit, equality2);
+      while (edit.charAt(0) === equality2.charAt(0)) {
+        equality1 += edit.charAt(0);
+        edit = edit.substring(1) + equality2.charAt(0);
+        equality2 = equality2.substring(1);
+        var score = diff_cleanupSemanticScore_(equality1, edit) +
+            diff_cleanupSemanticScore_(edit, equality2);
+        // The >= encourages trailing rather than leading whitespace on edits.
+        if (score >= bestScore) {
+          bestScore = score;
+          bestEquality1 = equality1;
+          bestEdit = edit;
+          bestEquality2 = equality2;
+        }
+      }
+
+      if (diffs[pointer - 1][1] != bestEquality1) {
+        // We have an improvement, save it back to the diff.
+        if (bestEquality1) {
+          diffs[pointer - 1][1] = bestEquality1;
+        } else {
+          diffs.splice(pointer - 1, 1);
+          pointer--;
+        }
+        diffs[pointer][1] = bestEdit;
+        if (bestEquality2) {
+          diffs[pointer + 1][1] = bestEquality2;
+        } else {
+          diffs.splice(pointer + 1, 1);
+          pointer--;
+        }
+      }
+    }
+    pointer++;
+  }
+};
+
+// Define some regex patterns for matching boundaries.
+diff_match_patch.nonAlphaNumericRegex_ = /[^a-zA-Z0-9]/;
+diff_match_patch.whitespaceRegex_ = /\s/;
+diff_match_patch.linebreakRegex_ = /[\r\n]/;
+diff_match_patch.blanklineEndRegex_ = /\n\r?\n$/;
+diff_match_patch.blanklineStartRegex_ = /^\r?\n\r?\n/;
+
+/**
+ * Reduce the number of edits by eliminating operationally trivial equalities.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ */
+diff_match_patch.prototype.diff_cleanupEfficiency = function(diffs) {
+  var changes = false;
+  var equalities = [];  // Stack of indices where equalities are found.
+  var equalitiesLength = 0;  // Keeping our own length var is faster in JS.
+  /** @type {?string} */
+  var lastequality = null;
+  // Always equal to diffs[equalities[equalitiesLength - 1]][1]
+  var pointer = 0;  // Index of current position.
+  // Is there an insertion operation before the last equality.
+  var pre_ins = false;
+  // Is there a deletion operation before the last equality.
+  var pre_del = false;
+  // Is there an insertion operation after the last equality.
+  var post_ins = false;
+  // Is there a deletion operation after the last equality.
+  var post_del = false;
+  while (pointer < diffs.length) {
+    if (diffs[pointer][0] == DIFF_EQUAL) {  // Equality found.
+      if (diffs[pointer][1].length < this.Diff_EditCost &&
+          (post_ins || post_del)) {
+        // Candidate found.
+        equalities[equalitiesLength++] = pointer;
+        pre_ins = post_ins;
+        pre_del = post_del;
+        lastequality = diffs[pointer][1];
+      } else {
+        // Not a candidate, and can never become one.
+        equalitiesLength = 0;
+        lastequality = null;
+      }
+      post_ins = post_del = false;
+    } else {  // An insertion or deletion.
+      if (diffs[pointer][0] == DIFF_DELETE) {
+        post_del = true;
+      } else {
+        post_ins = true;
+      }
+      /*
+       * Five types to be split:
+       * <ins>A</ins><del>B</del>XY<ins>C</ins><del>D</del>
+       * <ins>A</ins>X<ins>C</ins><del>D</del>
+       * <ins>A</ins><del>B</del>X<ins>C</ins>
+       * <ins>A</del>X<ins>C</ins><del>D</del>
+       * <ins>A</ins><del>B</del>X<del>C</del>
+       */
+      if (lastequality && ((pre_ins && pre_del && post_ins && post_del) ||
+                           ((lastequality.length < this.Diff_EditCost / 2) &&
+                            (pre_ins + pre_del + post_ins + post_del) == 3))) {
+        // Duplicate record.
+        diffs.splice(equalities[equalitiesLength - 1], 0,
+                     [DIFF_DELETE, lastequality]);
+        // Change second copy to insert.
+        diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT;
+        equalitiesLength--;  // Throw away the equality we just deleted;
+        lastequality = null;
+        if (pre_ins && pre_del) {
+          // No changes made which could affect previous entry, keep going.
+          post_ins = post_del = true;
+          equalitiesLength = 0;
+        } else {
+          equalitiesLength--;  // Throw away the previous equality.
+          pointer = equalitiesLength > 0 ?
+              equalities[equalitiesLength - 1] : -1;
+          post_ins = post_del = false;
+        }
+        changes = true;
+      }
+    }
+    pointer++;
+  }
+
+  if (changes) {
+    this.diff_cleanupMerge(diffs);
+  }
+};
+
+
+/**
+ * Reorder and merge like edit sections.  Merge equalities.
+ * Any edit section can move as long as it doesn't cross an equality.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ */
+diff_match_patch.prototype.diff_cleanupMerge = function(diffs) {
+  diffs.push([DIFF_EQUAL, '']);  // Add a dummy entry at the end.
+  var pointer = 0;
+  var count_delete = 0;
+  var count_insert = 0;
+  var text_delete = '';
+  var text_insert = '';
+  var commonlength;
+  while (pointer < diffs.length) {
+    switch (diffs[pointer][0]) {
+      case DIFF_INSERT:
+        count_insert++;
+        text_insert += diffs[pointer][1];
+        pointer++;
+        break;
+      case DIFF_DELETE:
+        count_delete++;
+        text_delete += diffs[pointer][1];
+        pointer++;
+        break;
+      case DIFF_EQUAL:
+        // Upon reaching an equality, check for prior redundancies.
+        if (count_delete + count_insert > 1) {
+          if (count_delete !== 0 && count_insert !== 0) {
+            // Factor out any common prefixies.
+            commonlength = this.diff_commonPrefix(text_insert, text_delete);
+            if (commonlength !== 0) {
+              if ((pointer - count_delete - count_insert) > 0 &&
+                  diffs[pointer - count_delete - count_insert - 1][0] ==
+                  DIFF_EQUAL) {
+                diffs[pointer - count_delete - count_insert - 1][1] +=
+                    text_insert.substring(0, commonlength);
+              } else {
+                diffs.splice(0, 0, [DIFF_EQUAL,
+                                    text_insert.substring(0, commonlength)]);
+                pointer++;
+              }
+              text_insert = text_insert.substring(commonlength);
+              text_delete = text_delete.substring(commonlength);
+            }
+            // Factor out any common suffixies.
+            commonlength = this.diff_commonSuffix(text_insert, text_delete);
+            if (commonlength !== 0) {
+              diffs[pointer][1] = text_insert.substring(text_insert.length -
+                  commonlength) + diffs[pointer][1];
+              text_insert = text_insert.substring(0, text_insert.length -
+                  commonlength);
+              text_delete = text_delete.substring(0, text_delete.length -
+                  commonlength);
+            }
+          }
+          // Delete the offending records and add the merged ones.
+          if (count_delete === 0) {
+            diffs.splice(pointer - count_insert,
+                count_delete + count_insert, [DIFF_INSERT, text_insert]);
+          } else if (count_insert === 0) {
+            diffs.splice(pointer - count_delete,
+                count_delete + count_insert, [DIFF_DELETE, text_delete]);
+          } else {
+            diffs.splice(pointer - count_delete - count_insert,
+                count_delete + count_insert, [DIFF_DELETE, text_delete],
+                [DIFF_INSERT, text_insert]);
+          }
+          pointer = pointer - count_delete - count_insert +
+                    (count_delete ? 1 : 0) + (count_insert ? 1 : 0) + 1;
+        } else if (pointer !== 0 && diffs[pointer - 1][0] == DIFF_EQUAL) {
+          // Merge this equality with the previous one.
+          diffs[pointer - 1][1] += diffs[pointer][1];
+          diffs.splice(pointer, 1);
+        } else {
+          pointer++;
+        }
+        count_insert = 0;
+        count_delete = 0;
+        text_delete = '';
+        text_insert = '';
+        break;
+    }
+  }
+  if (diffs[diffs.length - 1][1] === '') {
+    diffs.pop();  // Remove the dummy entry at the end.
+  }
+
+  // Second pass: look for single edits surrounded on both sides by equalities
+  // which can be shifted sideways to eliminate an equality.
+  // e.g: A<ins>BA</ins>C -> <ins>AB</ins>AC
+  var changes = false;
+  pointer = 1;
+  // Intentionally ignore the first and last element (don't need checking).
+  while (pointer < diffs.length - 1) {
+    if (diffs[pointer - 1][0] == DIFF_EQUAL &&
+        diffs[pointer + 1][0] == DIFF_EQUAL) {
+      // This is a single edit surrounded by equalities.
+      if (diffs[pointer][1].substring(diffs[pointer][1].length -
+          diffs[pointer - 1][1].length) == diffs[pointer - 1][1]) {
+        // Shift the edit over the previous equality.
+        diffs[pointer][1] = diffs[pointer - 1][1] +
+            diffs[pointer][1].substring(0, diffs[pointer][1].length -
+                                        diffs[pointer - 1][1].length);
+        diffs[pointer + 1][1] = diffs[pointer - 1][1] + diffs[pointer + 1][1];
+        diffs.splice(pointer - 1, 1);
+        changes = true;
+      } else if (diffs[pointer][1].substring(0, diffs[pointer + 1][1].length) ==
+          diffs[pointer + 1][1]) {
+        // Shift the edit over the next equality.
+        diffs[pointer - 1][1] += diffs[pointer + 1][1];
+        diffs[pointer][1] =
+            diffs[pointer][1].substring(diffs[pointer + 1][1].length) +
+            diffs[pointer + 1][1];
+        diffs.splice(pointer + 1, 1);
+        changes = true;
+      }
+    }
+    pointer++;
+  }
+  // If shifts were made, the diff needs reordering and another shift sweep.
+  if (changes) {
+    this.diff_cleanupMerge(diffs);
+  }
+};
+
+
+/**
+ * loc is a location in text1, compute and return the equivalent location in
+ * text2.
+ * e.g. 'The cat' vs 'The big cat', 1->1, 5->8
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @param {number} loc Location within text1.
+ * @return {number} Location within text2.
+ */
+diff_match_patch.prototype.diff_xIndex = function(diffs, loc) {
+  var chars1 = 0;
+  var chars2 = 0;
+  var last_chars1 = 0;
+  var last_chars2 = 0;
+  var x;
+  for (x = 0; x < diffs.length; x++) {
+    if (diffs[x][0] !== DIFF_INSERT) {  // Equality or deletion.
+      chars1 += diffs[x][1].length;
+    }
+    if (diffs[x][0] !== DIFF_DELETE) {  // Equality or insertion.
+      chars2 += diffs[x][1].length;
+    }
+    if (chars1 > loc) {  // Overshot the location.
+      break;
+    }
+    last_chars1 = chars1;
+    last_chars2 = chars2;
+  }
+  // Was the location was deleted?
+  if (diffs.length != x && diffs[x][0] === DIFF_DELETE) {
+    return last_chars2;
+  }
+  // Add the remaining character length.
+  return last_chars2 + (loc - last_chars1);
+};
+
+
+/**
+ * Convert a diff array into a pretty HTML report.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @return {string} HTML representation.
+ */
+diff_match_patch.prototype.diff_prettyHtml = function(diffs) {
+  var html = [];
+  var pattern_amp = /&/g;
+  var pattern_lt = /</g;
+  var pattern_gt = />/g;
+  var pattern_para = /\n/g;
+  for (var x = 0; x < diffs.length; x++) {
+    var op = diffs[x][0];    // Operation (insert, delete, equal)
+    var data = diffs[x][1];  // Text of change.
+    var text = data.replace(pattern_amp, '&amp;').replace(pattern_lt, '&lt;')
+        .replace(pattern_gt, '&gt;').replace(pattern_para, '&para;<br>');
+    switch (op) {
+      case DIFF_INSERT:
+        html[x] = '<ins style="background:#e6ffe6;">' + text + '</ins>';
+        break;
+      case DIFF_DELETE:
+        html[x] = '<del style="background:#ffe6e6;">' + text + '</del>';
+        break;
+      case DIFF_EQUAL:
+        html[x] = '<span>' + text + '</span>';
+        break;
+    }
+  }
+  return html.join('');
+};
+
+
+/**
+ * Compute and return the source text (all equalities and deletions).
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @return {string} Source text.
+ */
+diff_match_patch.prototype.diff_text1 = function(diffs) {
+  var text = [];
+  for (var x = 0; x < diffs.length; x++) {
+    if (diffs[x][0] !== DIFF_INSERT) {
+      text[x] = diffs[x][1];
+    }
+  }
+  return text.join('');
+};
+
+
+/**
+ * Compute and return the destination text (all equalities and insertions).
