diff --git a/README.md b/README.md index 43a515b..57a0285 100644 --- a/README.md +++ b/README.md @@ -16,7 +16,7 @@ message meets a specified criterion. - **Advanced parameters** – tune generation settings like temperature, top‑p and more from the options page. - **Markdown conversion** – optionally convert HTML bodies to Markdown before sending them to the AI service. - **Debug logging** – optional colorized logs help troubleshoot interactions with the AI service. -- **Debug tab** – view the last request payload sent to the AI service. +- **Debug tab** – view the last request payload and a diff between the unaltered message text and the final prompt. - **Light/Dark themes** – automatically match Thunderbird's appearance with optional manual override. - **Automatic rules** – create rules that tag, move, copy, forward, reply, delete, archive, mark read/unread or flag/unflag messages based on AI classification. Rules can optionally apply only to unread messages and can ignore messages outside a chosen age range. - **Rule ordering** – drag rules to prioritize them and optionally stop processing after a match. @@ -141,6 +141,8 @@ uses the following third party libraries: - MIT License - [turndown v7.2.0](https://github.com/mixmark-io/turndown/tree/v7.2.0) - MIT License +- [diff](https://github.com/google/diff-match-patch/blob/62f2e689f498f9c92dbc588c58750addec9b1654/javascript/diff_match_patch_uncompressed.js) + - Apache-2.0 license ## License diff --git a/ai-filter.sln b/ai-filter.sln index 57705eb..ea71f1b 100644 --- a/ai-filter.sln +++ b/ai-filter.sln @@ -108,6 +108,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "img", "img", "{F266602F-175 EndProject Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "js", "js", "{21D2A42C-3F85-465C-9141-C106AFD92B68}" ProjectSection(SolutionItems) = preProject + resources\js\diff_match_patch_uncompressed.js = resources\js\diff_match_patch_uncompressed.js resources\js\turndown.js = resources\js\turndown.js EndProjectSection EndProject diff --git a/background.js b/background.js index b5667e6..fc585ff 100644 --- a/background.js +++ b/background.js @@ -33,6 +33,7 @@ let userTheme = 'auto'; let currentTheme = 'light'; let detectSystemTheme; let errorPending = false; +let showDebugTab = false; const ERROR_NOTIFICATION_ID = 'sortana-error'; function normalizeRules(rules) { @@ -209,17 +210,38 @@ function collectText(part, bodyParts, attachments) { } } -function buildEmailText(full) { +function collectRawText(part, bodyParts, attachments) { + if (part.parts && part.parts.length) { + for (const p of part.parts) collectRawText(p, bodyParts, attachments); + return; + } + const ct = (part.contentType || "text/plain").toLowerCase(); + const cd = (part.headers?.["content-disposition"]?.[0] || "").toLowerCase(); + const body = String(part.body || ""); + if (cd.includes("attachment") || !ct.startsWith("text/")) { + const nameMatch = /filename\s*=\s*"?([^";]+)/i.exec(cd) || /name\s*=\s*"?([^";]+)/i.exec(part.headers?.["content-type"]?.[0] || ""); + const name = nameMatch ? nameMatch[1] : ""; + attachments.push(`${name} (${ct}, ${part.size || byteSize(body)} bytes)`); + } else if (ct.startsWith("text/html")) { + const doc = new DOMParser().parseFromString(body, 'text/html'); + bodyParts.push(doc.body.textContent || ""); + } else { + bodyParts.push(body); + } +} + +function buildEmailText(full, applyTransforms = true) { const bodyParts = []; const attachments = []; - collectText(full, bodyParts, attachments); + const collect = applyTransforms ? collectText : collectRawText; + collect(full, bodyParts, attachments); const headers = Object.entries(full.headers || {}) .map(([k, v]) => `${k}: ${v.join(' ')}`) .join('\n'); const attachInfo = `Attachments: ${attachments.length}` + (attachments.length ? "\n" + attachments.map(a => ` - ${a}`).join('\n') : ""); let combined = `${headers}\n${attachInfo}\n\n${bodyParts.join('\n')}`.trim(); - if (tokenReduction) { + if (applyTransforms && tokenReduction) { const seen = new Set(); combined = combined.split('\n').filter(l => { if (seen.has(l)) return false; @@ -227,7 +249,7 @@ function buildEmailText(full) { return true; }).join('\n'); } - return sanitizeString(combined); + return applyTransforms ? sanitizeString(combined) : combined; } function updateTimingStats(elapsed) { @@ -261,6 +283,7 @@ async function processMessage(id) { updateActionIcon(); try { const full = await messenger.messages.getFull(id); + const originalText = buildEmailText(full, false); let text = buildEmailText(full); if (tokenReduction && maxTokens > 0) { const limit = Math.floor(maxTokens * 0.9); @@ -268,6 +291,9 @@ async function processMessage(id) { text = text.slice(0, limit); } } + if (showDebugTab) { + await storage.local.set({ lastFullText: originalText, lastPromptText: text }); + } let hdr; let currentTags = []; let alreadyRead = false; @@ -425,7 +451,7 @@ async function clearCacheForMessages(idsInput) { } try { - const store = await storage.local.get(["endpoint", "templateName", "customTemplate", "customSystemPrompt", "aiParams", "debugLogging", "htmlToMarkdown", "stripUrlParams", "altTextImages", "collapseWhitespace", "tokenReduction", "aiRules", "theme", "errorPending"]); + const store = await storage.local.get(["endpoint", "templateName", "customTemplate", "customSystemPrompt", "aiParams", "debugLogging", "htmlToMarkdown", "stripUrlParams", "altTextImages", "collapseWhitespace", "tokenReduction", "aiRules", "theme", "errorPending", "showDebugTab"]); logger.setDebug(store.debugLogging); await AiClassifier.setConfig(store); userTheme = store.theme || 'auto'; @@ -440,6 +466,7 @@ async function clearCacheForMessages(idsInput) { maxTokens = parseInt(store.aiParams.max_tokens) || maxTokens; } errorPending = store.errorPending === true; + showDebugTab = store.showDebugTab === true; const savedStats = await storage.local.get('classifyStats'); if (savedStats.classifyStats && typeof savedStats.classifyStats === 'object') { Object.assign(timingStats, savedStats.classifyStats); @@ -494,6 +521,9 @@ async function clearCacheForMessages(idsInput) { tokenReduction = changes.tokenReduction.newValue === true; logger.aiLog("tokenReduction updated from storage change", { debug: true }, tokenReduction); } + if (changes.showDebugTab) { + showDebugTab = changes.showDebugTab.newValue === true; + } if (changes.errorPending) { errorPending = changes.errorPending.newValue === true; updateActionIcon(); diff --git a/manifest.json b/manifest.json index a3c9f7c..e7cb9d8 100644 --- a/manifest.json +++ b/manifest.json @@ -1,13 +1,13 @@ { "manifest_version": 2, "name": "Sortana", - "version": "2.1.2", + "version": "2.2.0", "default_locale": "en-US", "applications": { "gecko": { "id": "ai-filter@jordanwages", "strict_min_version": "128.0", - "strict_max_version": "139.*" + "strict_max_version": "140.*" } }, "icons": { diff --git a/options/options.html b/options/options.html index d14ce99..ddc5ee0 100644 --- a/options/options.html +++ b/options/options.html @@ -31,6 +31,10 @@ .tag { --bulma-tag-h: 318; } + #diff-display { + white-space: pre-wrap; + font-family: monospace; + } @@ -150,6 +154,11 @@ Aggressive token reduction +
+ +
@@ -216,11 +225,6 @@
-
- -
@@ -286,9 +290,14 @@ Debug

+                
             
         
     
+    
     
 
 
diff --git a/options/options.js b/options/options.js
index ebd7497..d881d6a 100644
--- a/options/options.js
+++ b/options/options.js
@@ -21,7 +21,9 @@ document.addEventListener('DOMContentLoaded', async () => {
         'aiCache',
         'theme',
         'showDebugTab',
-        'lastPayload'
+        'lastPayload',
+        'lastFullText',
+        'lastPromptText'
     ]);
     const tabButtons = document.querySelectorAll('#main-tabs li');
     const tabs = document.querySelectorAll('.tab-content');
@@ -67,8 +69,31 @@ document.addEventListener('DOMContentLoaded', async () => {
 
     await applyTheme(themeSelect.value);
