From 4946c757d975aefd7da3f142c46300eeb5daa940 Mon Sep 17 00:00:00 2001
From: Antonin Hildebrand <antonin@hildebrand.cz>
Date: Mon, 15 Jul 2019 22:20:31 +0200
Subject: [PATCH] squash 'resources/unpacked/devtools' changes from
 0c78716f4..cf9938897

cf9938897 DevTools: Roll CodeMirror to 5.48.1
f0a2566fb DevTools: Make Geolocation and Shortcut settings accessible
8ee7e48ad DevTools: Remove check for windows path forward slashes
7b0402e24 DevTools: Autofix grdp messages with the wrong IDS key in presubmit
b8f2598c2 [DevTools] Audits - Defer accessing Runtime.cachedResources for report assets.

git-subtree-dir: resources/unpacked/devtools
git-subtree-split: cf993889748ca599603cc83d0b54a36640665d68
---
 .../audits/lighthouse/report-generator.js     |   16 +-
 front_end/cm/README.md                        |    5 +-
 front_end/cm/brace-fold.js                    |  102 +-
 front_end/cm/closebrackets.js                 |    6 +-
 front_end/cm/codemirror.js                    | 3252 +++++++++--------
 front_end/cm/foldcode.js                      |  259 +-
 front_end/cm/foldgutter.js                    |  272 +-
 front_end/cm/matchbrackets.js                 |   13 +-
 front_end/cm/multiplex.js                     |    8 +-
 front_end/cm/overlay.js                       |    4 +-
 front_end/cm_modes/clike.js                   |    4 +-
 front_end/cm_modes/clojure.js                 |    2 +-
 front_end/cm_modes/jsx.js                     |    4 +-
 front_end/cm_modes/php.js                     |    8 +-
 front_end/cm_modes/python.js                  |   42 +-
 front_end/cm_web_modes/css.js                 |   11 +-
 front_end/cm_web_modes/htmlmixed.js           |    4 +-
 front_end/cm_web_modes/javascript.js          |   81 +-
 .../emulation/GeolocationsSettingsTab.js      |   58 +-
 front_end/emulation/emulation_strings.grdp    |   24 +
 front_end/persistence/WorkspaceSettingsTab.js |    2 +-
 front_end/ui/ShortcutsScreen.js               |    1 +
 scripts/check_localizable_resources.js        |   94 +-
 .../check_localized_strings.js                |   50 +-
 24 files changed, 2236 insertions(+), 2086 deletions(-)

diff --git a/front_end/audits/lighthouse/report-generator.js b/front_end/audits/lighthouse/report-generator.js
index 01257be666..cec8f79c8f 100644
--- a/front_end/audits/lighthouse/report-generator.js
+++ b/front_end/audits/lighthouse/report-generator.js
@@ -18,10 +18,18 @@
 const cachedResources = Runtime.cachedResources;
 
 module.exports = {
-  REPORT_CSS: cachedResources['audits/lighthouse/report.css'],
-  REPORT_JAVASCRIPT: cachedResources['audits/lighthouse/report.js'],
-  REPORT_TEMPLATE: cachedResources['audits/lighthouse/template.html'],
-  REPORT_TEMPLATES: cachedResources['audits/lighthouse/templates.html'],
+  get REPORT_CSS() {
+    return cachedResources['audits/lighthouse/report.css'];
+  },
+  get REPORT_JAVASCRIPT() {
+    return cachedResources['audits/lighthouse/report.js'];
+  },
+  get REPORT_TEMPLATE() {
+    return cachedResources['audits/lighthouse/template.html'];
+  },
+  get REPORT_TEMPLATES() {
+    return cachedResources['audits/lighthouse/templates.html'];
+  },
 };
 
 },{}],1:[function(require,module,exports){
diff --git a/front_end/cm/README.md b/front_end/cm/README.md
index cd6130f90b..6a8ff1a906 100644
--- a/front_end/cm/README.md
+++ b/front_end/cm/README.md
@@ -9,8 +9,9 @@ This requires the following steps to be done:
 1. File `headlesscodemirror.js` is a `runmode-standalone.js` file from CodeMirror distribution, but wrapped in `(function(window) { ... }(this))`
 construction. This is needed to support in web workers.
 2. File `markselection.js` is a `mark-selection.js` from CodeMirror distribution. The "dash" is removed due to the restriction on the chromium grd generator.
-4. File codemirror.css contains both the default theme of CodeMirror and structural css required for it to work. Discard everything in the file up to the word `/* STOP */`.
-3. All other files in front_end/cm/ folder should be substituted with their newer versions from the upstream.
+3. File codemirror.css contains both the default theme of CodeMirror and structural css required for it to work. Discard everything in the file up to the word `/* STOP */`.
+4. All other files in front_end/cm/ folder should be substituted with their newer versions from the upstream. Note that some need to be renamed to remove `-` from the file name.
+5. All files in front_end/cm_web_modes/ and front_end/cm_modes/ should be updated with newer versions from upstream.
 
 ## Testing
 DevTools wrap CodeMirror via `CodeMirrorTextEditor.js` and `cmdevtools.css` files.
diff --git a/front_end/cm/brace-fold.js b/front_end/cm/brace-fold.js
index 2fee403822..654d1fb691 100644
--- a/front_end/cm/brace-fold.js
+++ b/front_end/cm/brace-fold.js
@@ -1,17 +1,17 @@
 // CodeMirror, copyright (c) by Marijn Haverbeke and others
-// Distributed under an MIT license: http://codemirror.net/LICENSE
+// Distributed under an MIT license: https://codemirror.net/LICENSE
 
 (function(mod) {
-if (typeof exports == 'object' && typeof module == 'object')  // CommonJS
-  mod(require('../../lib/codemirror'));
-else if (typeof define == 'function' && define.amd)  // AMD
-  define(['../../lib/codemirror'], mod);
-else  // Plain browser env
-  mod(CodeMirror);
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
 })(function(CodeMirror) {
-'use strict';
+"use strict";
 
-CodeMirror.registerHelper('fold', 'brace', function(cm, start) {
+CodeMirror.registerHelper("fold", "brace", function(cm, start) {
   var line = start.line, lineText = cm.getLine(line);
   var tokenType;
 
@@ -19,72 +19,56 @@ CodeMirror.registerHelper('fold', 'brace', function(cm, start) {
     for (var at = start.ch, pass = 0;;) {
       var found = at <= 0 ? -1 : lineText.lastIndexOf(openCh, at - 1);
       if (found == -1) {
-        if (pass == 1)
-          break;
+        if (pass == 1) break;
         pass = 1;
         at = lineText.length;
         continue;
       }
-      if (pass == 1 && found < start.ch)
-        break;
+      if (pass == 1 && found < start.ch) break;
       tokenType = cm.getTokenTypeAt(CodeMirror.Pos(line, found + 1));
-      if (!/^(comment|string)/.test(tokenType))
-        return found + 1;
+      if (!/^(comment|string)/.test(tokenType)) return found + 1;
       at = found - 1;
     }
   }
 
-  var startToken = '{', endToken = '}', startCh = findOpening('{');
+  var startToken = "{", endToken = "}", startCh = findOpening("{");
   if (startCh == null) {
-    startToken = '[', endToken = ']';
-    startCh = findOpening('[');
+    startToken = "[", endToken = "]";
+    startCh = findOpening("[");
   }
 
-  if (startCh == null)
-    return;
+  if (startCh == null) return;
   var count = 1, lastLine = cm.lastLine(), end, endCh;
   outer: for (var i = line; i <= lastLine; ++i) {
     var text = cm.getLine(i), pos = i == line ? startCh : 0;
     for (;;) {
       var nextOpen = text.indexOf(startToken, pos), nextClose = text.indexOf(endToken, pos);
-      if (nextOpen < 0)
-        nextOpen = text.length;
-      if (nextClose < 0)
-        nextClose = text.length;
+      if (nextOpen < 0) nextOpen = text.length;
+      if (nextClose < 0) nextClose = text.length;
       pos = Math.min(nextOpen, nextClose);
-      if (pos == text.length)
-        break;
+      if (pos == text.length) break;
       if (cm.getTokenTypeAt(CodeMirror.Pos(i, pos + 1)) == tokenType) {
-        if (pos == nextOpen)
-          ++count;
-        else if (!--count) {
-          end = i;
-          endCh = pos;
-          break outer;
-        }
+        if (pos == nextOpen) ++count;
+        else if (!--count) { end = i; endCh = pos; break outer; }
       }
       ++pos;
     }
   }
-  if (end == null || line == end && endCh == startCh)
-    return;
-  return {from: CodeMirror.Pos(line, startCh), to: CodeMirror.Pos(end, endCh)};
+  if (end == null || line == end) return;
+  return {from: CodeMirror.Pos(line, startCh),
+          to: CodeMirror.Pos(end, endCh)};
 });
 
-CodeMirror.registerHelper('fold', 'import', function(cm, start) {
+CodeMirror.registerHelper("fold", "import", function(cm, start) {
   function hasImport(line) {
-    if (line < cm.firstLine() || line > cm.lastLine())
-      return null;
+    if (line < cm.firstLine() || line > cm.lastLine()) return null;
     var start = cm.getTokenAt(CodeMirror.Pos(line, 1));
-    if (!/\S/.test(start.string))
-      start = cm.getTokenAt(CodeMirror.Pos(line, start.end + 1));
-    if (start.type != 'keyword' || start.string != 'import')
-      return null;
+    if (!/\S/.test(start.string)) start = cm.getTokenAt(CodeMirror.Pos(line, start.end + 1));
+    if (start.type != "keyword" || start.string != "import") return null;
     // Now find closing semicolon, return its position
     for (var i = line, e = Math.min(cm.lastLine(), line + 10); i <= e; ++i) {
-      var text = cm.getLine(i), semi = text.indexOf(';');
-      if (semi != -1)
-        return {startCh: start.end, end: CodeMirror.Pos(i, semi)};
+      var text = cm.getLine(i), semi = text.indexOf(";");
+      if (semi != -1) return {startCh: start.end, end: CodeMirror.Pos(i, semi)};
     }
   }
 
@@ -93,33 +77,29 @@ CodeMirror.registerHelper('fold', 'import', function(cm, start) {
     return null;
   for (var end = has.end;;) {
     var next = hasImport(end.line + 1);
-    if (next == null)
-      break;
+    if (next == null) break;
     end = next.end;
   }
   return {from: cm.clipPos(CodeMirror.Pos(startLine, has.startCh + 1)), to: end};
 });
 
-CodeMirror.registerHelper('fold', 'include', function(cm, start) {
+CodeMirror.registerHelper("fold", "include", function(cm, start) {
   function hasInclude(line) {
-    if (line < cm.firstLine() || line > cm.lastLine())
-      return null;
+    if (line < cm.firstLine() || line > cm.lastLine()) return null;
     var start = cm.getTokenAt(CodeMirror.Pos(line, 1));
-    if (!/\S/.test(start.string))
-      start = cm.getTokenAt(CodeMirror.Pos(line, start.end + 1));
-    if (start.type == 'meta' && start.string.slice(0, 8) == '#include')
-      return start.start + 8;
+    if (!/\S/.test(start.string)) start = cm.getTokenAt(CodeMirror.Pos(line, start.end + 1));
+    if (start.type == "meta" && start.string.slice(0, 8) == "#include") return start.start + 8;
   }
 
   var startLine = start.line, has = hasInclude(startLine);
-  if (has == null || hasInclude(startLine - 1) != null)
-    return null;
+  if (has == null || hasInclude(startLine - 1) != null) return null;
   for (var end = startLine;;) {
     var next = hasInclude(end + 1);
-    if (next == null)
-      break;
+    if (next == null) break;
     ++end;
   }
-  return {from: CodeMirror.Pos(startLine, has + 1), to: cm.clipPos(CodeMirror.Pos(end))};
+  return {from: CodeMirror.Pos(startLine, has + 1),
+          to: cm.clipPos(CodeMirror.Pos(end))};
+});
+
 });
-});
\ No newline at end of file
diff --git a/front_end/cm/closebrackets.js b/front_end/cm/closebrackets.js
index ce1a4ac6b1..4415c39381 100644
--- a/front_end/cm/closebrackets.js
+++ b/front_end/cm/closebrackets.js
@@ -11,6 +11,7 @@
 })(function(CodeMirror) {
   var defaults = {
     pairs: "()[]{}''\"\"",
+    closeBefore: ")]}'\":;>",
     triples: "",
     explode: "[]{}"
   };
@@ -109,6 +110,9 @@
     var pairs = getOption(conf, "pairs");
     var pos = pairs.indexOf(ch);
     if (pos == -1) return CodeMirror.Pass;
+
+    var closeBefore = getOption(conf,"closeBefore");
+
     var triples = getOption(conf, "triples");
 
     var identical = pairs.charAt(pos + 1) == ch;
@@ -136,7 +140,7 @@
         var prev = cur.ch == 0 ? " " : cm.getRange(Pos(cur.line, cur.ch - 1), cur)
         if (!CodeMirror.isWordChar(next) && prev != ch && !CodeMirror.isWordChar(prev)) curType = "both";
         else return CodeMirror.Pass;
-      } else if (opening) {
+      } else if (opening && (next.length === 0 || /\s/.test(next) || closeBefore.indexOf(next) > -1)) {
         curType = "both";
       } else {
         return CodeMirror.Pass;
diff --git a/front_end/cm/codemirror.js b/front_end/cm/codemirror.js
index fabfe4cd21..9f9704ec09 100644
--- a/front_end/cm/codemirror.js
+++ b/front_end/cm/codemirror.js
@@ -292,1470 +292,1367 @@
     }
   }
 
-  // The display handles the DOM integration, both for input reading
-  // and content drawing. It holds references to DOM nodes and
-  // display-related state.
-
-  function Display(place, doc, input) {
-    var d = this;
-    this.input = input;
-
-    // Covers bottom-right square when both scrollbars are present.
-    d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
-    d.scrollbarFiller.setAttribute("cm-not-content", "true");
-    // Covers bottom of gutter when coverGutterNextToScrollbar is on
-    // and h scrollbar is present.
-    d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
-    d.gutterFiller.setAttribute("cm-not-content", "true");
-    // Will contain the actual code, positioned to cover the viewport.
-    d.lineDiv = eltP("div", null, "CodeMirror-code");
-    // Elements are added to these to represent selection and cursors.
-    d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
-    d.cursorDiv = elt("div", null, "CodeMirror-cursors");
-    // A visibility: hidden element used to find the size of things.
-    d.measure = elt("div", null, "CodeMirror-measure");
-    // When lines outside of the viewport are measured, they are drawn in this.
-    d.lineMeasure = elt("div", null, "CodeMirror-measure");
-    // Wraps everything that needs to exist inside the vertically-padded coordinate system
-    d.lineSpace = eltP("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
-                      null, "position: relative; outline: none");
-    var lines = eltP("div", [d.lineSpace], "CodeMirror-lines");
-    // Moved around its parent to cover visible view.
-    d.mover = elt("div", [lines], null, "position: relative");
-    // Set to the height of the document, allowing scrolling.
-    d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
-    d.sizerWidth = null;
-    // Behavior of elts with overflow: auto and padding is
-    // inconsistent across browsers. This is used to ensure the
-    // scrollable area is big enough.
-    d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerGap + "px; width: 1px;");
-    // Will contain the gutters, if any.
-    d.gutters = elt("div", null, "CodeMirror-gutters");
-    d.lineGutter = null;
-    // Actual scrollable element.
-    d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
-    d.scroller.setAttribute("tabIndex", "-1");
-    // The element in which the editor lives.
-    d.wrapper = elt("div", [d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
-
-    // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
-    if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
-    if (!webkit && !(gecko && mobile)) { d.scroller.draggable = true; }
+  // BIDI HELPERS
 
-    if (place) {
-      if (place.appendChild) { place.appendChild(d.wrapper); }
-      else { place(d.wrapper); }
+  function iterateBidiSections(order, from, to, f) {
+    if (!order) { return f(from, to, "ltr", 0) }
+    var found = false;
+    for (var i = 0; i < order.length; ++i) {
+      var part = order[i];
+      if (part.from < to && part.to > from || from == to && part.to == from) {
+        f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr", i);
+        found = true;
+      }
     }
-
-    // Current rendered range (may be bigger than the view window).
-    d.viewFrom = d.viewTo = doc.first;
-    d.reportedViewFrom = d.reportedViewTo = doc.first;
-    // Information about the rendered lines.
-    d.view = [];
-    d.renderedView = null;
-    // Holds info about a single rendered line when it was rendered
-    // for measurement, while not in view.
-    d.externalMeasured = null;
-    // Empty space (in pixels) above the view
-    d.viewOffset = 0;
-    d.lastWrapHeight = d.lastWrapWidth = 0;
-    d.updateLineNumbers = null;
-
-    d.nativeBarWidth = d.barHeight = d.barWidth = 0;
-    d.scrollbarsClipped = false;
-
-    // Used to only resize the line number gutter when necessary (when
-    // the amount of lines crosses a boundary that makes its width change)
-    d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
-    // Set to true when a non-horizontal-scrolling line widget is
-    // added. As an optimization, line widget aligning is skipped when
-    // this is false.
-    d.alignWidgets = false;
-
-    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
-
-    // Tracks the maximum line length so that the horizontal scrollbar
-    // can be kept static when scrolling.
-    d.maxLine = null;
-    d.maxLineLength = 0;
-    d.maxLineChanged = false;
-
-    // Used for measuring wheel scrolling granularity
-    d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
-
-    // True when shift is held down.
-    d.shift = false;
-
-    // Used to track whether anything happened since the context menu
-    // was opened.
-    d.selForContextMenu = null;
-
-    d.activeTouch = null;
-
-    input.init(d);
+    if (!found) { f(from, to, "ltr"); }
   }
 
-  // Find the line object corresponding to the given line number.
-  function getLine(doc, n) {
-    n -= doc.first;
-    if (n < 0 || n >= doc.size) { throw new Error("There is no line " + (n + doc.first) + " in the document.") }
-    var chunk = doc;
-    while (!chunk.lines) {
-      for (var i = 0;; ++i) {
-        var child = chunk.children[i], sz = child.chunkSize();
-        if (n < sz) { chunk = child; break }
-        n -= sz;
+  var bidiOther = null;
+  function getBidiPartAt(order, ch, sticky) {
+    var found;
+    bidiOther = null;
+    for (var i = 0; i < order.length; ++i) {
+      var cur = order[i];
+      if (cur.from < ch && cur.to > ch) { return i }
+      if (cur.to == ch) {
+        if (cur.from != cur.to && sticky == "before") { found = i; }
+        else { bidiOther = i; }
+      }
+      if (cur.from == ch) {
+        if (cur.from != cur.to && sticky != "before") { found = i; }
+        else { bidiOther = i; }
       }
     }
-    return chunk.lines[n]
+    return found != null ? found : bidiOther
   }
 
-  // Get the part of a document between two positions, as an array of
-  // strings.
-  function getBetween(doc, start, end) {
-    var out = [], n = start.line;
-    doc.iter(start.line, end.line + 1, function (line) {
-      var text = line.text;
-      if (n == end.line) { text = text.slice(0, end.ch); }
-      if (n == start.line) { text = text.slice(start.ch); }
-      out.push(text);
-      ++n;
-    });
-    return out
-  }
-  // Get the lines between from and to, as array of strings.
-  function getLines(doc, from, to) {
-    var out = [];
-    doc.iter(from, to, function (line) { out.push(line.text); }); // iter aborts when callback returns truthy value
-    return out
-  }
+  // Bidirectional ordering algorithm
+  // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
+  // that this (partially) implements.
 
-  // Update the height of a line, propagating the height change
-  // upwards to parent nodes.
-  function updateLineHeight(line, height) {
-    var diff = height - line.height;
-    if (diff) { for (var n = line; n; n = n.parent) { n.height += diff; } }
-  }
+  // One-char codes used for character types:
+  // L (L):   Left-to-Right
+  // R (R):   Right-to-Left
+  // r (AL):  Right-to-Left Arabic
+  // 1 (EN):  European Number
+  // + (ES):  European Number Separator
+  // % (ET):  European Number Terminator
+  // n (AN):  Arabic Number
+  // , (CS):  Common Number Separator
+  // m (NSM): Non-Spacing Mark
+  // b (BN):  Boundary Neutral
+  // s (B):   Paragraph Separator
+  // t (S):   Segment Separator
+  // w (WS):  Whitespace
+  // N (ON):  Other Neutrals
 
-  // Given a line object, find its line number by walking up through
-  // its parent links.
-  function lineNo(line) {
-    if (line.parent == null) { return null }
-    var cur = line.parent, no = indexOf(cur.lines, line);
-    for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
-      for (var i = 0;; ++i) {
-        if (chunk.children[i] == cur) { break }
-        no += chunk.children[i].chunkSize();
-      }
+  // Returns null if characters are ordered as they appear
+  // (left-to-right), or an array of sections ({from, to, level}
+  // objects) in the order in which they occur visually.
+  var bidiOrdering = (function() {
+    // Character types for codepoints 0 to 0xff
+    var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";
+    // Character types for codepoints 0x600 to 0x6f9
+    var arabicTypes = "nnnnnnNNr%%r,rNNmmmmmmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmmmnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmnNmmmmmmrrmmNmmmmrr1111111111";
+    function charType(code) {
+      if (code <= 0xf7) { return lowTypes.charAt(code) }
+      else if (0x590 <= code && code <= 0x5f4) { return "R" }
+      else if (0x600 <= code && code <= 0x6f9) { return arabicTypes.charAt(code - 0x600) }
+      else if (0x6ee <= code && code <= 0x8ac) { return "r" }
+      else if (0x2000 <= code && code <= 0x200b) { return "w" }
+      else if (code == 0x200c) { return "b" }
+      else { return "L" }
     }
-    return no + cur.first
-  }
 
-  // Find the line at the given vertical position, using the height
-  // information in the document tree.
-  function lineAtHeight(chunk, h) {
-    var n = chunk.first;
-    outer: do {
-      for (var i$1 = 0; i$1 < chunk.children.length; ++i$1) {
-        var child = chunk.children[i$1], ch = child.height;
-        if (h < ch) { chunk = child; continue outer }
-        h -= ch;
-        n += child.chunkSize();
-      }
-      return n
-    } while (!chunk.lines)
-    var i = 0;
-    for (; i < chunk.lines.length; ++i) {
-      var line = chunk.lines[i], lh = line.height;
-      if (h < lh) { break }
-      h -= lh;
+    var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
+    var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
+
+    function BidiSpan(level, from, to) {
+      this.level = level;
+      this.from = from; this.to = to;
     }
-    return n + i
-  }
 
-  function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size}
+    return function(str, direction) {
+      var outerType = direction == "ltr" ? "L" : "R";
 
-  function lineNumberFor(options, i) {
-    return String(options.lineNumberFormatter(i + options.firstLineNumber))
-  }
+      if (str.length == 0 || direction == "ltr" && !bidiRE.test(str)) { return false }
+      var len = str.length, types = [];
+      for (var i = 0; i < len; ++i)
+        { types.push(charType(str.charCodeAt(i))); }
 
-  // A Pos instance represents a position within the text.
-  function Pos(line, ch, sticky) {
-    if ( sticky === void 0 ) sticky = null;
+      // W1. Examine each non-spacing mark (NSM) in the level run, and
+      // change the type of the NSM to the type of the previous
+      // character. If the NSM is at the start of the level run, it will
+      // get the type of sor.
+      for (var i$1 = 0, prev = outerType; i$1 < len; ++i$1) {
+        var type = types[i$1];
+        if (type == "m") { types[i$1] = prev; }
+        else { prev = type; }
+      }
 
-    if (!(this instanceof Pos)) { return new Pos(line, ch, sticky) }
-    this.line = line;
-    this.ch = ch;
-    this.sticky = sticky;
-  }
+      // W2. Search backwards from each instance of a European number
+      // until the first strong type (R, L, AL, or sor) is found. If an
+      // AL is found, change the type of the European number to Arabic
+      // number.
+      // W3. Change all ALs to R.
+      for (var i$2 = 0, cur = outerType; i$2 < len; ++i$2) {
+        var type$1 = types[i$2];
+        if (type$1 == "1" && cur == "r") { types[i$2] = "n"; }
+        else if (isStrong.test(type$1)) { cur = type$1; if (type$1 == "r") { types[i$2] = "R"; } }
+      }
 
-  // Compare two positions, return 0 if they are the same, a negative
-  // number when a is less, and a positive number otherwise.
-  function cmp(a, b) { return a.line - b.line || a.ch - b.ch }
+      // W4. A single European separator between two European numbers
+      // changes to a European number. A single common separator between
+      // two numbers of the same type changes to that type.
+      for (var i$3 = 1, prev$1 = types[0]; i$3 < len - 1; ++i$3) {
+        var type$2 = types[i$3];
+        if (type$2 == "+" && prev$1 == "1" && types[i$3+1] == "1") { types[i$3] = "1"; }
+        else if (type$2 == "," && prev$1 == types[i$3+1] &&
+                 (prev$1 == "1" || prev$1 == "n")) { types[i$3] = prev$1; }
+        prev$1 = type$2;
+      }
 
-  function equalCursorPos(a, b) { return a.sticky == b.sticky && cmp(a, b) == 0 }
+      // W5. A sequence of European terminators adjacent to European
+      // numbers changes to all European numbers.
+      // W6. Otherwise, separators and terminators change to Other
+      // Neutral.
+      for (var i$4 = 0; i$4 < len; ++i$4) {
+        var type$3 = types[i$4];
+        if (type$3 == ",") { types[i$4] = "N"; }
+        else if (type$3 == "%") {
+          var end = (void 0);
+          for (end = i$4 + 1; end < len && types[end] == "%"; ++end) {}
+          var replace = (i$4 && types[i$4-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
+          for (var j = i$4; j < end; ++j) { types[j] = replace; }
+          i$4 = end - 1;
+        }
+      }
 
-  function copyPos(x) {return Pos(x.line, x.ch)}
-  function maxPos(a, b) { return cmp(a, b) < 0 ? b : a }
-  function minPos(a, b) { return cmp(a, b) < 0 ? a : b }
+      // W7. Search backwards from each instance of a European number
+      // until the first strong type (R, L, or sor) is found. If an L is
+      // found, then change the type of the European number to L.
+      for (var i$5 = 0, cur$1 = outerType; i$5 < len; ++i$5) {
+        var type$4 = types[i$5];
+        if (cur$1 == "L" && type$4 == "1") { types[i$5] = "L"; }
+        else if (isStrong.test(type$4)) { cur$1 = type$4; }
+      }
 