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @return {string} Destination text.
+ */
+diff_match_patch.prototype.diff_text2 = function(diffs) {
+  var text = [];
+  for (var x = 0; x < diffs.length; x++) {
+    if (diffs[x][0] !== DIFF_DELETE) {
+      text[x] = diffs[x][1];
+    }
+  }
+  return text.join('');
+};
+
+
+/**
+ * Compute the Levenshtein distance; the number of inserted, deleted or
+ * substituted characters.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @return {number} Number of changes.
+ */
+diff_match_patch.prototype.diff_levenshtein = function(diffs) {
+  var levenshtein = 0;
+  var insertions = 0;
+  var deletions = 0;
+  for (var x = 0; x < diffs.length; x++) {
+    var op = diffs[x][0];
+    var data = diffs[x][1];
+    switch (op) {
+      case DIFF_INSERT:
+        insertions += data.length;
+        break;
+      case DIFF_DELETE:
+        deletions += data.length;
+        break;
+      case DIFF_EQUAL:
+        // A deletion and an insertion is one substitution.
+        levenshtein += Math.max(insertions, deletions);
+        insertions = 0;
+        deletions = 0;
+        break;
+    }
+  }
+  levenshtein += Math.max(insertions, deletions);
+  return levenshtein;
+};
+
+
+/**
+ * Crush the diff into an encoded string which describes the operations
+ * required to transform text1 into text2.
+ * E.g. =3\t-2\t+ing  -> Keep 3 chars, delete 2 chars, insert 'ing'.
+ * Operations are tab-separated.  Inserted text is escaped using %xx notation.
+ * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+ * @return {string} Delta text.
+ */
+diff_match_patch.prototype.diff_toDelta = function(diffs) {
+  var text = [];
+  for (var x = 0; x < diffs.length; x++) {
+    switch (diffs[x][0]) {
+      case DIFF_INSERT:
+        text[x] = '+' + encodeURI(diffs[x][1]);
+        break;
+      case DIFF_DELETE:
+        text[x] = '-' + diffs[x][1].length;
+        break;
+      case DIFF_EQUAL:
+        text[x] = '=' + diffs[x][1].length;
+        break;
+    }
+  }
+  return text.join('\t').replace(/%20/g, ' ');
+};
+
+
+/**
+ * Given the original text1, and an encoded string which describes the
+ * operations required to transform text1 into text2, compute the full diff.
+ * @param {string} text1 Source string for the diff.
+ * @param {string} delta Delta text.
+ * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+ * @throws {!Error} If invalid input.
+ */
+diff_match_patch.prototype.diff_fromDelta = function(text1, delta) {
+  var diffs = [];
+  var diffsLength = 0;  // Keeping our own length var is faster in JS.
+  var pointer = 0;  // Cursor in text1
+  var tokens = delta.split(/\t/g);
+  for (var x = 0; x < tokens.length; x++) {
+    // Each token begins with a one character parameter which specifies the
+    // operation of this token (delete, insert, equality).
+    var param = tokens[x].substring(1);
+    switch (tokens[x].charAt(0)) {
+      case '+':
+        try {
+          diffs[diffsLength++] = [DIFF_INSERT, decodeURI(param)];
+        } catch (ex) {
+          // Malformed URI sequence.
+          throw new Error('Illegal escape in diff_fromDelta: ' + param);
+        }
+        break;
+      case '-':
+        // Fall through.
+      case '=':
+        var n = parseInt(param, 10);
+        if (isNaN(n) || n < 0) {
+          throw new Error('Invalid number in diff_fromDelta: ' + param);
+        }
+        var text = text1.substring(pointer, pointer += n);
+        if (tokens[x].charAt(0) == '=') {
+          diffs[diffsLength++] = [DIFF_EQUAL, text];
+        } else {
+          diffs[diffsLength++] = [DIFF_DELETE, text];
+        }
+        break;
+      default:
+        // Blank tokens are ok (from a trailing \t).
+        // Anything else is an error.
+        if (tokens[x]) {
+          throw new Error('Invalid diff operation in diff_fromDelta: ' +
+                          tokens[x]);
+        }
+    }
+  }
+  if (pointer != text1.length) {
+    throw new Error('Delta length (' + pointer +
+        ') does not equal source text length (' + text1.length + ').');
+  }
+  return diffs;
+};
+
+
+//  MATCH FUNCTIONS
+
+
+/**
+ * Locate the best instance of 'pattern' in 'text' near 'loc'.
+ * @param {string} text The text to search.
+ * @param {string} pattern The pattern to search for.
+ * @param {number} loc The location to search around.
+ * @return {number} Best match index or -1.
+ */
+diff_match_patch.prototype.match_main = function(text, pattern, loc) {
+  // Check for null inputs.
+  if (text == null || pattern == null || loc == null) {
+    throw new Error('Null input. (match_main)');
+  }
+
+  loc = Math.max(0, Math.min(loc, text.length));
+  if (text == pattern) {
+    // Shortcut (potentially not guaranteed by the algorithm)
+    return 0;
+  } else if (!text.length) {
+    // Nothing to match.
+    return -1;
+  } else if (text.substring(loc, loc + pattern.length) == pattern) {
+    // Perfect match at the perfect spot!  (Includes case of null pattern)
+    return loc;
+  } else {
+    // Do a fuzzy compare.
+    return this.match_bitap_(text, pattern, loc);
+  }
+};
+
+
+/**
+ * Locate the best instance of 'pattern' in 'text' near 'loc' using the
+ * Bitap algorithm.
+ * @param {string} text The text to search.
+ * @param {string} pattern The pattern to search for.
+ * @param {number} loc The location to search around.
+ * @return {number} Best match index or -1.
+ * @private
+ */
+diff_match_patch.prototype.match_bitap_ = function(text, pattern, loc) {
+  if (pattern.length > this.Match_MaxBits) {
+    throw new Error('Pattern too long for this browser.');
+  }
+
+  // Initialise the alphabet.
+  var s = this.match_alphabet_(pattern);
+
+  var dmp = this;  // 'this' becomes 'window' in a closure.
+
+  /**
+   * Compute and return the score for a match with e errors and x location.
+   * Accesses loc and pattern through being a closure.
+   * @param {number} e Number of errors in match.
+   * @param {number} x Location of match.
+   * @return {number} Overall score for match (0.0 = good, 1.0 = bad).
+   * @private
+   */
+  function match_bitapScore_(e, x) {
+    var accuracy = e / pattern.length;
+    var proximity = Math.abs(loc - x);
+    if (!dmp.Match_Distance) {
+      // Dodge divide by zero error.
+      return proximity ? 1.0 : accuracy;
+    }
+    return accuracy + (proximity / dmp.Match_Distance);
+  }
+
+  // Highest score beyond which we give up.
+  var score_threshold = this.Match_Threshold;
+  // Is there a nearby exact match? (speedup)
+  var best_loc = text.indexOf(pattern, loc);
+  if (best_loc != -1) {
+    score_threshold = Math.min(match_bitapScore_(0, best_loc), score_threshold);
+    // What about in the other direction? (speedup)
+    best_loc = text.lastIndexOf(pattern, loc + pattern.length);
+    if (best_loc != -1) {
+      score_threshold =
+          Math.min(match_bitapScore_(0, best_loc), score_threshold);
+    }
+  }
+
+  // Initialise the bit arrays.
+  var matchmask = 1 << (pattern.length - 1);
+  best_loc = -1;
+
+  var bin_min, bin_mid;
+  var bin_max = pattern.length + text.length;
+  var last_rd;
+  for (var d = 0; d < pattern.length; d++) {
+    // Scan for the best match; each iteration allows for one more error.
+    // Run a binary search to determine how far from 'loc' we can stray at this
+    // error level.
+    bin_min = 0;
+    bin_mid = bin_max;
+    while (bin_min < bin_mid) {
+      if (match_bitapScore_(d, loc + bin_mid) <= score_threshold) {
+        bin_min = bin_mid;
+      } else {
+        bin_max = bin_mid;
+      }
+      bin_mid = Math.floor((bin_max - bin_min) / 2 + bin_min);
+    }
+    // Use the result from this iteration as the maximum for the next.
+    bin_max = bin_mid;
+    var start = Math.max(1, loc - bin_mid + 1);
+    var finish = Math.min(loc + bin_mid, text.length) + pattern.length;
+
+    var rd = Array(finish + 2);
+    rd[finish + 1] = (1 << d) - 1;
+    for (var j = finish; j >= start; j--) {
+      // The alphabet (s) is a sparse hash, so the following line generates
+      // warnings.
+      var charMatch = s[text.charAt(j - 1)];
+      if (d === 0) {  // First pass: exact match.
+        rd[j] = ((rd[j + 1] << 1) | 1) & charMatch;
+      } else {  // Subsequent passes: fuzzy match.
+        rd[j] = (((rd[j + 1] << 1) | 1) & charMatch) |
+                (((last_rd[j + 1] | last_rd[j]) << 1) | 1) |
+                last_rd[j + 1];
+      }
+      if (rd[j] & matchmask) {
+        var score = match_bitapScore_(d, j - 1);
+        // This match will almost certainly be better than any existing match.
+        // But check anyway.
+        if (score <= score_threshold) {
+          // Told you so.
+          score_threshold = score;
+          best_loc = j - 1;
+          if (best_loc > loc) {
+            // When passing loc, don't exceed our current distance from loc.
+            start = Math.max(1, 2 * loc - best_loc);
+          } else {
+            // Already passed loc, downhill from here on in.
+            break;
+          }
+        }
+      }
+    }
+    // No hope for a (better) match at greater error levels.
+    if (match_bitapScore_(d + 1, loc) > score_threshold) {
+      break;
+    }
+    last_rd = rd;
+  }
+  return best_loc;
+};
+
+
+/**
+ * Initialise the alphabet for the Bitap algorithm.
+ * @param {string} pattern The text to encode.
+ * @return {!Object} Hash of character locations.
+ * @private
+ */
+diff_match_patch.prototype.match_alphabet_ = function(pattern) {
+  var s = {};
+  for (var i = 0; i < pattern.length; i++) {
+    s[pattern.charAt(i)] = 0;
+  }
+  for (var i = 0; i < pattern.length; i++) {
+    s[pattern.charAt(i)] |= 1 << (pattern.length - i - 1);
+  }
+  return s;
+};
+
+
+//  PATCH FUNCTIONS
+
+
+/**
+ * Increase the context until it is unique,
+ * but don't let the pattern expand beyond Match_MaxBits.
+ * @param {!diff_match_patch.patch_obj} patch The patch to grow.
+ * @param {string} text Source text.
+ * @private
+ */
+diff_match_patch.prototype.patch_addContext_ = function(patch, text) {
+  if (text.length == 0) {
+    return;
+  }
+  var pattern = text.substring(patch.start2, patch.start2 + patch.length1);
+  var padding = 0;
+
+  // Look for the first and last matches of pattern in text.  If two different
+  // matches are found, increase the pattern length.
+  while (text.indexOf(pattern) != text.lastIndexOf(pattern) &&
+         pattern.length < this.Match_MaxBits - this.Patch_Margin -
+         this.Patch_Margin) {
+    padding += this.Patch_Margin;
+    pattern = text.substring(patch.start2 - padding,
+                             patch.start2 + patch.length1 + padding);
+  }
+  // Add one chunk for good luck.
+  padding += this.Patch_Margin;
+
+  // Add the prefix.
+  var prefix = text.substring(patch.start2 - padding, patch.start2);
+  if (prefix) {
+    patch.diffs.unshift([DIFF_EQUAL, prefix]);
+  }
+  // Add the suffix.
+  var suffix = text.substring(patch.start2 + patch.length1,
+                              patch.start2 + patch.length1 + padding);
+  if (suffix) {
+    patch.diffs.push([DIFF_EQUAL, suffix]);
+  }
+
+  // Roll back the start points.
+  patch.start1 -= prefix.length;
+  patch.start2 -= prefix.length;
+  // Extend the lengths.
+  patch.length1 += prefix.length + suffix.length;
+  patch.length2 += prefix.length + suffix.length;
+};
+
+
+/**
+ * Compute a list of patches to turn text1 into text2.
+ * Use diffs if provided, otherwise compute it ourselves.
+ * There are four ways to call this function, depending on what data is
+ * available to the caller:
+ * Method 1:
+ * a = text1, b = text2
+ * Method 2:
+ * a = diffs
+ * Method 3 (optimal):
+ * a = text1, b = diffs
+ * Method 4 (deprecated, use method 3):
+ * a = text1, b = text2, c = diffs
+ *
+ * @param {string|!Array.<!diff_match_patch.Diff>} a text1 (methods 1,3,4) or
+ * Array of diff tuples for text1 to text2 (method 2).