     const payloadDisplay = document.getElementById('payload-display');
-    if (defaults.lastPayload) {
-        payloadDisplay.textContent = JSON.stringify(defaults.lastPayload, null, 2);
+    const diffDisplay = document.getElementById('diff-display');
+    const diffContainer = document.getElementById('diff-container');
+
+    let lastFullText = defaults.lastFullText || '';
+    let lastPromptText = defaults.lastPromptText || '';
+    let lastPayload = defaults.lastPayload ? JSON.stringify(defaults.lastPayload, null, 2) : '';
+
+    if (lastPayload) {
+        payloadDisplay.textContent = lastPayload;
+    }
+    if (lastFullText && lastPromptText && diff_match_patch) {
+        const dmp = new diff_match_patch();
+        dmp.Diff_EditCost = 4;
+        const diffs = dmp.diff_main(lastFullText, lastPromptText);
+        dmp.diff_cleanupEfficiency(diffs);
+        const hasDiff = diffs.some(d => d[0] !== 0);
+        if (hasDiff) {
+            diffDisplay.innerHTML = dmp.diff_prettyHtml(diffs);
+            diffContainer.classList.remove('is-hidden');
+        } else {
+            diffDisplay.innerHTML = '';
+            diffContainer.classList.add('is-hidden');
+        }
+    } else {
+        diffContainer.classList.add('is-hidden');
     }
     themeSelect.addEventListener('change', async () => {
         markDirty();
@@ -719,6 +744,38 @@ document.addEventListener('DOMContentLoaded', async () => {
         } catch {
             cacheCountEl.textContent = '?';
         }
+
+        try {
+            if (debugTabToggle.checked) {
+                const latest = await storage.local.get(['lastPayload', 'lastFullText', 'lastPromptText']);
+                const payloadStr = latest.lastPayload ? JSON.stringify(latest.lastPayload, null, 2) : '';
+                if (payloadStr !== lastPayload) {
+                    lastPayload = payloadStr;
+                    payloadDisplay.textContent = payloadStr;
+                }
+                if (latest.lastFullText !== lastFullText || latest.lastPromptText !== lastPromptText) {
+                    lastFullText = latest.lastFullText || '';
+                    lastPromptText = latest.lastPromptText || '';
+                    if (lastFullText && lastPromptText && diff_match_patch) {
+                        const dmp = new diff_match_patch();
+                        dmp.Diff_EditCost = 4;
+                        const diffs = dmp.diff_main(lastFullText, lastPromptText);
+                        dmp.diff_cleanupEfficiency(diffs);
+                        const hasDiff = diffs.some(d => d[0] !== 0);
+                        if (hasDiff) {
+                            diffDisplay.innerHTML = dmp.diff_prettyHtml(diffs);
+                            diffContainer.classList.remove('is-hidden');
+                        } else {
+                            diffDisplay.innerHTML = '';
+                            diffContainer.classList.add('is-hidden');
+                        }
+                    } else {
+                        diffDisplay.innerHTML = '';
+                        diffContainer.classList.add('is-hidden');
+                    }
+                }
+            }
+        } catch {}
     }
 
     refreshMaintenance();
diff --git a/resources/js/diff_match_patch_uncompressed.js b/resources/js/diff_match_patch_uncompressed.js
new file mode 100644
index 0000000..88a702c
--- /dev/null
+++ b/resources/js/diff_match_patch_uncompressed.js
@@ -0,0 +1,2236 @@
+/**
+ * Diff Match and Patch
+ * Copyright 2018 The diff-match-patch Authors.
+ * https://github.com/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
+ */
+var diff_match_patch = function() {
+
+  // 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;
+
+/**
+ * Class representing one diff tuple.
+ * Attempts to look like a two-element array (which is what this used to be).
+ * @param {number} op Operation, one of: DIFF_DELETE, DIFF_INSERT, DIFF_EQUAL.
+ * @param {string} text Text to be deleted, inserted, or retained.