-  // Most of the external API clips given positions to make sure they
-  // actually exist within the document.
-  function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1))}
-  function clipPos(doc, pos) {
-    if (pos.line < doc.first) { return Pos(doc.first, 0) }
-    var last = doc.first + doc.size - 1;
-    if (pos.line > last) { return Pos(last, getLine(doc, last).text.length) }
-    return clipToLen(pos, getLine(doc, pos.line).text.length)
+      // N1. A sequence of neutrals takes the direction of the
+      // surrounding strong text if the text on both sides has the same
+      // direction. European and Arabic numbers act as if they were R in
+      // terms of their influence on neutrals. Start-of-level-run (sor)
+      // and end-of-level-run (eor) are used at level run boundaries.
+      // N2. Any remaining neutrals take the embedding direction.
+      for (var i$6 = 0; i$6 < len; ++i$6) {
+        if (isNeutral.test(types[i$6])) {
+          var end$1 = (void 0);
+          for (end$1 = i$6 + 1; end$1 < len && isNeutral.test(types[end$1]); ++end$1) {}
+          var before = (i$6 ? types[i$6-1] : outerType) == "L";
+          var after = (end$1 < len ? types[end$1] : outerType) == "L";
+          var replace$1 = before == after ? (before ? "L" : "R") : outerType;
+          for (var j$1 = i$6; j$1 < end$1; ++j$1) { types[j$1] = replace$1; }
+          i$6 = end$1 - 1;
+        }
+      }
+
+      // Here we depart from the documented algorithm, in order to avoid
+      // building up an actual levels array. Since there are only three
+      // levels (0, 1, 2) in an implementation that doesn't take
+      // explicit embedding into account, we can build up the order on
+      // the fly, without following the level-based algorithm.
+      var order = [], m;
+      for (var i$7 = 0; i$7 < len;) {
+        if (countsAsLeft.test(types[i$7])) {
+          var start = i$7;
+          for (++i$7; i$7 < len && countsAsLeft.test(types[i$7]); ++i$7) {}
+          order.push(new BidiSpan(0, start, i$7));
+        } else {
+          var pos = i$7, at = order.length;
+          for (++i$7; i$7 < len && types[i$7] != "L"; ++i$7) {}
+          for (var j$2 = pos; j$2 < i$7;) {
+            if (countsAsNum.test(types[j$2])) {
+              if (pos < j$2) { order.splice(at, 0, new BidiSpan(1, pos, j$2)); }
+              var nstart = j$2;
+              for (++j$2; j$2 < i$7 && countsAsNum.test(types[j$2]); ++j$2) {}
+              order.splice(at, 0, new BidiSpan(2, nstart, j$2));
+              pos = j$2;
+            } else { ++j$2; }
+          }
+          if (pos < i$7) { order.splice(at, 0, new BidiSpan(1, pos, i$7)); }
+        }
+      }
+      if (direction == "ltr") {
+        if (order[0].level == 1 && (m = str.match(/^\s+/))) {
+          order[0].from = m[0].length;
+          order.unshift(new BidiSpan(0, 0, m[0].length));
+        }
+        if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
+          lst(order).to -= m[0].length;
+          order.push(new BidiSpan(0, len - m[0].length, len));
+        }
+      }
+
+      return direction == "rtl" ? order.reverse() : order
+    }
+  })();
+
+  // Get the bidi ordering for the given line (and cache it). Returns
+  // false for lines that are fully left-to-right, and an array of
+  // BidiSpan objects otherwise.
+  function getOrder(line, direction) {
+    var order = line.order;
+    if (order == null) { order = line.order = bidiOrdering(line.text, direction); }
+    return order
   }
-  function clipToLen(pos, linelen) {
-    var ch = pos.ch;
-    if (ch == null || ch > linelen) { return Pos(pos.line, linelen) }
-    else if (ch < 0) { return Pos(pos.line, 0) }
-    else { return pos }
+
+  // EVENT HANDLING
+
+  // Lightweight event framework. on/off also work on DOM nodes,
+  // registering native DOM handlers.
+
+  var noHandlers = [];
+
+  var on = function(emitter, type, f) {
+    if (emitter.addEventListener) {
+      emitter.addEventListener(type, f, false);
+    } else if (emitter.attachEvent) {
+      emitter.attachEvent("on" + type, f);
+    } else {
+      var map$$1 = emitter._handlers || (emitter._handlers = {});
+      map$$1[type] = (map$$1[type] || noHandlers).concat(f);
+    }
+  };
+
+  function getHandlers(emitter, type) {
+    return emitter._handlers && emitter._handlers[type] || noHandlers
   }
-  function clipPosArray(doc, array) {
-    var out = [];
-    for (var i = 0; i < array.length; i++) { out[i] = clipPos(doc, array[i]); }
-    return out
+
+  function off(emitter, type, f) {
+    if (emitter.removeEventListener) {
+      emitter.removeEventListener(type, f, false);
+    } else if (emitter.detachEvent) {
+      emitter.detachEvent("on" + type, f);
+    } else {
+      var map$$1 = emitter._handlers, arr = map$$1 && map$$1[type];
+      if (arr) {
+        var index = indexOf(arr, f);
+        if (index > -1)
+          { map$$1[type] = arr.slice(0, index).concat(arr.slice(index + 1)); }
+      }
+    }
   }
 
-  // Optimize some code when these features are not used.
-  var sawReadOnlySpans = false, sawCollapsedSpans = false;
+  function signal(emitter, type /*, values...*/) {
+    var handlers = getHandlers(emitter, type);
+    if (!handlers.length) { return }
+    var args = Array.prototype.slice.call(arguments, 2);
+    for (var i = 0; i < handlers.length; ++i) { handlers[i].apply(null, args); }
+  }
 
-  function seeReadOnlySpans() {
-    sawReadOnlySpans = true;
+  // The DOM events that CodeMirror handles can be overridden by
+  // registering a (non-DOM) handler on the editor for the event name,
+  // and preventDefault-ing the event in that handler.
+  function signalDOMEvent(cm, e, override) {
+    if (typeof e == "string")
+      { e = {type: e, preventDefault: function() { this.defaultPrevented = true; }}; }
+    signal(cm, override || e.type, cm, e);
+    return e_defaultPrevented(e) || e.codemirrorIgnore
   }
 
-  function seeCollapsedSpans() {
-    sawCollapsedSpans = true;
+  function signalCursorActivity(cm) {
+    var arr = cm._handlers && cm._handlers.cursorActivity;
+    if (!arr) { return }
+    var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);
+    for (var i = 0; i < arr.length; ++i) { if (indexOf(set, arr[i]) == -1)
+      { set.push(arr[i]); } }
   }
 
-  // TEXTMARKER SPANS
+  function hasHandler(emitter, type) {
+    return getHandlers(emitter, type).length > 0
+  }
 
-  function MarkedSpan(marker, from, to) {
-    this.marker = marker;
-    this.from = from; this.to = to;
+  // Add on and off methods to a constructor's prototype, to make
+  // registering events on such objects more convenient.
+  function eventMixin(ctor) {
+    ctor.prototype.on = function(type, f) {on(this, type, f);};
+    ctor.prototype.off = function(type, f) {off(this, type, f);};
   }
 
-  // Search an array of spans for a span matching the given marker.
-  function getMarkedSpanFor(spans, marker) {
-    if (spans) { for (var i = 0; i < spans.length; ++i) {
-      var span = spans[i];
-      if (span.marker == marker) { return span }
-    } }
+  // Due to the fact that we still support jurassic IE versions, some
+  // compatibility wrappers are needed.
+
+  function e_preventDefault(e) {
+    if (e.preventDefault) { e.preventDefault(); }
+    else { e.returnValue = false; }
   }
-  // Remove a span from an array, returning undefined if no spans are
-  // left (we don't store arrays for lines without spans).
-  function removeMarkedSpan(spans, span) {
-    var r;
-    for (var i = 0; i < spans.length; ++i)
-      { if (spans[i] != span) { (r || (r = [])).push(spans[i]); } }
-    return r
+  function e_stopPropagation(e) {
+    if (e.stopPropagation) { e.stopPropagation(); }
+    else { e.cancelBubble = true; }
   }
-  // Add a span to a line.
-  function addMarkedSpan(line, span) {
-    line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
-    span.marker.attachLine(line);
+  function e_defaultPrevented(e) {
+    return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false
   }
+  function e_stop(e) {e_preventDefault(e); e_stopPropagation(e);}
 
-  // Used for the algorithm that adjusts markers for a change in the
-  // document. These functions cut an array of spans at a given
-  // character position, returning an array of remaining chunks (or
-  // undefined if nothing remains).
-  function markedSpansBefore(old, startCh, isInsert) {
-    var nw;
-    if (old) { for (var i = 0; i < old.length; ++i) {
-      var span = old[i], marker = span.marker;
-      var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
-      if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {
-        var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh)
-        ;(nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));
-      }
-    } }
-    return nw
-  }
-  function markedSpansAfter(old, endCh, isInsert) {
-    var nw;
-    if (old) { for (var i = 0; i < old.length; ++i) {
-      var span = old[i], marker = span.marker;
-      var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
-      if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {
-        var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh)
-        ;(nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,
-                                              span.to == null ? null : span.to - endCh));
-      }
-    } }
-    return nw
+  function e_target(e) {return e.target || e.srcElement}
+  function e_button(e) {
+    var b = e.which;
+    if (b == null) {
+      if (e.button & 1) { b = 1; }
+      else if (e.button & 2) { b = 3; }
+      else if (e.button & 4) { b = 2; }
+    }
+    if (mac && e.ctrlKey && b == 1) { b = 3; }
+    return b
   }
 
-  // Given a change object, compute the new set of marker spans that
-  // cover the line in which the change took place. Removes spans
-  // entirely within the change, reconnects spans belonging to the
-  // same marker that appear on both sides of the change, and cuts off
-  // spans partially within the change. Returns an array of span
-  // arrays with one element for each line in (after) the change.
-  function stretchSpansOverChange(doc, change) {
-    if (change.full) { return null }
-    var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
-    var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
-    if (!oldFirst && !oldLast) { return null }
-
-    var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;
-    // Get the spans that 'stick out' on both sides
-    var first = markedSpansBefore(oldFirst, startCh, isInsert);
-    var last = markedSpansAfter(oldLast, endCh, isInsert);
-
-    // Next, merge those two ends
-    var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
-    if (first) {
-      // Fix up .to properties of first
-      for (var i = 0; i < first.length; ++i) {
-        var span = first[i];
-        if (span.to == null) {
-          var found = getMarkedSpanFor(last, span.marker);
-          if (!found) { span.to = startCh; }
-          else if (sameLine) { span.to = found.to == null ? null : found.to + offset; }
-        }
-      }
-    }
-    if (last) {
-      // Fix up .from in last (or move them into first in case of sameLine)
-      for (var i$1 = 0; i$1 < last.length; ++i$1) {
-        var span$1 = last[i$1];
-        if (span$1.to != null) { span$1.to += offset; }
-        if (span$1.from == null) {
-          var found$1 = getMarkedSpanFor(first, span$1.marker);
-          if (!found$1) {
-            span$1.from = offset;
-            if (sameLine) { (first || (first = [])).push(span$1); }
-          }
-        } else {
-          span$1.from += offset;
-          if (sameLine) { (first || (first = [])).push(span$1); }
-        }
-      }
-    }
-    // Make sure we didn't create any zero-length spans
-    if (first) { first = clearEmptySpans(first); }
-    if (last && last != first) { last = clearEmptySpans(last); }
+  // Detect drag-and-drop
+  var dragAndDrop = function() {
+    // There is *some* kind of drag-and-drop support in IE6-8, but I
+    // couldn't get it to work yet.
+    if (ie && ie_version < 9) { return false }
+    var div = elt('div');
+    return "draggable" in div || "dragDrop" in div
+  }();
 
-    var newMarkers = [first];
-    if (!sameLine) {
-      // Fill gap with whole-line-spans
-      var gap = change.text.length - 2, gapMarkers;
-      if (gap > 0 && first)
-        { for (var i$2 = 0; i$2 < first.length; ++i$2)
-          { if (first[i$2].to == null)
-            { (gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i$2].marker, null, null)); } } }
-      for (var i$3 = 0; i$3 < gap; ++i$3)
-        { newMarkers.push(gapMarkers); }
-      newMarkers.push(last);
+  var zwspSupported;
+  function zeroWidthElement(measure) {
+    if (zwspSupported == null) {
+      var test = elt("span", "\u200b");
+      removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
+      if (measure.firstChild.offsetHeight != 0)
+        { zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8); }
     }
-    return newMarkers
+    var node = zwspSupported ? elt("span", "\u200b") :
+      elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
+    node.setAttribute("cm-text", "");
+    return node
   }
 
-  // Remove spans that are empty and don't have a clearWhenEmpty
-  // option of false.
-  function clearEmptySpans(spans) {
-    for (var i = 0; i < spans.length; ++i) {
-      var span = spans[i];
-      if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)
-        { spans.splice(i--, 1); }
-    }
-    if (!spans.length) { return null }
-    return spans
+  // Feature-detect IE's crummy client rect reporting for bidi text
+  var badBidiRects;
+  function hasBadBidiRects(measure) {
+    if (badBidiRects != null) { return badBidiRects }
+    var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));
+    var r0 = range(txt, 0, 1).getBoundingClientRect();
+    var r1 = range(txt, 1, 2).getBoundingClientRect();
+    removeChildren(measure);
+    if (!r0 || r0.left == r0.right) { return false } // Safari returns null in some cases (#2780)
+    return badBidiRects = (r1.right - r0.right < 3)
   }
 
-  // Used to 'clip' out readOnly ranges when making a change.
-  function removeReadOnlyRanges(doc, from, to) {
-    var markers = null;
-    doc.iter(from.line, to.line + 1, function (line) {
-      if (line.markedSpans) { for (var i = 0; i < line.markedSpans.length; ++i) {
-        var mark = line.markedSpans[i].marker;
-        if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
-          { (markers || (markers = [])).push(mark); }
-      } }
-    });
-    if (!markers) { return null }
-    var parts = [{from: from, to: to}];
-    for (var i = 0; i < markers.length; ++i) {
-      var mk = markers[i], m = mk.find(0);
-      for (var j = 0; j < parts.length; ++j) {
-        var p = parts[j];
-        if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) { continue }
-        var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);
-        if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)
-          { newParts.push({from: p.from, to: m.from}); }
-        if (dto > 0 || !mk.inclusiveRight && !dto)
-          { newParts.push({from: m.to, to: p.to}); }
-        parts.splice.apply(parts, newParts);
-        j += newParts.length - 3;
+  // See if "".split is the broken IE version, if so, provide an
+  // alternative way to split lines.
+  var splitLinesAuto = "\n\nb".split(/\n/).length != 3 ? function (string) {
+    var pos = 0, result = [], l = string.length;
+    while (pos <= l) {
+      var nl = string.indexOf("\n", pos);
+      if (nl == -1) { nl = string.length; }
+      var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
+      var rt = line.indexOf("\r");
+      if (rt != -1) {
+        result.push(line.slice(0, rt));
+        pos += rt + 1;
+      } else {
+        result.push(line);
+        pos = nl + 1;
       }
     }
-    return parts
-  }
+    return result
+  } : function (string) { return string.split(/\r\n?|\n/); };
 
-  // Connect or disconnect spans from a line.
-  function detachMarkedSpans(line) {
-    var spans = line.markedSpans;
-    if (!spans) { return }
-    for (var i = 0; i < spans.length; ++i)
-      { spans[i].marker.detachLine(line); }
-    line.markedSpans = null;
-  }
-  function attachMarkedSpans(line, spans) {
-    if (!spans) { return }
-    for (var i = 0; i < spans.length; ++i)
-      { spans[i].marker.attachLine(line); }
-    line.markedSpans = spans;
-  }
+  var hasSelection = window.getSelection ? function (te) {
+    try { return te.selectionStart != te.selectionEnd }
+    catch(e) { return false }
+  } : function (te) {
+    var range$$1;
+    try {range$$1 = te.ownerDocument.selection.createRange();}
+    catch(e) {}
+    if (!range$$1 || range$$1.parentElement() != te) { return false }
+    return range$$1.compareEndPoints("StartToEnd", range$$1) != 0
+  };
 
-  // Helpers used when computing which overlapping collapsed span
-  // counts as the larger one.
-  function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0 }
-  function extraRight(marker) { return marker.inclusiveRight ? 1 : 0 }
+  var hasCopyEvent = (function () {
+    var e = elt("div");
+    if ("oncopy" in e) { return true }
+    e.setAttribute("oncopy", "return;");
+    return typeof e.oncopy == "function"
+  })();
 
-  // Returns a number indicating which of two overlapping collapsed
-  // spans is larger (and thus includes the other). Falls back to
-  // comparing ids when the spans cover exactly the same range.
-  function compareCollapsedMarkers(a, b) {
-    var lenDiff = a.lines.length - b.lines.length;
-    if (lenDiff != 0) { return lenDiff }
-    var aPos = a.find(), bPos = b.find();
-    var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);
-    if (fromCmp) { return -fromCmp }
-    var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);
-    if (toCmp) { return toCmp }
-    return b.id - a.id
+  var badZoomedRects = null;
+  function hasBadZoomedRects(measure) {
+    if (badZoomedRects != null) { return badZoomedRects }
+    var node = removeChildrenAndAdd(measure, elt("span", "x"));
+    var normal = node.getBoundingClientRect();
+    var fromRange = range(node, 0, 1).getBoundingClientRect();
+    return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1
   }
 
-  // Find out whether a line ends or starts in a collapsed span. If
-  // so, return the marker for that span.
-  function collapsedSpanAtSide(line, start) {
-    var sps = sawCollapsedSpans && line.markedSpans, found;
-    if (sps) { for (var sp = (void 0), i = 0; i < sps.length; ++i) {
-      sp = sps[i];
-      if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&
-          (!found || compareCollapsedMarkers(found, sp.marker) < 0))
-        { found = sp.marker; }
-    } }
-    return found
+  // Known modes, by name and by MIME
+  var modes = {}, mimeModes = {};
+
+  // Extra arguments are stored as the mode's dependencies, which is
+  // used by (legacy) mechanisms like loadmode.js to automatically
+  // load a mode. (Preferred mechanism is the require/define calls.)
+  function defineMode(name, mode) {
+    if (arguments.length > 2)
+      { mode.dependencies = Array.prototype.slice.call(arguments, 2); }
+    modes[name] = mode;
   }
-  function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true) }
-  function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false) }
 
-  function collapsedSpanAround(line, ch) {
-    var sps = sawCollapsedSpans && line.markedSpans, found;
-    if (sps) { for (var i = 0; i < sps.length; ++i) {
-      var sp = sps[i];
-      if (sp.marker.collapsed && (sp.from == null || sp.from < ch) && (sp.to == null || sp.to > ch) &&
-          (!found || compareCollapsedMarkers(found, sp.marker) < 0)) { found = sp.marker; }
-    } }
-    return found
+  function defineMIME(mime, spec) {
+    mimeModes[mime] = spec;
   }
 
-  // Test whether there exists a collapsed span that partially
-  // overlaps (covers the start or end, but not both) of a new span.
-  // Such overlap is not allowed.
-  function conflictingCollapsedRange(doc, lineNo$$1, from, to, marker) {
-    var line = getLine(doc, lineNo$$1);
-    var sps = sawCollapsedSpans && line.markedSpans;
-    if (sps) { for (var i = 0; i < sps.length; ++i) {
-      var sp = sps[i];
-      if (!sp.marker.collapsed) { continue }
-      var found = sp.marker.find(0);
-      var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);
-      var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);
-      if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) { continue }
-      if (fromCmp <= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.to, from) >= 0 : cmp(found.to, from) > 0) ||
-          fromCmp >= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.from, to) <= 0 : cmp(found.from, to) < 0))
-        { return true }
-    } }
+  // Given a MIME type, a {name, ...options} config object, or a name
+  // string, return a mode config object.
+  function resolveMode(spec) {
+    if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
+      spec = mimeModes[spec];
+    } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
+      var found = mimeModes[spec.name];
+      if (typeof found == "string") { found = {name: found}; }
+      spec = createObj(found, spec);
+      spec.name = found.name;
+    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
+      return resolveMode("application/xml")
+    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+json$/.test(spec)) {
+      return resolveMode("application/json")
+    }
+    if (typeof spec == "string") { return {name: spec} }
+    else { return spec || {name: "null"} }
   }
 
-  // A visual line is a line as drawn on the screen. Folding, for
-  // example, can cause multiple logical lines to appear on the same
-  // visual line. This finds the start of the visual line that the
-  // given line is part of (usually that is the line itself).
-  function visualLine(line) {
-    var merged;
-    while (merged = collapsedSpanAtStart(line))
-      { line = merged.find(-1, true).line; }
-    return line
+  // Given a mode spec (anything that resolveMode accepts), find and
+  // initialize an actual mode object.
+  function getMode(options, spec) {
+    spec = resolveMode(spec);
+    var mfactory = modes[spec.name];
+    if (!mfactory) { return getMode(options, "text/plain") }
+    var modeObj = mfactory(options, spec);
+    if (modeExtensions.hasOwnProperty(spec.name)) {
+      var exts = modeExtensions[spec.name];
+      for (var prop in exts) {
+        if (!exts.hasOwnProperty(prop)) { continue }
+        if (modeObj.hasOwnProperty(prop)) { modeObj["_" + prop] = modeObj[prop]; }
+        modeObj[prop] = exts[prop];
+      }
+    }
+    modeObj.name = spec.name;
+    if (spec.helperType) { modeObj.helperType = spec.helperType; }
+    if (spec.modeProps) { for (var prop$1 in spec.modeProps)
+      { modeObj[prop$1] = spec.modeProps[prop$1]; } }
+
+    return modeObj
   }
 
-  function visualLineEnd(line) {
-    var merged;
-    while (merged = collapsedSpanAtEnd(line))
-      { line = merged.find(1, true).line; }
-    return line
+  // This can be used to attach properties to mode objects from
+  // outside the actual mode definition.
+  var modeExtensions = {};
+  function extendMode(mode, properties) {
+    var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
+    copyObj(properties, exts);
   }
 
-  // Returns an array of logical lines that continue the visual line
-  // started by the argument, or undefined if there are no such lines.
-  function visualLineContinued(line) {
-    var merged, lines;
-    while (merged = collapsedSpanAtEnd(line)) {
-      line = merged.find(1, true).line
-      ;(lines || (lines = [])).push(line);
+  function copyState(mode, state) {
+    if (state === true) { return state }
+    if (mode.copyState) { return mode.copyState(state) }
+    var nstate = {};
+    for (var n in state) {
+      var val = state[n];
+      if (val instanceof Array) { val = val.concat([]); }
+      nstate[n] = val;
     }
-    return lines
+    return nstate
   }
 
-  // Get the line number of the start of the visual line that the
-  // given line number is part of.
-  function visualLineNo(doc, lineN) {
-    var line = getLine(doc, lineN), vis = visualLine(line);
-    if (line == vis) { return lineN }
-    return lineNo(vis)
+  // Given a mode and a state (for that mode), find the inner mode and
+  // state at the position that the state refers to.
+  function innerMode(mode, state) {
+    var info;
+    while (mode.innerMode) {
+      info = mode.innerMode(state);
+      if (!info || info.mode == mode) { break }
+      state = info.state;
+      mode = info.mode;
+    }
+    return info || {mode: mode, state: state}
   }
 
-  // Get the line number of the start of the next visual line after
-  // the given line.
-  function visualLineEndNo(doc, lineN) {
-    if (lineN > doc.lastLine()) { return lineN }
-    var line = getLine(doc, lineN), merged;
-    if (!lineIsHidden(doc, line)) { return lineN }
-    while (merged = collapsedSpanAtEnd(line))
-      { line = merged.find(1, true).line; }
-    return lineNo(line) + 1
+  function startState(mode, a1, a2) {
+    return mode.startState ? mode.startState(a1, a2) : true
   }
 
-  // Compute whether a line is hidden. Lines count as hidden when they
-  // are part of a visual line that starts with another line, or when
-  // they are entirely covered by collapsed, non-widget span.
-  function lineIsHidden(doc, line) {
-    var sps = sawCollapsedSpans && line.markedSpans;
-    if (sps) { for (var sp = (void 0), i = 0; i < sps.length; ++i) {
-      sp = sps[i];
-      if (!sp.marker.collapsed) { continue }
-      if (sp.from == null) { return true }
-      if (sp.marker.widgetNode) { continue }
-      if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
-        { return true }
-    } }
-  }
-  function lineIsHiddenInner(doc, line, span) {
-    if (span.to == null) {
-      var end = span.marker.find(1, true);
-      return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker))
-    }
-    if (span.marker.inclusiveRight && span.to == line.text.length)
-      { return true }
-    for (var sp = (void 0), i = 0; i < line.markedSpans.length; ++i) {
-      sp = line.markedSpans[i];
-      if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&
-          (sp.to == null || sp.to != span.from) &&
-          (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
-          lineIsHiddenInner(doc, line, sp)) { return true }
-    }
-  }
+  // STRING STREAM
 
-  // Find the height above the given line.
-  function heightAtLine(lineObj) {
-    lineObj = visualLine(lineObj);
+  // Fed to the mode parsers, provides helper functions to make
+  // parsers more succinct.
 
-    var h = 0, chunk = lineObj.parent;
-    for (var i = 0; i < chunk.lines.length; ++i) {
-      var line = chunk.lines[i];
-      if (line == lineObj) { break }
-      else { h += line.height; }
+  var StringStream = function(string, tabSize, lineOracle) {
+    this.pos = this.start = 0;
+    this.string = string;
+    this.tabSize = tabSize || 8;
+    this.lastColumnPos = this.lastColumnValue = 0;
+    this.lineStart = 0;
+    this.lineOracle = lineOracle;
+  };
+
+  StringStream.prototype.eol = function () {return this.pos >= this.string.length};
+  StringStream.prototype.sol = function () {return this.pos == this.lineStart};
+  StringStream.prototype.peek = function () {return this.string.charAt(this.pos) || undefined};
+  StringStream.prototype.next = function () {
+    if (this.pos < this.string.length)
+      { return this.string.charAt(this.pos++) }
+  };
+  StringStream.prototype.eat = function (match) {
+    var ch = this.string.charAt(this.pos);
+    var ok;
+    if (typeof match == "string") { ok = ch == match; }
+    else { ok = ch && (match.test ? match.test(ch) : match(ch)); }
+    if (ok) {++this.pos; return ch}
+  };
+  StringStream.prototype.eatWhile = function (match) {
+    var start = this.pos;
+    while (this.eat(match)){}
+    return this.pos > start
+  };
+  StringStream.prototype.eatSpace = function () {
+    var start = this.pos;
+    while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) { ++this.pos; }
+    return this.pos > start
+  };
+  StringStream.prototype.skipToEnd = function () {this.pos = this.string.length;};
+  StringStream.prototype.skipTo = function (ch) {
+    var found = this.string.indexOf(ch, this.pos);
+    if (found > -1) {this.pos = found; return true}
+  };
+  StringStream.prototype.backUp = function (n) {this.pos -= n;};
+  StringStream.prototype.column = function () {
+    if (this.lastColumnPos < this.start) {
+      this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
+      this.lastColumnPos = this.start;
     }
-    for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
-      for (var i$1 = 0; i$1 < p.children.length; ++i$1) {
-        var cur = p.children[i$1];
-        if (cur == chunk) { break }
-        else { h += cur.height; }
+    return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
+  };
+  StringStream.prototype.indentation = function () {
+    return countColumn(this.string, null, this.tabSize) -
+      (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
+  };
+  StringStream.prototype.match = function (pattern, consume, caseInsensitive) {
+    if (typeof pattern == "string") {
+      var cased = function (str) { return caseInsensitive ? str.toLowerCase() : str; };
+      var substr = this.string.substr(this.pos, pattern.length);
+      if (cased(substr) == cased(pattern)) {
+        if (consume !== false) { this.pos += pattern.length; }
+        return true
       }
+    } else {
+      var match = this.string.slice(this.pos).match(pattern);
+      if (match && match.index > 0) { return null }
+      if (match && consume !== false) { this.pos += match[0].length; }
+      return match
     }
-    return h
+  };
+  StringStream.prototype.current = function (){return this.string.slice(this.start, this.pos)};
+  StringStream.prototype.hideFirstChars = function (n, inner) {
+    this.lineStart += n;
+    try { return inner() }
+    finally { this.lineStart -= n; }
+  };
+  StringStream.prototype.lookAhead = function (n) {
+    var oracle = this.lineOracle;
+    return oracle && oracle.lookAhead(n)
+  };
+  StringStream.prototype.baseToken = function () {
+    var oracle = this.lineOracle;
+    return oracle && oracle.baseToken(this.pos)
+  };
+
+  // Find the line object corresponding to the given line number.
+  function getLine(doc, n) {
+    n -= doc.first;
+    if (n < 0 || n >= doc.size) { throw new Error("There is no line " + (n + doc.first) + " in the document.") }
+    var chunk = doc;
+    while (!chunk.lines) {
+      for (var i = 0;; ++i) {
+        var child = chunk.children[i], sz = child.chunkSize();
+        if (n < sz) { chunk = child; break }
+        n -= sz;
+      }
+    }
+    return chunk.lines[n]
   }
 
-  // Compute the character length of a line, taking into account
-  // collapsed ranges (see markText) that might hide parts, and join
-  // other lines onto it.
-  function lineLength(line) {
-    if (line.height == 0) { return 0 }
-    var len = line.text.length, merged, cur = line;
-    while (merged = collapsedSpanAtStart(cur)) {
-      var found = merged.find(0, true);
-      cur = found.from.line;
-      len += found.from.ch - found.to.ch;
-    }
-    cur = line;
-    while (merged = collapsedSpanAtEnd(cur)) {
-      var found$1 = merged.find(0, true);
-      len -= cur.text.length - found$1.from.ch;
-      cur = found$1.to.line;
-      len += cur.text.length - found$1.to.ch;
-    }
-    return len
-  }
-
-  // Find the longest line in the document.
-  function findMaxLine(cm) {
-    var d = cm.display, doc = cm.doc;
-    d.maxLine = getLine(doc, doc.first);
-    d.maxLineLength = lineLength(d.maxLine);
-    d.maxLineChanged = true;
-    doc.iter(function (line) {
-      var len = lineLength(line);
-      if (len > d.maxLineLength) {
-        d.maxLineLength = len;
-        d.maxLine = line;
-      }
+  // Get the part of a document between two positions, as an array of
+  // strings.
+  function getBetween(doc, start, end) {
+    var out = [], n = start.line;
+    doc.iter(start.line, end.line + 1, function (line) {
+      var text = line.text;
+      if (n == end.line) { text = text.slice(0, end.ch); }
+      if (n == start.line) { text = text.slice(start.ch); }
+      out.push(text);
+      ++n;
     });
+    return out
+  }
+  // Get the lines between from and to, as array of strings.
+  function getLines(doc, from, to) {
+    var out = [];
+    doc.iter(from, to, function (line) { out.push(line.text); }); // iter aborts when callback returns truthy value
+    return out
   }
 