+ * @param {string|!Array.<!diff_match_patch.Diff>} opt_b text2 (methods 1,4) or
+ * Array of diff tuples for text1 to text2 (method 3) or undefined (method 2).
+ * @param {string|!Array.<!diff_match_patch.Diff>} opt_c Array of diff tuples
+ * for text1 to text2 (method 4) or undefined (methods 1,2,3).
+ * @return {!Array.<!diff_match_patch.patch_obj>} Array of Patch objects.
+ */
+diff_match_patch.prototype.patch_make = function(a, opt_b, opt_c) {
+  var text1, diffs;
+  if (typeof a == 'string' && typeof opt_b == 'string' &&
+      typeof opt_c == 'undefined') {
+    // Method 1: text1, text2
+    // Compute diffs from text1 and text2.
+    text1 = /** @type {string} */(a);
+    diffs = this.diff_main(text1, /** @type {string} */(opt_b), true);
+    if (diffs.length > 2) {
+      this.diff_cleanupSemantic(diffs);
+      this.diff_cleanupEfficiency(diffs);
+    }
+  } else if (a && typeof a == 'object' && typeof opt_b == 'undefined' &&
+      typeof opt_c == 'undefined') {
+    // Method 2: diffs
+    // Compute text1 from diffs.
+    diffs = /** @type {!Array.<!diff_match_patch.Diff>} */(a);
+    text1 = this.diff_text1(diffs);
+  } else if (typeof a == 'string' && opt_b && typeof opt_b == 'object' &&
+      typeof opt_c == 'undefined') {
+    // Method 3: text1, diffs
+    text1 = /** @type {string} */(a);
+    diffs = /** @type {!Array.<!diff_match_patch.Diff>} */(opt_b);
+  } else if (typeof a == 'string' && typeof opt_b == 'string' &&
+      opt_c && typeof opt_c == 'object') {
+    // Method 4: text1, text2, diffs
+    // text2 is not used.
+    text1 = /** @type {string} */(a);
+    diffs = /** @type {!Array.<!diff_match_patch.Diff>} */(opt_c);
+  } else {
+    throw new Error('Unknown call format to patch_make.');
+  }
+
+  if (diffs.length === 0) {
+    return [];  // Get rid of the null case.
+  }
+  var patches = [];
+  var patch = new diff_match_patch.patch_obj();
+  var patchDiffLength = 0;  // Keeping our own length var is faster in JS.
+  var char_count1 = 0;  // Number of characters into the text1 string.
+  var char_count2 = 0;  // Number of characters into the text2 string.
+  // Start with text1 (prepatch_text) and apply the diffs until we arrive at
+  // text2 (postpatch_text).  We recreate the patches one by one to determine
+  // context info.
+  var prepatch_text = text1;
+  var postpatch_text = text1;
+  for (var x = 0; x < diffs.length; x++) {
+    var diff_type = diffs[x][0];
+    var diff_text = diffs[x][1];
+
+    if (!patchDiffLength && diff_type !== DIFF_EQUAL) {
+      // A new patch starts here.
+      patch.start1 = char_count1;
+      patch.start2 = char_count2;
+    }
+
+    switch (diff_type) {
+      case DIFF_INSERT:
+        patch.diffs[patchDiffLength++] = diffs[x];
+        patch.length2 += diff_text.length;
+        postpatch_text = postpatch_text.substring(0, char_count2) + diff_text +
+                         postpatch_text.substring(char_count2);
+        break;
+      case DIFF_DELETE:
+        patch.length1 += diff_text.length;
+        patch.diffs[patchDiffLength++] = diffs[x];
+        postpatch_text = postpatch_text.substring(0, char_count2) +
+                         postpatch_text.substring(char_count2 +
+                             diff_text.length);
+        break;
+      case DIFF_EQUAL:
+        if (diff_text.length <= 2 * this.Patch_Margin &&
+            patchDiffLength && diffs.length != x + 1) {
+          // Small equality inside a patch.
+          patch.diffs[patchDiffLength++] = diffs[x];
+          patch.length1 += diff_text.length;
+          patch.length2 += diff_text.length;
+        } else if (diff_text.length >= 2 * this.Patch_Margin) {
+          // Time for a new patch.
+          if (patchDiffLength) {
+            this.patch_addContext_(patch, prepatch_text);
+            patches.push(patch);
+            patch = new diff_match_patch.patch_obj();
+            patchDiffLength = 0;
+            // Unlike Unidiff, our patch lists have a rolling context.
+            // http://code.google.com/p/google-diff-match-patch/wiki/Unidiff
+            // Update prepatch text & pos to reflect the application of the
+            // just completed patch.
+            prepatch_text = postpatch_text;
+            char_count1 = char_count2;
+          }
+        }
+        break;
+    }
+
+    // Update the current character count.
+    if (diff_type !== DIFF_INSERT) {
+      char_count1 += diff_text.length;
+    }
+    if (diff_type !== DIFF_DELETE) {
+      char_count2 += diff_text.length;
+    }
+  }
+  // Pick up the leftover patch if not empty.
+  if (patchDiffLength) {
+    this.patch_addContext_(patch, prepatch_text);
+    patches.push(patch);
+  }
+
+  return patches;
+};
+
+
+/**
+ * Given an array of patches, return another array that is identical.
+ * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of Patch objects.
+ * @return {!Array.<!diff_match_patch.patch_obj>} Array of Patch objects.
+ */
+diff_match_patch.prototype.patch_deepCopy = function(patches) {
+  // Making deep copies is hard in JavaScript.
+  var patchesCopy = [];
+  for (var x = 0; x < patches.length; x++) {
+    var patch = patches[x];
+    var patchCopy = new diff_match_patch.patch_obj();
+    patchCopy.diffs = [];
+    for (var y = 0; y < patch.diffs.length; y++) {
+      patchCopy.diffs[y] = patch.diffs[y].slice();
+    }
+    patchCopy.start1 = patch.start1;
+    patchCopy.start2 = patch.start2;
+    patchCopy.length1 = patch.length1;
+    patchCopy.length2 = patch.length2;
+    patchesCopy[x] = patchCopy;
+  }
+  return patchesCopy;
+};
+
+
+/**
+ * Merge a set of patches onto the text.  Return a patched text, as well
+ * as a list of true/false values indicating which patches were applied.
+ * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of Patch objects.
+ * @param {string} text Old text.
+ * @return {!Array.<string|!Array.<boolean>>} Two element Array, containing the
+ *      new text and an array of boolean values.
+ */
+diff_match_patch.prototype.patch_apply = function(patches, text) {
+  if (patches.length == 0) {
+    return [text, []];
+  }
+
+  // Deep copy the patches so that no changes are made to originals.
+  patches = this.patch_deepCopy(patches);
+
+  var nullPadding = this.patch_addPadding(patches);
+  text = nullPadding + text + nullPadding;
+
+  this.patch_splitMax(patches);
+  // delta keeps track of the offset between the expected and actual location
+  // of the previous patch.  If there are patches expected at positions 10 and
+  // 20, but the first patch was found at 12, delta is 2 and the second patch
+  // has an effective expected position of 22.
+  var delta = 0;
+  var results = [];
+  for (var x = 0; x < patches.length; x++) {
+    var expected_loc = patches[x].start2 + delta;
+    var text1 = this.diff_text1(patches[x].diffs);
+    var start_loc;
+    var end_loc = -1;
+    if (text1.length > this.Match_MaxBits) {
+      // patch_splitMax will only provide an oversized pattern in the case of
+      // a monster delete.
+      start_loc = this.match_main(text, text1.substring(0, this.Match_MaxBits),
+                                  expected_loc);
+      if (start_loc != -1) {
+        end_loc = this.match_main(text,
+            text1.substring(text1.length - this.Match_MaxBits),
+            expected_loc + text1.length - this.Match_MaxBits);
+        if (end_loc == -1 || start_loc >= end_loc) {
+          // Can't find valid trailing context.  Drop this patch.
+          start_loc = -1;
+        }
+      }
+    } else {
+      start_loc = this.match_main(text, text1, expected_loc);
+    }
+    if (start_loc == -1) {
+      // No match found.  :(
+      results[x] = false;
+      // Subtract the delta for this failed patch from subsequent patches.
+      delta -= patches[x].length2 - patches[x].length1;
+    } else {
+      // Found a match.  :)
+      results[x] = true;
+      delta = start_loc - expected_loc;
+      var text2;
+      if (end_loc == -1) {
+        text2 = text.substring(start_loc, start_loc + text1.length);
+      } else {
+        text2 = text.substring(start_loc, end_loc + this.Match_MaxBits);
+      }
+      if (text1 == text2) {
+        // Perfect match, just shove the replacement text in.
+        text = text.substring(0, start_loc) +
+               this.diff_text2(patches[x].diffs) +
+               text.substring(start_loc + text1.length);
+      } else {
+        // Imperfect match.  Run a diff to get a framework of equivalent
+        // indices.
+        var diffs = this.diff_main(text1, text2, false);
+        if (text1.length > this.Match_MaxBits &&
+            this.diff_levenshtein(diffs) / text1.length >
+            this.Patch_DeleteThreshold) {
+          // The end points match, but the content is unacceptably bad.
+          results[x] = false;
+        } else {
+          this.diff_cleanupSemanticLossless(diffs);
+          var index1 = 0;
+          var index2;
+          for (var y = 0; y < patches[x].diffs.length; y++) {
+            var mod = patches[x].diffs[y];
+            if (mod[0] !== DIFF_EQUAL) {
+              index2 = this.diff_xIndex(diffs, index1);
+            }
+            if (mod[0] === DIFF_INSERT) {  // Insertion
+              text = text.substring(0, start_loc + index2) + mod[1] +
+                     text.substring(start_loc + index2);
+            } else if (mod[0] === DIFF_DELETE) {  // Deletion
+              text = text.substring(0, start_loc + index2) +
+                     text.substring(start_loc + this.diff_xIndex(diffs,
+                         index1 + mod[1].length));
+            }
+            if (mod[0] !== DIFF_DELETE) {
+              index1 += mod[1].length;
+            }
+          }
+        }
+      }
+    }
+  }
+  // Strip the padding off.
+  text = text.substring(nullPadding.length, text.length - nullPadding.length);
+  return [text, results];
+};
+
+
+/**
+ * Add some padding on text start and end so that edges can match something.
+ * Intended to be called only from within patch_apply.
+ * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of Patch objects.
+ * @return {string} The padding string added to each side.
+ */
+diff_match_patch.prototype.patch_addPadding = function(patches) {
+  var paddingLength = this.Patch_Margin;
+  var nullPadding = '';
+  for (var x = 1; x <= paddingLength; x++) {
+    nullPadding += String.fromCharCode(x);
+  }
+
+  // Bump all the patches forward.
+  for (var x = 0; x < patches.length; x++) {
+    patches[x].start1 += paddingLength;
+    patches[x].start2 += paddingLength;
+  }
+
+  // Add some padding on start of first diff.
+  var patch = patches[0];
+  var diffs = patch.diffs;
+  if (diffs.length == 0 || diffs[0][0] != DIFF_EQUAL) {
+    // Add nullPadding equality.
+    diffs.unshift([DIFF_EQUAL, nullPadding]);
+    patch.start1 -= paddingLength;  // Should be 0.
+    patch.start2 -= paddingLength;  // Should be 0.
+    patch.length1 += paddingLength;
+    patch.length2 += paddingLength;
+  } else if (paddingLength > diffs[0][1].length) {
+    // Grow first equality.
+    var extraLength = paddingLength - diffs[0][1].length;
+    diffs[0][1] = nullPadding.substring(diffs[0][1].length) + diffs[0][1];
+    patch.start1 -= extraLength;
+    patch.start2 -= extraLength;
+    patch.length1 += extraLength;
+    patch.length2 += extraLength;
+  }
+
+  // Add some padding on end of last diff.
+  patch = patches[patches.length - 1];
+  diffs = patch.diffs;
+  if (diffs.length == 0 || diffs[diffs.length - 1][0] != DIFF_EQUAL) {
+    // Add nullPadding equality.
+    diffs.push([DIFF_EQUAL, nullPadding]);
+    patch.length1 += paddingLength;
+    patch.length2 += paddingLength;
+  } else if (paddingLength > diffs[diffs.length - 1][1].length) {
+    // Grow last equality.
+    var extraLength = paddingLength - diffs[diffs.length - 1][1].length;
+    diffs[diffs.length - 1][1] += nullPadding.substring(0, extraLength);
+    patch.length1 += extraLength;
+    patch.length2 += extraLength;
+  }
+
+  return nullPadding;
+};
+
+
+/**
+ * Look through the patches and break up any which are longer than the maximum
+ * limit of the match algorithm.
+ * Intended to be called only from within patch_apply.
+ * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of Patch objects.