+ * @constructor
+ */
+diff_match_patch.Diff = function(op, text) {
+  this[0] = op;
+  this[1] = text;
+};
+
+diff_match_patch.Diff.prototype.length = 2;
+
+/**
+ * Emulate the output of a two-element array.
+ * @return {string} Diff operation as a string.
+ */
+diff_match_patch.Diff.prototype.toString = function() {
+  return this[0] + ',' + this[1];
+};
+
+
+/**
+ * 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.} 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 [new diff_match_patch.Diff(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(new diff_match_patch.Diff(DIFF_EQUAL, commonprefix));
+  }
+  if (commonsuffix) {
+    diffs.push(new diff_match_patch.Diff(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.} 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 [new diff_match_patch.Diff(DIFF_INSERT, text2)];
+  }
+
+  if (!text2) {
+    // Just delete some text (speedup).
+    return [new diff_match_patch.Diff(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 = [new diff_match_patch.Diff(DIFF_INSERT, longtext.substring(0, i)),
+             new diff_match_patch.Diff(DIFF_EQUAL, shorttext),
+             new diff_match_patch.Diff(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 [new diff_match_patch.Diff(DIFF_DELETE, text1),
+            new diff_match_patch.Diff(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([new diff_match_patch.Diff(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.} 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(new diff_match_patch.Diff(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 subDiff =
+              this.diff_main(text_delete, text_insert, false, deadline);
+          for (var j = subDiff.length - 1; j >= 0; j--) {
+            diffs.splice(pointer, 0, subDiff[j]);
+          }
+          pointer = pointer + subDiff.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.} 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 [new diff_match_patch.Diff(DIFF_DELETE, text1),
+          new diff_match_patch.Diff(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.} 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.}}
+ *     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);
+
+      if (lineHash.hasOwnProperty ? lineHash.hasOwnProperty(line) :
+          (lineHash[line] !== undefined)) {
+        chars += String.fromCharCode(lineHash[line]);
+      } else {
+        if (lineArrayLength == maxLines) {
+          // Bail out at 65535 because
+          // String.fromCharCode(65536) == String.fromCharCode(0)
+          line = text.substring(lineStart);
+          lineEnd = text.length;
+        }
+        chars += String.fromCharCode(lineArrayLength);
+        lineHash[line] = lineArrayLength;
+        lineArray[lineArrayLength++] = line;
+      }
+      lineStart = lineEnd + 1;
+    }
+    return chars;
+  }
+  // Allocate 2/3rds of the space for text1, the rest for text2.
+  var maxLines = 40000;
+  var chars1 = diff_linesToCharsMunge_(text1);
+  maxLines = 65535;
+  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.} diffs Array of diff tuples.
+ * @param {!Array.} lineArray Array of unique strings.
+ * @private
+ */
+diff_match_patch.prototype.diff_charsToLines_ = function(diffs, lineArray) {
+  for (var i = 0; i < diffs.length; i++) {
+    var chars = diffs[i][1];
+    var text = [];
+    for (var j = 0; j < chars.length; j++) {
+      text[j] = lineArray[chars.charCodeAt(j)];
+    }
+    diffs[i][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: https://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: https://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: https://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.} 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.} 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.} 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,
+                     new diff_match_patch.Diff(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: abcxxxxxxdef
+  //   -> abcxxxdef
+  // e.g: xxxabcdefxxx
+  //   -> defxxxabc
+  // 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, new diff_match_patch.Diff(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, new diff_match_patch.Diff(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 cat came. -> The cat came.
+ * @param {!Array.} 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.} 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:
+       * ABXYCD
+       * AXCD
+       * ABXC
+       * AXCD
+       * ABXC
+       */
+      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,
+                     new diff_match_patch.Diff(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.} diffs Array of diff tuples.
+ */
+diff_match_patch.prototype.diff_cleanupMerge = function(diffs) {
+  // Add a dummy entry at the end.
+  diffs.push(new diff_match_patch.Diff(DIFF_EQUAL, ''));
+  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, new diff_match_patch.Diff(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.