-  // BIDI HELPERS
+  // Update the height of a line, propagating the height change
+  // upwards to parent nodes.
+  function updateLineHeight(line, height) {
+    var diff = height - line.height;
+    if (diff) { for (var n = line; n; n = n.parent) { n.height += diff; } }
+  }
 
-  function iterateBidiSections(order, from, to, f) {
-    if (!order) { return f(from, to, "ltr", 0) }
-    var found = false;
-    for (var i = 0; i < order.length; ++i) {
-      var part = order[i];
-      if (part.from < to && part.to > from || from == to && part.to == from) {
-        f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr", i);
-        found = true;
+  // Given a line object, find its line number by walking up through
+  // its parent links.
+  function lineNo(line) {
+    if (line.parent == null) { return null }
+    var cur = line.parent, no = indexOf(cur.lines, line);
+    for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
+      for (var i = 0;; ++i) {
+        if (chunk.children[i] == cur) { break }
+        no += chunk.children[i].chunkSize();
       }
     }
-    if (!found) { f(from, to, "ltr"); }
+    return no + cur.first
   }
 
-  var bidiOther = null;
-  function getBidiPartAt(order, ch, sticky) {
-    var found;
-    bidiOther = null;
-    for (var i = 0; i < order.length; ++i) {
-      var cur = order[i];
-      if (cur.from < ch && cur.to > ch) { return i }
-      if (cur.to == ch) {
-        if (cur.from != cur.to && sticky == "before") { found = i; }
-        else { bidiOther = i; }
-      }
-      if (cur.from == ch) {
-        if (cur.from != cur.to && sticky != "before") { found = i; }
-        else { bidiOther = i; }
+  // Find the line at the given vertical position, using the height
+  // information in the document tree.
+  function lineAtHeight(chunk, h) {
+    var n = chunk.first;
+    outer: do {
+      for (var i$1 = 0; i$1 < chunk.children.length; ++i$1) {
+        var child = chunk.children[i$1], ch = child.height;
+        if (h < ch) { chunk = child; continue outer }
+        h -= ch;
+        n += child.chunkSize();
       }
+      return n
+    } while (!chunk.lines)
+    var i = 0;
+    for (; i < chunk.lines.length; ++i) {
+      var line = chunk.lines[i], lh = line.height;
+      if (h < lh) { break }
+      h -= lh;
     }
-    return found != null ? found : bidiOther
+    return n + i
   }
 
-  // Bidirectional ordering algorithm
-  // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
-  // that this (partially) implements.
+  function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size}
 
-  // One-char codes used for character types:
-  // L (L):   Left-to-Right
-  // R (R):   Right-to-Left
-  // r (AL):  Right-to-Left Arabic
-  // 1 (EN):  European Number
-  // + (ES):  European Number Separator
-  // % (ET):  European Number Terminator
-  // n (AN):  Arabic Number
-  // , (CS):  Common Number Separator
-  // m (NSM): Non-Spacing Mark
-  // b (BN):  Boundary Neutral
-  // s (B):   Paragraph Separator
-  // t (S):   Segment Separator
-  // w (WS):  Whitespace
-  // N (ON):  Other Neutrals
+  function lineNumberFor(options, i) {
+    return String(options.lineNumberFormatter(i + options.firstLineNumber))
+  }
 
-  // Returns null if characters are ordered as they appear
-  // (left-to-right), or an array of sections ({from, to, level}
-  // objects) in the order in which they occur visually.
-  var bidiOrdering = (function() {
-    // Character types for codepoints 0 to 0xff
-    var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";
-    // Character types for codepoints 0x600 to 0x6f9
-    var arabicTypes = "nnnnnnNNr%%r,rNNmmmmmmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmmmnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmnNmmmmmmrrmmNmmmmrr1111111111";
-    function charType(code) {
-      if (code <= 0xf7) { return lowTypes.charAt(code) }
-      else if (0x590 <= code && code <= 0x5f4) { return "R" }
-      else if (0x600 <= code && code <= 0x6f9) { return arabicTypes.charAt(code - 0x600) }
-      else if (0x6ee <= code && code <= 0x8ac) { return "r" }
-      else if (0x2000 <= code && code <= 0x200b) { return "w" }
-      else if (code == 0x200c) { return "b" }
-      else { return "L" }
-    }
+  // A Pos instance represents a position within the text.
+  function Pos(line, ch, sticky) {
+    if ( sticky === void 0 ) sticky = null;
 
-    var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
-    var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
+    if (!(this instanceof Pos)) { return new Pos(line, ch, sticky) }
+    this.line = line;
+    this.ch = ch;
+    this.sticky = sticky;
+  }
 
-    function BidiSpan(level, from, to) {
-      this.level = level;
-      this.from = from; this.to = to;
-    }
+  // Compare two positions, return 0 if they are the same, a negative
+  // number when a is less, and a positive number otherwise.
+  function cmp(a, b) { return a.line - b.line || a.ch - b.ch }
 
-    return function(str, direction) {
-      var outerType = direction == "ltr" ? "L" : "R";
+  function equalCursorPos(a, b) { return a.sticky == b.sticky && cmp(a, b) == 0 }
 
-      if (str.length == 0 || direction == "ltr" && !bidiRE.test(str)) { return false }
-      var len = str.length, types = [];
-      for (var i = 0; i < len; ++i)
-        { types.push(charType(str.charCodeAt(i))); }
+  function copyPos(x) {return Pos(x.line, x.ch)}
+  function maxPos(a, b) { return cmp(a, b) < 0 ? b : a }
+  function minPos(a, b) { return cmp(a, b) < 0 ? a : b }
 
-      // W1. Examine each non-spacing mark (NSM) in the level run, and
-      // change the type of the NSM to the type of the previous
-      // character. If the NSM is at the start of the level run, it will
-      // get the type of sor.
-      for (var i$1 = 0, prev = outerType; i$1 < len; ++i$1) {
-        var type = types[i$1];
-        if (type == "m") { types[i$1] = prev; }
-        else { prev = type; }
-      }
+  // Most of the external API clips given positions to make sure they
+  // actually exist within the document.
+  function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1))}
+  function clipPos(doc, pos) {
+    if (pos.line < doc.first) { return Pos(doc.first, 0) }
+    var last = doc.first + doc.size - 1;
+    if (pos.line > last) { return Pos(last, getLine(doc, last).text.length) }
+    return clipToLen(pos, getLine(doc, pos.line).text.length)
+  }
+  function clipToLen(pos, linelen) {
+    var ch = pos.ch;
+    if (ch == null || ch > linelen) { return Pos(pos.line, linelen) }
+    else if (ch < 0) { return Pos(pos.line, 0) }
+    else { return pos }
+  }
+  function clipPosArray(doc, array) {
+    var out = [];
+    for (var i = 0; i < array.length; i++) { out[i] = clipPos(doc, array[i]); }
+    return out
+  }
 
-      // W2. Search backwards from each instance of a European number
-      // until the first strong type (R, L, AL, or sor) is found. If an
-      // AL is found, change the type of the European number to Arabic
-      // number.
-      // W3. Change all ALs to R.
-      for (var i$2 = 0, cur = outerType; i$2 < len; ++i$2) {
-        var type$1 = types[i$2];
-        if (type$1 == "1" && cur == "r") { types[i$2] = "n"; }
-        else if (isStrong.test(type$1)) { cur = type$1; if (type$1 == "r") { types[i$2] = "R"; } }
-      }
+  var SavedContext = function(state, lookAhead) {
+    this.state = state;
+    this.lookAhead = lookAhead;
+  };
 
-      // W4. A single European separator between two European numbers
-      // changes to a European number. A single common separator between
-      // two numbers of the same type changes to that type.
-      for (var i$3 = 1, prev$1 = types[0]; i$3 < len - 1; ++i$3) {
-        var type$2 = types[i$3];
-        if (type$2 == "+" && prev$1 == "1" && types[i$3+1] == "1") { types[i$3] = "1"; }
-        else if (type$2 == "," && prev$1 == types[i$3+1] &&
-                 (prev$1 == "1" || prev$1 == "n")) { types[i$3] = prev$1; }
-        prev$1 = type$2;
-      }
+  var Context = function(doc, state, line, lookAhead) {
+    this.state = state;
+    this.doc = doc;
+    this.line = line;
+    this.maxLookAhead = lookAhead || 0;
+    this.baseTokens = null;
+    this.baseTokenPos = 1;
+  };
 
-      // W5. A sequence of European terminators adjacent to European
-      // numbers changes to all European numbers.
-      // W6. Otherwise, separators and terminators change to Other
-      // Neutral.
-      for (var i$4 = 0; i$4 < len; ++i$4) {
-        var type$3 = types[i$4];
-        if (type$3 == ",") { types[i$4] = "N"; }
-        else if (type$3 == "%") {
-          var end = (void 0);
-          for (end = i$4 + 1; end < len && types[end] == "%"; ++end) {}
-          var replace = (i$4 && types[i$4-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
-          for (var j = i$4; j < end; ++j) { types[j] = replace; }
-          i$4 = end - 1;
-        }
-      }
+  Context.prototype.lookAhead = function (n) {
+    var line = this.doc.getLine(this.line + n);
+    if (line != null && n > this.maxLookAhead) { this.maxLookAhead = n; }
+    return line
+  };
 
-      // W7. Search backwards from each instance of a European number
-      // until the first strong type (R, L, or sor) is found. If an L is
-      // found, then change the type of the European number to L.
-      for (var i$5 = 0, cur$1 = outerType; i$5 < len; ++i$5) {
-        var type$4 = types[i$5];
-        if (cur$1 == "L" && type$4 == "1") { types[i$5] = "L"; }
-        else if (isStrong.test(type$4)) { cur$1 = type$4; }
-      }
-
-      // N1. A sequence of neutrals takes the direction of the
-      // surrounding strong text if the text on both sides has the same
-      // direction. European and Arabic numbers act as if they were R in
-      // terms of their influence on neutrals. Start-of-level-run (sor)
-      // and end-of-level-run (eor) are used at level run boundaries.
-      // N2. Any remaining neutrals take the embedding direction.
-      for (var i$6 = 0; i$6 < len; ++i$6) {
-        if (isNeutral.test(types[i$6])) {
-          var end$1 = (void 0);
-          for (end$1 = i$6 + 1; end$1 < len && isNeutral.test(types[end$1]); ++end$1) {}
-          var before = (i$6 ? types[i$6-1] : outerType) == "L";
-          var after = (end$1 < len ? types[end$1] : outerType) == "L";
-          var replace$1 = before == after ? (before ? "L" : "R") : outerType;
-          for (var j$1 = i$6; j$1 < end$1; ++j$1) { types[j$1] = replace$1; }
-          i$6 = end$1 - 1;
-        }
-      }
+  Context.prototype.baseToken = function (n) {
+    if (!this.baseTokens) { return null }
+    while (this.baseTokens[this.baseTokenPos] <= n)
+      { this.baseTokenPos += 2; }
+    var type = this.baseTokens[this.baseTokenPos + 1];
+    return {type: type && type.replace(/( |^)overlay .*/, ""),
+            size: this.baseTokens[this.baseTokenPos] - n}
+  };
 
-      // Here we depart from the documented algorithm, in order to avoid
-      // building up an actual levels array. Since there are only three
-      // levels (0, 1, 2) in an implementation that doesn't take
-      // explicit embedding into account, we can build up the order on
-      // the fly, without following the level-based algorithm.
-      var order = [], m;
-      for (var i$7 = 0; i$7 < len;) {
-        if (countsAsLeft.test(types[i$7])) {
-          var start = i$7;
-          for (++i$7; i$7 < len && countsAsLeft.test(types[i$7]); ++i$7) {}
-          order.push(new BidiSpan(0, start, i$7));
-        } else {
-          var pos = i$7, at = order.length;
-          for (++i$7; i$7 < len && types[i$7] != "L"; ++i$7) {}
-          for (var j$2 = pos; j$2 < i$7;) {
-            if (countsAsNum.test(types[j$2])) {
-              if (pos < j$2) { order.splice(at, 0, new BidiSpan(1, pos, j$2)); }
-              var nstart = j$2;
-              for (++j$2; j$2 < i$7 && countsAsNum.test(types[j$2]); ++j$2) {}
-              order.splice(at, 0, new BidiSpan(2, nstart, j$2));
-              pos = j$2;
-            } else { ++j$2; }
-          }
-          if (pos < i$7) { order.splice(at, 0, new BidiSpan(1, pos, i$7)); }
-        }
-      }
-      if (direction == "ltr") {
-        if (order[0].level == 1 && (m = str.match(/^\s+/))) {
-          order[0].from = m[0].length;
-          order.unshift(new BidiSpan(0, 0, m[0].length));
-        }
-        if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
-          lst(order).to -= m[0].length;
-          order.push(new BidiSpan(0, len - m[0].length, len));
-        }
-      }
+  Context.prototype.nextLine = function () {
+    this.line++;
+    if (this.maxLookAhead > 0) { this.maxLookAhead--; }
+  };
 
-      return direction == "rtl" ? order.reverse() : order
-    }
-  })();
+  Context.fromSaved = function (doc, saved, line) {
+    if (saved instanceof SavedContext)
+      { return new Context(doc, copyState(doc.mode, saved.state), line, saved.lookAhead) }
+    else
+      { return new Context(doc, copyState(doc.mode, saved), line) }
+  };
 
-  // Get the bidi ordering for the given line (and cache it). Returns
-  // false for lines that are fully left-to-right, and an array of
-  // BidiSpan objects otherwise.
-  function getOrder(line, direction) {
-    var order = line.order;
-    if (order == null) { order = line.order = bidiOrdering(line.text, direction); }
-    return order
-  }
+  Context.prototype.save = function (copy) {
+    var state = copy !== false ? copyState(this.doc.mode, this.state) : this.state;
+    return this.maxLookAhead > 0 ? new SavedContext(state, this.maxLookAhead) : state
+  };
 
-  // EVENT HANDLING
 
-  // Lightweight event framework. on/off also work on DOM nodes,
-  // registering native DOM handlers.
+  // Compute a style array (an array starting with a mode generation
+  // -- for invalidation -- followed by pairs of end positions and
+  // style strings), which is used to highlight the tokens on the
+  // line.
+  function highlightLine(cm, line, context, forceToEnd) {
+    // A styles array always starts with a number identifying the
+    // mode/overlays that it is based on (for easy invalidation).
+    var st = [cm.state.modeGen], lineClasses = {};
+    // Compute the base array of styles
+    runMode(cm, line.text, cm.doc.mode, context, function (end, style) { return st.push(end, style); },
+            lineClasses, forceToEnd);
+    var state = context.state;
 
-  var noHandlers = [];
+    // Run overlays, adjust style array.
+    var loop = function ( o ) {
+      context.baseTokens = st;
+      var overlay = cm.state.overlays[o], i = 1, at = 0;
+      context.state = true;
+      runMode(cm, line.text, overlay.mode, context, function (end, style) {
+        var start = i;
+        // Ensure there's a token end at the current position, and that i points at it
+        while (at < end) {
+          var i_end = st[i];
+          if (i_end > end)
+            { st.splice(i, 1, end, st[i+1], i_end); }
+          i += 2;
+          at = Math.min(end, i_end);
+        }
+        if (!style) { return }
+        if (overlay.opaque) {
+          st.splice(start, i - start, end, "overlay " + style);
+          i = start + 2;
+        } else {
+          for (; start < i; start += 2) {
+            var cur = st[start+1];
+            st[start+1] = (cur ? cur + " " : "") + "overlay " + style;
+          }
+        }
+      }, lineClasses);
+      context.state = state;
+      context.baseTokens = null;
+      context.baseTokenPos = 1;
+    };
 
-  var on = function(emitter, type, f) {
-    if (emitter.addEventListener) {
-      emitter.addEventListener(type, f, false);
-    } else if (emitter.attachEvent) {
-      emitter.attachEvent("on" + type, f);
-    } else {
-      var map$$1 = emitter._handlers || (emitter._handlers = {});
-      map$$1[type] = (map$$1[type] || noHandlers).concat(f);
-    }
-  };
+    for (var o = 0; o < cm.state.overlays.length; ++o) loop( o );
 
-  function getHandlers(emitter, type) {
-    return emitter._handlers && emitter._handlers[type] || noHandlers
+    return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null}
   }
 
-  function off(emitter, type, f) {
-    if (emitter.removeEventListener) {
-      emitter.removeEventListener(type, f, false);
-    } else if (emitter.detachEvent) {
-      emitter.detachEvent("on" + type, f);
-    } else {
-      var map$$1 = emitter._handlers, arr = map$$1 && map$$1[type];
-      if (arr) {
-        var index = indexOf(arr, f);
-        if (index > -1)
-          { map$$1[type] = arr.slice(0, index).concat(arr.slice(index + 1)); }
-      }
+  function getLineStyles(cm, line, updateFrontier) {
+    if (!line.styles || line.styles[0] != cm.state.modeGen) {
+      var context = getContextBefore(cm, lineNo(line));
+      var resetState = line.text.length > cm.options.maxHighlightLength && copyState(cm.doc.mode, context.state);
+      var result = highlightLine(cm, line, context);
+      if (resetState) { context.state = resetState; }
+      line.stateAfter = context.save(!resetState);
+      line.styles = result.styles;
+      if (result.classes) { line.styleClasses = result.classes; }
+      else if (line.styleClasses) { line.styleClasses = null; }
+      if (updateFrontier === cm.doc.highlightFrontier)
+        { cm.doc.modeFrontier = Math.max(cm.doc.modeFrontier, ++cm.doc.highlightFrontier); }
     }
+    return line.styles
   }
 
-  function signal(emitter, type /*, values...*/) {
-    var handlers = getHandlers(emitter, type);
-    if (!handlers.length) { return }
-    var args = Array.prototype.slice.call(arguments, 2);
-    for (var i = 0; i < handlers.length; ++i) { handlers[i].apply(null, args); }
-  }
+  function getContextBefore(cm, n, precise) {
+    var doc = cm.doc, display = cm.display;
+    if (!doc.mode.startState) { return new Context(doc, true, n) }
+    var start = findStartLine(cm, n, precise);
+    var saved = start > doc.first && getLine(doc, start - 1).stateAfter;
+    var context = saved ? Context.fromSaved(doc, saved, start) : new Context(doc, startState(doc.mode), start);
 
-  // The DOM events that CodeMirror handles can be overridden by
-  // registering a (non-DOM) handler on the editor for the event name,
-  // and preventDefault-ing the event in that handler.
-  function signalDOMEvent(cm, e, override) {
-    if (typeof e == "string")
-      { e = {type: e, preventDefault: function() { this.defaultPrevented = true; }}; }
-    signal(cm, override || e.type, cm, e);
-    return e_defaultPrevented(e) || e.codemirrorIgnore
+    doc.iter(start, n, function (line) {
+      processLine(cm, line.text, context);
+      var pos = context.line;
+      line.stateAfter = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo ? context.save() : null;
+      context.nextLine();
+    });
+    if (precise) { doc.modeFrontier = context.line; }
+    return context
   }
 
-  function signalCursorActivity(cm) {
-    var arr = cm._handlers && cm._handlers.cursorActivity;
-    if (!arr) { return }
-    var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);
-    for (var i = 0; i < arr.length; ++i) { if (indexOf(set, arr[i]) == -1)
-      { set.push(arr[i]); } }
+  // Lightweight form of highlight -- proceed over this line and
+  // update state, but don't save a style array. Used for lines that
+  // aren't currently visible.
+  function processLine(cm, text, context, startAt) {
+    var mode = cm.doc.mode;
+    var stream = new StringStream(text, cm.options.tabSize, context);
+    stream.start = stream.pos = startAt || 0;
+    if (text == "") { callBlankLine(mode, context.state); }
+    while (!stream.eol()) {
+      readToken(mode, stream, context.state);
+      stream.start = stream.pos;
+    }
   }
 
-  function hasHandler(emitter, type) {
-    return getHandlers(emitter, type).length > 0
+  function callBlankLine(mode, state) {
+    if (mode.blankLine) { return mode.blankLine(state) }
+    if (!mode.innerMode) { return }
+    var inner = innerMode(mode, state);
+    if (inner.mode.blankLine) { return inner.mode.blankLine(inner.state) }
   }
 
-  // Add on and off methods to a constructor's prototype, to make
-  // registering events on such objects more convenient.
-  function eventMixin(ctor) {
-    ctor.prototype.on = function(type, f) {on(this, type, f);};
-    ctor.prototype.off = function(type, f) {off(this, type, f);};
+  function readToken(mode, stream, state, inner) {
+    for (var i = 0; i < 10; i++) {
+      if (inner) { inner[0] = innerMode(mode, state).mode; }
+      var style = mode.token(stream, state);
+      if (stream.pos > stream.start) { return style }
+    }
+    throw new Error("Mode " + mode.name + " failed to advance stream.")
   }
 
-  // Due to the fact that we still support jurassic IE versions, some
-  // compatibility wrappers are needed.
+  var Token = function(stream, type, state) {
+    this.start = stream.start; this.end = stream.pos;
+    this.string = stream.current();
+    this.type = type || null;
+    this.state = state;
+  };
 
-  function e_preventDefault(e) {
-    if (e.preventDefault) { e.preventDefault(); }
-    else { e.returnValue = false; }
-  }
-  function e_stopPropagation(e) {
-    if (e.stopPropagation) { e.stopPropagation(); }
-    else { e.cancelBubble = true; }
-  }
-  function e_defaultPrevented(e) {
-    return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false
-  }
-  function e_stop(e) {e_preventDefault(e); e_stopPropagation(e);}
-
-  function e_target(e) {return e.target || e.srcElement}
-  function e_button(e) {
-    var b = e.which;
-    if (b == null) {
-      if (e.button & 1) { b = 1; }
-      else if (e.button & 2) { b = 3; }
-      else if (e.button & 4) { b = 2; }
+  // Utility for getTokenAt and getLineTokens
+  function takeToken(cm, pos, precise, asArray) {
+    var doc = cm.doc, mode = doc.mode, style;
+    pos = clipPos(doc, pos);
+    var line = getLine(doc, pos.line), context = getContextBefore(cm, pos.line, precise);
+    var stream = new StringStream(line.text, cm.options.tabSize, context), tokens;
+    if (asArray) { tokens = []; }
+    while ((asArray || stream.pos < pos.ch) && !stream.eol()) {
+      stream.start = stream.pos;
+      style = readToken(mode, stream, context.state);
+      if (asArray) { tokens.push(new Token(stream, style, copyState(doc.mode, context.state))); }
     }
-    if (mac && e.ctrlKey && b == 1) { b = 3; }
-    return b
+    return asArray ? tokens : new Token(stream, style, context.state)
   }
 
-  // Detect drag-and-drop
-  var dragAndDrop = function() {
-    // There is *some* kind of drag-and-drop support in IE6-8, but I
-    // couldn't get it to work yet.
-    if (ie && ie_version < 9) { return false }
-    var div = elt('div');
-    return "draggable" in div || "dragDrop" in div
-  }();
+  function extractLineClasses(type, output) {
+    if (type) { for (;;) {
+      var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);
+      if (!lineClass) { break }
+      type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);
+      var prop = lineClass[1] ? "bgClass" : "textClass";
+      if (output[prop] == null)
+        { output[prop] = lineClass[2]; }
+      else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))
+        { output[prop] += " " + lineClass[2]; }
+    } }
+    return type
+  }
 
-  var zwspSupported;
-  function zeroWidthElement(measure) {
-    if (zwspSupported == null) {
-      var test = elt("span", "\u200b");
-      removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
-      if (measure.firstChild.offsetHeight != 0)
-        { zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8); }
+  // Run the given mode's parser over a line, calling f for each token.
+  function runMode(cm, text, mode, context, f, lineClasses, forceToEnd) {
+    var flattenSpans = mode.flattenSpans;
+    if (flattenSpans == null) { flattenSpans = cm.options.flattenSpans; }
+    var curStart = 0, curStyle = null;
+    var stream = new StringStream(text, cm.options.tabSize, context), style;
+    var inner = cm.options.addModeClass && [null];
+    if (text == "") { extractLineClasses(callBlankLine(mode, context.state), lineClasses); }
+    while (!stream.eol()) {
+      if (stream.pos > cm.options.maxHighlightLength) {
+        flattenSpans = false;
+        if (forceToEnd) { processLine(cm, text, context, stream.pos); }
+        stream.pos = text.length;
+        style = null;
+      } else {
+        style = extractLineClasses(readToken(mode, stream, context.state, inner), lineClasses);
+      }
+      if (inner) {
+        var mName = inner[0].name;
+        if (mName) { style = "m-" + (style ? mName + " " + style : mName); }
+      }
+      if (!flattenSpans || curStyle != style) {
+        while (curStart < stream.start) {
+          curStart = Math.min(stream.start, curStart + 5000);
+          f(curStart, curStyle);
+        }
+        curStyle = style;
+      }
+      stream.start = stream.pos;
+    }
+    while (curStart < stream.pos) {
+      // Webkit seems to refuse to render text nodes longer than 57444
+      // characters, and returns inaccurate measurements in nodes
+      // starting around 5000 chars.
+      var pos = Math.min(stream.pos, curStart + 5000);
+      f(pos, curStyle);
+      curStart = pos;
     }
-    var node = zwspSupported ? elt("span", "\u200b") :
-      elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
-    node.setAttribute("cm-text", "");
-    return node
   }
 
-  // Feature-detect IE's crummy client rect reporting for bidi text
-  var badBidiRects;
-  function hasBadBidiRects(measure) {
-    if (badBidiRects != null) { return badBidiRects }
-    var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));
-    var r0 = range(txt, 0, 1).getBoundingClientRect();
-    var r1 = range(txt, 1, 2).getBoundingClientRect();
-    removeChildren(measure);
-    if (!r0 || r0.left == r0.right) { return false } // Safari returns null in some cases (#2780)
-    return badBidiRects = (r1.right - r0.right < 3)
+  // Finds the line to start with when starting a parse. Tries to
+  // find a line with a stateAfter, so that it can start with a
+  // valid state. If that fails, it returns the line with the
+  // smallest indentation, which tends to need the least context to
+  // parse correctly.
+  function findStartLine(cm, n, precise) {
+    var minindent, minline, doc = cm.doc;
+    var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
+    for (var search = n; search > lim; --search) {
+      if (search <= doc.first) { return doc.first }
+      var line = getLine(doc, search - 1), after = line.stateAfter;
+      if (after && (!precise || search + (after instanceof SavedContext ? after.lookAhead : 0) <= doc.modeFrontier))
+        { return search }
+      var indented = countColumn(line.text, null, cm.options.tabSize);
+      if (minline == null || minindent > indented) {
+        minline = search - 1;
+        minindent = indented;
+      }
+    }
+    return minline
   }
 
-  // See if "".split is the broken IE version, if so, provide an
-  // alternative way to split lines.
-  var splitLinesAuto = "\n\nb".split(/\n/).length != 3 ? function (string) {
-    var pos = 0, result = [], l = string.length;
-    while (pos <= l) {
-      var nl = string.indexOf("\n", pos);
-      if (nl == -1) { nl = string.length; }
-      var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
-      var rt = line.indexOf("\r");
-      if (rt != -1) {
-        result.push(line.slice(0, rt));
-        pos += rt + 1;
-      } else {
-        result.push(line);
-        pos = nl + 1;
+  function retreatFrontier(doc, n) {
+    doc.modeFrontier = Math.min(doc.modeFrontier, n);
+    if (doc.highlightFrontier < n - 10) { return }
+    var start = doc.first;
+    for (var line = n - 1; line > start; line--) {
+      var saved = getLine(doc, line).stateAfter;
+      // change is on 3
+      // state on line 1 looked ahead 2 -- so saw 3
+      // test 1 + 2 < 3 should cover this
+      if (saved && (!(saved instanceof SavedContext) || line + saved.lookAhead < n)) {
+        start = line + 1;
+        break
       }
     }
-    return result
-  } : function (string) { return string.split(/\r\n?|\n/); };
-
-  var hasSelection = window.getSelection ? function (te) {
-    try { return te.selectionStart != te.selectionEnd }
-    catch(e) { return false }
-  } : function (te) {
-    var range$$1;
-    try {range$$1 = te.ownerDocument.selection.createRange();}
-    catch(e) {}
-    if (!range$$1 || range$$1.parentElement() != te) { return false }
-    return range$$1.compareEndPoints("StartToEnd", range$$1) != 0
-  };
-
-  var hasCopyEvent = (function () {
-    var e = elt("div");
-    if ("oncopy" in e) { return true }
-    e.setAttribute("oncopy", "return;");
-    return typeof e.oncopy == "function"
-  })();
-
-  var badZoomedRects = null;
-  function hasBadZoomedRects(measure) {
-    if (badZoomedRects != null) { return badZoomedRects }
-    var node = removeChildrenAndAdd(measure, elt("span", "x"));
-    var normal = node.getBoundingClientRect();
-    var fromRange = range(node, 0, 1).getBoundingClientRect();
-    return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1
+    doc.highlightFrontier = Math.min(doc.highlightFrontier, start);
   }
 