+ */
+diff_match_patch.prototype.patch_splitMax = function(patches) {
+  var patch_size = this.Match_MaxBits;
+  for (var x = 0; x < patches.length; x++) {
+    if (patches[x].length1 <= patch_size) {
+      continue;
+    }
+    var bigpatch = patches[x];
+    // Remove the big old patch.
+    patches.splice(x--, 1);
+    var start1 = bigpatch.start1;
+    var start2 = bigpatch.start2;
+    var precontext = '';
+    while (bigpatch.diffs.length !== 0) {
+      // Create one of several smaller patches.
+      var patch = new diff_match_patch.patch_obj();
+      var empty = true;
+      patch.start1 = start1 - precontext.length;
+      patch.start2 = start2 - precontext.length;
+      if (precontext !== '') {
+        patch.length1 = patch.length2 = precontext.length;
+        patch.diffs.push([DIFF_EQUAL, precontext]);
+      }
+      while (bigpatch.diffs.length !== 0 &&
+             patch.length1 < patch_size - this.Patch_Margin) {
+        var diff_type = bigpatch.diffs[0][0];
+        var diff_text = bigpatch.diffs[0][1];
+        if (diff_type === DIFF_INSERT) {
+          // Insertions are harmless.
+          patch.length2 += diff_text.length;
+          start2 += diff_text.length;
+          patch.diffs.push(bigpatch.diffs.shift());
+          empty = false;
+        } else if (diff_type === DIFF_DELETE && patch.diffs.length == 1 &&
+                   patch.diffs[0][0] == DIFF_EQUAL &&
+                   diff_text.length > 2 * patch_size) {
+          // This is a large deletion.  Let it pass in one chunk.
+          patch.length1 += diff_text.length;
+          start1 += diff_text.length;
+          empty = false;
+          patch.diffs.push([diff_type, diff_text]);
+          bigpatch.diffs.shift();
+        } else {
+          // Deletion or equality.  Only take as much as we can stomach.
+          diff_text = diff_text.substring(0,
+              patch_size - patch.length1 - this.Patch_Margin);
+          patch.length1 += diff_text.length;
+          start1 += diff_text.length;
+          if (diff_type === DIFF_EQUAL) {
+            patch.length2 += diff_text.length;
+            start2 += diff_text.length;
+          } else {
+            empty = false;
+          }
+          patch.diffs.push([diff_type, diff_text]);
+          if (diff_text == bigpatch.diffs[0][1]) {
+            bigpatch.diffs.shift();
+          } else {
+            bigpatch.diffs[0][1] =
+                bigpatch.diffs[0][1].substring(diff_text.length);
+          }
+        }
+      }
+      // Compute the head context for the next patch.
+      precontext = this.diff_text2(patch.diffs);
+      precontext =
+          precontext.substring(precontext.length - this.Patch_Margin);
+      // Append the end context for this patch.
+      var postcontext = this.diff_text1(bigpatch.diffs)
+                            .substring(0, this.Patch_Margin);
+      if (postcontext !== '') {
+        patch.length1 += postcontext.length;
+        patch.length2 += postcontext.length;
+        if (patch.diffs.length !== 0 &&
+            patch.diffs[patch.diffs.length - 1][0] === DIFF_EQUAL) {
+          patch.diffs[patch.diffs.length - 1][1] += postcontext;
+        } else {
+          patch.diffs.push([DIFF_EQUAL, postcontext]);
+        }
+      }
+      if (!empty) {
+        patches.splice(++x, 0, patch);
+      }
+    }
+  }
+};
+
+
+/**
+ * Take a list of patches and return a textual representation.
+ * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of Patch objects.
+ * @return {string} Text representation of patches.
+ */
+diff_match_patch.prototype.patch_toText = function(patches) {
+  var text = [];
+  for (var x = 0; x < patches.length; x++) {
+    text[x] = patches[x];
+  }
+  return text.join('');
+};
+
+
+/**
+ * Parse a textual representation of patches and return a list of Patch objects.
+ * @param {string} textline Text representation of patches.
+ * @return {!Array.<!diff_match_patch.patch_obj>} Array of Patch objects.
+ * @throws {!Error} If invalid input.
+ */
+diff_match_patch.prototype.patch_fromText = function(textline) {
+  var patches = [];
+  if (!textline) {
+    return patches;
+  }
+  var text = textline.split('\n');
+  var textPointer = 0;
+  var patchHeader = /^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@$/;
+  while (textPointer < text.length) {
+    var m = text[textPointer].match(patchHeader);
+    if (!m) {
+      throw new Error('Invalid patch string: ' + text[textPointer]);
+    }
+    var patch = new diff_match_patch.patch_obj();
+    patches.push(patch);
+    patch.start1 = parseInt(m[1], 10);
+    if (m[2] === '') {
+      patch.start1--;
+      patch.length1 = 1;
+    } else if (m[2] == '0') {
+      patch.length1 = 0;
+    } else {
+      patch.start1--;
+      patch.length1 = parseInt(m[2], 10);
+    }
+
+    patch.start2 = parseInt(m[3], 10);
+    if (m[4] === '') {
+      patch.start2--;
+      patch.length2 = 1;
+    } else if (m[4] == '0') {
+      patch.length2 = 0;
+    } else {
+      patch.start2--;
+      patch.length2 = parseInt(m[4], 10);
+    }
+    textPointer++;
+
+    while (textPointer < text.length) {
+      var sign = text[textPointer].charAt(0);
+      try {
+        var line = decodeURI(text[textPointer].substring(1));
+      } catch (ex) {
+        // Malformed URI sequence.
+        throw new Error('Illegal escape in patch_fromText: ' + line);
+      }
+      if (sign == '-') {
+        // Deletion.
+        patch.diffs.push([DIFF_DELETE, line]);
+      } else if (sign == '+') {
+        // Insertion.
+        patch.diffs.push([DIFF_INSERT, line]);
+      } else if (sign == ' ') {
+        // Minor equality.
+        patch.diffs.push([DIFF_EQUAL, line]);
+      } else if (sign == '@') {
+        // Start of next patch.
+        break;
+      } else if (sign === '') {
+        // Blank line?  Whatever.
+      } else {
+        // WTF?
+        throw new Error('Invalid patch mode "' + sign + '" in: ' + line);
+      }
+      textPointer++;
+    }
+  }
+  return patches;
+};
+
+
+/**
+ * Class representing one patch operation.
+ * @constructor
+ */
+diff_match_patch.patch_obj = function() {
+  /** @type {!Array.<!diff_match_patch.Diff>} */
+  this.diffs = [];
+  /** @type {?number} */
+  this.start1 = null;
+  /** @type {?number} */
+  this.start2 = null;
+  /** @type {number} */
+  this.length1 = 0;
+  /** @type {number} */
+  this.length2 = 0;
+};
+
+
+/**
+ * Emmulate GNU diff's format.
+ * Header: @@ -382,8 +481,9 @@
+ * Indicies are printed as 1-based, not 0-based.
+ * @return {string} The GNU diff string.
+ */
+diff_match_patch.patch_obj.prototype.toString = function() {
+  var coords1, coords2;
+  if (this.length1 === 0) {
+    coords1 = this.start1 + ',0';
+  } else if (this.length1 == 1) {
+    coords1 = this.start1 + 1;
+  } else {
+    coords1 = (this.start1 + 1) + ',' + this.length1;
+  }
+  if (this.length2 === 0) {
+    coords2 = this.start2 + ',0';
+  } else if (this.length2 == 1) {
+    coords2 = this.start2 + 1;
+  } else {
+    coords2 = (this.start2 + 1) + ',' + this.length2;
+  }
+  var text = ['@@ -' + coords1 + ' +' + coords2 + ' @@\n'];
+  var op;
+  // Escape the body of the patch with %xx notation.
+  for (var x = 0; x < this.diffs.length; x++) {
+    switch (this.diffs[x][0]) {
+      case DIFF_INSERT:
+        op = '+';
+        break;
+      case DIFF_DELETE:
+        op = '-';
+        break;
+      case DIFF_EQUAL:
+        op = ' ';
+        break;
+    }
+    text[x + 1] = op + encodeURI(this.diffs[x][1]) + '\n';
+  }
+  return text.join('').replace(/%20/g, ' ');
+};
+
+
+// The following export code was added by @ForbesLindesay
+module.exports = diff_match_patch;
+module.exports['diff_match_patch'] = diff_match_patch;
+module.exports['DIFF_DELETE'] = DIFF_DELETE;
+module.exports['DIFF_INSERT'] = DIFF_INSERT;
+module.exports['DIFF_EQUAL'] = DIFF_EQUAL;
diff --git a/node_modules/diff-match-patch/package.json b/node_modules/diff-match-patch/package.json
new file mode 100644
index 000000000..79b2961b0
--- /dev/null
+++ b/node_modules/diff-match-patch/package.json
@@ -0,0 +1,18 @@
+{
+  "name": "diff-match-patch",
+  "version": "1.0.0",
+  "description": "npm package for https://code.google.com/p/google-diff-match-patch/",
+  "keywords": [],
+  "dependencies": {},
+  "devDependencies": {
+    "testit": "~1.1.0"
+  },
+  "scripts": {
+    "test": "node test"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/ForbesLindesay/diff-match-patch.git"
+  },
+  "license": "http://www.apache.org/licenses/LICENSE-2.0"
+}
diff --git a/node_modules/diff-match-patch/test/index.js b/node_modules/diff-match-patch/test/index.js
new file mode 100644
index 000000000..52dba19c2
--- /dev/null
+++ b/node_modules/diff-match-patch/test/index.js
@@ -0,0 +1,1022 @@
+'use strict'
+
+var assert = require('assert');
+var test = require('testit');
+var diff_match_patch = require('../');
+var DIFF_DELETE = diff_match_patch.DIFF_DELETE;
+var DIFF_INSERT = diff_match_patch.DIFF_INSERT;
+var DIFF_EQUAL = diff_match_patch.DIFF_EQUAL;
+
+
+
+/**
+ * Test Harness for Diff Match and Patch
+ *
+ * Copyright 2006 Google Inc.
+ * http://code.google.com/p/google-diff-match-patch/
+ *
+ * Licensed 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.
+ */
+
+
+// If expected and actual are the equivalent, pass the test.
+function assertEquivalent(msg, expected, actual) {
+  if (typeof actual == 'undefined') {
+    // msg is optional.
+    actual = expected;
+    expected = msg;
+    msg = 'Expected: \'' + expected + '\' Actual: \'' + actual + '\'';
+  }
+  if (_equivalent(expected, actual)) {
+    assertEquals(msg, String.toString(expected), String.toString(actual));
+  } else {
+    assertEquals(msg, expected, actual);
+  }
+}
+
+
+// Are a and b the equivalent? -- Recursive.
+function _equivalent(a, b) {
+  if (a == b) {
+    return true;
+  }
+  if (typeof a == 'object' && typeof b == 'object' && a !== null && b !== null) {
+    if (a.toString() != b.toString()) {
+      return false;
+    }
+    for (var p in a) {
+      if (!_equivalent(a[p], b[p])) {
+        return false;
+      }
+    }
+    for (var p in b) {
+      if (!_equivalent(a[p], b[p])) {
+        return false;
+      }
+    }
+    return true;
+  }
+  return false;
+}
+
+
+function diff_rebuildtexts(diffs) {
+  // Construct the two texts which made up the diff originally.
+  var text1 = '';
+  var text2 = '';
+  for (var x = 0; x < diffs.length; x++) {
+    if (diffs[x][0] != DIFF_INSERT) {
+      text1 += diffs[x][1];
+    }
+    if (diffs[x][0] != DIFF_DELETE) {
+      text2 += diffs[x][1];
+    }
+  }
+  return [text1, text2];
+}
+
+var dmp = new diff_match_patch();
+
+
+// DIFF TEST FUNCTIONS
+
+
+function testDiffCommonPrefix() {
+  // Detect any common prefix.
+  // Null case.
+  assertEquals(0, dmp.diff_commonPrefix('abc', 'xyz'));
+
+  // Non-null case.
+  assertEquals(4, dmp.diff_commonPrefix('1234abcdef', '1234xyz'));
+
+  // Whole case.
+  assertEquals(4, dmp.diff_commonPrefix('1234', '1234xyz'));
+}
+
+function testDiffCommonSuffix() {
+  // Detect any common suffix.
+  // Null case.
+  assertEquals(0, dmp.diff_commonSuffix('abc', 'xyz'));
+
+  // Non-null case.
+  assertEquals(4, dmp.diff_commonSuffix('abcdef1234', 'xyz1234'));
+
+  // Whole case.
+  assertEquals(4, dmp.diff_commonSuffix('1234', 'xyz1234'));
+}
+
+function testDiffCommonOverlap() {
+  // Detect any suffix/prefix overlap.
+  // Null case.