+          pointer -= count_delete + count_insert;
+          diffs.splice(pointer, count_delete + count_insert);
+          if (text_delete.length) {
+            diffs.splice(pointer, 0,
+                new diff_match_patch.Diff(DIFF_DELETE, text_delete));
+            pointer++;
+          }
+          if (text_insert.length) {
+            diffs.splice(pointer, 0,
+                new diff_match_patch.Diff(DIFF_INSERT, text_insert));
+            pointer++;
+          }
+          pointer++;
+        } 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: ABAC -> ABAC
+  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.} 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.} 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_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, '&').replace(pattern_lt, '<')
+        .replace(pattern_gt, '>').replace(pattern_para, '¶
'); + switch (op) { + case DIFF_INSERT: + html[x] = '' + text + ''; + break; + case DIFF_DELETE: + html[x] = '' + text + ''; + break; + case DIFF_EQUAL: + html[x] = '' + text + ''; + break; + } + } + return html.join(''); +}; + + +/** + * Compute and return the source text (all equalities and deletions). + * @param {!Array.} 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.} 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.} 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.} 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.} 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++] = + new diff_match_patch.Diff(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++] = new diff_match_patch.Diff(DIFF_EQUAL, text); + } else { + diffs[diffsLength++] = new diff_match_patch.Diff(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; + } + if (patch.start2 === null) { + throw Error('patch not initialized'); + } + 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(new diff_match_patch.Diff(DIFF_EQUAL, prefix)); + } + // Add the suffix. + var suffix = text.substring(patch.start2 + patch.length1, + patch.start2 + patch.length1 + padding); + if (suffix) { + patch.diffs.push(new diff_match_patch.Diff(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.} a text1 (methods 1,3,4) or + * Array of diff tuples for text1 to text2 (method 2). + * @param {string|!Array.=} opt_b text2 (methods 1,4) or + * Array of diff tuples for text1 to text2 (method 3) or undefined (method 2). + * @param {string|!Array.=} opt_c Array of diff tuples + * for text1 to text2 (method 4) or undefined (methods 1,2,3). + * @return {!Array.} 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.} */(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.} */(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.} */(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. + // https://github.com/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.} patches Array of Patch objects. + * @return {!Array.} 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] = + new diff_match_patch.Diff(patch.diffs[y][0], patch.diffs[y][1]); + } + 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.} patches Array of Patch objects. + * @param {string} text Old text. + * @return {!Array.>} 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.} 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(new diff_match_patch.Diff(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(new diff_match_patch.Diff(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.} 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(new diff_match_patch.Diff(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(new diff_match_patch.Diff(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(new diff_match_patch.Diff(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(new diff_match_patch.Diff(DIFF_EQUAL, postcontext)); + } + } + if (!empty) { + patches.splice(++x, 0, patch); + } + } + } +}; + + +/** + * Take a list of patches and return a textual representation. + * @param {!Array.} 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.} 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(new diff_match_patch.Diff(DIFF_DELETE, line)); + } else if (sign == '+') { + // Insertion. + patch.diffs.push(new diff_match_patch.Diff(DIFF_INSERT, line)); + } else if (sign == ' ') { + // Minor equality. + patch.diffs.push(new diff_match_patch.Diff(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.} */ + this.diffs = []; + /** @type {?number} */ + this.start1 = null; + /** @type {?number} */ + this.start2 = null; + /** @type {number} */ + this.length1 = 0; + /** @type {number} */ + this.length2 = 0; +}; + + +/** + * Emulate GNU diff's format. + * Header: @@ -382,8 +481,9 @@ + * Indices 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, ' '); +}; + +// CLOSURE:begin_strip +// Lines below here will not be included in the Closure-compatible library. + +// Export these global variables so that they survive Google's JS compiler. +// In a browser, 'this' will be 'window'. +// Users of node.js should 'require' the uncompressed version since Google's +// JS compiler may break the following exports for non-browser environments. +/** @suppress {globalThis} */ +this['diff_match_patch'] = diff_match_patch; +/** @suppress {globalThis} */ +this['DIFF_DELETE'] = DIFF_DELETE; +/** @suppress {globalThis} */ +this['DIFF_INSERT'] = DIFF_INSERT; +/** @suppress {globalThis} */ +this['DIFF_EQUAL'] = DIFF_EQUAL;