tor-browser

codemirror.js (397755B)

---

// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

// This is CodeMirror (https://codemirror.net), a code editor
// implemented in JavaScript on top of the browser's DOM.
//
// You can find some technical background for some of the code below
// at http://marijnhaverbeke.nl/blog/#cm-internals .

(function (global, factory) {
 typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
 typeof define === 'function' && define.amd ? define(factory) :
 (global = global || self, global.CodeMirror = factory());
}(this, (function () { 'use strict';

 // Kludges for bugs and behavior differences that can't be feature
 // detected are enabled based on userAgent etc sniffing.
 var userAgent = navigator.userAgent;
 var platform = navigator.platform;

 var gecko = /gecko\/\d/i.test(userAgent);
 var ie_upto10 = /MSIE \d/.test(userAgent);
 var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(userAgent);
 var edge = /Edge\/(\d+)/.exec(userAgent);
 var ie = ie_upto10 || ie_11up || edge;
 var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : +(edge || ie_11up)[1]);
 var webkit = !edge && /WebKit\//.test(userAgent);
 var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(userAgent);
 var chrome = !edge && /Chrome\//.test(userAgent);
 var presto = /Opera\//.test(userAgent);
 var safari = /Apple Computer/.test(navigator.vendor);
 var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(userAgent);
 var phantom = /PhantomJS/.test(userAgent);

 var ios = !edge && /AppleWebKit/.test(userAgent) && /Mobile\/\w+/.test(userAgent);
 var android = /Android/.test(userAgent);
 // This is woefully incomplete. Suggestions for alternative methods welcome.
 var mobile = ios || android || /webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(userAgent);
 var mac = ios || /Mac/.test(platform);
 var chromeOS = /\bCrOS\b/.test(userAgent);
 var windows = /win/i.test(platform);

 var presto_version = presto && userAgent.match(/Version\/(\d*\.\d*)/);
 if (presto_version) { presto_version = Number(presto_version[1]); }
 if (presto_version && presto_version >= 15) { presto = false; webkit = true; }
 // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
 var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));
 var captureRightClick = gecko || (ie && ie_version >= 9);

 function classTest(cls) { return new RegExp("(^|\\s)" + cls + "(?:$|\\s)\\s*") }

 var rmClass = function(node, cls) {
   var current = node.className;
   var match = classTest(cls).exec(current);
   if (match) {
     var after = current.slice(match.index + match[0].length);
     node.className = current.slice(0, match.index) + (after ? match[1] + after : "");
   }
 };

 function removeChildren(e) {
   for (var count = e.childNodes.length; count > 0; --count)
     { e.removeChild(e.firstChild); }
   return e
 }

 function removeChildrenAndAdd(parent, e) {
   return removeChildren(parent).appendChild(e)
 }

 function elt(tag, content, className, style) {
   var e = document.createElement(tag);
   if (className) { e.className = className; }
   if (style) { e.style.cssText = style; }
   if (typeof content == "string") { e.appendChild(document.createTextNode(content)); }
   else if (content) { for (var i = 0; i < content.length; ++i) { e.appendChild(content[i]); } }
   return e
 }
 // wrapper for elt, which removes the elt from the accessibility tree
 function eltP(tag, content, className, style) {
   var e = elt(tag, content, className, style);
   e.setAttribute("role", "presentation");
   return e
 }

 var range;
 if (document.createRange) { range = function(node, start, end, endNode) {
   var r = document.createRange();
   r.setEnd(endNode || node, end);
   r.setStart(node, start);
   return r
 }; }
 else { range = function(node, start, end) {
   var r = document.body.createTextRange();
   try { r.moveToElementText(node.parentNode); }
   catch(e) { return r }
   r.collapse(true);
   r.moveEnd("character", end);
   r.moveStart("character", start);
   return r
 }; }

 function contains(parent, child) {
   if (child.nodeType == 3) // Android browser always returns false when child is a textnode
     { child = child.parentNode; }
   if (parent.contains)
     { return parent.contains(child) }
   do {
     if (child.nodeType == 11) { child = child.host; }
     if (child == parent) { return true }
   } while (child = child.parentNode)
 }