+  assertEquals(0, dmp.diff_commonOverlap_('', 'abcd'));
+
+  // Whole case.
+  assertEquals(3, dmp.diff_commonOverlap_('abc', 'abcd'));
+
+  // No overlap.
+  assertEquals(0, dmp.diff_commonOverlap_('123456', 'abcd'));
+
+  // Overlap.
+  assertEquals(3, dmp.diff_commonOverlap_('123456xxx', 'xxxabcd'));
+
+  // Unicode.
+  // Some overly clever languages (C#) may treat ligatures as equal to their
+  // component letters.  E.g. U+FB01 == 'fi'
+  assertEquals(0, dmp.diff_commonOverlap_('fi', '\ufb01i'));
+}
+
+function testDiffHalfMatch() {
+  // Detect a halfmatch.
+  dmp.Diff_Timeout = 1;
+  // No match.
+  assertEquals(null, dmp.diff_halfMatch_('1234567890', 'abcdef'));
+
+  assertEquals(null, dmp.diff_halfMatch_('12345', '23'));
+
+  // Single Match.
+  assertEquivalent(['12', '90', 'a', 'z', '345678'], dmp.diff_halfMatch_('1234567890', 'a345678z'));
+
+  assertEquivalent(['a', 'z', '12', '90', '345678'], dmp.diff_halfMatch_('a345678z', '1234567890'));
+
+  assertEquivalent(['abc', 'z', '1234', '0', '56789'], dmp.diff_halfMatch_('abc56789z', '1234567890'));
+
+  assertEquivalent(['a', 'xyz', '1', '7890', '23456'], dmp.diff_halfMatch_('a23456xyz', '1234567890'));
+
+  // Multiple Matches.
+  assertEquivalent(['12123', '123121', 'a', 'z', '1234123451234'], dmp.diff_halfMatch_('121231234123451234123121', 'a1234123451234z'));
+
+  assertEquivalent(['', '-=-=-=-=-=', 'x', '', 'x-=-=-=-=-=-=-='], dmp.diff_halfMatch_('x-=-=-=-=-=-=-=-=-=-=-=-=', 'xx-=-=-=-=-=-=-='));
+
+  assertEquivalent(['-=-=-=-=-=', '', '', 'y', '-=-=-=-=-=-=-=y'], dmp.diff_halfMatch_('-=-=-=-=-=-=-=-=-=-=-=-=y', '-=-=-=-=-=-=-=yy'));
+
+  // Non-optimal halfmatch.
+  // Optimal diff would be -q+x=H-i+e=lloHe+Hu=llo-Hew+y not -qHillo+x=HelloHe-w+Hulloy
+  assertEquivalent(['qHillo', 'w', 'x', 'Hulloy', 'HelloHe'], dmp.diff_halfMatch_('qHilloHelloHew', 'xHelloHeHulloy'));
+
+  // Optimal no halfmatch.
+  dmp.Diff_Timeout = 0;
+  assertEquals(null, dmp.diff_halfMatch_('qHilloHelloHew', 'xHelloHeHulloy'));
+}
+
+function testDiffLinesToChars() {
+  function assertLinesToCharsResultEquals(a, b) {
+    assertEquals(a.chars1, b.chars1);
+    assertEquals(a.chars2, b.chars2);
+    assertEquivalent(a.lineArray, b.lineArray);
+  }
+
+  // Convert lines down to characters.
+  assertLinesToCharsResultEquals({chars1: '\x01\x02\x01', chars2: '\x02\x01\x02', lineArray: ['', 'alpha\n', 'beta\n']}, dmp.diff_linesToChars_('alpha\nbeta\nalpha\n', 'beta\nalpha\nbeta\n'));
+
+  assertLinesToCharsResultEquals({chars1: '', chars2: '\x01\x02\x03\x03', lineArray: ['', 'alpha\r\n', 'beta\r\n', '\r\n']}, dmp.diff_linesToChars_('', 'alpha\r\nbeta\r\n\r\n\r\n'));
+
+  assertLinesToCharsResultEquals({chars1: '\x01', chars2: '\x02', lineArray: ['', 'a', 'b']}, dmp.diff_linesToChars_('a', 'b'));
+
+  // More than 256 to reveal any 8-bit limitations.
+  var n = 300;
+  var lineList = [];
+  var charList = [];
+  for (var x = 1; x < n + 1; x++) {
+    lineList[x - 1] = x + '\n';
+    charList[x - 1] = String.fromCharCode(x);
+  }
+  assertEquals(n, lineList.length);
+  var lines = lineList.join('');
+  var chars = charList.join('');
+  assertEquals(n, chars.length);
+  lineList.unshift('');
+  assertLinesToCharsResultEquals({chars1: chars, chars2: '', lineArray: lineList}, dmp.diff_linesToChars_(lines, ''));
+}
+
+function testDiffCharsToLines() {
+  // Convert chars up to lines.
+  var diffs = [[DIFF_EQUAL, '\x01\x02\x01'], [DIFF_INSERT, '\x02\x01\x02']];
+  dmp.diff_charsToLines_(diffs, ['', 'alpha\n', 'beta\n']);
+  assertEquivalent([[DIFF_EQUAL, 'alpha\nbeta\nalpha\n'], [DIFF_INSERT, 'beta\nalpha\nbeta\n']], diffs);
+
+  // More than 256 to reveal any 8-bit limitations.
+  var n = 300;
+  var lineList = [];
+  var charList = [];
+  for (var x = 1; x < n + 1; x++) {
+    lineList[x - 1] = x + '\n';
+    charList[x - 1] = String.fromCharCode(x);
+  }
+  assertEquals(n, lineList.length);
+  var lines = lineList.join('');
+  var chars = charList.join('');
+  assertEquals(n, chars.length);
+  lineList.unshift('');
+  var diffs = [[DIFF_DELETE, chars]];
+  dmp.diff_charsToLines_(diffs, lineList);
+  assertEquivalent([[DIFF_DELETE, lines]], diffs);
+}
+
+function testDiffCleanupMerge() {
+  // Cleanup a messy diff.
+  // Null case.
+  var diffs = [];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([], diffs);
+
+  // No change case.
+  diffs = [[DIFF_EQUAL, 'a'], [DIFF_DELETE, 'b'], [DIFF_INSERT, 'c']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'a'], [DIFF_DELETE, 'b'], [DIFF_INSERT, 'c']], diffs);
+
+  // Merge equalities.
+  diffs = [[DIFF_EQUAL, 'a'], [DIFF_EQUAL, 'b'], [DIFF_EQUAL, 'c']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'abc']], diffs);
+
+  // Merge deletions.
+  diffs = [[DIFF_DELETE, 'a'], [DIFF_DELETE, 'b'], [DIFF_DELETE, 'c']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abc']], diffs);
+
+  // Merge insertions.
+  diffs = [[DIFF_INSERT, 'a'], [DIFF_INSERT, 'b'], [DIFF_INSERT, 'c']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_INSERT, 'abc']], diffs);
+
+  // Merge interweave.
+  diffs = [[DIFF_DELETE, 'a'], [DIFF_INSERT, 'b'], [DIFF_DELETE, 'c'], [DIFF_INSERT, 'd'], [DIFF_EQUAL, 'e'], [DIFF_EQUAL, 'f']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_DELETE, 'ac'], [DIFF_INSERT, 'bd'], [DIFF_EQUAL, 'ef']], diffs);
+
+  // Prefix and suffix detection.
+  diffs = [[DIFF_DELETE, 'a'], [DIFF_INSERT, 'abc'], [DIFF_DELETE, 'dc']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'a'], [DIFF_DELETE, 'd'], [DIFF_INSERT, 'b'], [DIFF_EQUAL, 'c']], diffs);
+
+  // Prefix and suffix detection with equalities.
+  diffs = [[DIFF_EQUAL, 'x'], [DIFF_DELETE, 'a'], [DIFF_INSERT, 'abc'], [DIFF_DELETE, 'dc'], [DIFF_EQUAL, 'y']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'xa'], [DIFF_DELETE, 'd'], [DIFF_INSERT, 'b'], [DIFF_EQUAL, 'cy']], diffs);
+
+  // Slide edit left.
+  diffs = [[DIFF_EQUAL, 'a'], [DIFF_INSERT, 'ba'], [DIFF_EQUAL, 'c']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_INSERT, 'ab'], [DIFF_EQUAL, 'ac']], diffs);
+
+  // Slide edit right.
+  diffs = [[DIFF_EQUAL, 'c'], [DIFF_INSERT, 'ab'], [DIFF_EQUAL, 'a']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'ca'], [DIFF_INSERT, 'ba']], diffs);
+
+  // Slide edit left recursive.
+  diffs = [[DIFF_EQUAL, 'a'], [DIFF_DELETE, 'b'], [DIFF_EQUAL, 'c'], [DIFF_DELETE, 'ac'], [DIFF_EQUAL, 'x']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abc'], [DIFF_EQUAL, 'acx']], diffs);
+
+  // Slide edit right recursive.
+  diffs = [[DIFF_EQUAL, 'x'], [DIFF_DELETE, 'ca'], [DIFF_EQUAL, 'c'], [DIFF_DELETE, 'b'], [DIFF_EQUAL, 'a']];
+  dmp.diff_cleanupMerge(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'xca'], [DIFF_DELETE, 'cba']], diffs);
+}
+
+function testDiffCleanupSemanticLossless() {
+  // Slide diffs to match logical boundaries.
+  // Null case.
+  var diffs = [];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([], diffs);
+
+  // Blank lines.
+  diffs = [[DIFF_EQUAL, 'AAA\r\n\r\nBBB'], [DIFF_INSERT, '\r\nDDD\r\n\r\nBBB'], [DIFF_EQUAL, '\r\nEEE']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'AAA\r\n\r\n'], [DIFF_INSERT, 'BBB\r\nDDD\r\n\r\n'], [DIFF_EQUAL, 'BBB\r\nEEE']], diffs);
+
+  // Line boundaries.
+  diffs = [[DIFF_EQUAL, 'AAA\r\nBBB'], [DIFF_INSERT, ' DDD\r\nBBB'], [DIFF_EQUAL, ' EEE']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'AAA\r\n'], [DIFF_INSERT, 'BBB DDD\r\n'], [DIFF_EQUAL, 'BBB EEE']], diffs);
+
+  // Word boundaries.
+  diffs = [[DIFF_EQUAL, 'The c'], [DIFF_INSERT, 'ow and the c'], [DIFF_EQUAL, 'at.']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'The '], [DIFF_INSERT, 'cow and the '], [DIFF_EQUAL, 'cat.']], diffs);
+
+  // Alphanumeric boundaries.
+  diffs = [[DIFF_EQUAL, 'The-c'], [DIFF_INSERT, 'ow-and-the-c'], [DIFF_EQUAL, 'at.']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'The-'], [DIFF_INSERT, 'cow-and-the-'], [DIFF_EQUAL, 'cat.']], diffs);
+
+  // Hitting the start.
+  diffs = [[DIFF_EQUAL, 'a'], [DIFF_DELETE, 'a'], [DIFF_EQUAL, 'ax']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_DELETE, 'a'], [DIFF_EQUAL, 'aax']], diffs);
+
+  // Hitting the end.
+  diffs = [[DIFF_EQUAL, 'xa'], [DIFF_DELETE, 'a'], [DIFF_EQUAL, 'a']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'xaa'], [DIFF_DELETE, 'a']], diffs);
+
+  // Sentence boundaries.
+  diffs = [[DIFF_EQUAL, 'The xxx. The '], [DIFF_INSERT, 'zzz. The '], [DIFF_EQUAL, 'yyy.']];
+  dmp.diff_cleanupSemanticLossless(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'The xxx.'], [DIFF_INSERT, ' The zzz.'], [DIFF_EQUAL, ' The yyy.']], diffs);
+}
+
+function testDiffCleanupSemantic() {
+  // Cleanup semantically trivial equalities.
+  // Null case.
+  var diffs = [];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([], diffs);
+
+  // No elimination #1.
+  diffs = [[DIFF_DELETE, 'ab'], [DIFF_INSERT, 'cd'], [DIFF_EQUAL, '12'], [DIFF_DELETE, 'e']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'ab'], [DIFF_INSERT, 'cd'], [DIFF_EQUAL, '12'], [DIFF_DELETE, 'e']], diffs);
+
+  // No elimination #2.
+  diffs = [[DIFF_DELETE, 'abc'], [DIFF_INSERT, 'ABC'], [DIFF_EQUAL, '1234'], [DIFF_DELETE, 'wxyz']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abc'], [DIFF_INSERT, 'ABC'], [DIFF_EQUAL, '1234'], [DIFF_DELETE, 'wxyz']], diffs);
+
+  // Simple elimination.