-  // Known modes, by name and by MIME
-  var modes = {}, mimeModes = {};
-
-  // Extra arguments are stored as the mode's dependencies, which is
-  // used by (legacy) mechanisms like loadmode.js to automatically
-  // load a mode. (Preferred mechanism is the require/define calls.)
-  function defineMode(name, mode) {
-    if (arguments.length > 2)
-      { mode.dependencies = Array.prototype.slice.call(arguments, 2); }
-    modes[name] = mode;
-  }
+  // Optimize some code when these features are not used.
+  var sawReadOnlySpans = false, sawCollapsedSpans = false;
 
-  function defineMIME(mime, spec) {
-    mimeModes[mime] = spec;
+  function seeReadOnlySpans() {
+    sawReadOnlySpans = true;
   }
 
-  // Given a MIME type, a {name, ...options} config object, or a name
-  // string, return a mode config object.
-  function resolveMode(spec) {
-    if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
-      spec = mimeModes[spec];
-    } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
-      var found = mimeModes[spec.name];
-      if (typeof found == "string") { found = {name: found}; }
-      spec = createObj(found, spec);
-      spec.name = found.name;
-    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
-      return resolveMode("application/xml")
-    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+json$/.test(spec)) {
-      return resolveMode("application/json")
-    }
-    if (typeof spec == "string") { return {name: spec} }
-    else { return spec || {name: "null"} }
+  function seeCollapsedSpans() {
+    sawCollapsedSpans = true;
   }
 
-  // Given a mode spec (anything that resolveMode accepts), find and
-  // initialize an actual mode object.
-  function getMode(options, spec) {
-    spec = resolveMode(spec);
-    var mfactory = modes[spec.name];
-    if (!mfactory) { return getMode(options, "text/plain") }
-    var modeObj = mfactory(options, spec);
-    if (modeExtensions.hasOwnProperty(spec.name)) {
-      var exts = modeExtensions[spec.name];
-      for (var prop in exts) {
-        if (!exts.hasOwnProperty(prop)) { continue }
-        if (modeObj.hasOwnProperty(prop)) { modeObj["_" + prop] = modeObj[prop]; }
-        modeObj[prop] = exts[prop];
-      }
-    }
-    modeObj.name = spec.name;
-    if (spec.helperType) { modeObj.helperType = spec.helperType; }
-    if (spec.modeProps) { for (var prop$1 in spec.modeProps)
-      { modeObj[prop$1] = spec.modeProps[prop$1]; } }
+  // TEXTMARKER SPANS
 
-    return modeObj
+  function MarkedSpan(marker, from, to) {
+    this.marker = marker;
+    this.from = from; this.to = to;
   }
 
-  // This can be used to attach properties to mode objects from
-  // outside the actual mode definition.
-  var modeExtensions = {};
-  function extendMode(mode, properties) {
-    var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
-    copyObj(properties, exts);
+  // Search an array of spans for a span matching the given marker.
+  function getMarkedSpanFor(spans, marker) {
+    if (spans) { for (var i = 0; i < spans.length; ++i) {
+      var span = spans[i];
+      if (span.marker == marker) { return span }
+    } }
   }
-
-  function copyState(mode, state) {
-    if (state === true) { return state }
-    if (mode.copyState) { return mode.copyState(state) }
-    var nstate = {};
-    for (var n in state) {
-      var val = state[n];
-      if (val instanceof Array) { val = val.concat([]); }
-      nstate[n] = val;
-    }
-    return nstate
+  // Remove a span from an array, returning undefined if no spans are
+  // left (we don't store arrays for lines without spans).
+  function removeMarkedSpan(spans, span) {
+    var r;
+    for (var i = 0; i < spans.length; ++i)
+      { if (spans[i] != span) { (r || (r = [])).push(spans[i]); } }
+    return r
   }
-
-  // Given a mode and a state (for that mode), find the inner mode and
-  // state at the position that the state refers to.
-  function innerMode(mode, state) {
-    var info;
-    while (mode.innerMode) {
-      info = mode.innerMode(state);
-      if (!info || info.mode == mode) { break }
-      state = info.state;
-      mode = info.mode;
-    }
-    return info || {mode: mode, state: state}
+  // Add a span to a line.
+  function addMarkedSpan(line, span) {
+    line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
+    span.marker.attachLine(line);
   }
 
-  function startState(mode, a1, a2) {
-    return mode.startState ? mode.startState(a1, a2) : true
+  // Used for the algorithm that adjusts markers for a change in the
+  // document. These functions cut an array of spans at a given
+  // character position, returning an array of remaining chunks (or
+  // undefined if nothing remains).
+  function markedSpansBefore(old, startCh, isInsert) {
+    var nw;
+    if (old) { for (var i = 0; i < old.length; ++i) {
+      var span = old[i], marker = span.marker;
+      var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
+      if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {
+        var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh)
+        ;(nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));
+      }
+    } }
+    return nw
+  }
+  function markedSpansAfter(old, endCh, isInsert) {
+    var nw;
+    if (old) { for (var i = 0; i < old.length; ++i) {
+      var span = old[i], marker = span.marker;
+      var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
+      if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {
+        var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh)
+        ;(nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,
+                                              span.to == null ? null : span.to - endCh));
+      }
+    } }
+    return nw
   }
 
-  // STRING STREAM
-
-  // Fed to the mode parsers, provides helper functions to make
-  // parsers more succinct.
+  // Given a change object, compute the new set of marker spans that
+  // cover the line in which the change took place. Removes spans
+  // entirely within the change, reconnects spans belonging to the
+  // same marker that appear on both sides of the change, and cuts off
+  // spans partially within the change. Returns an array of span
+  // arrays with one element for each line in (after) the change.
+  function stretchSpansOverChange(doc, change) {
+    if (change.full) { return null }
+    var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
+    var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
+    if (!oldFirst && !oldLast) { return null }
 
-  var StringStream = function(string, tabSize, lineOracle) {
-    this.pos = this.start = 0;
-    this.string = string;
-    this.tabSize = tabSize || 8;
-    this.lastColumnPos = this.lastColumnValue = 0;
-    this.lineStart = 0;
-    this.lineOracle = lineOracle;
-  };
+    var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;
+    // Get the spans that 'stick out' on both sides
+    var first = markedSpansBefore(oldFirst, startCh, isInsert);
+    var last = markedSpansAfter(oldLast, endCh, isInsert);
 
-  StringStream.prototype.eol = function () {return this.pos >= this.string.length};
-  StringStream.prototype.sol = function () {return this.pos == this.lineStart};
-  StringStream.prototype.peek = function () {return this.string.charAt(this.pos) || undefined};
-  StringStream.prototype.next = function () {
-    if (this.pos < this.string.length)
-      { return this.string.charAt(this.pos++) }
-  };
-  StringStream.prototype.eat = function (match) {
-    var ch = this.string.charAt(this.pos);
-    var ok;
-    if (typeof match == "string") { ok = ch == match; }
-    else { ok = ch && (match.test ? match.test(ch) : match(ch)); }
-    if (ok) {++this.pos; return ch}
-  };
-  StringStream.prototype.eatWhile = function (match) {
-    var start = this.pos;
-    while (this.eat(match)){}
-    return this.pos > start
-  };
-  StringStream.prototype.eatSpace = function () {
-    var start = this.pos;
-    while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) { ++this.pos; }
-    return this.pos > start
-  };
-  StringStream.prototype.skipToEnd = function () {this.pos = this.string.length;};
-  StringStream.prototype.skipTo = function (ch) {
-    var found = this.string.indexOf(ch, this.pos);
-    if (found > -1) {this.pos = found; return true}
-  };
-  StringStream.prototype.backUp = function (n) {this.pos -= n;};
-  StringStream.prototype.column = function () {
-    if (this.lastColumnPos < this.start) {
-      this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
-      this.lastColumnPos = this.start;
+    // Next, merge those two ends
+    var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
+    if (first) {
+      // Fix up .to properties of first
+      for (var i = 0; i < first.length; ++i) {
+        var span = first[i];
+        if (span.to == null) {
+          var found = getMarkedSpanFor(last, span.marker);
+          if (!found) { span.to = startCh; }
+          else if (sameLine) { span.to = found.to == null ? null : found.to + offset; }
+        }
+      }
     }
-    return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
-  };
-  StringStream.prototype.indentation = function () {
-    return countColumn(this.string, null, this.tabSize) -
-      (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
-  };
-  StringStream.prototype.match = function (pattern, consume, caseInsensitive) {
-    if (typeof pattern == "string") {
-      var cased = function (str) { return caseInsensitive ? str.toLowerCase() : str; };
-      var substr = this.string.substr(this.pos, pattern.length);
-      if (cased(substr) == cased(pattern)) {
-        if (consume !== false) { this.pos += pattern.length; }
-        return true
+    if (last) {
+      // Fix up .from in last (or move them into first in case of sameLine)
+      for (var i$1 = 0; i$1 < last.length; ++i$1) {
+        var span$1 = last[i$1];
+        if (span$1.to != null) { span$1.to += offset; }
+        if (span$1.from == null) {
+          var found$1 = getMarkedSpanFor(first, span$1.marker);
+          if (!found$1) {
+            span$1.from = offset;
+            if (sameLine) { (first || (first = [])).push(span$1); }
+          }
+        } else {
+          span$1.from += offset;
+          if (sameLine) { (first || (first = [])).push(span$1); }
+        }
       }
-    } else {
-      var match = this.string.slice(this.pos).match(pattern);
-      if (match && match.index > 0) { return null }
-      if (match && consume !== false) { this.pos += match[0].length; }
-      return match
     }
-  };
-  StringStream.prototype.current = function (){return this.string.slice(this.start, this.pos)};
-  StringStream.prototype.hideFirstChars = function (n, inner) {
-    this.lineStart += n;
-    try { return inner() }
-    finally { this.lineStart -= n; }
-  };
-  StringStream.prototype.lookAhead = function (n) {
-    var oracle = this.lineOracle;
-    return oracle && oracle.lookAhead(n)
-  };
-  StringStream.prototype.baseToken = function () {
-    var oracle = this.lineOracle;
-    return oracle && oracle.baseToken(this.pos)
-  };
-
-  var SavedContext = function(state, lookAhead) {
-    this.state = state;
-    this.lookAhead = lookAhead;
-  };
-
-  var Context = function(doc, state, line, lookAhead) {
-    this.state = state;
-    this.doc = doc;
-    this.line = line;
-    this.maxLookAhead = lookAhead || 0;
-    this.baseTokens = null;
-    this.baseTokenPos = 1;
-  };
-
-  Context.prototype.lookAhead = function (n) {
-    var line = this.doc.getLine(this.line + n);
-    if (line != null && n > this.maxLookAhead) { this.maxLookAhead = n; }
-    return line
-  };
-
-  Context.prototype.baseToken = function (n) {
-    if (!this.baseTokens) { return null }
-    while (this.baseTokens[this.baseTokenPos] <= n)
-      { this.baseTokenPos += 2; }
-    var type = this.baseTokens[this.baseTokenPos + 1];
-    return {type: type && type.replace(/( |^)overlay .*/, ""),
-            size: this.baseTokens[this.baseTokenPos] - n}
-  };
+    // Make sure we didn't create any zero-length spans
+    if (first) { first = clearEmptySpans(first); }
+    if (last && last != first) { last = clearEmptySpans(last); }
 
-  Context.prototype.nextLine = function () {
-    this.line++;
-    if (this.maxLookAhead > 0) { this.maxLookAhead--; }
-  };
+    var newMarkers = [first];
+    if (!sameLine) {
+      // Fill gap with whole-line-spans
+      var gap = change.text.length - 2, gapMarkers;
+      if (gap > 0 && first)
+        { for (var i$2 = 0; i$2 < first.length; ++i$2)
+          { if (first[i$2].to == null)
+            { (gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i$2].marker, null, null)); } } }
+      for (var i$3 = 0; i$3 < gap; ++i$3)
+        { newMarkers.push(gapMarkers); }
+      newMarkers.push(last);
+    }
+    return newMarkers
+  }
 
-  Context.fromSaved = function (doc, saved, line) {
-    if (saved instanceof SavedContext)
-      { return new Context(doc, copyState(doc.mode, saved.state), line, saved.lookAhead) }
-    else
-      { return new Context(doc, copyState(doc.mode, saved), line) }
-  };
+  // Remove spans that are empty and don't have a clearWhenEmpty
+  // option of false.
+  function clearEmptySpans(spans) {
+    for (var i = 0; i < spans.length; ++i) {
+      var span = spans[i];
+      if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)
+        { spans.splice(i--, 1); }
+    }
+    if (!spans.length) { return null }
+    return spans
+  }
 
-  Context.prototype.save = function (copy) {
-    var state = copy !== false ? copyState(this.doc.mode, this.state) : this.state;
-    return this.maxLookAhead > 0 ? new SavedContext(state, this.maxLookAhead) : state
-  };
+  // Used to 'clip' out readOnly ranges when making a change.
+  function removeReadOnlyRanges(doc, from, to) {
+    var markers = null;
+    doc.iter(from.line, to.line + 1, function (line) {
+      if (line.markedSpans) { for (var i = 0; i < line.markedSpans.length; ++i) {
+        var mark = line.markedSpans[i].marker;
+        if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
+          { (markers || (markers = [])).push(mark); }
+      } }
+    });
+    if (!markers) { return null }
+    var parts = [{from: from, to: to}];
+    for (var i = 0; i < markers.length; ++i) {
+      var mk = markers[i], m = mk.find(0);
+      for (var j = 0; j < parts.length; ++j) {
+        var p = parts[j];
+        if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) { continue }
+        var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);
+        if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)
+          { newParts.push({from: p.from, to: m.from}); }
+        if (dto > 0 || !mk.inclusiveRight && !dto)
+          { newParts.push({from: m.to, to: p.to}); }
+        parts.splice.apply(parts, newParts);
+        j += newParts.length - 3;
+      }
+    }
+    return parts
+  }
 
+  // Connect or disconnect spans from a line.
+  function detachMarkedSpans(line) {
+    var spans = line.markedSpans;
+    if (!spans) { return }
+    for (var i = 0; i < spans.length; ++i)
+      { spans[i].marker.detachLine(line); }
+    line.markedSpans = null;
+  }
+  function attachMarkedSpans(line, spans) {
+    if (!spans) { return }
+    for (var i = 0; i < spans.length; ++i)
+      { spans[i].marker.attachLine(line); }
+    line.markedSpans = spans;
+  }
 
-  // Compute a style array (an array starting with a mode generation
-  // -- for invalidation -- followed by pairs of end positions and
-  // style strings), which is used to highlight the tokens on the
-  // line.
-  function highlightLine(cm, line, context, forceToEnd) {
-    // A styles array always starts with a number identifying the
-    // mode/overlays that it is based on (for easy invalidation).
-    var st = [cm.state.modeGen], lineClasses = {};
-    // Compute the base array of styles
-    runMode(cm, line.text, cm.doc.mode, context, function (end, style) { return st.push(end, style); },
-            lineClasses, forceToEnd);
-    var state = context.state;
+  // Helpers used when computing which overlapping collapsed span
+  // counts as the larger one.
+  function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0 }
+  function extraRight(marker) { return marker.inclusiveRight ? 1 : 0 }
 
-    // Run overlays, adjust style array.
-    var loop = function ( o ) {
-      context.baseTokens = st;
-      var overlay = cm.state.overlays[o], i = 1, at = 0;
-      context.state = true;
-      runMode(cm, line.text, overlay.mode, context, function (end, style) {
-        var start = i;
-        // Ensure there's a token end at the current position, and that i points at it
-        while (at < end) {
-          var i_end = st[i];
-          if (i_end > end)
-            { st.splice(i, 1, end, st[i+1], i_end); }
-          i += 2;
-          at = Math.min(end, i_end);
-        }
-        if (!style) { return }
-        if (overlay.opaque) {
-          st.splice(start, i - start, end, "overlay " + style);
-          i = start + 2;
-        } else {
-          for (; start < i; start += 2) {
-            var cur = st[start+1];
-            st[start+1] = (cur ? cur + " " : "") + "overlay " + style;
-          }
-        }
-      }, lineClasses);
-      context.state = state;
-      context.baseTokens = null;
-      context.baseTokenPos = 1;
-    };
+  // Returns a number indicating which of two overlapping collapsed
+  // spans is larger (and thus includes the other). Falls back to
+  // comparing ids when the spans cover exactly the same range.
+  function compareCollapsedMarkers(a, b) {
+    var lenDiff = a.lines.length - b.lines.length;
+    if (lenDiff != 0) { return lenDiff }
+    var aPos = a.find(), bPos = b.find();
+    var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);
+    if (fromCmp) { return -fromCmp }
+    var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);
+    if (toCmp) { return toCmp }
+    return b.id - a.id
+  }
 
-    for (var o = 0; o < cm.state.overlays.length; ++o) loop( o );
+  // Find out whether a line ends or starts in a collapsed span. If
+  // so, return the marker for that span.
+  function collapsedSpanAtSide(line, start) {
+    var sps = sawCollapsedSpans && line.markedSpans, found;
+    if (sps) { for (var sp = (void 0), i = 0; i < sps.length; ++i) {
+      sp = sps[i];
+      if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&
+          (!found || compareCollapsedMarkers(found, sp.marker) < 0))
+        { found = sp.marker; }
+    } }
+    return found
+  }
+  function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true) }
+  function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false) }
 
-    return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null}
+  function collapsedSpanAround(line, ch) {
+    var sps = sawCollapsedSpans && line.markedSpans, found;
+    if (sps) { for (var i = 0; i < sps.length; ++i) {
+      var sp = sps[i];
+      if (sp.marker.collapsed && (sp.from == null || sp.from < ch) && (sp.to == null || sp.to > ch) &&
+          (!found || compareCollapsedMarkers(found, sp.marker) < 0)) { found = sp.marker; }
+    } }
+    return found
   }
 
-  function getLineStyles(cm, line, updateFrontier) {
-    if (!line.styles || line.styles[0] != cm.state.modeGen) {
-      var context = getContextBefore(cm, lineNo(line));
-      var resetState = line.text.length > cm.options.maxHighlightLength && copyState(cm.doc.mode, context.state);
-      var result = highlightLine(cm, line, context);
-      if (resetState) { context.state = resetState; }
-      line.stateAfter = context.save(!resetState);
-      line.styles = result.styles;
-      if (result.classes) { line.styleClasses = result.classes; }
-      else if (line.styleClasses) { line.styleClasses = null; }
-      if (updateFrontier === cm.doc.highlightFrontier)
-        { cm.doc.modeFrontier = Math.max(cm.doc.modeFrontier, ++cm.doc.highlightFrontier); }
-    }
-    return line.styles
+  // Test whether there exists a collapsed span that partially
+  // overlaps (covers the start or end, but not both) of a new span.
+  // Such overlap is not allowed.
+  function conflictingCollapsedRange(doc, lineNo$$1, from, to, marker) {
+    var line = getLine(doc, lineNo$$1);
+    var sps = sawCollapsedSpans && line.markedSpans;
+    if (sps) { for (var i = 0; i < sps.length; ++i) {
+      var sp = sps[i];
+      if (!sp.marker.collapsed) { continue }
+      var found = sp.marker.find(0);
+      var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);
+      var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);
+      if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) { continue }
+      if (fromCmp <= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.to, from) >= 0 : cmp(found.to, from) > 0) ||
+          fromCmp >= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.from, to) <= 0 : cmp(found.from, to) < 0))
+        { return true }
+    } }
   }
 
-  function getContextBefore(cm, n, precise) {
-    var doc = cm.doc, display = cm.display;
-    if (!doc.mode.startState) { return new Context(doc, true, n) }
-    var start = findStartLine(cm, n, precise);
-    var saved = start > doc.first && getLine(doc, start - 1).stateAfter;
-    var context = saved ? Context.fromSaved(doc, saved, start) : new Context(doc, startState(doc.mode), start);
+  // A visual line is a line as drawn on the screen. Folding, for
+  // example, can cause multiple logical lines to appear on the same
+  // visual line. This finds the start of the visual line that the
+  // given line is part of (usually that is the line itself).
+  function visualLine(line) {
+    var merged;
+    while (merged = collapsedSpanAtStart(line))
+      { line = merged.find(-1, true).line; }
+    return line
+  }
 
-    doc.iter(start, n, function (line) {
-      processLine(cm, line.text, context);
-      var pos = context.line;
-      line.stateAfter = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo ? context.save() : null;
-      context.nextLine();
-    });
-    if (precise) { doc.modeFrontier = context.line; }
-    return context
+  function visualLineEnd(line) {
+    var merged;
+    while (merged = collapsedSpanAtEnd(line))
+      { line = merged.find(1, true).line; }
+    return line
   }
 
-  // Lightweight form of highlight -- proceed over this line and
-  // update state, but don't save a style array. Used for lines that
-  // aren't currently visible.
-  function processLine(cm, text, context, startAt) {
-    var mode = cm.doc.mode;
-    var stream = new StringStream(text, cm.options.tabSize, context);
-    stream.start = stream.pos = startAt || 0;
-    if (text == "") { callBlankLine(mode, context.state); }
-    while (!stream.eol()) {
-      readToken(mode, stream, context.state);
-      stream.start = stream.pos;
+  // Returns an array of logical lines that continue the visual line
+  // started by the argument, or undefined if there are no such lines.
+  function visualLineContinued(line) {
+    var merged, lines;
+    while (merged = collapsedSpanAtEnd(line)) {
+      line = merged.find(1, true).line
+      ;(lines || (lines = [])).push(line);
     }
+    return lines
   }
 
-  function callBlankLine(mode, state) {
-    if (mode.blankLine) { return mode.blankLine(state) }
-    if (!mode.innerMode) { return }
-    var inner = innerMode(mode, state);
-    if (inner.mode.blankLine) { return inner.mode.blankLine(inner.state) }
+  // Get the line number of the start of the visual line that the
+  // given line number is part of.
+  function visualLineNo(doc, lineN) {
+    var line = getLine(doc, lineN), vis = visualLine(line);
+    if (line == vis) { return lineN }
+    return lineNo(vis)
   }
 
-  function readToken(mode, stream, state, inner) {
-    for (var i = 0; i < 10; i++) {
-      if (inner) { inner[0] = innerMode(mode, state).mode; }
-      var style = mode.token(stream, state);
-      if (stream.pos > stream.start) { return style }
-    }
-    throw new Error("Mode " + mode.name + " failed to advance stream.")
+  // Get the line number of the start of the next visual line after
+  // the given line.
+  function visualLineEndNo(doc, lineN) {
+    if (lineN > doc.lastLine()) { return lineN }
+    var line = getLine(doc, lineN), merged;
+    if (!lineIsHidden(doc, line)) { return lineN }
+    while (merged = collapsedSpanAtEnd(line))
+      { line = merged.find(1, true).line; }
+    return lineNo(line) + 1
   }
 
-  var Token = function(stream, type, state) {
-    this.start = stream.start; this.end = stream.pos;
-    this.string = stream.current();
-    this.type = type || null;
-    this.state = state;
-  };
-
-  // Utility for getTokenAt and getLineTokens
-  function takeToken(cm, pos, precise, asArray) {
-    var doc = cm.doc, mode = doc.mode, style;
-    pos = clipPos(doc, pos);
-    var line = getLine(doc, pos.line), context = getContextBefore(cm, pos.line, precise);
-    var stream = new StringStream(line.text, cm.options.tabSize, context), tokens;
-    if (asArray) { tokens = []; }
-    while ((asArray || stream.pos < pos.ch) && !stream.eol()) {
-      stream.start = stream.pos;
-      style = readToken(mode, stream, context.state);
-      if (asArray) { tokens.push(new Token(stream, style, copyState(doc.mode, context.state))); }
+  // Compute whether a line is hidden. Lines count as hidden when they
+  // are part of a visual line that starts with another line, or when
+  // they are entirely covered by collapsed, non-widget span.
+  function lineIsHidden(doc, line) {
+    var sps = sawCollapsedSpans && line.markedSpans;
+    if (sps) { for (var sp = (void 0), i = 0; i < sps.length; ++i) {
+      sp = sps[i];
+      if (!sp.marker.collapsed) { continue }
+      if (sp.from == null) { return true }
+      if (sp.marker.widgetNode) { continue }
+      if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
+        { return true }
+    } }
+  }
+  function lineIsHiddenInner(doc, line, span) {
+    if (span.to == null) {
+      var end = span.marker.find(1, true);
+      return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker))
+    }
+    if (span.marker.inclusiveRight && span.to == line.text.length)
+      { return true }
+    for (var sp = (void 0), i = 0; i < line.markedSpans.length; ++i) {
+      sp = line.markedSpans[i];
+      if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&
+          (sp.to == null || sp.to != span.from) &&
+          (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
+          lineIsHiddenInner(doc, line, sp)) { return true }
     }
-    return asArray ? tokens : new Token(stream, style, context.state)
   }
 
-  function extractLineClasses(type, output) {
-    if (type) { for (;;) {
-      var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);
-      if (!lineClass) { break }
-      type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);
-      var prop = lineClass[1] ? "bgClass" : "textClass";
-      if (output[prop] == null)
-        { output[prop] = lineClass[2]; }
-      else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))
-        { output[prop] += " " + lineClass[2]; }
-    } }
-    return type
-  }
+  // Find the height above the given line.
+  function heightAtLine(lineObj) {
+    lineObj = visualLine(lineObj);
 
-  // Run the given mode's parser over a line, calling f for each token.
-  function runMode(cm, text, mode, context, f, lineClasses, forceToEnd) {
-    var flattenSpans = mode.flattenSpans;
-    if (flattenSpans == null) { flattenSpans = cm.options.flattenSpans; }
-    var curStart = 0, curStyle = null;
-    var stream = new StringStream(text, cm.options.tabSize, context), style;
-    var inner = cm.options.addModeClass && [null];
-    if (text == "") { extractLineClasses(callBlankLine(mode, context.state), lineClasses); }
-    while (!stream.eol()) {
-      if (stream.pos > cm.options.maxHighlightLength) {
-        flattenSpans = false;
-        if (forceToEnd) { processLine(cm, text, context, stream.pos); }
-        stream.pos = text.length;
-        style = null;
-      } else {
-        style = extractLineClasses(readToken(mode, stream, context.state, inner), lineClasses);
-      }
-      if (inner) {
-        var mName = inner[0].name;
-        if (mName) { style = "m-" + (style ? mName + " " + style : mName); }
-      }
-      if (!flattenSpans || curStyle != style) {
-        while (curStart < stream.start) {
-          curStart = Math.min(stream.start, curStart + 5000);
-          f(curStart, curStyle);
-        }
-        curStyle = style;
-      }
-      stream.start = stream.pos;
+    var h = 0, chunk = lineObj.parent;
+    for (var i = 0; i < chunk.lines.length; ++i) {
+      var line = chunk.lines[i];
+      if (line == lineObj) { break }
+      else { h += line.height; }
     }
-    while (curStart < stream.pos) {
-      // Webkit seems to refuse to render text nodes longer than 57444
-      // characters, and returns inaccurate measurements in nodes
-      // starting around 5000 chars.
-      var pos = Math.min(stream.pos, curStart + 5000);
-      f(pos, curStyle);
-      curStart = pos;
+    for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
+      for (var i$1 = 0; i$1 < p.children.length; ++i$1) {
+        var cur = p.children[i$1];
+        if (cur == chunk) { break }
+        else { h += cur.height; }
+      }
     }
+    return h
   }
 
-  // Finds the line to start with when starting a parse. Tries to
-  // find a line with a stateAfter, so that it can start with a
-  // valid state. If that fails, it returns the line with the
-  // smallest indentation, which tends to need the least context to
-  // parse correctly.
-  function findStartLine(cm, n, precise) {
-    var minindent, minline, doc = cm.doc;
-    var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
-    for (var search = n; search > lim; --search) {
-      if (search <= doc.first) { return doc.first }
-      var line = getLine(doc, search - 1), after = line.stateAfter;
-      if (after && (!precise || search + (after instanceof SavedContext ? after.lookAhead : 0) <= doc.modeFrontier))
-        { return search }
-      var indented = countColumn(line.text, null, cm.options.tabSize);
-      if (minline == null || minindent > indented) {
-        minline = search - 1;
-        minindent = indented;
-      }
+  // Compute the character length of a line, taking into account
+  // collapsed ranges (see markText) that might hide parts, and join
+  // other lines onto it.
+  function lineLength(line) {
+    if (line.height == 0) { return 0 }
+    var len = line.text.length, merged, cur = line;
+    while (merged = collapsedSpanAtStart(cur)) {
+      var found = merged.find(0, true);
+      cur = found.from.line;
+      len += found.from.ch - found.to.ch;
     }
-    return minline
+    cur = line;
+    while (merged = collapsedSpanAtEnd(cur)) {
+      var found$1 = merged.find(0, true);
+      len -= cur.text.length - found$1.from.ch;
+      cur = found$1.to.line;
+      len += cur.text.length - found$1.to.ch;
+    }
+    return len
   }
 