 function activeElt() {
   // IE and Edge may throw an "Unspecified Error" when accessing document.activeElement.
   // IE < 10 will throw when accessed while the page is loading or in an iframe.
   // IE > 9 and Edge will throw when accessed in an iframe if document.body is unavailable.
   var activeElement;
   try {
     activeElement = document.activeElement;
   } catch(e) {
     activeElement = document.body || null;
   }
   while (activeElement && activeElement.shadowRoot && activeElement.shadowRoot.activeElement)
     { activeElement = activeElement.shadowRoot.activeElement; }
   return activeElement
 }

 function addClass(node, cls) {
   var current = node.className;
   if (!classTest(cls).test(current)) { node.className += (current ? " " : "") + cls; }
 }
 function joinClasses(a, b) {
   var as = a.split(" ");
   for (var i = 0; i < as.length; i++)
     { if (as[i] && !classTest(as[i]).test(b)) { b += " " + as[i]; } }
   return b
 }

 var selectInput = function(node) { node.select(); };
 if (ios) // Mobile Safari apparently has a bug where select() is broken.
   { selectInput = function(node) { node.selectionStart = 0; node.selectionEnd = node.value.length; }; }
 else if (ie) // Suppress mysterious IE10 errors
   { selectInput = function(node) { try { node.select(); } catch(_e) {} }; }

 function bind(f) {
   var args = Array.prototype.slice.call(arguments, 1);
   return function(){return f.apply(null, args)}
 }

 function copyObj(obj, target, overwrite) {
   if (!target) { target = {}; }
   for (var prop in obj)
     { if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
       { target[prop] = obj[prop]; } }
   return target
 }

 // Counts the column offset in a string, taking tabs into account.
 // Used mostly to find indentation.
 function countColumn(string, end, tabSize, startIndex, startValue) {
   if (end == null) {
     end = string.search(/[^\s\u00a0]/);
     if (end == -1) { end = string.length; }
   }
   for (var i = startIndex || 0, n = startValue || 0;;) {
     var nextTab = string.indexOf("\t", i);
     if (nextTab < 0 || nextTab >= end)
       { return n + (end - i) }
     n += nextTab - i;
     n += tabSize - (n % tabSize);
     i = nextTab + 1;
   }
 }

 var Delayed = function() {
   this.id = null;
   this.f = null;
   this.time = 0;
   this.handler = bind(this.onTimeout, this);
 };
 Delayed.prototype.onTimeout = function (self) {
   self.id = 0;
   if (self.time <= +new Date) {
     self.f();
   } else {
     setTimeout(self.handler, self.time - +new Date);
   }
 };
 Delayed.prototype.set = function (ms, f) {
   this.f = f;
   var time = +new Date + ms;
   if (!this.id || time < this.time) {
     clearTimeout(this.id);
     this.id = setTimeout(this.handler, ms);
     this.time = time;
   }
 };

 function indexOf(array, elt) {
   for (var i = 0; i < array.length; ++i)
     { if (array[i] == elt) { return i } }
   return -1
 }

 // Number of pixels added to scroller and sizer to hide scrollbar
 var scrollerGap = 50;

 // Returned or thrown by various protocols to signal 'I'm not
 // handling this'.
 var Pass = {toString: function(){return "CodeMirror.Pass"}};

 // Reused option objects for setSelection & friends
 var sel_dontScroll = {scroll: false}, sel_mouse = {origin: "*mouse"}, sel_move = {origin: "+move"};