+  diffs = [[DIFF_DELETE, 'a'], [DIFF_EQUAL, 'b'], [DIFF_DELETE, 'c']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abc'], [DIFF_INSERT, 'b']], diffs);
+
+  // Backpass elimination.
+  diffs = [[DIFF_DELETE, 'ab'], [DIFF_EQUAL, 'cd'], [DIFF_DELETE, 'e'], [DIFF_EQUAL, 'f'], [DIFF_INSERT, 'g']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abcdef'], [DIFF_INSERT, 'cdfg']], diffs);
+
+  // Multiple eliminations.
+  diffs = [[DIFF_INSERT, '1'], [DIFF_EQUAL, 'A'], [DIFF_DELETE, 'B'], [DIFF_INSERT, '2'], [DIFF_EQUAL, '_'], [DIFF_INSERT, '1'], [DIFF_EQUAL, 'A'], [DIFF_DELETE, 'B'], [DIFF_INSERT, '2']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'AB_AB'], [DIFF_INSERT, '1A2_1A2']], diffs);
+
+  // Word boundaries.
+  diffs = [[DIFF_EQUAL, 'The c'], [DIFF_DELETE, 'ow and the c'], [DIFF_EQUAL, 'at.']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_EQUAL, 'The '], [DIFF_DELETE, 'cow and the '], [DIFF_EQUAL, 'cat.']], diffs);
+
+  // No overlap elimination.
+  diffs = [[DIFF_DELETE, 'abcxx'], [DIFF_INSERT, 'xxdef']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abcxx'], [DIFF_INSERT, 'xxdef']], diffs);
+
+  // Overlap elimination.
+  diffs = [[DIFF_DELETE, 'abcxxx'], [DIFF_INSERT, 'xxxdef']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abc'], [DIFF_EQUAL, 'xxx'], [DIFF_INSERT, 'def']], diffs);
+
+  // Reverse overlap elimination.
+  diffs = [[DIFF_DELETE, 'xxxabc'], [DIFF_INSERT, 'defxxx']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_INSERT, 'def'], [DIFF_EQUAL, 'xxx'], [DIFF_DELETE, 'abc']], diffs);
+
+  // Two overlap eliminations.
+  diffs = [[DIFF_DELETE, 'abcd1212'], [DIFF_INSERT, '1212efghi'], [DIFF_EQUAL, '----'], [DIFF_DELETE, 'A3'], [DIFF_INSERT, '3BC']];
+  dmp.diff_cleanupSemantic(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abcd'], [DIFF_EQUAL, '1212'], [DIFF_INSERT, 'efghi'], [DIFF_EQUAL, '----'], [DIFF_DELETE, 'A'], [DIFF_EQUAL, '3'], [DIFF_INSERT, 'BC']], diffs);
+}
+
+function testDiffCleanupEfficiency() {
+  // Cleanup operationally trivial equalities.
+  dmp.Diff_EditCost = 4;
+  // Null case.
+  var diffs = [];
+  dmp.diff_cleanupEfficiency(diffs);
+  assertEquivalent([], diffs);
+
+  // No elimination.
+  diffs = [[DIFF_DELETE, 'ab'], [DIFF_INSERT, '12'], [DIFF_EQUAL, 'wxyz'], [DIFF_DELETE, 'cd'], [DIFF_INSERT, '34']];
+  dmp.diff_cleanupEfficiency(diffs);
+  assertEquivalent([[DIFF_DELETE, 'ab'], [DIFF_INSERT, '12'], [DIFF_EQUAL, 'wxyz'], [DIFF_DELETE, 'cd'], [DIFF_INSERT, '34']], diffs);
+
+  // Four-edit elimination.
+  diffs = [[DIFF_DELETE, 'ab'], [DIFF_INSERT, '12'], [DIFF_EQUAL, 'xyz'], [DIFF_DELETE, 'cd'], [DIFF_INSERT, '34']];
+  dmp.diff_cleanupEfficiency(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abxyzcd'], [DIFF_INSERT, '12xyz34']], diffs);
+
+  // Three-edit elimination.
+  diffs = [[DIFF_INSERT, '12'], [DIFF_EQUAL, 'x'], [DIFF_DELETE, 'cd'], [DIFF_INSERT, '34']];
+  dmp.diff_cleanupEfficiency(diffs);
+  assertEquivalent([[DIFF_DELETE, 'xcd'], [DIFF_INSERT, '12x34']], diffs);
+
+  // Backpass elimination.
+  diffs = [[DIFF_DELETE, 'ab'], [DIFF_INSERT, '12'], [DIFF_EQUAL, 'xy'], [DIFF_INSERT, '34'], [DIFF_EQUAL, 'z'], [DIFF_DELETE, 'cd'], [DIFF_INSERT, '56']];
+  dmp.diff_cleanupEfficiency(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abxyzcd'], [DIFF_INSERT, '12xy34z56']], diffs);
+
+  // High cost elimination.
+  dmp.Diff_EditCost = 5;
+  diffs = [[DIFF_DELETE, 'ab'], [DIFF_INSERT, '12'], [DIFF_EQUAL, 'wxyz'], [DIFF_DELETE, 'cd'], [DIFF_INSERT, '34']];
+  dmp.diff_cleanupEfficiency(diffs);
+  assertEquivalent([[DIFF_DELETE, 'abwxyzcd'], [DIFF_INSERT, '12wxyz34']], diffs);
+  dmp.Diff_EditCost = 4;
+}
+
+function testDiffPrettyHtml() {
+  // Pretty print.
+  var diffs = [[DIFF_EQUAL, 'a\n'], [DIFF_DELETE, '<B>b</B>'], [DIFF_INSERT, 'c&d']];
+  assertEquals('<span>a&para;<br></span><del style="background:#ffe6e6;">&lt;B&gt;b&lt;/B&gt;</del><ins style="background:#e6ffe6;">c&amp;d</ins>', dmp.diff_prettyHtml(diffs));
+}
+
+function testDiffText() {
+  // Compute the source and destination texts.
+  var diffs = [[DIFF_EQUAL, 'jump'], [DIFF_DELETE, 's'], [DIFF_INSERT, 'ed'], [DIFF_EQUAL, ' over '], [DIFF_DELETE, 'the'], [DIFF_INSERT, 'a'], [DIFF_EQUAL, ' lazy']];
+  assertEquals('jumps over the lazy', dmp.diff_text1(diffs));
+
+  assertEquals('jumped over a lazy', dmp.diff_text2(diffs));
+}
+
+function testDiffDelta() {
+  // Convert a diff into delta string.
+  var diffs = [[DIFF_EQUAL, 'jump'], [DIFF_DELETE, 's'], [DIFF_INSERT, 'ed'], [DIFF_EQUAL, ' over '], [DIFF_DELETE, 'the'], [DIFF_INSERT, 'a'], [DIFF_EQUAL, ' lazy'], [DIFF_INSERT, 'old dog']];
+  var text1 = dmp.diff_text1(diffs);
+  assertEquals('jumps over the lazy', text1);
+
+  var delta = dmp.diff_toDelta(diffs);
+  assertEquals('=4\t-1\t+ed\t=6\t-3\t+a\t=5\t+old dog', delta);
+
+  // Convert delta string into a diff.
+  assertEquivalent(diffs, dmp.diff_fromDelta(text1, delta));
+
+  // Generates error (19 != 20).
+  try {
+    dmp.diff_fromDelta(text1 + 'x', delta);
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+
+  // Generates error (19 != 18).
+  try {
+    dmp.diff_fromDelta(text1.substring(1), delta);
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+
+  // Generates error (%c3%xy invalid Unicode).
+  try {
+    dmp.diff_fromDelta('', '+%c3%xy');
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+
+  // Test deltas with special characters.
+  diffs = [[DIFF_EQUAL, '\u0680 \x00 \t %'], [DIFF_DELETE, '\u0681 \x01 \n ^'], [DIFF_INSERT, '\u0682 \x02 \\ |']];
+  text1 = dmp.diff_text1(diffs);
+  assertEquals('\u0680 \x00 \t %\u0681 \x01 \n ^', text1);
+
+  delta = dmp.diff_toDelta(diffs);
+  assertEquals('=7\t-7\t+%DA%82 %02 %5C %7C', delta);
+
+  // Convert delta string into a diff.
+  assertEquivalent(diffs, dmp.diff_fromDelta(text1, delta));
+
+  // Verify pool of unchanged characters.
+  diffs = [[DIFF_INSERT, 'A-Z a-z 0-9 - _ . ! ~ * \' ( ) ; / ? : @ & = + $ , # ']];
+  var text2 = dmp.diff_text2(diffs);
+  assertEquals('A-Z a-z 0-9 - _ . ! ~ * \' ( ) ; / ? : @ & = + $ , # ', text2);
+
+  delta = dmp.diff_toDelta(diffs);
+  assertEquals('+A-Z a-z 0-9 - _ . ! ~ * \' ( ) ; / ? : @ & = + $ , # ', delta);
+
+  // Convert delta string into a diff.
+  assertEquivalent(diffs, dmp.diff_fromDelta('', delta));
+}
+
+function testDiffXIndex() {
+  // Translate a location in text1 to text2.
+  // Translation on equality.
+  assertEquals(5, dmp.diff_xIndex([[DIFF_DELETE, 'a'], [DIFF_INSERT, '1234'], [DIFF_EQUAL, 'xyz']], 2));
+
+  // Translation on deletion.
+  assertEquals(1, dmp.diff_xIndex([[DIFF_EQUAL, 'a'], [DIFF_DELETE, '1234'], [DIFF_EQUAL, 'xyz']], 3));
+}
+
+function testDiffLevenshtein() {
+  // Levenshtein with trailing equality.
+  assertEquals(4, dmp.diff_levenshtein([[DIFF_DELETE, 'abc'], [DIFF_INSERT, '1234'], [DIFF_EQUAL, 'xyz']]));
+  // Levenshtein with leading equality.
+  assertEquals(4, dmp.diff_levenshtein([[DIFF_EQUAL, 'xyz'], [DIFF_DELETE, 'abc'], [DIFF_INSERT, '1234']]));
+  // Levenshtein with middle equality.
+  assertEquals(7, dmp.diff_levenshtein([[DIFF_DELETE, 'abc'], [DIFF_EQUAL, 'xyz'], [DIFF_INSERT, '1234']]));
+}
+
+function testDiffBisect() {
+  // Normal.
+  var a = 'cat';
+  var b = 'map';
+  // Since the resulting diff hasn't been normalized, it would be ok if
+  // the insertion and deletion pairs are swapped.
+  // If the order changes, tweak this test as required.
+  assertEquivalent([[DIFF_DELETE, 'c'], [DIFF_INSERT, 'm'], [DIFF_EQUAL, 'a'], [DIFF_DELETE, 't'], [DIFF_INSERT, 'p']], dmp.diff_bisect_(a, b, Number.MAX_VALUE));
+
+  // Timeout.
+  assertEquivalent([[DIFF_DELETE, 'cat'], [DIFF_INSERT, 'map']], dmp.diff_bisect_(a, b, 0));
+}
+
+function testDiffMain() {
+  // Perform a trivial diff.
+  // Null case.
+  assertEquivalent([], dmp.diff_main('', '', false));
+
+  // Equality.
+  assertEquivalent([[DIFF_EQUAL, 'abc']], dmp.diff_main('abc', 'abc', false));
+
+  // Simple insertion.
+  assertEquivalent([[DIFF_EQUAL, 'ab'], [DIFF_INSERT, '123'], [DIFF_EQUAL, 'c']], dmp.diff_main('abc', 'ab123c', false));
+
+  // Simple deletion.
+  assertEquivalent([[DIFF_EQUAL, 'a'], [DIFF_DELETE, '123'], [DIFF_EQUAL, 'bc']], dmp.diff_main('a123bc', 'abc', false));
+
+  // Two insertions.
+  assertEquivalent([[DIFF_EQUAL, 'a'], [DIFF_INSERT, '123'], [DIFF_EQUAL, 'b'], [DIFF_INSERT, '456'], [DIFF_EQUAL, 'c']], dmp.diff_main('abc', 'a123b456c', false));
+
+  // Two deletions.
+  assertEquivalent([[DIFF_EQUAL, 'a'], [DIFF_DELETE, '123'], [DIFF_EQUAL, 'b'], [DIFF_DELETE, '456'], [DIFF_EQUAL, 'c']], dmp.diff_main('a123b456c', 'abc', false));
+
+  // Perform a real diff.
+  // Switch off the timeout.
+  dmp.Diff_Timeout = 0;
+  // Simple cases.