-  function retreatFrontier(doc, n) {
-    doc.modeFrontier = Math.min(doc.modeFrontier, n);
-    if (doc.highlightFrontier < n - 10) { return }
-    var start = doc.first;
-    for (var line = n - 1; line > start; line--) {
-      var saved = getLine(doc, line).stateAfter;
-      // change is on 3
-      // state on line 1 looked ahead 2 -- so saw 3
-      // test 1 + 2 < 3 should cover this
-      if (saved && (!(saved instanceof SavedContext) || line + saved.lookAhead < n)) {
-        start = line + 1;
-        break
+  // Find the longest line in the document.
+  function findMaxLine(cm) {
+    var d = cm.display, doc = cm.doc;
+    d.maxLine = getLine(doc, doc.first);
+    d.maxLineLength = lineLength(d.maxLine);
+    d.maxLineChanged = true;
+    doc.iter(function (line) {
+      var len = lineLength(line);
+      if (len > d.maxLineLength) {
+        d.maxLineLength = len;
+        d.maxLine = line;
       }
-    }
-    doc.highlightFrontier = Math.min(doc.highlightFrontier, start);
+    });
   }
 
   // LINE DATA STRUCTURE
@@ -2279,8 +2176,8 @@
           elt("div", lineNumberFor(cm.options, lineN),
               "CodeMirror-linenumber CodeMirror-gutter-elt",
               ("left: " + (dims.gutterLeft["CodeMirror-linenumbers"]) + "px; width: " + (cm.display.lineNumInnerWidth) + "px"))); }
-      if (markers) { for (var k = 0; k < cm.options.gutters.length; ++k) {
-        var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
+      if (markers) { for (var k = 0; k < cm.display.gutterSpecs.length; ++k) {
+        var id = cm.display.gutterSpecs[k].className, found = markers.hasOwnProperty(id) && markers[id];
         if (found)
           { gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt",
                                      ("left: " + (dims.gutterLeft[id]) + "px; width: " + (dims.gutterWidth[id]) + "px"))); }
@@ -2985,8 +2882,9 @@
     var d = cm.display, left = {}, width = {};
     var gutterLeft = d.gutters.clientLeft;
     for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
-      left[cm.options.gutters[i]] = n.offsetLeft + n.clientLeft + gutterLeft;
-      width[cm.options.gutters[i]] = n.clientWidth;
+      var id = cm.display.gutterSpecs[i].className;
+      left[id] = n.offsetLeft + n.clientLeft + gutterLeft;
+      width[id] = n.clientWidth;
     }
     return {fixedPos: compensateForHScroll(d),
             gutterTotalWidth: d.gutters.offsetWidth,
@@ -3023,46 +2921,194 @@
     }
   }
 
-  function estimateLineHeights(cm) {
-    var doc = cm.doc, est = estimateHeight(cm);
-    doc.iter(function (line) {
-      var estHeight = est(line);
-      if (estHeight != line.height) { updateLineHeight(line, estHeight); }
-    });
+  function estimateLineHeights(cm) {
+    var doc = cm.doc, est = estimateHeight(cm);
+    doc.iter(function (line) {
+      var estHeight = est(line);
+      if (estHeight != line.height) { updateLineHeight(line, estHeight); }
+    });
+  }
+
+  // Given a mouse event, find the corresponding position. If liberal
+  // is false, it checks whether a gutter or scrollbar was clicked,
+  // and returns null if it was. forRect is used by rectangular
+  // selections, and tries to estimate a character position even for
+  // coordinates beyond the right of the text.
+  function posFromMouse(cm, e, liberal, forRect) {
+    var display = cm.display;
+    if (!liberal && e_target(e).getAttribute("cm-not-content") == "true") { return null }
+
+    var x, y, space = display.lineSpace.getBoundingClientRect();
+    // Fails unpredictably on IE[67] when mouse is dragged around quickly.
+    try { x = e.clientX - space.left; y = e.clientY - space.top; }
+    catch (e) { return null }
+    var coords = coordsChar(cm, x, y), line;
+    if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
+      var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
+      coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
+    }
+    return coords
+  }
+
+  // Find the view element corresponding to a given line. Return null
+  // when the line isn't visible.
+  function findViewIndex(cm, n) {
+    if (n >= cm.display.viewTo) { return null }
+    n -= cm.display.viewFrom;
+    if (n < 0) { return null }
+    var view = cm.display.view;
+    for (var i = 0; i < view.length; i++) {
+      n -= view[i].size;
+      if (n < 0) { return i }
+    }
+  }
+
+  // Updates the display.view data structure for a given change to the
+  // document. From and to are in pre-change coordinates. Lendiff is
+  // the amount of lines added or subtracted by the change. This is
+  // used for changes that span multiple lines, or change the way
+  // lines are divided into visual lines. regLineChange (below)
+  // registers single-line changes.
+  function regChange(cm, from, to, lendiff) {
+    if (from == null) { from = cm.doc.first; }
+    if (to == null) { to = cm.doc.first + cm.doc.size; }
+    if (!lendiff) { lendiff = 0; }
+
+    var display = cm.display;
+    if (lendiff && to < display.viewTo &&
+        (display.updateLineNumbers == null || display.updateLineNumbers > from))
+      { display.updateLineNumbers = from; }
+
+    cm.curOp.viewChanged = true;
+
+    if (from >= display.viewTo) { // Change after
+      if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
+        { resetView(cm); }
+    } else if (to <= display.viewFrom) { // Change before
+      if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
+        resetView(cm);
+      } else {
+        display.viewFrom += lendiff;
+        display.viewTo += lendiff;
+      }
+    } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
+      resetView(cm);
+    } else if (from <= display.viewFrom) { // Top overlap
+      var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
+      if (cut) {
+        display.view = display.view.slice(cut.index);
+        display.viewFrom = cut.lineN;
+        display.viewTo += lendiff;
+      } else {
+        resetView(cm);
+      }
+    } else if (to >= display.viewTo) { // Bottom overlap
+      var cut$1 = viewCuttingPoint(cm, from, from, -1);
+      if (cut$1) {
+        display.view = display.view.slice(0, cut$1.index);
+        display.viewTo = cut$1.lineN;
+      } else {
+        resetView(cm);
+      }
+    } else { // Gap in the middle
+      var cutTop = viewCuttingPoint(cm, from, from, -1);
+      var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
+      if (cutTop && cutBot) {
+        display.view = display.view.slice(0, cutTop.index)
+          .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
+          .concat(display.view.slice(cutBot.index));
+        display.viewTo += lendiff;
+      } else {
+        resetView(cm);
+      }
+    }
+
+    var ext = display.externalMeasured;
+    if (ext) {
+      if (to < ext.lineN)
+        { ext.lineN += lendiff; }
+      else if (from < ext.lineN + ext.size)
+        { display.externalMeasured = null; }
+    }
+  }
+
+  // Register a change to a single line. Type must be one of "text",
+  // "gutter", "class", "widget"
+  function regLineChange(cm, line, type) {
+    cm.curOp.viewChanged = true;
+    var display = cm.display, ext = cm.display.externalMeasured;
+    if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
+      { display.externalMeasured = null; }
+
+    if (line < display.viewFrom || line >= display.viewTo) { return }
+    var lineView = display.view[findViewIndex(cm, line)];
+    if (lineView.node == null) { return }
+    var arr = lineView.changes || (lineView.changes = []);
+    if (indexOf(arr, type) == -1) { arr.push(type); }
+  }
+
+  // Clear the view.
+  function resetView(cm) {
+    cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
+    cm.display.view = [];
+    cm.display.viewOffset = 0;
   }
 
-  // Given a mouse event, find the corresponding position. If liberal
-  // is false, it checks whether a gutter or scrollbar was clicked,
-  // and returns null if it was. forRect is used by rectangular
-  // selections, and tries to estimate a character position even for
-  // coordinates beyond the right of the text.
-  function posFromMouse(cm, e, liberal, forRect) {
-    var display = cm.display;
-    if (!liberal && e_target(e).getAttribute("cm-not-content") == "true") { return null }
+  function viewCuttingPoint(cm, oldN, newN, dir) {
+    var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
+    if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
+      { return {index: index, lineN: newN} }
+    var n = cm.display.viewFrom;
+    for (var i = 0; i < index; i++)
+      { n += view[i].size; }
+    if (n != oldN) {
+      if (dir > 0) {
+        if (index == view.length - 1) { return null }
+        diff = (n + view[index].size) - oldN;
+        index++;
+      } else {
+        diff = n - oldN;
+      }
+      oldN += diff; newN += diff;
+    }
+    while (visualLineNo(cm.doc, newN) != newN) {
+      if (index == (dir < 0 ? 0 : view.length - 1)) { return null }
+      newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
+      index += dir;
+    }
+    return {index: index, lineN: newN}
+  }
 
-    var x, y, space = display.lineSpace.getBoundingClientRect();
-    // Fails unpredictably on IE[67] when mouse is dragged around quickly.
-    try { x = e.clientX - space.left; y = e.clientY - space.top; }
-    catch (e) { return null }
-    var coords = coordsChar(cm, x, y), line;
-    if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
-      var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
-      coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
+  // Force the view to cover a given range, adding empty view element
+  // or clipping off existing ones as needed.
+  function adjustView(cm, from, to) {
+    var display = cm.display, view = display.view;
+    if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
+      display.view = buildViewArray(cm, from, to);
+      display.viewFrom = from;
+    } else {
+      if (display.viewFrom > from)
+        { display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view); }
+      else if (display.viewFrom < from)
+        { display.view = display.view.slice(findViewIndex(cm, from)); }
+      display.viewFrom = from;
+      if (display.viewTo < to)
+        { display.view = display.view.concat(buildViewArray(cm, display.viewTo, to)); }
+      else if (display.viewTo > to)
+        { display.view = display.view.slice(0, findViewIndex(cm, to)); }
     }
-    return coords
+    display.viewTo = to;
   }
 
-  // Find the view element corresponding to a given line. Return null
-  // when the line isn't visible.
-  function findViewIndex(cm, n) {
-    if (n >= cm.display.viewTo) { return null }
-    n -= cm.display.viewFrom;
-    if (n < 0) { return null }
-    var view = cm.display.view;
+  // Count the number of lines in the view whose DOM representation is
+  // out of date (or nonexistent).
+  function countDirtyView(cm) {
+    var view = cm.display.view, dirty = 0;
     for (var i = 0; i < view.length; i++) {
-      n -= view[i].size;
-      if (n < 0) { return i }
+      var lineView = view[i];
+      if (!lineView.hidden && (!lineView.node || lineView.changes)) { ++dirty; }
     }
+    return dirty
   }
 
   function updateSelection(cm) {
@@ -3282,7 +3328,6 @@
           { width = cur.text.firstChild.getBoundingClientRect().right - box.left - 1; }
       }
       var diff = cur.line.height - height;
-      if (height < 2) { height = textHeight(display); }
       if (diff > .005 || diff < -.005) {
         updateLineHeight(cur.line, height);
         updateWidgetHeight(cur.line);
@@ -3333,49 +3378,6 @@
     return {from: from, to: Math.max(to, from + 1)}
   }
 
-  // Re-align line numbers and gutter marks to compensate for
-  // horizontal scrolling.
-  function alignHorizontally(cm) {
-    var display = cm.display, view = display.view;
-    if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) { return }
-    var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
-    var gutterW = display.gutters.offsetWidth, left = comp + "px";
-    for (var i = 0; i < view.length; i++) { if (!view[i].hidden) {
-      if (cm.options.fixedGutter) {
-        if (view[i].gutter)
-          { view[i].gutter.style.left = left; }
-        if (view[i].gutterBackground)
-          { view[i].gutterBackground.style.left = left; }
-      }
-      var align = view[i].alignable;
-      if (align) { for (var j = 0; j < align.length; j++)
-        { align[j].style.left = left; } }
-    } }
-    if (cm.options.fixedGutter)
-      { display.gutters.style.left = (comp + gutterW) + "px"; }
-  }
-
-  // Used to ensure that the line number gutter is still the right
-  // size for the current document size. Returns true when an update
-  // is needed.
-  function maybeUpdateLineNumberWidth(cm) {
-    if (!cm.options.lineNumbers) { return false }
-    var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
-    if (last.length != display.lineNumChars) {
-      var test = display.measure.appendChild(elt("div", [elt("div", last)],
-                                                 "CodeMirror-linenumber CodeMirror-gutter-elt"));
-      var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
-      display.lineGutter.style.width = "";
-      display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1;
-      display.lineNumWidth = display.lineNumInnerWidth + padding;
-      display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
-      display.lineGutter.style.width = display.lineNumWidth + "px";
-      updateGutterSpace(cm);
-      return true
-    }
-    return false
-  }
-
   // SCROLLING THINGS INTO VIEW
 
   // If an editor sits on the top or bottom of the window, partially
@@ -3878,197 +3880,49 @@
       { if (unhidden[i$1].lines.length) { signal(unhidden[i$1], "unhide"); } } }
 
     if (display.wrapper.offsetHeight)
-      { doc.scrollTop = cm.display.scroller.scrollTop; }
-
-    // Fire change events, and delayed event handlers
-    if (op.changeObjs)
-      { signal(cm, "changes", cm, op.changeObjs); }
-    if (op.update)
-      { op.update.finish(); }
-  }
-
-  // Run the given function in an operation
-  function runInOp(cm, f) {
-    if (cm.curOp) { return f() }
-    startOperation(cm);
-    try { return f() }
-    finally { endOperation(cm); }
-  }
-  // Wraps a function in an operation. Returns the wrapped function.
-  function operation(cm, f) {
-    return function() {
-      if (cm.curOp) { return f.apply(cm, arguments) }
-      startOperation(cm);
-      try { return f.apply(cm, arguments) }
-      finally { endOperation(cm); }
-    }
-  }
-  // Used to add methods to editor and doc instances, wrapping them in
-  // operations.
-  function methodOp(f) {
-    return function() {
-      if (this.curOp) { return f.apply(this, arguments) }
-      startOperation(this);
-      try { return f.apply(this, arguments) }
-      finally { endOperation(this); }
-    }
-  }
-  function docMethodOp(f) {
-    return function() {
-      var cm = this.cm;
-      if (!cm || cm.curOp) { return f.apply(this, arguments) }
-      startOperation(cm);
-      try { return f.apply(this, arguments) }
-      finally { endOperation(cm); }
-    }
-  }
-
-  // Updates the display.view data structure for a given change to the
-  // document. From and to are in pre-change coordinates. Lendiff is
-  // the amount of lines added or subtracted by the change. This is
-  // used for changes that span multiple lines, or change the way
-  // lines are divided into visual lines. regLineChange (below)
-  // registers single-line changes.
-  function regChange(cm, from, to, lendiff) {
-    if (from == null) { from = cm.doc.first; }
-    if (to == null) { to = cm.doc.first + cm.doc.size; }
-    if (!lendiff) { lendiff = 0; }
-
-    var display = cm.display;
-    if (lendiff && to < display.viewTo &&
-        (display.updateLineNumbers == null || display.updateLineNumbers > from))
-      { display.updateLineNumbers = from; }
-
-    cm.curOp.viewChanged = true;
-
-    if (from >= display.viewTo) { // Change after
-      if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
-        { resetView(cm); }
-    } else if (to <= display.viewFrom) { // Change before
-      if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
-        resetView(cm);
-      } else {
-        display.viewFrom += lendiff;
-        display.viewTo += lendiff;
-      }
-    } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
-      resetView(cm);
-    } else if (from <= display.viewFrom) { // Top overlap
-      var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
-      if (cut) {
-        display.view = display.view.slice(cut.index);
-        display.viewFrom = cut.lineN;
-        display.viewTo += lendiff;
-      } else {
-        resetView(cm);
-      }
-    } else if (to >= display.viewTo) { // Bottom overlap
-      var cut$1 = viewCuttingPoint(cm, from, from, -1);
-      if (cut$1) {
-        display.view = display.view.slice(0, cut$1.index);
-        display.viewTo = cut$1.lineN;
-      } else {
-        resetView(cm);
-      }
-    } else { // Gap in the middle
-      var cutTop = viewCuttingPoint(cm, from, from, -1);
-      var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
-      if (cutTop && cutBot) {
-        display.view = display.view.slice(0, cutTop.index)
-          .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
-          .concat(display.view.slice(cutBot.index));
-        display.viewTo += lendiff;
-      } else {
-        resetView(cm);
-      }
-    }
-
-    var ext = display.externalMeasured;
-    if (ext) {
-      if (to < ext.lineN)
-        { ext.lineN += lendiff; }
-      else if (from < ext.lineN + ext.size)
-        { display.externalMeasured = null; }
-    }
-  }
-
-  // Register a change to a single line. Type must be one of "text",
-  // "gutter", "class", "widget"
-  function regLineChange(cm, line, type) {
-    cm.curOp.viewChanged = true;
-    var display = cm.display, ext = cm.display.externalMeasured;
-    if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
-      { display.externalMeasured = null; }
-
-    if (line < display.viewFrom || line >= display.viewTo) { return }
-    var lineView = display.view[findViewIndex(cm, line)];
-    if (lineView.node == null) { return }
-    var arr = lineView.changes || (lineView.changes = []);
-    if (indexOf(arr, type) == -1) { arr.push(type); }
-  }
+      { doc.scrollTop = cm.display.scroller.scrollTop; }
 
-  // Clear the view.
-  function resetView(cm) {
-    cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
-    cm.display.view = [];
-    cm.display.viewOffset = 0;
+    // Fire change events, and delayed event handlers
+    if (op.changeObjs)
+      { signal(cm, "changes", cm, op.changeObjs); }
+    if (op.update)
+      { op.update.finish(); }
   }
 
-  function viewCuttingPoint(cm, oldN, newN, dir) {
-    var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
-    if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
-      { return {index: index, lineN: newN} }
-    var n = cm.display.viewFrom;
-    for (var i = 0; i < index; i++)
-      { n += view[i].size; }
-    if (n != oldN) {
-      if (dir > 0) {
-        if (index == view.length - 1) { return null }
-        diff = (n + view[index].size) - oldN;
-        index++;
-      } else {
-        diff = n - oldN;
-      }
-      oldN += diff; newN += diff;
-    }
-    while (visualLineNo(cm.doc, newN) != newN) {
-      if (index == (dir < 0 ? 0 : view.length - 1)) { return null }
-      newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
-      index += dir;
+  // Run the given function in an operation
+  function runInOp(cm, f) {
+    if (cm.curOp) { return f() }
+    startOperation(cm);
+    try { return f() }
+    finally { endOperation(cm); }
+  }
+  // Wraps a function in an operation. Returns the wrapped function.
+  function operation(cm, f) {
+    return function() {
+      if (cm.curOp) { return f.apply(cm, arguments) }
+      startOperation(cm);
+      try { return f.apply(cm, arguments) }
+      finally { endOperation(cm); }
     }
-    return {index: index, lineN: newN}
   }
-
-  // Force the view to cover a given range, adding empty view element
-  // or clipping off existing ones as needed.
-  function adjustView(cm, from, to) {
-    var display = cm.display, view = display.view;
-    if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
-      display.view = buildViewArray(cm, from, to);
-      display.viewFrom = from;
-    } else {
-      if (display.viewFrom > from)
-        { display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view); }
-      else if (display.viewFrom < from)
-        { display.view = display.view.slice(findViewIndex(cm, from)); }
-      display.viewFrom = from;
-      if (display.viewTo < to)
-        { display.view = display.view.concat(buildViewArray(cm, display.viewTo, to)); }
-      else if (display.viewTo > to)
-        { display.view = display.view.slice(0, findViewIndex(cm, to)); }
+  // Used to add methods to editor and doc instances, wrapping them in
+  // operations.
+  function methodOp(f) {
+    return function() {
+      if (this.curOp) { return f.apply(this, arguments) }
+      startOperation(this);
+      try { return f.apply(this, arguments) }
+      finally { endOperation(this); }
     }
-    display.viewTo = to;
   }
-
-  // Count the number of lines in the view whose DOM representation is
-  // out of date (or nonexistent).
-  function countDirtyView(cm) {
-    var view = cm.display.view, dirty = 0;
-    for (var i = 0; i < view.length; i++) {
-      var lineView = view[i];
-      if (!lineView.hidden && (!lineView.node || lineView.changes)) { ++dirty; }
+  function docMethodOp(f) {
+    return function() {
+      var cm = this.cm;
+      if (!cm || cm.curOp) { return f.apply(this, arguments) }
+      startOperation(cm);
+      try { return f.apply(this, arguments) }
+      finally { endOperation(cm); }
     }
-    return dirty
   }
 
   // HIGHLIGHT WORKER
@@ -4350,9 +4204,9 @@
     while (cur) { cur = rm(cur); }
   }
 
-  function updateGutterSpace(cm) {
-    var width = cm.display.gutters.offsetWidth;
-    cm.display.sizer.style.marginLeft = width + "px";
+  function updateGutterSpace(display) {
+    var width = display.gutters.offsetWidth;
+    display.sizer.style.marginLeft = width + "px";
   }
 
   function setDocumentHeight(cm, measure) {
@@ -4361,34 +4215,195 @@
     cm.display.gutters.style.height = (measure.docHeight + cm.display.barHeight + scrollGap(cm)) + "px";
   }
 
+  // Re-align line numbers and gutter marks to compensate for
+  // horizontal scrolling.
+  function alignHorizontally(cm) {
+    var display = cm.display, view = display.view;
+    if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) { return }
+    var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
+    var gutterW = display.gutters.offsetWidth, left = comp + "px";
+    for (var i = 0; i < view.length; i++) { if (!view[i].hidden) {
+      if (cm.options.fixedGutter) {
+        if (view[i].gutter)
+          { view[i].gutter.style.left = left; }
+        if (view[i].gutterBackground)
+          { view[i].gutterBackground.style.left = left; }
+      }
+      var align = view[i].alignable;
+      if (align) { for (var j = 0; j < align.length; j++)
+        { align[j].style.left = left; } }
+    } }
+    if (cm.options.fixedGutter)
+      { display.gutters.style.left = (comp + gutterW) + "px"; }
+  }
+
+  // Used to ensure that the line number gutter is still the right
+  // size for the current document size. Returns true when an update
+  // is needed.
+  function maybeUpdateLineNumberWidth(cm) {
+    if (!cm.options.lineNumbers) { return false }
+    var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
+    if (last.length != display.lineNumChars) {
+      var test = display.measure.appendChild(elt("div", [elt("div", last)],
+                                                 "CodeMirror-linenumber CodeMirror-gutter-elt"));
+      var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
+      display.lineGutter.style.width = "";
+      display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1;
+      display.lineNumWidth = display.lineNumInnerWidth + padding;
+      display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
+      display.lineGutter.style.width = display.lineNumWidth + "px";
+      updateGutterSpace(cm.display);
+      return true
+    }
+    return false
+  }
+
+  function getGutters(gutters, lineNumbers) {
+    var result = [], sawLineNumbers = false;
+    for (var i = 0; i < gutters.length; i++) {
+      var name = gutters[i], style = null;
+      if (typeof name != "string") { style = name.style; name = name.className; }
+      if (name == "CodeMirror-linenumbers") {
+        if (!lineNumbers) { continue }
+        else { sawLineNumbers = true; }
+      }
+      result.push({className: name, style: style});
+    }
+    if (lineNumbers && !sawLineNumbers) { result.push({className: "CodeMirror-linenumbers", style: null}); }
+    return result
+  }
+
   // Rebuild the gutter elements, ensure the margin to the left of the
   // code matches their width.
-  function updateGutters(cm) {
-    var gutters = cm.display.gutters, specs = cm.options.gutters;
+  function renderGutters(display) {
+    var gutters = display.gutters, specs = display.gutterSpecs;
     removeChildren(gutters);
-    var i = 0;
-    for (; i < specs.length; ++i) {
-      var gutterClass = specs[i];
-      var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
-      if (gutterClass == "CodeMirror-linenumbers") {
-        cm.display.lineGutter = gElt;
-        gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
+    display.lineGutter = null;
+    for (var i = 0; i < specs.length; ++i) {
+      var ref = specs[i];
+      var className = ref.className;
+      var style = ref.style;
+      var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + className));
+      if (style) { gElt.style.cssText = style; }
+      if (className == "CodeMirror-linenumbers") {
+        display.lineGutter = gElt;
+        gElt.style.width = (display.lineNumWidth || 1) + "px";
       }
     }
-    gutters.style.display = i ? "" : "none";
-    updateGutterSpace(cm);
+    gutters.style.display = specs.length ? "" : "none";
+    updateGutterSpace(display);
+  }
+
+  function updateGutters(cm) {
+    renderGutters(cm.display);
+    regChange(cm);
+    alignHorizontally(cm);
   }
 
-  // Make sure the gutters options contains the element
-  // "CodeMirror-linenumbers" when the lineNumbers option is true.
-  function setGuttersForLineNumbers(options) {
-    var found = indexOf(options.gutters, "CodeMirror-linenumbers");
-    if (found == -1 && options.lineNumbers) {
-      options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);
-    } else if (found > -1 && !options.lineNumbers) {
-      options.gutters = options.gutters.slice(0);
-      options.gutters.splice(found, 1);
+  // The display handles the DOM integration, both for input reading
+  // and content drawing. It holds references to DOM nodes and
+  // display-related state.
+
+  function Display(place, doc, input, options) {
+    var d = this;
+    this.input = input;
+
+    // Covers bottom-right square when both scrollbars are present.
+    d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
+    d.scrollbarFiller.setAttribute("cm-not-content", "true");
+    // Covers bottom of gutter when coverGutterNextToScrollbar is on
+    // and h scrollbar is present.
+    d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
+    d.gutterFiller.setAttribute("cm-not-content", "true");
+    // Will contain the actual code, positioned to cover the viewport.
+    d.lineDiv = eltP("div", null, "CodeMirror-code");
+    // Elements are added to these to represent selection and cursors.
+    d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
+    d.cursorDiv = elt("div", null, "CodeMirror-cursors");
+    // A visibility: hidden element used to find the size of things.
+    d.measure = elt("div", null, "CodeMirror-measure");
+    // When lines outside of the viewport are measured, they are drawn in this.
+    d.lineMeasure = elt("div", null, "CodeMirror-measure");
+    // Wraps everything that needs to exist inside the vertically-padded coordinate system
+    d.lineSpace = eltP("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
+                      null, "position: relative; outline: none");
+    var lines = eltP("div", [d.lineSpace], "CodeMirror-lines");
+    // Moved around its parent to cover visible view.
+    d.mover = elt("div", [lines], null, "position: relative");
+    // Set to the height of the document, allowing scrolling.
+    d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
+    d.sizerWidth = null;
+    // Behavior of elts with overflow: auto and padding is
+    // inconsistent across browsers. This is used to ensure the
+    // scrollable area is big enough.
+    d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerGap + "px; width: 1px;");
+    // Will contain the gutters, if any.
+    d.gutters = elt("div", null, "CodeMirror-gutters");
+    d.lineGutter = null;
+    // Actual scrollable element.
+    d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
+    d.scroller.setAttribute("tabIndex", "-1");
+    // The element in which the editor lives.
+    d.wrapper = elt("div", [d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
+
+    // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
+    if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
+    if (!webkit && !(gecko && mobile)) { d.scroller.draggable = true; }
+
+    if (place) {
+      if (place.appendChild) { place.appendChild(d.wrapper); }
+      else { place(d.wrapper); }
     }
+
+    // Current rendered range (may be bigger than the view window).
+    d.viewFrom = d.viewTo = doc.first;
+    d.reportedViewFrom = d.reportedViewTo = doc.first;
+    // Information about the rendered lines.
+    d.view = [];
+    d.renderedView = null;
+    // Holds info about a single rendered line when it was rendered
+    // for measurement, while not in view.
+    d.externalMeasured = null;
+    // Empty space (in pixels) above the view
+    d.viewOffset = 0;
+    d.lastWrapHeight = d.lastWrapWidth = 0;
+    d.updateLineNumbers = null;
+
+    d.nativeBarWidth = d.barHeight = d.barWidth = 0;
+    d.scrollbarsClipped = false;
+
+    // Used to only resize the line number gutter when necessary (when
+    // the amount of lines crosses a boundary that makes its width change)
+    d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
+    // Set to true when a non-horizontal-scrolling line widget is
+    // added. As an optimization, line widget aligning is skipped when
+    // this is false.
+    d.alignWidgets = false;
+
+    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
+
+    // Tracks the maximum line length so that the horizontal scrollbar
+    // can be kept static when scrolling.
+    d.maxLine = null;
+    d.maxLineLength = 0;
+    d.maxLineChanged = false;
+
+    // Used for measuring wheel scrolling granularity
+    d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
+
+    // True when shift is held down.
+    d.shift = false;
+
+    // Used to track whether anything happened since the context menu
+    // was opened.
+    d.selForContextMenu = null;
+
+    d.activeTouch = null;
+
+    d.gutterSpecs = getGutters(options.gutters, options.lineNumbers);
+    renderGutters(d);
+
+    input.init(d);
   }
 