+  assertEquivalent([[DIFF_DELETE, 'a'], [DIFF_INSERT, 'b']], dmp.diff_main('a', 'b', false));
+
+  assertEquivalent([[DIFF_DELETE, 'Apple'], [DIFF_INSERT, 'Banana'], [DIFF_EQUAL, 's are a'], [DIFF_INSERT, 'lso'], [DIFF_EQUAL, ' fruit.']], dmp.diff_main('Apples are a fruit.', 'Bananas are also fruit.', false));
+
+  assertEquivalent([[DIFF_DELETE, 'a'], [DIFF_INSERT, '\u0680'], [DIFF_EQUAL, 'x'], [DIFF_DELETE, '\t'], [DIFF_INSERT, '\0']], dmp.diff_main('ax\t', '\u0680x\0', false));
+
+  // Overlaps.
+  assertEquivalent([[DIFF_DELETE, '1'], [DIFF_EQUAL, 'a'], [DIFF_DELETE, 'y'], [DIFF_EQUAL, 'b'], [DIFF_DELETE, '2'], [DIFF_INSERT, 'xab']], dmp.diff_main('1ayb2', 'abxab', false));
+
+  assertEquivalent([[DIFF_INSERT, 'xaxcx'], [DIFF_EQUAL, 'abc'], [DIFF_DELETE, 'y']], dmp.diff_main('abcy', 'xaxcxabc', false));
+
+  assertEquivalent([[DIFF_DELETE, 'ABCD'], [DIFF_EQUAL, 'a'], [DIFF_DELETE, '='], [DIFF_INSERT, '-'], [DIFF_EQUAL, 'bcd'], [DIFF_DELETE, '='], [DIFF_INSERT, '-'], [DIFF_EQUAL, 'efghijklmnopqrs'], [DIFF_DELETE, 'EFGHIJKLMNOefg']], dmp.diff_main('ABCDa=bcd=efghijklmnopqrsEFGHIJKLMNOefg', 'a-bcd-efghijklmnopqrs', false));
+
+  // Large equality.
+  assertEquivalent([[DIFF_INSERT, ' '], [DIFF_EQUAL, 'a'], [DIFF_INSERT, 'nd'], [DIFF_EQUAL, ' [[Pennsylvania]]'], [DIFF_DELETE, ' and [[New']], dmp.diff_main('a [[Pennsylvania]] and [[New', ' and [[Pennsylvania]]', false));
+
+  // Timeout.
+  dmp.Diff_Timeout = 0.1;  // 100ms
+  var a = '`Twas brillig, and the slithy toves\nDid gyre and gimble in the wabe:\nAll mimsy were the borogoves,\nAnd the mome raths outgrabe.\n';
+  var b = 'I am the very model of a modern major general,\nI\'ve information vegetable, animal, and mineral,\nI know the kings of England, and I quote the fights historical,\nFrom Marathon to Waterloo, in order categorical.\n';
+  // Increase the text lengths by 1024 times to ensure a timeout.
+  for (var x = 0; x < 10; x++) {
+    a = a + a;
+    b = b + b;
+  }
+  var startTime = (new Date()).getTime();
+  dmp.diff_main(a, b);
+  var endTime = (new Date()).getTime();
+  // Test that we took at least the timeout period.
+  assertTrue(dmp.Diff_Timeout * 1000 <= endTime - startTime);
+  // Test that we didn't take forever (be forgiving).
+  // Theoretically this test could fail very occasionally if the
+  // OS task swaps or locks up for a second at the wrong moment.
+  // ****
+  // TODO(fraser): For unknown reasons this is taking 500 ms on Google's
+  // internal test system.  Whereas browsers take 140 ms.
+  //assertTrue(dmp.Diff_Timeout * 1000 * 2 > endTime - startTime);
+  // ****
+  dmp.Diff_Timeout = 0;
+
+  // Test the linemode speedup.
+  // Must be long to pass the 100 char cutoff.
+  // Simple line-mode.
+  a = '1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n';
+  b = 'abcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\nabcdefghij\n';
+  assertEquivalent(dmp.diff_main(a, b, false), dmp.diff_main(a, b, true));
+
+  // Single line-mode.
+  a = '1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890';
+  b = 'abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij';
+  assertEquivalent(dmp.diff_main(a, b, false), dmp.diff_main(a, b, true));
+
+  // Overlap line-mode.
+  a = '1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n1234567890\n';
+  b = 'abcdefghij\n1234567890\n1234567890\n1234567890\nabcdefghij\n1234567890\n1234567890\n1234567890\nabcdefghij\n1234567890\n1234567890\n1234567890\nabcdefghij\n';
+  var texts_linemode = diff_rebuildtexts(dmp.diff_main(a, b, true));
+  var texts_textmode = diff_rebuildtexts(dmp.diff_main(a, b, false));
+  assertEquivalent(texts_textmode, texts_linemode);
+
+  // Test null inputs.
+  try {
+    dmp.diff_main(null, null);
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+}
+
+
+// MATCH TEST FUNCTIONS
+
+
+function testMatchAlphabet() {
+  // Initialise the bitmasks for Bitap.
+  // Unique.
+  assertEquivalent({'a':4, 'b':2, 'c':1}, dmp.match_alphabet_('abc'));
+
+  // Duplicates.
+  assertEquivalent({'a':37, 'b':18, 'c':8}, dmp.match_alphabet_('abcaba'));
+}
+
+function testMatchBitap() {
+  // Bitap algorithm.
+  dmp.Match_Distance = 100;
+  dmp.Match_Threshold = 0.5;
+  // Exact matches.
+  assertEquals(5, dmp.match_bitap_('abcdefghijk', 'fgh', 5));
+
+  assertEquals(5, dmp.match_bitap_('abcdefghijk', 'fgh', 0));
+
+  // Fuzzy matches.
+  assertEquals(4, dmp.match_bitap_('abcdefghijk', 'efxhi', 0));
+
+  assertEquals(2, dmp.match_bitap_('abcdefghijk', 'cdefxyhijk', 5));
+
+  assertEquals(-1, dmp.match_bitap_('abcdefghijk', 'bxy', 1));
+
+  // Overflow.
+  assertEquals(2, dmp.match_bitap_('123456789xx0', '3456789x0', 2));
+
+  // Threshold test.
+  dmp.Match_Threshold = 0.4;
+  assertEquals(4, dmp.match_bitap_('abcdefghijk', 'efxyhi', 1));
+
+  dmp.Match_Threshold = 0.3;
+  assertEquals(-1, dmp.match_bitap_('abcdefghijk', 'efxyhi', 1));
+
+  dmp.Match_Threshold = 0.0;
+  assertEquals(1, dmp.match_bitap_('abcdefghijk', 'bcdef', 1));
+  dmp.Match_Threshold = 0.5;
+
+  // Multiple select.
+  assertEquals(0, dmp.match_bitap_('abcdexyzabcde', 'abccde', 3));
+
+  assertEquals(8, dmp.match_bitap_('abcdexyzabcde', 'abccde', 5));
+
+  // Distance test.
+  dmp.Match_Distance = 10;  // Strict location.
+  assertEquals(-1, dmp.match_bitap_('abcdefghijklmnopqrstuvwxyz', 'abcdefg', 24));
+
+  assertEquals(0, dmp.match_bitap_('abcdefghijklmnopqrstuvwxyz', 'abcdxxefg', 1));
+
+  dmp.Match_Distance = 1000;  // Loose location.
+  assertEquals(0, dmp.match_bitap_('abcdefghijklmnopqrstuvwxyz', 'abcdefg', 24));
+}
+
+function testMatchMain() {
+  // Full match.
+  // Shortcut matches.
+  assertEquals(0, dmp.match_main('abcdef', 'abcdef', 1000));
+
+  assertEquals(-1, dmp.match_main('', 'abcdef', 1));
+
+  assertEquals(3, dmp.match_main('abcdef', '', 3));
+
+  assertEquals(3, dmp.match_main('abcdef', 'de', 3));
+
+  // Beyond end match.
+  assertEquals(3, dmp.match_main("abcdef", "defy", 4));
+
+  // Oversized pattern.
+  assertEquals(0, dmp.match_main("abcdef", "abcdefy", 0));
+
+  // Complex match.
+  assertEquals(4, dmp.match_main('I am the very model of a modern major general.', ' that berry ', 5));
+
+  // Test null inputs.
+  try {
+    dmp.match_main(null, null, 0);
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+}
+
+
+// PATCH TEST FUNCTIONS
+
+
+function testPatchObj() {
+  // Patch Object.
+  var p = new diff_match_patch.patch_obj();
+  p.start1 = 20;
+  p.start2 = 21;
+  p.length1 = 18;
+  p.length2 = 17;
+  p.diffs = [[DIFF_EQUAL, 'jump'], [DIFF_DELETE, 's'], [DIFF_INSERT, 'ed'], [DIFF_EQUAL, ' over '], [DIFF_DELETE, 'the'], [DIFF_INSERT, 'a'], [DIFF_EQUAL, '\nlaz']];
+  var strp = p.toString();
+  assertEquals('@@ -21,18 +22,17 @@\n jump\n-s\n+ed\n  over \n-the\n+a\n %0Alaz\n', strp);
+}
+
+function testPatchFromText() {
+  assertEquivalent([], dmp.patch_fromText(strp));
+
+  var strp = '@@ -21,18 +22,17 @@\n jump\n-s\n+ed\n  over \n-the\n+a\n %0Alaz\n';
+  assertEquals(strp, dmp.patch_fromText(strp)[0].toString());
+
+  assertEquals('@@ -1 +1 @@\n-a\n+b\n', dmp.patch_fromText('@@ -1 +1 @@\n-a\n+b\n')[0].toString());
+
+  assertEquals('@@ -1,3 +0,0 @@\n-abc\n', dmp.patch_fromText('@@ -1,3 +0,0 @@\n-abc\n')[0].toString());
+
+  assertEquals('@@ -0,0 +1,3 @@\n+abc\n', dmp.patch_fromText('@@ -0,0 +1,3 @@\n+abc\n')[0].toString());
+
+  // Generates error.
+  try {
+    dmp.patch_fromText('Bad\nPatch\n');
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+}
+
+function testPatchToText() {
+  var strp = '@@ -21,18 +22,17 @@\n jump\n-s\n+ed\n  over \n-the\n+a\n  laz\n';
+  var p = dmp.patch_fromText(strp);
+  assertEquals(strp, dmp.patch_toText(p));
+
+  strp = '@@ -1,9 +1,9 @@\n-f\n+F\n oo+fooba\n@@ -7,9 +7,9 @@\n obar\n-,\n+.\n  tes\n';
+  p = dmp.patch_fromText(strp);
+  assertEquals(strp, dmp.patch_toText(p));
+}
+
+function testPatchAddContext() {
+  dmp.Patch_Margin = 4;
+  var p = dmp.patch_fromText('@@ -21,4 +21,10 @@\n-jump\n+somersault\n')[0];
+  dmp.patch_addContext_(p, 'The quick brown fox jumps over the lazy dog.');
+  assertEquals('@@ -17,12 +17,18 @@\n fox \n-jump\n+somersault\n s ov\n', p.toString());
+
+  // Same, but not enough trailing context.
+  p = dmp.patch_fromText('@@ -21,4 +21,10 @@\n-jump\n+somersault\n')[0];
+  dmp.patch_addContext_(p, 'The quick brown fox jumps.');
+  assertEquals('@@ -17,10 +17,16 @@\n fox \n-jump\n+somersault\n s.\n', p.toString());
+
+  // Same, but not enough leading context.
+  p = dmp.patch_fromText('@@ -3 +3,2 @@\n-e\n+at\n')[0];
+  dmp.patch_addContext_(p, 'The quick brown fox jumps.');
+  assertEquals('@@ -1,7 +1,8 @@\n Th\n-e\n+at\n  qui\n', p.toString());
+
+  // Same, but with ambiguity.
+  p = dmp.patch_fromText('@@ -3 +3,2 @@\n-e\n+at\n')[0];
+  dmp.patch_addContext_(p, 'The quick brown fox jumps.  The quick brown fox crashes.');
+  assertEquals('@@ -1,27 +1,28 @@\n Th\n-e\n+at\n  quick brown fox jumps. \n', p.toString());
+}
+
+function testPatchMake() {
+  // Null case.
+  var patches = dmp.patch_make('', '');
+  assertEquals('', dmp.patch_toText(patches));
+
+  var text1 = 'The quick brown fox jumps over the lazy dog.';
+  var text2 = 'That quick brown fox jumped over a lazy dog.';
+  // Text2+Text1 inputs.
+  var expectedPatch = '@@ -1,8 +1,7 @@\n Th\n-at\n+e\n  qui\n@@ -21,17 +21,18 @@\n jump\n-ed\n+s\n  over \n-a\n+the\n  laz\n';
+  // The second patch must be "-21,17 +21,18", not "-22,17 +21,18" due to rolling context.
+  patches = dmp.patch_make(text2, text1);
+  assertEquals(expectedPatch, dmp.patch_toText(patches));
+
+  // Text1+Text2 inputs.
+  expectedPatch = '@@ -1,11 +1,12 @@\n Th\n-e\n+at\n  quick b\n@@ -22,18 +22,17 @@\n jump\n-s\n+ed\n  over \n-the\n+a\n  laz\n';
+  patches = dmp.patch_make(text1, text2);
+  assertEquals(expectedPatch, dmp.patch_toText(patches));
+
+  // Diff input.
+  var diffs = dmp.diff_main(text1, text2, false);
+  patches = dmp.patch_make(diffs);
+  assertEquals(expectedPatch, dmp.patch_toText(patches));
+
+  // Text1+Diff inputs.
+  patches = dmp.patch_make(text1, diffs);
+  assertEquals(expectedPatch, dmp.patch_toText(patches));
+
+  // Text1+Text2+Diff inputs (deprecated).
+  patches = dmp.patch_make(text1, text2, diffs);
+  assertEquals(expectedPatch, dmp.patch_toText(patches));
+
+  // Character encoding.
+  patches = dmp.patch_make('`1234567890-=[]\\;\',./', '~!@#$%^&*()_+{}|:"<>?');
+  assertEquals('@@ -1,21 +1,21 @@\n-%601234567890-=%5B%5D%5C;\',./\n+~!@#$%25%5E&*()_+%7B%7D%7C:%22%3C%3E?\n', dmp.patch_toText(patches));
+
+  // Character decoding.
+  diffs = [[DIFF_DELETE, '`1234567890-=[]\\;\',./'], [DIFF_INSERT, '~!@#$%^&*()_+{}|:"<>?']];
+  assertEquivalent(diffs, dmp.patch_fromText('@@ -1,21 +1,21 @@\n-%601234567890-=%5B%5D%5C;\',./\n+~!@#$%25%5E&*()_+%7B%7D%7C:%22%3C%3E?\n')[0].diffs);
+
+  // Long string with repeats.
+  text1 = '';
+  for (var x = 0; x < 100; x++) {
+    text1 += 'abcdef';
+  }
+  text2 = text1 + '123';
+  expectedPatch = '@@ -573,28 +573,31 @@\n cdefabcdefabcdefabcdefabcdef\n+123\n';
+  patches = dmp.patch_make(text1, text2);
+  assertEquals(expectedPatch, dmp.patch_toText(patches));
+
+  // Test null inputs.
+  try {
+    dmp.patch_make(null);
+    assertEquals(Error, null);
+  } catch (e) {
+    // Exception expected.
+  }
+}
+
+function testPatchSplitMax() {
+  // Assumes that dmp.Match_MaxBits is 32.
+  var patches = dmp.patch_make('abcdefghijklmnopqrstuvwxyz01234567890', 'XabXcdXefXghXijXklXmnXopXqrXstXuvXwxXyzX01X23X45X67X89X0');
+  dmp.patch_splitMax(patches);
+  assertEquals('@@ -1,32 +1,46 @@\n+X\n ab\n+X\n cd\n+X\n ef\n+X\n gh\n+X\n ij\n+X\n kl\n+X\n mn\n+X\n op\n+X\n qr\n+X\n st\n+X\n uv\n+X\n wx\n+X\n yz\n+X\n 012345\n@@ -25,13 +39,18 @@\n zX01\n+X\n 23\n+X\n 45\n+X\n 67\n+X\n 89\n+X\n 0\n', dmp.patch_toText(patches));
+
+  patches = dmp.patch_make('abcdef1234567890123456789012345678901234567890123456789012345678901234567890uvwxyz', 'abcdefuvwxyz');
+  var oldToText = dmp.patch_toText(patches);
+  dmp.patch_splitMax(patches);
+  assertEquals(oldToText, dmp.patch_toText(patches));
+
+  patches = dmp.patch_make('1234567890123456789012345678901234567890123456789012345678901234567890', 'abc');
+  dmp.patch_splitMax(patches);
+  assertEquals('@@ -1,32 +1,4 @@\n-1234567890123456789012345678\n 9012\n@@ -29,32 +1,4 @@\n-9012345678901234567890123456\n 7890\n@@ -57,14 +1,3 @@\n-78901234567890\n+abc\n', dmp.patch_toText(patches));
+
+  patches = dmp.patch_make('abcdefghij , h : 0 , t : 1 abcdefghij , h : 0 , t : 1 abcdefghij , h : 0 , t : 1', 'abcdefghij , h : 1 , t : 1 abcdefghij , h : 1 , t : 1 abcdefghij , h : 0 , t : 1');
+  dmp.patch_splitMax(patches);
+  assertEquals('@@ -2,32 +2,32 @@\n bcdefghij , h : \n-0\n+1\n  , t : 1 abcdef\n@@ -29,32 +29,32 @@\n bcdefghij , h : \n-0\n+1\n  , t : 1 abcdef\n', dmp.patch_toText(patches));
+}
+
+function testPatchAddPadding() {
+  // Both edges full.
+  var patches = dmp.patch_make('', 'test');
+  assertEquals('@@ -0,0 +1,4 @@\n+test\n', dmp.patch_toText(patches));
+  dmp.patch_addPadding(patches);
+  assertEquals('@@ -1,8 +1,12 @@\n %01%02%03%04\n+test\n %01%02%03%04\n', dmp.patch_toText(patches));
+
+  // Both edges partial.
+  patches = dmp.patch_make('XY', 'XtestY');
+  assertEquals('@@ -1,2 +1,6 @@\n X\n+test\n Y\n', dmp.patch_toText(patches));
+  dmp.patch_addPadding(patches);
+  assertEquals('@@ -2,8 +2,12 @@\n %02%03%04X\n+test\n Y%01%02%03\n', dmp.patch_toText(patches));
+
+  // Both edges none.
+  patches = dmp.patch_make('XXXXYYYY', 'XXXXtestYYYY');
+  assertEquals('@@ -1,8 +1,12 @@\n XXXX\n+test\n YYYY\n', dmp.patch_toText(patches));
+  dmp.patch_addPadding(patches);
+  assertEquals('@@ -5,8 +5,12 @@\n XXXX\n+test\n YYYY\n', dmp.patch_toText(patches));
+}
+
+function testPatchApply() {
+  dmp.Match_Distance = 1000;
+  dmp.Match_Threshold = 0.5;
+  dmp.Patch_DeleteThreshold = 0.5;
+  // Null case.
+  var patches = dmp.patch_make('', '');
+  var results = dmp.patch_apply(patches, 'Hello world.');
+  assertEquivalent(['Hello world.', []], results);
+
+  // Exact match.
+  patches = dmp.patch_make('The quick brown fox jumps over the lazy dog.', 'That quick brown fox jumped over a lazy dog.');
+  results = dmp.patch_apply(patches, 'The quick brown fox jumps over the lazy dog.');
+  assertEquivalent(['That quick brown fox jumped over a lazy dog.', [true, true]], results);
+
+  // Partial match.
+  results = dmp.patch_apply(patches, 'The quick red rabbit jumps over the tired tiger.');
+  assertEquivalent(['That quick red rabbit jumped over a tired tiger.', [true, true]], results);
+
+  // Failed match.
+  results = dmp.patch_apply(patches, 'I am the very model of a modern major general.');
+  assertEquivalent(['I am the very model of a modern major general.', [false, false]], results);
+
+  // Big delete, small change.
+  patches = dmp.patch_make('x1234567890123456789012345678901234567890123456789012345678901234567890y', 'xabcy');
+  results = dmp.patch_apply(patches, 'x123456789012345678901234567890-----++++++++++-----123456789012345678901234567890y');
+  assertEquivalent(['xabcy', [true, true]], results);
+
+  // Big delete, big change 1.
+  patches = dmp.patch_make('x1234567890123456789012345678901234567890123456789012345678901234567890y', 'xabcy');
+  results = dmp.patch_apply(patches, 'x12345678901234567890---------------++++++++++---------------12345678901234567890y');
+  assertEquivalent(['xabc12345678901234567890---------------++++++++++---------------12345678901234567890y', [false, true]], results);
+
+  // Big delete, big change 2.
+  dmp.Patch_DeleteThreshold = 0.6;
+  patches = dmp.patch_make('x1234567890123456789012345678901234567890123456789012345678901234567890y', 'xabcy');
+  results = dmp.patch_apply(patches, 'x12345678901234567890---------------++++++++++---------------12345678901234567890y');
+  assertEquivalent(['xabcy', [true, true]], results);
+  dmp.Patch_DeleteThreshold = 0.5;
+
+  // Compensate for failed patch.
+  dmp.Match_Threshold = 0.0;
+  dmp.Match_Distance = 0;
+  patches = dmp.patch_make('abcdefghijklmnopqrstuvwxyz--------------------1234567890', 'abcXXXXXXXXXXdefghijklmnopqrstuvwxyz--------------------1234567YYYYYYYYYY890');
+  results = dmp.patch_apply(patches, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ--------------------1234567890');
+  assertEquivalent(['ABCDEFGHIJKLMNOPQRSTUVWXYZ--------------------1234567YYYYYYYYYY890', [false, true]], results);
+  dmp.Match_Threshold = 0.5;
+  dmp.Match_Distance = 1000;
+
+  // No side effects.
+  patches = dmp.patch_make('', 'test');
+  var patchstr = dmp.patch_toText(patches);
+  dmp.patch_apply(patches, '');
+  assertEquals(patchstr, dmp.patch_toText(patches));
+
+  // No side effects with major delete.
+  patches = dmp.patch_make('The quick brown fox jumps over the lazy dog.', 'Woof');
+  patchstr = dmp.patch_toText(patches);
+  dmp.patch_apply(patches, 'The quick brown fox jumps over the lazy dog.');
+  assertEquals(patchstr, dmp.patch_toText(patches));
+
+  // Edge exact match.
+  patches = dmp.patch_make('', 'test');
+  results = dmp.patch_apply(patches, '');
+  assertEquivalent(['test', [true]], results);
+
+  // Near edge exact match.
+  patches = dmp.patch_make('XY', 'XtestY');
+  results = dmp.patch_apply(patches, 'XY');
+  assertEquivalent(['XtestY', [true]], results);
+
+  // Edge partial match.
+  patches = dmp.patch_make('y', 'y123');
+  results = dmp.patch_apply(patches, 'x');
+  assertEquivalent(['x123', [true]], results);
+}
+
+
+/**
+ * End of test harness, now run tests
+ */
+
+// If expected and actual are the identical, print 'Ok', otherwise 'Fail!'
+function assertEquals(msg, expected, actual) {
+  if (typeof actual == 'undefined') {
+    // msg is optional.
+    actual = expected;
+    expected = msg;
+    msg = undefined;
+  }
+  assert.equal(actual, expected, msg);
+}
+
+function assertTrue(msg, actual) {
+  if (typeof actual == 'undefined') {
+    // msg is optional.
+    actual = msg;
+    assertEquals(true, actual);
+  } else {
+    assertEquals(msg, true, actual);
+  }
+}
+
+function assertFalse(msg, actual) {
+  if (typeof actual == 'undefined') {
+    // msg is optional.
+    actual = msg;
+    assertEquals(false, actual);
+  } else {
+    assertEquals(msg, false, actual);
+  }
+}
+
+var tests = [
+    'testDiffCommonPrefix',
+    'testDiffCommonSuffix',
+    'testDiffCommonOverlap',
+    'testDiffHalfMatch',
+    'testDiffLinesToChars',
+    'testDiffCharsToLines',
+    'testDiffCleanupMerge',
+    'testDiffCleanupSemanticLossless',
+    'testDiffCleanupSemantic',
+    'testDiffCleanupEfficiency',
+    'testDiffPrettyHtml',
+    'testDiffText',
+    'testDiffDelta',
+    'testDiffXIndex',
+    'testDiffLevenshtein',
+    'testDiffBisect',
+    'testDiffMain',
+
+    'testMatchAlphabet',
+    'testMatchBitap',
+    'testMatchMain',
+
+    'testPatchObj',
+    'testPatchFromText',
+    'testPatchToText',
+    'testPatchAddContext',
+    'testPatchMake',
+    'testPatchSplitMax',
+    'testPatchAddPadding',
+    'testPatchApply'];
+
+
+  for (var x = 0; x < tests.length; x++) {
+    test(tests[x], eval(tests[x]))
+  }
+\ No newline at end of file
author	Florian Dold <florian.dold@gmail.com>	2017-05-28 00:38:50 +0200
committer	Florian Dold <florian.dold@gmail.com>	2017-05-28 00:40:43 +0200
commit	7fff4499fd915bcea3fa93b1aa8b35f4fe7a6027 (patch)
tree	6de9a1aebd150a23b7f8c273ec657a5d0a18fe3e /node_modules/diff-match-patch
parent	963b7a41feb29cc4be090a2446bdfe0c1f1bcd81 (diff)