   // Since the delta values reported on mouse wheel events are
@@ -5116,8 +5131,15 @@
     var line = getLine(doc, pos.line);
     if (line.markedSpans) { for (var i = 0; i < line.markedSpans.length; ++i) {
       var sp = line.markedSpans[i], m = sp.marker;
-      if ((sp.from == null || (m.inclusiveLeft ? sp.from <= pos.ch : sp.from < pos.ch)) &&
-          (sp.to == null || (m.inclusiveRight ? sp.to >= pos.ch : sp.to > pos.ch))) {
+
+      // Determine if we should prevent the cursor being placed to the left/right of an atomic marker
+      // Historically this was determined using the inclusiveLeft/Right option, but the new way to control it
+      // is with selectLeft/Right
+      var preventCursorLeft = ("selectLeft" in m) ? !m.selectLeft : m.inclusiveLeft;
+      var preventCursorRight = ("selectRight" in m) ? !m.selectRight : m.inclusiveRight;
+
+      if ((sp.from == null || (preventCursorLeft ? sp.from <= pos.ch : sp.from < pos.ch)) &&
+          (sp.to == null || (preventCursorRight ? sp.to >= pos.ch : sp.to > pos.ch))) {
         if (mayClear) {
           signal(m, "beforeCursorEnter");
           if (m.explicitlyCleared) {
@@ -5129,14 +5151,14 @@
 
         if (oldPos) {
           var near = m.find(dir < 0 ? 1 : -1), diff = (void 0);
-          if (dir < 0 ? m.inclusiveRight : m.inclusiveLeft)
+          if (dir < 0 ? preventCursorRight : preventCursorLeft)
             { near = movePos(doc, near, -dir, near && near.line == pos.line ? line : null); }
           if (near && near.line == pos.line && (diff = cmp(near, oldPos)) && (dir < 0 ? diff < 0 : diff > 0))
             { return skipAtomicInner(doc, near, pos, dir, mayClear) }
         }
 
         var far = m.find(dir < 0 ? -1 : 1);
-        if (dir < 0 ? m.inclusiveLeft : m.inclusiveRight)
+        if (dir < 0 ? preventCursorLeft : preventCursorRight)
           { far = movePos(doc, far, dir, far.line == pos.line ? line : null); }
         return far ? skipAtomicInner(doc, far, pos, dir, mayClear) : null
       }
@@ -6576,7 +6598,7 @@
     19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",
     36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",
     46: "Delete", 59: ";", 61: "=", 91: "Mod", 92: "Mod", 93: "Mod",
-    106: "*", 107: "=", 109: "-", 110: ".", 111: "/", 127: "Delete", 145: "ScrollLock",
+    106: "*", 107: "=", 109: "-", 110: ".", 111: "/", 145: "ScrollLock",
     173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
     221: "]", 222: "'", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",
     63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"
@@ -7463,8 +7485,13 @@
     function done(e) {
       cm.state.selectingText = false;
       counter = Infinity;
-      e_preventDefault(e);
-      display.input.focus();
+      // If e is null or undefined we interpret this as someone trying
+      // to explicitly cancel the selection rather than the user
+      // letting go of the mouse button.
+      if (e) {
+        e_preventDefault(e);
+        display.input.focus();
+      }
       off(display.wrapper.ownerDocument, "mousemove", move);
       off(display.wrapper.ownerDocument, "mouseup", up);
       doc.history.lastSelOrigin = null;
@@ -7535,12 +7562,12 @@
     if (mY > lineBox.bottom || !hasHandler(cm, type)) { return e_defaultPrevented(e) }
     mY -= lineBox.top - display.viewOffset;
 
-    for (var i = 0; i < cm.options.gutters.length; ++i) {
+    for (var i = 0; i < cm.display.gutterSpecs.length; ++i) {
       var g = display.gutters.childNodes[i];
       if (g && g.getBoundingClientRect().right >= mX) {
         var line = lineAtHeight(cm.doc, mY);
-        var gutter = cm.options.gutters[i];
-        signal(cm, type, cm, line, gutter, e);
+        var gutter = cm.display.gutterSpecs[i];
+        signal(cm, type, cm, line, gutter.className, e);
         return e_defaultPrevented(e)
       }
     }
@@ -7624,7 +7651,7 @@
       for (var i = newBreaks.length - 1; i >= 0; i--)
         { replaceRange(cm.doc, val, newBreaks[i], Pos(newBreaks[i].line, newBreaks[i].ch + val.length)); }
     });
-    option("specialChars", /[\u0000-\u001f\u007f-\u009f\u00ad\u061c\u200b-\u200f\u2028\u2029\ufeff]/g, function (cm, val, old) {
+    option("specialChars", /[\u0000-\u001f\u007f-\u009f\u00ad\u061c\u200b-\u200f\u2028\u2029\ufeff\ufff9-\ufffc]/g, function (cm, val, old) {
       cm.state.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g");
       if (old != Init) { cm.refresh(); }
     });
@@ -7634,12 +7661,14 @@
       throw new Error("inputStyle can not (yet) be changed in a running editor") // FIXME
     }, true);
     option("spellcheck", false, function (cm, val) { return cm.getInputField().spellcheck = val; }, true);
+    option("autocorrect", false, function (cm, val) { return cm.getInputField().autocorrect = val; }, true);
+    option("autocapitalize", false, function (cm, val) { return cm.getInputField().autocapitalize = val; }, true);
     option("rtlMoveVisually", !windows);
     option("wholeLineUpdateBefore", true);
 
     option("theme", "default", function (cm) {
       themeChanged(cm);
-      guttersChanged(cm);
+      updateGutters(cm);
     }, true);
     option("keyMap", "default", function (cm, val, old) {
       var next = getKeyMap(val);
@@ -7651,9 +7680,9 @@
     option("configureMouse", null);
 
     option("lineWrapping", false, wrappingChanged, true);
-    option("gutters", [], function (cm) {
-      setGuttersForLineNumbers(cm.options);
-      guttersChanged(cm);
+    option("gutters", [], function (cm, val) {
+      cm.display.gutterSpecs = getGutters(val, cm.options.lineNumbers);
+      updateGutters(cm);
     }, true);
     option("fixedGutter", true, function (cm, val) {
       cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";
@@ -7666,12 +7695,12 @@
       cm.display.scrollbars.setScrollTop(cm.doc.scrollTop);
       cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft);
     }, true);
-    option("lineNumbers", false, function (cm) {
-      setGuttersForLineNumbers(cm.options);
-      guttersChanged(cm);
+    option("lineNumbers", false, function (cm, val) {
+      cm.display.gutterSpecs = getGutters(cm.options.gutters, val);
+      updateGutters(cm);
     }, true);
-    option("firstLineNumber", 1, guttersChanged, true);
-    option("lineNumberFormatter", function (integer) { return integer; }, guttersChanged, true);
+    option("firstLineNumber", 1, updateGutters, true);
+    option("lineNumberFormatter", function (integer) { return integer; }, updateGutters, true);
     option("showCursorWhenSelecting", false, updateSelection, true);
 
     option("resetSelectionOnContextMenu", true);
@@ -7713,12 +7742,6 @@
     option("phrases", null);
   }
 
-  function guttersChanged(cm) {
-    updateGutters(cm);
-    regChange(cm);
-    alignHorizontally(cm);
-  }
-
   function dragDropChanged(cm, value, old) {
     var wasOn = old && old != Init;
     if (!value != !wasOn) {
@@ -7758,7 +7781,6 @@
     this.options = options = options ? copyObj(options) : {};
     // Determine effective options based on given values and defaults.
     copyObj(defaults, options, false);
-    setGuttersForLineNumbers(options);
 
     var doc = options.value;
     if (typeof doc == "string") { doc = new Doc(doc, options.mode, null, options.lineSeparator, options.direction); }
@@ -7766,9 +7788,8 @@
     this.doc = doc;
 
     var input = new CodeMirror.inputStyles[options.inputStyle](this);
-    var display = this.display = new Display(place, doc, input);
+    var display = this.display = new Display(place, doc, input, options);
     display.wrapper.CodeMirror = this;
-    updateGutters(this);
     themeChanged(this);
     if (options.lineWrapping)
       { this.display.wrapper.className += " CodeMirror-wrap"; }
@@ -7782,7 +7803,7 @@
       delayingBlurEvent: false,
       focused: false,
       suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
-      pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in input.poll
+      pasteIncoming: -1, cutIncoming: -1, // help recognize paste/cut edits in input.poll
       selectingText: false,
       draggingText: false,
       highlight: new Delayed(), // stores highlight worker timeout
@@ -8015,7 +8036,8 @@
     cm.display.shift = false;
     if (!sel) { sel = doc.sel; }
 
-    var paste = cm.state.pasteIncoming || origin == "paste";
+    var recent = +new Date - 200;
+    var paste = origin == "paste" || cm.state.pasteIncoming > recent;
     var textLines = splitLinesAuto(inserted), multiPaste = null;
     // When pasting N lines into N selections, insert one line per selection
     if (paste && sel.ranges.length > 1) {
@@ -8044,7 +8066,7 @@
           { from = to = Pos(from.line, 0); }
       }
       var changeEvent = {from: from, to: to, text: multiPaste ? multiPaste[i$1 % multiPaste.length] : textLines,
-                         origin: origin || (paste ? "paste" : cm.state.cutIncoming ? "cut" : "+input")};
+                         origin: origin || (paste ? "paste" : cm.state.cutIncoming > recent ? "cut" : "+input")};
       makeChange(cm.doc, changeEvent);
       signalLater(cm, "inputRead", cm, changeEvent);
     }
@@ -8054,7 +8076,7 @@
     ensureCursorVisible(cm);
     if (cm.curOp.updateInput < 2) { cm.curOp.updateInput = updateInput; }
     cm.curOp.typing = true;
-    cm.state.pasteIncoming = cm.state.cutIncoming = false;
+    cm.state.pasteIncoming = cm.state.cutIncoming = -1;
   }
 
   function handlePaste(e, cm) {
@@ -8102,9 +8124,9 @@
     return {text: text, ranges: ranges}
   }
 
-  function disableBrowserMagic(field, spellcheck) {
-    field.setAttribute("autocorrect", "off");
-    field.setAttribute("autocapitalize", "off");
+  function disableBrowserMagic(field, spellcheck, autocorrect, autocapitalize) {
+    field.setAttribute("autocorrect", autocorrect ? "" : "off");
+    field.setAttribute("autocapitalize", autocapitalize ? "" : "off");
     field.setAttribute("spellcheck", !!spellcheck);
   }
 
@@ -8520,7 +8542,7 @@
         this.curOp.forceUpdate = true;
         clearCaches(this);
         scrollToCoords(this, this.doc.scrollLeft, this.doc.scrollTop);
-        updateGutterSpace(this);
+        updateGutterSpace(this.display);
         if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5)
           { estimateLineHeights(this); }
         signal(this, "refresh", this);
@@ -8529,6 +8551,8 @@
       swapDoc: methodOp(function(doc) {
         var old = this.doc;
         old.cm = null;
+        // Cancel the current text selection if any (#5821)
+        if (this.state.selectingText) { this.state.selectingText(); }
         attachDoc(this, doc);
         clearCaches(this);
         this.display.input.reset();
@@ -8665,7 +8689,7 @@
 
     var input = this, cm = input.cm;
     var div = input.div = display.lineDiv;
-    disableBrowserMagic(div, cm.options.spellcheck);
+    disableBrowserMagic(div, cm.options.spellcheck, cm.options.autocorrect, cm.options.autocapitalize);
 
     on(div, "paste", function (e) {
       if (signalDOMEvent(cm, e) || handlePaste(e, cm)) { return }
@@ -8874,7 +8898,7 @@
     // Because Android doesn't allow us to actually detect backspace
     // presses in a sane way, this code checks for when that happens
     // and simulates a backspace press in this case.
-    if (android && chrome && this.cm.options.gutters.length && isInGutter(sel.anchorNode)) {
+    if (android && chrome && this.cm.display.gutterSpecs.length && isInGutter(sel.anchorNode)) {
       this.cm.triggerOnKeyDown({type: "keydown", keyCode: 8, preventDefault: Math.abs});
       this.blur();
       this.focus();
@@ -9205,7 +9229,7 @@
     on(te, "paste", function (e) {
       if (signalDOMEvent(cm, e) || handlePaste(e, cm)) { return }
 
-      cm.state.pasteIncoming = true;
+      cm.state.pasteIncoming = +new Date;
       input.fastPoll();
     });
 
@@ -9226,15 +9250,23 @@
           selectInput(te);
         }
       }
-      if (e.type == "cut") { cm.state.cutIncoming = true; }
+      if (e.type == "cut") { cm.state.cutIncoming = +new Date; }
     }
     on(te, "cut", prepareCopyCut);
     on(te, "copy", prepareCopyCut);
 
     on(display.scroller, "paste", function (e) {
       if (eventInWidget(display, e) || signalDOMEvent(cm, e)) { return }
-      cm.state.pasteIncoming = true;
-      input.focus();
+      if (!te.dispatchEvent) {
+        cm.state.pasteIncoming = +new Date;
+        input.focus();
+        return
+      }
+
+      // Pass the `paste` event to the textarea so it's handled by its event listener.
+      var event = new Event("paste");
+      event.clipboardData = e.clipboardData;
+      te.dispatchEvent(event);
     });
 
     // Prevent normal selection in the editor (we handle our own)
@@ -9425,6 +9457,7 @@
 
   TextareaInput.prototype.onContextMenu = function (e) {
     var input = this, cm = input.cm, display = cm.display, te = input.textarea;
+    if (input.contextMenuPending) { input.contextMenuPending(); }
     var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
     if (!pos || presto) { return } // Opera is difficult.
 
@@ -9435,8 +9468,8 @@
       { operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll); }
 
     var oldCSS = te.style.cssText, oldWrapperCSS = input.wrapper.style.cssText;
-    input.wrapper.style.cssText = "position: absolute";
-    var wrapperBox = input.wrapper.getBoundingClientRect();
+    var wrapperBox = input.wrapper.offsetParent.getBoundingClientRect();
+    input.wrapper.style.cssText = "position: static";
     te.style.cssText = "position: absolute; width: 30px; height: 30px;\n      top: " + (e.clientY - wrapperBox.top - 5) + "px; left: " + (e.clientX - wrapperBox.left - 5) + "px;\n      z-index: 1000; background: " + (ie ? "rgba(255, 255, 255, .05)" : "transparent") + ";\n      outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";
     var oldScrollY;
     if (webkit) { oldScrollY = window.scrollY; } // Work around Chrome issue (#2712)
@@ -9445,7 +9478,7 @@
     display.input.reset();
     // Adds "Select all" to context menu in FF
     if (!cm.somethingSelected()) { te.value = input.prevInput = " "; }
-    input.contextMenuPending = true;
+    input.contextMenuPending = rehide;
     display.selForContextMenu = cm.doc.sel;
     clearTimeout(display.detectingSelectAll);
 
@@ -9466,6 +9499,7 @@
       }
     }
     function rehide() {
+      if (input.contextMenuPending != rehide) { return }
       input.contextMenuPending = false;
       input.wrapper.style.cssText = oldWrapperCSS;
       te.style.cssText = oldCSS;
@@ -9655,7 +9689,7 @@
 
   addLegacyProps(CodeMirror);
 
-  CodeMirror.version = "5.42.1";
+  CodeMirror.version = "5.48.1";
 
   return CodeMirror;
 
diff --git a/front_end/cm/foldcode.js b/front_end/cm/foldcode.js
index 0727bf48e5..e146fb9f3e 100644
--- a/front_end/cm/foldcode.js
+++ b/front_end/cm/foldcode.js
@@ -1,155 +1,152 @@
 // CodeMirror, copyright (c) by Marijn Haverbeke and others
-// Distributed under an MIT license: http://codemirror.net/LICENSE
+// Distributed under an MIT license: https://codemirror.net/LICENSE
 
 (function(mod) {
-if (typeof exports == 'object' && typeof module == 'object')  // CommonJS
-  mod(require('../../lib/codemirror'));
-else if (typeof define == 'function' && define.amd)  // AMD
-  define(['../../lib/codemirror'], mod);
-else  // Plain browser env
-  mod(CodeMirror);
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
 })(function(CodeMirror) {
-'use strict';
-
-function doFold(cm, pos, options, force) {
-  if (options && options.call) {
-    var finder = options;
-    options = null;
-  } else {
-    var finder = getOption(cm, options, 'rangeFinder');
-  }
-  if (typeof pos == 'number')
-    pos = CodeMirror.Pos(pos, 0);
-  var minSize = getOption(cm, options, 'minFoldSize');
-
-  function getRange(allowFolded) {
-    var range = finder(cm, pos);
-    if (!range || range.to.line - range.from.line < minSize)
-      return null;
-    var marks = cm.findMarksAt(range.from);
-    for (var i = 0; i < marks.length; ++i) {
-      if (marks[i].__isFold && force !== 'fold') {
-        if (!allowFolded)
-          return null;
-        range.cleared = true;
-        marks[i].clear();
+  "use strict";
+
+  function doFold(cm, pos, options, force) {
+    if (options && options.call) {
+      var finder = options;
+      options = null;
+    } else {
+      var finder = getOption(cm, options, "rangeFinder");
+    }
+    if (typeof pos == "number") pos = CodeMirror.Pos(pos, 0);
+    var minSize = getOption(cm, options, "minFoldSize");
+
+    function getRange(allowFolded) {
+      var range = finder(cm, pos);
+      if (!range || range.to.line - range.from.line < minSize) return null;
+      var marks = cm.findMarksAt(range.from);
+      for (var i = 0; i < marks.length; ++i) {
+        if (marks[i].__isFold && force !== "fold") {
+          if (!allowFolded) return null;
+          range.cleared = true;
+          marks[i].clear();
+        }
       }
+      return range;
     }
-    return range;
-  }
 
-  var range = getRange(true);
-  if (getOption(cm, options, 'scanUp'))
-    while (!range && pos.line > cm.firstLine()) {
+    var range = getRange(true);
+    if (getOption(cm, options, "scanUp")) while (!range && pos.line > cm.firstLine()) {
       pos = CodeMirror.Pos(pos.line - 1, 0);
       range = getRange(false);
     }
-  if (!range || range.cleared || force === 'unfold')
-    return;
+    if (!range || range.cleared || force === "unfold") return;
+
+    var myWidget = makeWidget(cm, options);
+    CodeMirror.on(myWidget, "mousedown", function(e) {
+      myRange.clear();
+      CodeMirror.e_preventDefault(e);
+    });
+    var myRange = cm.markText(range.from, range.to, {
+      replacedWith: myWidget,
+      clearOnEnter: getOption(cm, options, "clearOnEnter"),
+      __isFold: true
+    });
+    myRange.on("clear", function(from, to) {
+      CodeMirror.signal(cm, "unfold", cm, from, to);
+    });
+    CodeMirror.signal(cm, "fold", cm, range.from, range.to);
+  }
 
-  var myWidget = makeWidget(cm, options);
-  CodeMirror.on(myWidget, 'mousedown', function(e) {
-    myRange.clear();
-    CodeMirror.e_preventDefault(e);
-  });
-  var myRange = cm.markText(
-      range.from, range.to,
-      {replacedWith: myWidget, clearOnEnter: getOption(cm, options, 'clearOnEnter'), __isFold: true});
-  myRange.on('clear', function(from, to) {
-    CodeMirror.signal(cm, 'unfold', cm, from, to);
-  });
-  CodeMirror.signal(cm, 'fold', cm, range.from, range.to);
-}
-
-function makeWidget(cm, options) {
-  var widget = getOption(cm, options, 'widget');
-  if (typeof widget == 'string') {
-    var text = document.createTextNode(widget);
-    widget = document.createElement('span');
-    widget.appendChild(text);
-    widget.className = 'CodeMirror-foldmarker';
-  } else if (widget) {
-    widget = widget.cloneNode(true)
+  function makeWidget(cm, options) {
+    var widget = getOption(cm, options, "widget");
+    if (typeof widget == "string") {
+      var text = document.createTextNode(widget);
+      widget = document.createElement("span");
+      widget.appendChild(text);
+      widget.className = "CodeMirror-foldmarker";
+    } else if (widget) {
+      widget = widget.cloneNode(true)
+    }
+    return widget;
   }
-  return widget;
-}
 
-// Clumsy backwards-compatible interface
-CodeMirror.newFoldFunction = function(rangeFinder, widget) {
-  return function(cm, pos) {
-    doFold(cm, pos, {rangeFinder: rangeFinder, widget: widget});
+  // Clumsy backwards-compatible interface
+  CodeMirror.newFoldFunction = function(rangeFinder, widget) {
+    return function(cm, pos) { doFold(cm, pos, {rangeFinder: rangeFinder, widget: widget}); };
   };
-};
 
-// New-style interface
-CodeMirror.defineExtension('foldCode', function(pos, options, force) {
-  doFold(this, pos, options, force);
-});
-
-CodeMirror.defineExtension('isFolded', function(pos) {
-  var marks = this.findMarksAt(pos);
-  for (var i = 0; i < marks.length; ++i)
-    if (marks[i].__isFold)
-      return true;
-});
-
-CodeMirror.commands.toggleFold = function(cm) {
-  cm.foldCode(cm.getCursor());
-};
-CodeMirror.commands.fold = function(cm) {
-  cm.foldCode(cm.getCursor(), null, 'fold');
-};
-CodeMirror.commands.unfold = function(cm) {
-  cm.foldCode(cm.getCursor(), null, 'unfold');
-};
-CodeMirror.commands.foldAll = function(cm) {
-  cm.operation(function() {
-    for (var i = cm.firstLine(), e = cm.lastLine(); i <= e; i++)
-      cm.foldCode(CodeMirror.Pos(i, 0), null, 'fold');
+  // New-style interface
+  CodeMirror.defineExtension("foldCode", function(pos, options, force) {
+    doFold(this, pos, options, force);
   });
-};
-CodeMirror.commands.unfoldAll = function(cm) {
-  cm.operation(function() {
-    for (var i = cm.firstLine(), e = cm.lastLine(); i <= e; i++)
-      cm.foldCode(CodeMirror.Pos(i, 0), null, 'unfold');
+
+  CodeMirror.defineExtension("isFolded", function(pos) {
+    var marks = this.findMarksAt(pos);
+    for (var i = 0; i < marks.length; ++i)
+      if (marks[i].__isFold) return true;
   });
-};
-
-CodeMirror.registerHelper('fold', 'combine', function() {
-  var funcs = Array.prototype.slice.call(arguments, 0);
-  return function(cm, start) {
-    for (var i = 0; i < funcs.length; ++i) {
-      var found = funcs[i](cm, start);
-      if (found)
-        return found;
-    }
+
+  CodeMirror.commands.toggleFold = function(cm) {
+    cm.foldCode(cm.getCursor());
+  };
+  CodeMirror.commands.fold = function(cm) {
+    cm.foldCode(cm.getCursor(), null, "fold");
+  };
+  CodeMirror.commands.unfold = function(cm) {
+    cm.foldCode(cm.getCursor(), null, "unfold");
+  };
+  CodeMirror.commands.foldAll = function(cm) {
+    cm.operation(function() {
+      for (var i = cm.firstLine(), e = cm.lastLine(); i <= e; i++)
+        cm.foldCode(CodeMirror.Pos(i, 0), null, "fold");
+    });
+  };
+  CodeMirror.commands.unfoldAll = function(cm) {
+    cm.operation(function() {
+      for (var i = cm.firstLine(), e = cm.lastLine(); i <= e; i++)
+        cm.foldCode(CodeMirror.Pos(i, 0), null, "unfold");
+    });
   };
-});
 
-CodeMirror.registerHelper('fold', 'auto', function(cm, start) {
-  var helpers = cm.getHelpers(start, 'fold');
-  for (var i = 0; i < helpers.length; i++) {
-    var cur = helpers[i](cm, start);
-    if (cur)
-      return cur;
-  }
-});
+  CodeMirror.registerHelper("fold", "combine", function() {
+    var funcs = Array.prototype.slice.call(arguments, 0);
+    return function(cm, start) {
+      for (var i = 0; i < funcs.length; ++i) {
+        var found = funcs[i](cm, start);
+        if (found) return found;
+      }
+    };
+  });
 
-var defaultOptions =
-    {rangeFinder: CodeMirror.fold.auto, widget: '\u2194', minFoldSize: 0, scanUp: false, clearOnEnter: true};
+  CodeMirror.registerHelper("fold", "auto", function(cm, start) {
+    var helpers = cm.getHelpers(start, "fold");
+    for (var i = 0; i < helpers.length; i++) {
+      var cur = helpers[i](cm, start);
+      if (cur) return cur;
+    }
+  });
 
-CodeMirror.defineOption('foldOptions', null);
+  var defaultOptions = {
+    rangeFinder: CodeMirror.fold.auto,
+    widget: "\u2194",
+    minFoldSize: 0,
+    scanUp: false,
+    clearOnEnter: true
+  };
 
-function getOption(cm, options, name) {
-  if (options && options[name] !== undefined)
-    return options[name];
-  var editorOptions = cm.options.foldOptions;
-  if (editorOptions && editorOptions[name] !== undefined)
-    return editorOptions[name];
-  return defaultOptions[name];
-}
+  CodeMirror.defineOption("foldOptions", null);
 
-CodeMirror.defineExtension('foldOption', function(options, name) {
-  return getOption(this, options, name);
+  function getOption(cm, options, name) {
+    if (options && options[name] !== undefined)
+      return options[name];
+    var editorOptions = cm.options.foldOptions;
+    if (editorOptions && editorOptions[name] !== undefined)
+      return editorOptions[name];
+    return defaultOptions[name];
+  }
+
+  CodeMirror.defineExtension("foldOption", function(options, name) {
+    return getOption(this, options, name);
+  });
 });
-});
\ No newline at end of file
diff --git a/front_end/cm/foldgutter.js b/front_end/cm/foldgutter.js
index 979bccea90..988c67c450 100644
--- a/front_end/cm/foldgutter.js
+++ b/front_end/cm/foldgutter.js
@@ -1,162 +1,146 @@
 // CodeMirror, copyright (c) by Marijn Haverbeke and others
-// Distributed under an MIT license: http://codemirror.net/LICENSE
+// Distributed under an MIT license: https://codemirror.net/LICENSE
 
 (function(mod) {
-if (typeof exports == 'object' && typeof module == 'object')  // CommonJS
-  mod(require('../../lib/codemirror'), require('./foldcode'));
-else if (typeof define == 'function' && define.amd)  // AMD
-  define(['../../lib/codemirror', './foldcode'], mod);
-else  // Plain browser env
-  mod(CodeMirror);
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"), require("./foldcode"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror", "./foldcode"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
 })(function(CodeMirror) {
-'use strict';
+  "use strict";
 
-CodeMirror.defineOption('foldGutter', false, function(cm, val, old) {
-  if (old && old != CodeMirror.Init) {
-    cm.clearGutter(cm.state.foldGutter.options.gutter);
-    cm.state.foldGutter = null;
-    cm.off('gutterClick', onGutterClick);
-    cm.off('change', onChange);
-    cm.off('viewportChange', onViewportChange);
-    cm.off('fold', onFold);
-    cm.off('unfold', onFold);
-    cm.off('swapDoc', onChange);
-  }
-  if (val) {
-    cm.state.foldGutter = new State(parseOptions(val));
-    updateInViewport(cm);
-    cm.on('gutterClick', onGutterClick);
-    cm.on('change', onChange);
-    cm.on('viewportChange', onViewportChange);
-    cm.on('fold', onFold);
-    cm.on('unfold', onFold);
-    cm.on('swapDoc', onChange);
-  }
-});
-
-var Pos = CodeMirror.Pos;
+  CodeMirror.defineOption("foldGutter", false, function(cm, val, old) {
+    if (old && old != CodeMirror.Init) {
+      cm.clearGutter(cm.state.foldGutter.options.gutter);
+      cm.state.foldGutter = null;
+      cm.off("gutterClick", onGutterClick);
+      cm.off("change", onChange);
+      cm.off("viewportChange", onViewportChange);
+      cm.off("fold", onFold);
+      cm.off("unfold", onFold);
+      cm.off("swapDoc", onChange);
+    }
+    if (val) {
+      cm.state.foldGutter = new State(parseOptions(val));
+      updateInViewport(cm);
+      cm.on("gutterClick", onGutterClick);
+      cm.on("change", onChange);
+      cm.on("viewportChange", onViewportChange);
+      cm.on("fold", onFold);
+      cm.on("unfold", onFold);
+      cm.on("swapDoc", onChange);
+    }
+  });
 
-function State(options) {
-  this.options = options;
-  this.from = this.to = 0;
-}
+  var Pos = CodeMirror.Pos;
 
-function parseOptions(opts) {
-  if (opts === true)
-    opts = {};
-  if (opts.gutter == null)
-    opts.gutter = 'CodeMirror-foldgutter';
-  if (opts.indicatorOpen == null)
-    opts.indicatorOpen = 'CodeMirror-foldgutter-open';
-  if (opts.indicatorFolded == null)
-    opts.indicatorFolded = 'CodeMirror-foldgutter-folded';
-  return opts;
-}
+  function State(options) {
+    this.options = options;
+    this.from = this.to = 0;
+  }
 
-function isFolded(cm, line) {
-  var marks = cm.findMarks(Pos(line, 0), Pos(line + 1, 0));
-  for (var i = 0; i < marks.length; ++i)
-    if (marks[i].__isFold && marks[i].find().from.line == line)
-      return marks[i];
-}
+  function parseOptions(opts) {
+    if (opts === true) opts = {};
+    if (opts.gutter == null) opts.gutter = "CodeMirror-foldgutter";
+    if (opts.indicatorOpen == null) opts.indicatorOpen = "CodeMirror-foldgutter-open";
+    if (opts.indicatorFolded == null) opts.indicatorFolded = "CodeMirror-foldgutter-folded";
+    return opts;
+  }
 
-function marker(spec) {
-  if (typeof spec == 'string') {
-    var elt = document.createElement('div');
-    elt.className = spec + ' CodeMirror-guttermarker-subtle';
-    return elt;
-  } else {
-    return spec.cloneNode(true);
+  function isFolded(cm, line) {
+    var marks = cm.findMarks(Pos(line, 0), Pos(line + 1, 0));
+    for (var i = 0; i < marks.length; ++i)
+      if (marks[i].__isFold && marks[i].find().from.line == line) return marks[i];
   }
-}
 
-function updateFoldInfo(cm, from, to) {
-  var opts = cm.state.foldGutter.options, cur = from;
-  var minSize = cm.foldOption(opts, 'minFoldSize');
-  var func = cm.foldOption(opts, 'rangeFinder');
-  cm.eachLine(from, to, function(line) {
-    var mark = null;
-    if (isFolded(cm, cur)) {
-      mark = marker(opts.indicatorFolded);
+  function marker(spec) {
+    if (typeof spec == "string") {
+      var elt = document.createElement("div");
+      elt.className = spec + " CodeMirror-guttermarker-subtle";
+      return elt;
     } else {
-      var pos = Pos(cur, 0);
-      var range = func && func(cm, pos);
-      if (range && range.to.line - range.from.line >= minSize)
-        mark = marker(opts.indicatorOpen);
+      return spec.cloneNode(true);
     }
-    cm.setGutterMarker(line, opts.gutter, mark);
-    ++cur;
-  });
-}
+  }
 
-function updateInViewport(cm) {
-  var vp = cm.getViewport(), state = cm.state.foldGutter;
-  if (!state)
-    return;
-  cm.operation(function() {
-    updateFoldInfo(cm, vp.from, vp.to);
-  });
-  state.from = vp.from;
-  state.to = vp.to;
-}
+  function updateFoldInfo(cm, from, to) {
+    var opts = cm.state.foldGutter.options, cur = from;
+    var minSize = cm.foldOption(opts, "minFoldSize");
+    var func = cm.foldOption(opts, "rangeFinder");
+    cm.eachLine(from, to, function(line) {
+      var mark = null;
+      if (isFolded(cm, cur)) {
+        mark = marker(opts.indicatorFolded);
+      } else {
+        var pos = Pos(cur, 0);
+        var range = func && func(cm, pos);
+        if (range && range.to.line - range.from.line >= minSize)
+          mark = marker(opts.indicatorOpen);
+      }
+      cm.setGutterMarker(line, opts.gutter, mark);
+      ++cur;
+    });
+  }
 
-function onGutterClick(cm, line, gutter) {
-  var state = cm.state.foldGutter;
-  if (!state)
-    return;
-  var opts = state.options;
-  if (gutter != opts.gutter)
-    return;
-  var folded = isFolded(cm, line);
-  if (folded)
-    folded.clear();
-  else
-    cm.foldCode(Pos(line, 0), opts.rangeFinder);
-}
+  function updateInViewport(cm) {
+    var vp = cm.getViewport(), state = cm.state.foldGutter;
+    if (!state) return;
+    cm.operation(function() {
+      updateFoldInfo(cm, vp.from, vp.to);
+    });
+    state.from = vp.from; state.to = vp.to;
+  }
 
-function onChange(cm) {
-  var state = cm.state.foldGutter;
-  if (!state)
-    return;
-  var opts = state.options;
-  state.from = state.to = 0;
-  clearTimeout(state.changeUpdate);
-  state.changeUpdate = setTimeout(function() {
-    updateInViewport(cm);
-  }, opts.foldOnChangeTimeSpan || 600);
-}
+  function onGutterClick(cm, line, gutter) {
+    var state = cm.state.foldGutter;
+    if (!state) return;
+    var opts = state.options;
+    if (gutter != opts.gutter) return;
+    var folded = isFolded(cm, line);
+    if (folded) folded.clear();
+    else cm.foldCode(Pos(line, 0), opts.rangeFinder);
+  }
 
-function onViewportChange(cm) {
-  var state = cm.state.foldGutter;
-  if (!state)
-    return;
-  var opts = state.options;
-  clearTimeout(state.changeUpdate);
-  state.changeUpdate = setTimeout(function() {
-    var vp = cm.getViewport();
-    if (state.from == state.to || vp.from - state.to > 20 || state.from - vp.to > 20) {
-      updateInViewport(cm);
-    } else {
-      cm.operation(function() {
-        if (vp.from < state.from) {
-          updateFoldInfo(cm, vp.from, state.from);
-          state.from = vp.from;
-        }
-        if (vp.to > state.to) {
-          updateFoldInfo(cm, state.to, vp.to);
-          state.to = vp.to;
-        }
-      });
-    }
-  }, opts.updateViewportTimeSpan || 400);
-}
+  function onChange(cm) {
+    var state = cm.state.foldGutter;
+    if (!state) return;
+    var opts = state.options;
+    state.from = state.to = 0;
+    clearTimeout(state.changeUpdate);
+    state.changeUpdate = setTimeout(function() { updateInViewport(cm); }, opts.foldOnChangeTimeSpan || 600);
+  }
+
+  function onViewportChange(cm) {
+    var state = cm.state.foldGutter;
+    if (!state) return;
+    var opts = state.options;
+    clearTimeout(state.changeUpdate);
+    state.changeUpdate = setTimeout(function() {
+      var vp = cm.getViewport();
+      if (state.from == state.to || vp.from - state.to > 20 || state.from - vp.to > 20) {
+        updateInViewport(cm);
+      } else {
+        cm.operation(function() {
+          if (vp.from < state.from) {
+            updateFoldInfo(cm, vp.from, state.from);
+            state.from = vp.from;
+          }
+          if (vp.to > state.to) {
+            updateFoldInfo(cm, state.to, vp.to);
+            state.to = vp.to;
+          }
+        });
+      }
+    }, opts.updateViewportTimeSpan || 400);
+  }
 
-function onFold(cm, from) {
-  var state = cm.state.foldGutter;
-  if (!state)
-    return;
-  var line = from.line;
-  if (line >= state.from && line < state.to)
-    updateFoldInfo(cm, line, line + 1);
-}
-});
\ No newline at end of file
+  function onFold(cm, from) {
+    var state = cm.state.foldGutter;
+    if (!state) return;
+    var line = from.line;
+    if (line >= state.from && line < state.to)
+      updateFoldInfo(cm, line, line + 1);
+  }
+});
diff --git a/front_end/cm/matchbrackets.js b/front_end/cm/matchbrackets.js
index 6ad5a01229..2a147282c4 100644
--- a/front_end/cm/matchbrackets.js
+++ b/front_end/cm/matchbrackets.js
@@ -16,18 +16,23 @@
 
   var matching = {"(": ")>", ")": "(<", "[": "]>", "]": "[<", "{": "}>", "}": "{<", "<": ">>", ">": "<<"};
 
+  function bracketRegex(config) {
+    return config && config.bracketRegex || /[(){}[\]]/
+  }
+
   function findMatchingBracket(cm, where, config) {
     var line = cm.getLineHandle(where.line), pos = where.ch - 1;
     var afterCursor = config && config.afterCursor
     if (afterCursor == null)
       afterCursor = /(^| )cm-fat-cursor($| )/.test(cm.getWrapperElement().className)
+    var re = bracketRegex(config)
 
     // A cursor is defined as between two characters, but in in vim command mode
     // (i.e. not insert mode), the cursor is visually represented as a
     // highlighted box on top of the 2nd character. Otherwise, we allow matches
     // from before or after the cursor.
-    var match = (!afterCursor && pos >= 0 && matching[line.text.charAt(pos)]) ||
-        matching[line.text.charAt(++pos)];
+    var match = (!afterCursor && pos >= 0 && re.test(line.text.charAt(pos)) && matching[line.text.charAt(pos)]) ||
+        re.test(line.text.charAt(pos + 1)) && matching[line.text.charAt(++pos)];
     if (!match) return null;
     var dir = match.charAt(1) == ">" ? 1 : -1;
     if (config && config.strict && (dir > 0) != (pos == where.ch)) return null;
@@ -51,7 +56,7 @@
     var maxScanLines = (config && config.maxScanLines) || 1000;
 
     var stack = [];
-    var re = config && config.bracketRegex ? config.bracketRegex : /[(){}[\]<>]/;
+    var re = bracketRegex(config)
     var lineEnd = dir > 0 ? Math.min(where.line + maxScanLines, cm.lastLine() + 1)
                           : Math.max(cm.firstLine() - 1, where.line - maxScanLines);
     for (var lineNo = where.line; lineNo != lineEnd; lineNo += dir) {
@@ -64,7 +69,7 @@
         var ch = line.charAt(pos);
         if (re.test(ch) && (style === undefined || cm.getTokenTypeAt(Pos(lineNo, pos + 1)) == style)) {
           var match = matching[ch];
-          if ((match.charAt(1) == ">") == (dir > 0)) stack.push(ch);
+          if (match && (match.charAt(1) == ">") == (dir > 0)) stack.push(ch);
           else if (!stack.length) return {pos: Pos(lineNo, pos), ch: ch};
           else stack.pop();
         }
diff --git a/front_end/cm/multiplex.js b/front_end/cm/multiplex.js
index 738ea98a0d..93fd9a5a46 100644
--- a/front_end/cm/multiplex.js
+++ b/front_end/cm/multiplex.js
@@ -54,7 +54,7 @@ CodeMirror.multiplexingMode = function(outer /*, others */) {
             // Get the outer indent, making sure to handle CodeMirror.Pass
             var outerIndent = 0;
             if (outer.indent) {
-              var possibleOuterIndent = outer.indent(state.outer, "");
+              var possibleOuterIndent = outer.indent(state.outer, "", "");
               if (possibleOuterIndent !== CodeMirror.Pass) outerIndent = possibleOuterIndent;
             }
 
@@ -96,10 +96,10 @@ CodeMirror.multiplexingMode = function(outer /*, others */) {
       }
     },
 
-    indent: function(state, textAfter) {
+    indent: function(state, textAfter, line) {
       var mode = state.innerActive ? state.innerActive.mode : outer;
       if (!mode.indent) return CodeMirror.Pass;
-      return mode.indent(state.innerActive ? state.inner : state.outer, textAfter);
+      return mode.indent(state.innerActive ? state.inner : state.outer, textAfter, line);
     },
 
     blankLine: function(state) {
@@ -112,7 +112,7 @@ CodeMirror.multiplexingMode = function(outer /*, others */) {
           var other = others[i];
           if (other.open === "\n") {
             state.innerActive = other;
-            state.inner = CodeMirror.startState(other.mode, mode.indent ? mode.indent(state.outer, "") : 0);
+            state.inner = CodeMirror.startState(other.mode, mode.indent ? mode.indent(state.outer, "", "") : 0);
           }
         }
       } else if (state.innerActive.close === "\n") {
diff --git a/front_end/cm/overlay.js b/front_end/cm/overlay.js
index 839d9e552e..016e3c28cc 100644
--- a/front_end/cm/overlay.js
+++ b/front_end/cm/overlay.js
@@ -68,8 +68,8 @@ CodeMirror.overlayMode = function(base, overlay, combine) {
       else return state.overlayCur;
     },
 
-    indent: base.indent && function(state, textAfter) {
-      return base.indent(state.base, textAfter);
+    indent: base.indent && function(state, textAfter, line) {
+      return base.indent(state.base, textAfter, line);
     },
     electricChars: base.electricChars,
 
diff --git a/front_end/cm_modes/clike.js b/front_end/cm_modes/clike.js
index 924a0fc092..4c8b9937d6 100644
--- a/front_end/cm_modes/clike.js
+++ b/front_end/cm_modes/clike.js
@@ -284,7 +284,7 @@ CodeMirror.defineMode("clike", function(config, parserConfig) {
   // and those that end in _t (Reserved by POSIX for types)
   // http://www.gnu.org/software/libc/manual/html_node/Reserved-Names.html
   function cTypes(identifier) {
-    return contains(basicCTypes, identifier) || /.+_t/.test(identifier);
+    return contains(basicCTypes, identifier) || /.+_t$/.test(identifier);
   }
 
   // Returns true if identifier is a "Objective C" type.
@@ -467,7 +467,7 @@ CodeMirror.defineMode("clike", function(config, parserConfig) {
   def("text/x-java", {
     name: "clike",
     keywords: words("abstract assert break case catch class const continue default " +
-                    "do else enum extends final finally float for goto if implements import " +
+                    "do else enum extends final finally for goto if implements import " +
                     "instanceof interface native new package private protected public " +
                     "return static strictfp super switch synchronized this throw throws transient " +
                     "try volatile while @interface"),
diff --git a/front_end/cm_modes/clojure.js b/front_end/cm_modes/clojure.js
index 9823d812c5..25d308ab4c 100644
--- a/front_end/cm_modes/clojure.js
+++ b/front_end/cm_modes/clojure.js
@@ -166,7 +166,7 @@ CodeMirror.defineMode("clojure", function (options) {
   var qualifiedSymbol = /^(?:(?:[^\\\/\[\]\d\s"#'(),;@^`{}~][^\\\[\]\s"(),;@^`{}~]*(?:\.[^\\\/\[\]\d\s"#'(),;@^`{}~][^\\\[\]\s"(),;@^`{}~]*)*\/)?(?:\/|[^\\\/\[\]\d\s"#'(),;@^`{}~][^\\\[\]\s"(),;@^`{}~]*)*(?=[\\\[\]\s"(),;@^`{}~]|$))/;
 
   function base(stream, state) {
-    if (stream.eatSpace()) return ["space", null];
+    if (stream.eatSpace() || stream.eat(",")) return ["space", null];
     if (stream.match(numberLiteral)) return [null, "number"];
     if (stream.match(characterLiteral)) return [null, "string-2"];
     if (stream.eat(/^"/)) return (state.tokenize = inString)(stream, state);
diff --git a/front_end/cm_modes/jsx.js b/front_end/cm_modes/jsx.js
index 2c91beb955..889d3fe5e7 100644
--- a/front_end/cm_modes/jsx.js
+++ b/front_end/cm_modes/jsx.js
@@ -32,7 +32,7 @@
     function flatXMLIndent(state) {
       var tagName = state.tagName
       state.tagName = null
-      var result = xmlMode.indent(state, "")
+      var result = xmlMode.indent(state, "", "")
       state.tagName = tagName
       return result
     }
@@ -105,7 +105,7 @@
     function jsToken(stream, state, cx) {
       if (stream.peek() == "<" && jsMode.expressionAllowed(stream, cx.state)) {
         jsMode.skipExpression(cx.state)
-        state.context = new Context(CodeMirror.startState(xmlMode, jsMode.indent(cx.state, "")),
+        state.context = new Context(CodeMirror.startState(xmlMode, jsMode.indent(cx.state, "", "")),
                                     xmlMode, 0, state.context)
         return null
       }
diff --git a/front_end/cm_modes/php.js b/front_end/cm_modes/php.js
index 80e2f20bf1..5f3a143999 100644
--- a/front_end/cm_modes/php.js
+++ b/front_end/cm_modes/php.js
@@ -160,7 +160,7 @@
       if (!isPHP) {
         if (stream.match(/^<\?\w*/)) {
           state.curMode = phpMode;
-          if (!state.php) state.php = CodeMirror.startState(phpMode, htmlMode.indent(state.html, ""))
+          if (!state.php) state.php = CodeMirror.startState(phpMode, htmlMode.indent(state.html, "", ""))
           state.curState = state.php;
           return "meta";
         }
@@ -213,11 +213,11 @@
 
       token: dispatch,
 
-      indent: function(state, textAfter) {
+      indent: function(state, textAfter, line) {
         if ((state.curMode != phpMode && /^\s*<\//.test(textAfter)) ||
             (state.curMode == phpMode && /^\?>/.test(textAfter)))
-          return htmlMode.indent(state.html, textAfter);
-        return state.curMode.indent(state.curState, textAfter);
+          return htmlMode.indent(state.html, textAfter, line);
+        return state.curMode.indent(state.curState, textAfter, line);
       },
 
       blockCommentStart: "/*",
diff --git a/front_end/cm_modes/python.js b/front_end/cm_modes/python.js
index 1ebe180a97..9745103829 100644
--- a/front_end/cm_modes/python.js
+++ b/front_end/cm_modes/python.js
@@ -44,7 +44,7 @@
     var delimiters = parserConf.delimiters || parserConf.singleDelimiters || /^[\(\)\[\]\{\}@,:`=;\.\\]/;
     //               (Backwards-compatiblity with old, cumbersome config system)
     var operators = [parserConf.singleOperators, parserConf.doubleOperators, parserConf.doubleDelimiters, parserConf.tripleDelimiters,
-                     parserConf.operators || /^([-+*/%\/&|^]=?|[<>=]+|\/\/=?|\*\*=?|!=|[~!@])/]
+                     parserConf.operators || /^([-+*/%\/&|^]=?|[<>=]+|\/\/=?|\*\*=?|!=|[~!@]|\.\.\.)/]
     for (var i = 0; i < operators.length; i++) if (!operators[i]) operators.splice(i--, 1)
 
     var hangingIndent = parserConf.hangingIndent || conf.indentUnit;
@@ -187,23 +187,18 @@
       var singleline = delimiter.length == 1;
       var OUTCLASS = "string";
 
-      function tokenFString(stream, state) {
-        // inside f-str Expression
-        if (stream.match(delimiter)) {
-          // expression ends pre-maturally, but very common in editing
-          // Could show error to remind users to close brace here
-          state.tokenize = tokenString
-          return OUTCLASS;
-        } else if (stream.match('{')) {
-          // starting brace, if not eaten below
-          return "punctuation";
-        } else if (stream.match('}')) {
-          // return to regular inside string state
-          state.tokenize = tokenString
-          return "punctuation";
-        } else {
-          // use tokenBaseInner to parse the expression
-          return tokenBaseInner(stream, state);
+      function tokenNestedExpr(depth) {
+        return function(stream, state) {
+          var inner = tokenBaseInner(stream, state)
+          if (inner == "punctuation") {
+            if (stream.current() == "{") {
+              state.tokenize = tokenNestedExpr(depth + 1)
+            } else if (stream.current() == "}") {
+              if (depth > 1) state.tokenize = tokenNestedExpr(depth - 1)
+              else state.tokenize = tokenString
+            }
+          }
+          return inner
         }
       }
 
@@ -222,14 +217,9 @@
             return OUTCLASS;
           } else if (stream.match('{', false)) {
             // switch to nested mode
-            state.tokenize = tokenFString
-            if (stream.current()) {
-              return OUTCLASS;
-            } else {
-              // need to return something, so eat the starting {
-              stream.next();
-              return "punctuation";
-            }
+            state.tokenize = tokenNestedExpr(0)
+            if (stream.current()) return OUTCLASS;
+            else return state.tokenize(stream, state)
           } else if (stream.match('}}')) {
             return OUTCLASS;
           } else if (stream.match('}')) {
diff --git a/front_end/cm_web_modes/css.js b/front_end/cm_web_modes/css.js
index d82de4045d..05742c5c45 100644
--- a/front_end/cm_web_modes/css.js
+++ b/front_end/cm_web_modes/css.js
@@ -77,12 +77,11 @@ CodeMirror.defineMode("css", function(config, parserConfig) {
       return ret("qualifier", "qualifier");
     } else if (/[:;{}\[\]\(\)]/.test(ch)) {
       return ret(null, ch);
-    } else if (((ch == "u" || ch == "U") && stream.match(/rl(-prefix)?\(/i)) ||
-               ((ch == "d" || ch == "D") && stream.match("omain(", true, true)) ||
-               ((ch == "r" || ch == "R") && stream.match("egexp(", true, true))) {
-      stream.backUp(1);
-      state.tokenize = tokenParenthesized;
-      return ret("property", "word");
+    } else if (stream.match(/[\w-.]+(?=\()/)) {
+      if (/^(url(-prefix)?|domain|regexp)$/.test(stream.current().toLowerCase())) {
+        state.tokenize = tokenParenthesized;
+      }
+      return ret("variable callee", "variable");
     } else if (/[\w\\\-]/.test(ch)) {
       stream.eatWhile(/[\w\\\-]/);
       return ret("property", "word");
diff --git a/front_end/cm_web_modes/htmlmixed.js b/front_end/cm_web_modes/htmlmixed.js
index c992538477..8341ac8261 100644
--- a/front_end/cm_web_modes/htmlmixed.js
+++ b/front_end/cm_web_modes/htmlmixed.js
@@ -105,7 +105,7 @@
           return maybeBackup(stream, endTag, state.localMode.token(stream, state.localState));
         };
         state.localMode = mode;
-        state.localState = CodeMirror.startState(mode, htmlMode.indent(state.htmlState, ""));
+        state.localState = CodeMirror.startState(mode, htmlMode.indent(state.htmlState, "", ""));
       } else if (state.inTag) {
         state.inTag += stream.current()
         if (stream.eol()) state.inTag += " "
@@ -135,7 +135,7 @@
 
       indent: function (state, textAfter, line) {
         if (!state.localMode || /^\s*<\//.test(textAfter))
-          return htmlMode.indent(state.htmlState, textAfter);
+          return htmlMode.indent(state.htmlState, textAfter, line);
         else if (state.localMode.indent)
           return state.localMode.indent(state.localState, textAfter, line);
         else
diff --git a/front_end/cm_web_modes/javascript.js b/front_end/cm_web_modes/javascript.js
index 42b4b191f1..85cb666a04 100644
--- a/front_end/cm_web_modes/javascript.js
+++ b/front_end/cm_web_modes/javascript.js
@@ -67,7 +67,7 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
     if (ch == '"' || ch == "'") {
       state.tokenize = tokenString(ch);
       return state.tokenize(stream, state);
-    } else if (ch == "." && stream.match(/^\d+(?:[eE][+\-]?\d+)?/)) {
+    } else if (ch == "." && stream.match(/^[\d_]+(?:[eE][+\-]?[\d_]+)?/)) {
       return ret("number", "number");
     } else if (ch == "." && stream.match("..")) {
       return ret("spread", "meta");
@@ -75,10 +75,10 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
       return ret(ch);
     } else if (ch == "=" && stream.eat(">")) {
       return ret("=>", "operator");
-    } else if (ch == "0" && stream.match(/^(?:x[\da-f]+|o[0-7]+|b[01]+)n?/i)) {
+    } else if (ch == "0" && stream.match(/^(?:x[\dA-Fa-f_]+|o[0-7_]+|b[01_]+)n?/)) {
       return ret("number", "number");
     } else if (/\d/.test(ch)) {
-      stream.match(/^\d*(?:n|(?:\.\d*)?(?:[eE][+\-]?\d+)?)?/);
+      stream.match(/^[\d_]*(?:n|(?:\.[\d_]*)?(?:[eE][+\-]?[\d_]+)?)?/);
       return ret("number", "number");
     } else if (ch == "/") {
       if (stream.eat("*")) {
@@ -365,7 +365,10 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
     }
     if (type == "function") return cont(functiondef);
     if (type == "for") return cont(pushlex("form"), forspec, statement, poplex);
-    if (type == "class" || (isTS && value == "interface")) { cx.marked = "keyword"; return cont(pushlex("form"), className, poplex); }
+    if (type == "class" || (isTS && value == "interface")) {
+      cx.marked = "keyword"
+      return cont(pushlex("form", type == "class" ? type : value), className, poplex)
+    }
     if (type == "variable") {
       if (isTS && value == "declare") {
         cx.marked = "keyword"
@@ -373,11 +376,11 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
       } else if (isTS && (value == "module" || value == "enum" || value == "type") && cx.stream.match(/^\s*\w/, false)) {
         cx.marked = "keyword"
         if (value == "enum") return cont(enumdef);
-        else if (value == "type") return cont(typeexpr, expect("operator"), typeexpr, expect(";"));
+        else if (value == "type") return cont(typename, expect("operator"), typeexpr, expect(";"));
         else return cont(pushlex("form"), pattern, expect("{"), pushlex("}"), block, poplex, poplex)
       } else if (isTS && value == "namespace") {
         cx.marked = "keyword"
-        return cont(pushlex("form"), expression, block, poplex)
+        return cont(pushlex("form"), expression, statement, poplex)
       } else if (isTS && value == "abstract") {
         cx.marked = "keyword"
         return cont(statement)
@@ -552,6 +555,7 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
         }, proceed);
       }
       if (type == end || value == end) return cont();
+      if (sep && sep.indexOf(";") > -1) return pass(what)
       return cont(expect(end));
     }
     return function(type, value) {
@@ -574,6 +578,9 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
       if (value == "?") return cont(maybetype);
     }
   }
+  function maybetypeOrIn(type, value) {
+    if (isTS && (type == ":" || value == "in")) return cont(typeexpr)
+  }
   function mayberettype(type) {
     if (isTS && type == ":") {
       if (cx.stream.match(/^\s*\w+\s+is\b/, false)) return cont(expression, isKW, typeexpr)
@@ -587,18 +594,19 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
     }
   }
   function typeexpr(type, value) {
-    if (value == "keyof" || value == "typeof") {
+    if (value == "keyof" || value == "typeof" || value == "infer") {
       cx.marked = "keyword"
-      return cont(value == "keyof" ? typeexpr : expressionNoComma)
+      return cont(value == "typeof" ? expressionNoComma : typeexpr)
     }
     if (type == "variable" || value == "void") {
       cx.marked = "type"
       return cont(afterType)
     }
+    if (value == "|" || value == "&") return cont(typeexpr)
     if (type == "string" || type == "number" || type == "atom") return cont(afterType);
     if (type == "[") return cont(pushlex("]"), commasep(typeexpr, "]", ","), poplex, afterType)
     if (type == "{") return cont(pushlex("}"), commasep(typeprop, "}", ",;"), poplex, afterType)
-    if (type == "(") return cont(commasep(typearg, ")"), maybeReturnType)
+    if (type == "(") return cont(commasep(typearg, ")"), maybeReturnType, afterType)
     if (type == "<") return cont(commasep(typeexpr, ">"), typeexpr)
   }
   function maybeReturnType(type) {
@@ -608,24 +616,28 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
     if (type == "variable" || cx.style == "keyword") {
       cx.marked = "property"
       return cont(typeprop)
-    } else if (value == "?") {
+    } else if (value == "?" || type == "number" || type == "string") {
       return cont(typeprop)
     } else if (type == ":") {
       return cont(typeexpr)
     } else if (type == "[") {
-      return cont(expression, maybetype, expect("]"), typeprop)
+      return cont(expect("variable"), maybetypeOrIn, expect("]"), typeprop)
+    } else if (type == "(") {
+      return pass(functiondecl, typeprop)
     }
   }
   function typearg(type, value) {
     if (type == "variable" && cx.stream.match(/^\s*[?:]/, false) || value == "?") return cont(typearg)
     if (type == ":") return cont(typeexpr)
+    if (type == "spread") return cont(typearg)
     return pass(typeexpr)
   }
   function afterType(type, value) {
     if (value == "<") return cont(pushlex(">"), commasep(typeexpr, ">"), poplex, afterType)
     if (value == "|" || type == "." || value == "&") return cont(typeexpr)
-    if (type == "[") return cont(expect("]"), afterType)
+    if (type == "[") return cont(typeexpr, expect("]"), afterType)
     if (value == "extends" || value == "implements") { cx.marked = "keyword"; return cont(typeexpr) }
+    if (value == "?") return cont(typeexpr, expect(":"), typeexpr)
   }
   function maybeTypeArgs(_, value) {
     if (value == "<") return cont(pushlex(">"), commasep(typeexpr, ">"), poplex, afterType)
@@ -672,25 +684,18 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
   }
   function forspec(type, value) {
     if (value == "await") return cont(forspec);
-    if (type == "(") return cont(pushlex(")"), forspec1, expect(")"), poplex);
+    if (type == "(") return cont(pushlex(")"), forspec1, poplex);
   }
   function forspec1(type) {
-    if (type == "var") return cont(vardef, expect(";"), forspec2);
-    if (type == ";") return cont(forspec2);
-    if (type == "variable") return cont(formaybeinof);
-    return pass(expression, expect(";"), forspec2);
-  }
-  function formaybeinof(_type, value) {
-    if (value == "in" || value == "of") { cx.marked = "keyword"; return cont(expression); }
-    return cont(maybeoperatorComma, forspec2);
+    if (type == "var") return cont(vardef, forspec2);
+    if (type == "variable") return cont(forspec2);
+    return pass(forspec2)
   }
   function forspec2(type, value) {
-    if (type == ";") return cont(forspec3);
-    if (value == "in" || value == "of") { cx.marked = "keyword"; return cont(expression); }
-    return pass(expression, expect(";"), forspec3);
-  }
-  function forspec3(type) {
-    if (type != ")") cont(expression);
+    if (type == ")") return cont()
+    if (type == ";") return cont(forspec2)
+    if (value == "in" || value == "of") { cx.marked = "keyword"; return cont(expression, forspec2) }
+    return pass(expression, forspec2)
   }
   function functiondef(type, value) {
     if (value == "*") {cx.marked = "keyword"; return cont(functiondef);}
@@ -698,10 +703,25 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
     if (type == "(") return cont(pushcontext, pushlex(")"), commasep(funarg, ")"), poplex, mayberettype, statement, popcontext);
     if (isTS && value == "<") return cont(pushlex(">"), commasep(typeparam, ">"), poplex, functiondef)
   }
+  function functiondecl(type, value) {
+    if (value == "*") {cx.marked = "keyword"; return cont(functiondecl);}
+    if (type == "variable") {register(value); return cont(functiondecl);}
+    if (type == "(") return cont(pushcontext, pushlex(")"), commasep(funarg, ")"), poplex, mayberettype, popcontext);
+    if (isTS && value == "<") return cont(pushlex(">"), commasep(typeparam, ">"), poplex, functiondecl)
+  }
+  function typename(type, value) {
+    if (type == "keyword" || type == "variable") {
+      cx.marked = "type"
+      return cont(typename)
+    } else if (value == "<") {
+      return cont(pushlex(">"), commasep(typeparam, ">"), poplex)
+    }
+  }
   function funarg(type, value) {
     if (value == "@") cont(expression, funarg)
     if (type == "spread") return cont(funarg);
     if (isTS && isModifier(value)) { cx.marked = "keyword"; return cont(funarg); }
+    if (isTS && type == "this") return cont(maybetype, maybeAssign)
     return pass(pattern, maybetype, maybeAssign);
   }
   function classExpression(type, value) {
@@ -732,13 +752,15 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
       cx.marked = "property";
       return cont(isTS ? classfield : functiondef, classBody);
     }
+    if (type == "number" || type == "string") return cont(isTS ? classfield : functiondef, classBody);
     if (type == "[")
       return cont(expression, maybetype, expect("]"), isTS ? classfield : functiondef, classBody)
     if (value == "*") {
       cx.marked = "keyword";
       return cont(classBody);
     }
-    if (type == ";") return cont(classBody);
+    if (isTS && type == "(") return pass(functiondecl, classBody)
+    if (type == ";" || type == ",") return cont(classBody);
     if (type == "}") return cont();
     if (value == "@") return cont(expression, classBody)
   }
@@ -746,7 +768,8 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
     if (value == "?") return cont(classfield)
     if (type == ":") return cont(typeexpr, maybeAssign)
     if (value == "=") return cont(expressionNoComma)
-    return pass(functiondef)
+    var context = cx.state.lexical.prev, isInterface = context && context.info == "interface"
+    return pass(isInterface ? functiondecl : functiondef)
   }
   function afterExport(type, value) {
     if (value == "*") { cx.marked = "keyword"; return cont(maybeFrom, expect(";")); }
diff --git a/front_end/emulation/GeolocationsSettingsTab.js b/front_end/emulation/GeolocationsSettingsTab.js
index 9229d7237d..1f1b28288c 100644
--- a/front_end/emulation/GeolocationsSettingsTab.js
+++ b/front_end/emulation/GeolocationsSettingsTab.js
@@ -26,7 +26,6 @@ Emulation.GeolocationsSettingsTab = class extends UI.VBox {
     this._customSetting.addChangeListener(this._geolocationsUpdated, this);
 
     this.setDefaultFocusedElement(addButton);
-    this.contentElement.tabIndex = 0;
   }
 
   /**
@@ -137,15 +136,15 @@ Emulation.GeolocationsSettingsTab = class extends UI.VBox {
 
     const fields = content.createChild('div', 'geolocations-edit-row');
     fields.createChild('div', 'geolocations-list-text geolocations-list-title')
-        .appendChild(editor.createInput('title', 'text', '', titleValidator));
+        .appendChild(editor.createInput('title', 'text', ls`Location name`, titleValidator));
     fields.createChild('div', 'geolocations-list-separator geolocations-list-separator-invisible');
 
     let cell = fields.createChild('div', 'geolocations-list-text');
-    cell.appendChild(editor.createInput('lat', 'text', '', latValidator));
+    cell.appendChild(editor.createInput('lat', 'text', ls`Latitude`, latValidator));
     fields.createChild('div', 'geolocations-list-separator geolocations-list-separator-invisible');
 
     cell = fields.createChild('div', 'geolocations-list-text');
-    cell.appendChild(editor.createInput('long', 'text', '', longValidator));
+    cell.appendChild(editor.createInput('long', 'text', ls`Longitude`, longValidator));
 
     return editor;
 
@@ -156,9 +155,18 @@ Emulation.GeolocationsSettingsTab = class extends UI.VBox {
      * @return {!UI.ListWidget.ValidatorResult}
      */
     function titleValidator(item, index, input) {
+      const maxLength = 50;
       const value = input.value.trim();
-      const valid = value.length > 0 && value.length < 50;
-      return {valid};
+
+      let errorMessage;
+      if (!value.length)
+        errorMessage = ls`Location name cannot be empty`;
+      else if (value.length > maxLength)
+        errorMessage = ls`Location name must be less than ${maxLength} characters`;
+
+      if (errorMessage)
+        return {valid: false, errorMessage};
+      return {valid: true};
     }
 
     /**
@@ -168,9 +176,24 @@ Emulation.GeolocationsSettingsTab = class extends UI.VBox {
      * @return {!UI.ListWidget.ValidatorResult}
      */
     function latValidator(item, index, input) {
+      const minLat = -90;
+      const maxLat = 90;
       const value = input.value.trim();
-      const valid = !value || (/^-?[\d]+(\.\d+)?|\.\d+$/.test(value) && value >= -90 && value <= 90);
-      return {valid};
+
+      if (!value)
+        return {valid: true};
+
+      let errorMessage;
+      if (!/^-?[\d]+(\.\d+)?|\.\d+$/.test(value))
+        errorMessage = ls`Latitude must be a number`;
+      else if (parseFloat(value) < minLat)
+        errorMessage = ls`Latitude must be greater than or equal to ${minLat}`;
+      else if (parseFloat(value) > maxLat)
+        errorMessage = ls`Latitude must be less than or equal to ${maxLat}`;
+
+      if (errorMessage)
+        return {valid: false, errorMessage};
+      return {valid: true};
     }
 
     /**
@@ -180,9 +203,24 @@ Emulation.GeolocationsSettingsTab = class extends UI.VBox {
      * @return {!UI.ListWidget.ValidatorResult}
      */
     function longValidator(item, index, input) {
+      const minLong = -180;
+      const maxLong = 180;
       const value = input.value.trim();
-      const valid = !value || (/^-?[\d]+(\.\d+)?|\.\d+$/.test(value) && value >= -180 && value <= 180);
-      return {valid};
+
+      if (!value)
+        return {valid: true};
+
+      let errorMessage;
+      if (!/^-?[\d]+(\.\d+)?|\.\d+$/.test(value))
+        errorMessage = ls`Longitude must be a number`;
+      else if (parseFloat(value) < minLong)
+        errorMessage = ls`Longitude must be greater than or equal to ${minLong}`;
+      else if (parseFloat(value) > maxLong)
+        errorMessage = ls`Longitude must be less than or equal to ${maxLong}`;
+
+      if (errorMessage)
+        return {valid: false, errorMessage};
+      return {valid: true};
     }
   }
 };
diff --git a/front_end/emulation/emulation_strings.grdp b/front_end/emulation/emulation_strings.grdp
index 97cc8f6146..f9cd044e99 100644
--- a/front_end/emulation/emulation_strings.grdp
+++ b/front_end/emulation/emulation_strings.grdp
@@ -36,6 +36,9 @@
   <message name="IDS_DEVTOOLS_1c7444be9626d149ab598fb79b639f96" desc="Text in Device Mode Toolbar of the Device Toolbar">
     Portrait
   </message>
+  <message name="IDS_DEVTOOLS_1ef9df27aa7a5f5c87af01dbcbb1e7fc" desc="Error message in the Geolocations settings pane that declares the maximum length of the location name">
+    Location name must be less than <ph name="MAXLENGTH">$1s</ph> characters
+  </message>
   <message name="IDS_DEVTOOLS_21e2bb42873eddcb9b476b8eafbe0c18" desc="A context menu item in the Device Mode Toolbar of the Device Toolbar">
     Reset to defaults
   </message>
@@ -75,6 +78,9 @@
   <message name="IDS_DEVTOOLS_34e34c43ec6b943c10a3cc1a1a16fb11" desc="Text of button in Sensors View of the Device Toolbar">
     Manage
   </message>
+  <message name="IDS_DEVTOOLS_34fbcb0154374365e4a109c39b7dfe3a" desc="Error message in the Geolocations settings pane that declares the maximum value for the longitude input">
+    Longitude must be less than or equal to <ph name="MAXLONG">$1s</ph>
+  </message>
   <message name="IDS_DEVTOOLS_36384a9ea3ec791e6bd4ab6b36f2ff2a" desc="Text in Device Mode View of the Device Toolbar">
     Tablet
   </message>
@@ -129,6 +135,9 @@
   <message name="IDS_DEVTOOLS_649676015173b6195516eed77e5aee60" desc="Text in Device Mode Toolbar of the Device Toolbar">
     125%
   </message>
+  <message name="IDS_DEVTOOLS_673a7b89eb57bf2bf891306c98cbecc3" desc="Error message in the Geolocations settings pane that declares that the value for the latitude input must be a number">
+    Latitude must be a number
+  </message>
   <message name="IDS_DEVTOOLS_6adf97f83acf6453d4a6a4b1070f3754" desc="Text in Device Mode Toolbar of the Device Toolbar">
     None
   </message>
@@ -141,6 +150,9 @@
   <message name="IDS_DEVTOOLS_711da7870457fec714278672385be3d8" desc="Error message in the Devices settings pane that declares that the width input must be a number">
     Width must be a number.
   </message>
+  <message name="IDS_DEVTOOLS_741f22b07be0231ec5e3040ae4291710" desc="Error message in the Geolocations settings pane that declares the maximum value for the latitude input">
+    Latitude must be less than or equal to <ph name="MAXLAT">$1s</ph>
+  </message>
   <message name="IDS_DEVTOOLS_75a37bfcbfe2678114513aef903c4ba5" desc="Text in Device Mode Toolbar of the Device Toolbar">
     Default: <ph name="DEFAULTVALUE">$1.1f<ex>4.3</ex></ph>
   </message>
@@ -183,6 +195,9 @@
   <message name="IDS_DEVTOOLS_92394ac4969be25aa83d1c928f6a7dbc" desc="Label in the Devices settings pane for the device name input of a custom device">
     Device Name
   </message>
+  <message name="IDS_DEVTOOLS_9242eae40fda9aae67b37f9f3a7f4fdc" desc="Error message in the Geolocations settings pane that declares that the value for the longitude input must be a number">
+    Longitude must be a number
+  </message>
   <message name="IDS_DEVTOOLS_95129d2a7de16087427f1632dc691287" desc="Text in Device Mode Toolbar of the Device Toolbar">
     Hide media queries
   </message>
@@ -192,6 +207,9 @@
   <message name="IDS_DEVTOOLS_9b4dabc50f0b8ccba1c8981831abdad8" desc="Text in Sensors View of the Device Toolbar">
     Longitude
   </message>
+  <message name="IDS_DEVTOOLS_9d3d232f9353731108f5756ec4bfa4b6" desc="Error message in the Geolocations settings pane that declares the minimum value for the latitude input">
+    Latitude must be greater than or equal to <ph name="MINLAT">$1s</ph>
+  </message>
   <message name="IDS_DEVTOOLS_9fa08fa6b5a65fd3a2e14858a2559027" desc="Text in Sensors View of the Device Toolbar">
     β (beta)
   </message>
@@ -267,6 +285,9 @@
   <message name="IDS_DEVTOOLS_cb4ebbdb6a71353036b6f3b759ad7918" desc="Error message in the Devices settings pane that declares the maximum value for the height input">
     Height must be less than or equal to <ph name="EMULATION_DEVICEMODEMODEL_MAXDEVICESIZE">$1s<ex>9999</ex></ph>.
   </message>
+  <message name="IDS_DEVTOOLS_d0f57f3a1b5b308c6cd7af48b420eb03" desc="Error message in the Geolocations settings pane that declares the minimum value for the longitude input">
+    Longitude must be greater than or equal to <ph name="MINLONG">$1s</ph>
+  </message>
   <message name="IDS_DEVTOOLS_d15305d7a4e34e02489c74a5ef542f36" desc="Text in Sensors View of the Device Toolbar">
     Off
   </message>
@@ -294,6 +315,9 @@
   <message name="IDS_DEVTOOLS_eec6c4bdbd339edf8cbea68becb85244" desc="Label in the Devices settings pane for the height input of a custom device">
     Height
   </message>
+  <message name="IDS_DEVTOOLS_f01ee7fedba5e392f6f9adab7ec0c74a" desc="Error message in the Geolocations settings pane that declares the location name input must not be empty">
+    Location name cannot be empty
+  </message>
   <message name="IDS_DEVTOOLS_f0f31c9700c6b10d8a20dc487b2ae6a8" desc="Text in Sensors View of the Device Toolbar">
     Touch
   </message>
diff --git a/front_end/persistence/WorkspaceSettingsTab.js b/front_end/persistence/WorkspaceSettingsTab.js
index a5342459a6..f0e40db617 100644
--- a/front_end/persistence/WorkspaceSettingsTab.js
+++ b/front_end/persistence/WorkspaceSettingsTab.js
@@ -105,7 +105,7 @@ Persistence.WorkspaceSettingsTab = class extends UI.VBox {
    */
   _renderFileSystem(fileSystem) {
     const fileSystemPath = fileSystem.path();
-    const lastIndexOfSlash = fileSystemPath.lastIndexOf(Host.isWin() ? '\\' : '/');
+    const lastIndexOfSlash = fileSystemPath.lastIndexOf('/');
     const folderName = fileSystemPath.substr(lastIndexOfSlash + 1);
 
     const element = createElementWithClass('div', 'file-system-container');
diff --git a/front_end/ui/ShortcutsScreen.js b/front_end/ui/ShortcutsScreen.js
index 8c528d1382..82b58fa715 100644
--- a/front_end/ui/ShortcutsScreen.js
+++ b/front_end/ui/ShortcutsScreen.js
@@ -329,6 +329,7 @@ UI.ShortcutsSection = class {
     const headLine = parent.createChild('div', 'settings-line');
     headLine.createChild('div', 'settings-key-cell');
     headLine.createChild('div', 'settings-section-title settings-cell').textContent = this.name;
+    UI.ARIAUtils.markAsHeading(headLine, /* level */ 2);
 
     for (let i = 0; i < this._lines.length; ++i) {
       const line = parent.createChild('div', 'settings-line');
diff --git a/scripts/check_localizable_resources.js b/scripts/check_localizable_resources.js
index 525bc054bc..bec1895d82 100644
--- a/scripts/check_localizable_resources.js
+++ b/scripts/check_localizable_resources.js
@@ -44,8 +44,9 @@ main();
 
 async function getErrors(frontendStrings, IDSkeys) {
   const toAddError = await checkLocalizedStrings.getAndReportResourcesToAdd(frontendStrings, IDSkeys);
+  const toModifyError = checkLocalizedStrings.getAndReportIDSKeysToModify();
   const toRemoveError = checkLocalizedStrings.getAndReportResourcesToRemove(frontendStrings, IDSkeys);
-  let error = `${toAddError ? toAddError : ''}${toRemoveError ? toRemoveError : ''}`;
+  let error = `${toAddError || ''}${toModifyError || ''}${toRemoveError || ''}`;
 
   if (error === '') {
     console.log('DevTools localizable resources checker passed.');
@@ -61,9 +62,10 @@ async function autofix(frontendStrings, IDSkeys) {
   const keysToAddToGRD = checkLocalizedStrings.getDifference(IDSkeys, frontendStrings);
   const keysToRemoveFromGRD = checkLocalizedStrings.getDifference(frontendStrings, IDSkeys);
   const resourceAdded = await addResourcesToGRDP(keysToAddToGRD, keysToRemoveFromGRD);
+  const resourceModified = await modifyResourcesInGRDP();
   const resourceRemoved = await removeResourcesFromGRDP(keysToRemoveFromGRD);
 
-  if (!resourceAdded && !resourceRemoved) {
+  if (!resourceAdded && !resourceRemoved && !resourceModified) {
     console.log('DevTools localizable resources checker passed.');
     return;
   }
@@ -78,27 +80,30 @@ async function autofix(frontendStrings, IDSkeys) {
 
 // Return true if any resources are added
 async function addResourcesToGRDP(keysToAddToGRD, keysToRemoveFromGRD) {
+  function mapGRDPFilePathToStrings(keysToAddToGRD, keysToRemoveFromGRD) {
+    const grdpFilePathToStrings = new Map();
+    // Get the grdp files that need to be modified
+    for (const [key, stringObj] of keysToAddToGRD) {
+      if (!grdpFilePathToStrings.has(stringObj.grdpPath))
+        grdpFilePathToStrings.set(stringObj.grdpPath, []);
+
+      // Add the IDS key to stringObj so we have access to it later
+      stringObj.ids = key;
+      // If the same key is to be removed, this is likely a string copy
+      // to another folder. Keep the description.
+      if (keysToRemoveFromGRD.has(key))
+        stringObj.description = keysToRemoveFromGRD.get(key).description;
+      grdpFilePathToStrings.get(stringObj.grdpPath).push(stringObj);
+    }
+    return grdpFilePathToStrings;
+  }
+
   if (keysToAddToGRD.size === 0)
     return false;
 
   // Map grdp file path to strings to be added to that file so that we only need to
   // modify every grdp file once
-  const grdpFilePathToStrings = new Map();
-
-  // Get the grdp files that need to be modified
-  for (const [key, stringObj] of keysToAddToGRD) {
-    if (!grdpFilePathToStrings.has(stringObj.grdpPath))
-      grdpFilePathToStrings.set(stringObj.grdpPath, []);
-
-    // Add the IDS key to stringObj so we have access to it later
-    stringObj.ids = key;
-    // If the same key is to be removed, this is likely a string copy
-    // to another folder. Keep the description.
-    if (keysToRemoveFromGRD.has(key))
-      stringObj.description = keysToRemoveFromGRD.get(key).description;
-    grdpFilePathToStrings.get(stringObj.grdpPath).push(stringObj);
-  }
-
+  const grdpFilePathToStrings = mapGRDPFilePathToStrings(keysToAddToGRD, keysToRemoveFromGRD);
   const promises = [];
 
   const grdpFilePathsToAdd = [];
@@ -188,28 +193,44 @@ async function addChildGRDPFilePathsToGRD(relativeGrdpFilePaths) {
   return writeFileAsync(localizationUtils.GRD_PATH, newGrdFileContent);
 }
 
-// Return true if any resources are removed
-async function removeResourcesFromGRDP(keysToRemoveFromGRD) {
-  if (keysToRemoveFromGRD.size === 0)
+// Return true if any resources are updated
+async function modifyResourcesInGRDP() {
+  const messagesToModify = checkLocalizedStrings.getIDSKeysToModify();
+  if (messagesToModify.size === 0)
     return false;
 
-  // Map grdp file path to message IDS keys to remove
-  const grdpFilePathToKeys = new Map();
-  for (const [key, messageObj] of keysToRemoveFromGRD) {
-    if (!grdpFilePathToKeys.has(messageObj.grdpPath))
-      grdpFilePathToKeys.set(messageObj.grdpPath, []);
+  const grdpToMessages = mapGRDPFilePathToMessages(messagesToModify);
+  const promises = [];
+  for (const [grdpPath, messages] of grdpToMessages) {
+    let fileContent = await localizationUtils.parseFileContent(grdpPath);
+    for (const message of messages) {
+      const idsRegex = new RegExp(`name="${message.actualIDSKey}"`);
+      fileContent = fileContent.replace(idsRegex, `name="${message.ids}"`);
+    }
+    promises.push(writeFileAsync(grdpPath, fileContent));
+  }
+  await Promise.all(promises);
+  return true;
+}
 
-    grdpFilePathToKeys.get(messageObj.grdpPath).push(key);
+// Return true if any resources are removed
+async function removeResourcesFromGRDP(keysToRemoveFromGRD) {
+  function lineContainsIDS(line, messages) {
+    return messages.some(message => line.includes(message.ids));
   }
 
+  if (keysToRemoveFromGRD.size === 0)
+    return false;
+
+  const grdpToMessages = mapGRDPFilePathToMessages(keysToRemoveFromGRD);
   const promises = [];
-  for (const [grdpFilePath, listOfKeys] of grdpFilePathToKeys) {
+  for (const [grdpFilePath, messages] of grdpToMessages) {
     let newGrdpFileContent = '';
     const grdpFileContent = await localizationUtils.parseFileContent(grdpFilePath);
     const grdpFileLines = grdpFileContent.split('\n');
 
     for (let i = 0; i < grdpFileLines.length; i++) {
-      if (!lineContainsIDS(grdpFileLines[i], listOfKeys)) {
+      if (!lineContainsIDS(grdpFileLines[i], messages)) {
         newGrdpFileContent += grdpFileLines[i];
         if (i < grdpFileLines.length - 1)
           newGrdpFileContent += '\n';
@@ -226,6 +247,17 @@ async function removeResourcesFromGRDP(keysToRemoveFromGRD) {
   return true;
 }
 
-function lineContainsIDS(line, listOfIDS) {
-  return listOfIDS.some(ids => line.includes(ids));
+// Given a map from IDS key to a list of messages, return a map
+// from grdp file path to a list of messages with a new property
+// `ids` set to the key.
+function mapGRDPFilePathToMessages(keyToMessages) {
+  const grdpFilePathToMessages = new Map();
+  for (const [ids, message] of keyToMessages) {
+    if (!grdpFilePathToMessages.has(message.grdpPath))
+      grdpFilePathToMessages.set(message.grdpPath, []);
+
+    message.ids = ids;
+    grdpFilePathToMessages.get(message.grdpPath).push(message);
+  }
+  return grdpFilePathToMessages;
 }
diff --git a/scripts/localization_utils/check_localized_strings.js b/scripts/localization_utils/check_localized_strings.js
index 0a912dc92a..32e1dde386 100644
--- a/scripts/localization_utils/check_localized_strings.js
+++ b/scripts/localization_utils/check_localized_strings.js
@@ -42,6 +42,7 @@ const frontendStrings = new Map();
 // Format
 // {
 //   IDS_KEY => {
+//     actualIDSKey: string,  // the IDS key in the message tag
 //     description: string,
 //     filepath: string,
 //     location: {
@@ -297,31 +298,33 @@ async function parseGRDPFile(filePath) {
   }
 
   // Example:
-  //  <message name="IDS_*" desc="Description of this message">
+  //  <message name="IDS_DEVTOOLS_md5_hash" desc="Description of this message">
   //      Message text here with optional placeholders <ph name="phname">$1s</ph>
   //  </message>
   // match[0]: the entire '<message>...</message>' block.
-  // match[1]: 'Description of this message'
-  // match[2]: '     Message text here with optional placeholders <ph name="phname">$1s</ph>\n  '
-  const messageRegex = new RegExp('<message[^>]*desc="([^"]*)"[^>]*>\s*\n(.*?)<\/message>', 'gms');
+  // match[1]: 'IDS_DEVTOOLS_md5_hash'
+  // match[2]: 'Description of this message'
+  // match[3]: '     Message text here with optional placeholders <ph name="phname">$1s</ph>\n  '
+  const messageRegex = new RegExp('<message[^>]*name="([^"]*)"[^>]*desc="([^"]*)"[^>]*>\s*\n(.*?)<\/message>', 'gms');
   let match;
   while ((match = messageRegex.exec(fileContent)) !== null) {
     const line = lineNumberOfIndex(fileContent, match.index);
-    const description = match[1];
-    let message = match[2];
+    const actualIDSKey = match[1];
+    const description = match[2];
+    let message = match[3];
     message = convertToFrontendPlaceholders(message.trim());
     message = stripWhitespacePadding(message);
     message = localizationUtils.sanitizeStringIntoFrontendFormat(message);
 
     const ids = localizationUtils.getIDSKey(message);
-    IDSkeys.set(ids, {grdpPath: filePath, location: {start: {line}, end: {line}}, description});
+    IDSkeys.set(ids, {actualIDSKey, grdpPath: filePath, location: {start: {line}, end: {line}}, description});
   }
 }
 
 /**
  * The following functions compare frontend localizable strings
- * with grdp <message>s and report error of resources to add or
- * remove.
+ * with grdp <message>s and report error of resources to add,
+ * remove or modify.
  */
 async function getAndReportResourcesToAdd(frontendStrings, IDSkeys) {
   const keysToAddToGRD = getDifference(IDSkeys, frontendStrings);
@@ -363,6 +366,22 @@ function getAndReportResourcesToRemove(frontendStrings, IDSkeys) {
   return errorStr;
 }
 
+function getAndReportIDSKeysToModify() {
+  const messagesToModify = getIDSKeysToModify();
+  if (messagesToModify.size === 0)
+    return;
+
+  let errorStr = '\nThe following GRD/GRDP message(s) do not have the correct IDS key.\n';
+  errorStr += 'Please update the key(s) by changing the "name" value.\n\n';
+
+  for (const [expectedIDSKey, message] of messagesToModify) {
+    errorStr += `${localizationUtils.getRelativeFilePathFromSrc(message.grdpPath)}${
+        localizationUtils.getLocationMessage(message.location)}:\n`;
+    errorStr += `${message.actualIDSKey} --> ${expectedIDSKey}\n\n`;
+  }
+  return errorStr;
+}
+
 /**
  * Output a Map containing sorted entries that are in @comparison but not @reference,
  * or entries that are in both but belong to different grdp files.
@@ -376,11 +395,22 @@ function getDifference(reference, comparison) {
   return new Map(difference.sort());
 }
 
+function getIDSKeysToModify() {
+  const messagesToModify = new Map();
+  for (const [expectedIDSKey, message] of IDSkeys) {
+    if (expectedIDSKey !== message.actualIDSKey)
+      messagesToModify.set(expectedIDSKey, message);
+  }
+  return messagesToModify;
+}
+
 module.exports = {
   frontendStrings,
   IDSkeys,
   parseLocalizableResourceMaps,
+  getAndReportIDSKeysToModify,
   getAndReportResourcesToAdd,
   getAndReportResourcesToRemove,
-  getDifference
+  getDifference,
+  getIDSKeysToModify
 };