 // The inverse of countColumn -- find the offset that corresponds to
 // a particular column.
 function findColumn(string, goal, tabSize) {
   for (var pos = 0, col = 0;;) {
     var nextTab = string.indexOf("\t", pos);
     if (nextTab == -1) { nextTab = string.length; }
     var skipped = nextTab - pos;
     if (nextTab == string.length || col + skipped >= goal)
       { return pos + Math.min(skipped, goal - col) }
     col += nextTab - pos;
     col += tabSize - (col % tabSize);
     pos = nextTab + 1;
     if (col >= goal) { return pos }
   }
 }

 var spaceStrs = [""];
 function spaceStr(n) {
   while (spaceStrs.length <= n)
     { spaceStrs.push(lst(spaceStrs) + " "); }
   return spaceStrs[n]
 }

 function lst(arr) { return arr[arr.length-1] }

 function map(array, f) {
   var out = [];
   for (var i = 0; i < array.length; i++) { out[i] = f(array[i], i); }
   return out
 }

 function insertSorted(array, value, score) {
   var pos = 0, priority = score(value);
   while (pos < array.length && score(array[pos]) <= priority) { pos++; }
   array.splice(pos, 0, value);
 }

 function nothing() {}

 function createObj(base, props) {
   var inst;
   if (Object.create) {
     inst = Object.create(base);
   } else {
     nothing.prototype = base;
     inst = new nothing();
   }
   if (props) { copyObj(props, inst); }
   return inst
 }

 var nonASCIISingleCaseWordChar = /[\u00df\u0587\u0590-\u05f4\u0600-\u06ff\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
 function isWordCharBasic(ch) {
   return /\w/.test(ch) || ch > "\x80" &&
     (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch))
 }
 function isWordChar(ch, helper) {
   if (!helper) { return isWordCharBasic(ch) }
   if (helper.source.indexOf("\\w") > -1 && isWordCharBasic(ch)) { return true }
   return helper.test(ch)
 }

 function isEmpty(obj) {
   for (var n in obj) { if (obj.hasOwnProperty(n) && obj[n]) { return false } }
   return true
 }

 // Extending unicode characters. A series of a non-extending char +
 // any number of extending chars is treated as a single unit as far
 // as editing and measuring is concerned. This is not fully correct,
 // since some scripts/fonts/browsers also treat other configurations
 // of code points as a group.
 var extendingChars = /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/;
 function isExtendingChar(ch) { return ch.charCodeAt(0) >= 768 && extendingChars.test(ch) }

 // Returns a number from the range [`0`; `str.length`] unless `pos` is outside that range.
 function skipExtendingChars(str, pos, dir) {
   while ((dir < 0 ? pos > 0 : pos < str.length) && isExtendingChar(str.charAt(pos))) { pos += dir; }
   return pos
 }

 // Returns the value from the range [`from`; `to`] that satisfies
 // `pred` and is closest to `from`. Assumes that at least `to`
 // satisfies `pred`. Supports `from` being greater than `to`.
 function findFirst(pred, from, to) {
   // At any point we are certain `to` satisfies `pred`, don't know
   // whether `from` does.
   var dir = from > to ? -1 : 1;
   for (;;) {
     if (from == to) { return from }
     var midF = (from + to) / 2, mid = dir < 0 ? Math.ceil(midF) : Math.floor(midF);
     if (mid == from) { return pred(mid) ? from : to }
     if (pred(mid)) { to = mid; }
     else { from = mid + dir; }
   }
 }

 // BIDI HELPERS

 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;
     }
   }
   if (!found) { f(from, to, "ltr"); }
 }

 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 found != null ? found : bidiOther
 }

 // Bidirectional ordering algorithm
 // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
 // that this (partially) implements.

 // 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

 // 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" }
   }

   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 function(str, direction) {
     var outerType = direction == "ltr" ? "L" : "R";

     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))); }

     // 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; }
     }

     // 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"; } }
     }

     // 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;
     }

     // 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;
       }
     }

     // 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;
       }
     }

     // 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, isRTL = direction == "rtl" ? 1 : 0;
         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)); at += isRTL; }
             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));
             at += isRTL;
             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
 }

 // 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 = emitter._handlers || (emitter._handlers = {});
     map[type] = (map[type] || noHandlers).concat(f);
   }
 };

 function getHandlers(emitter, type) {
   return emitter._handlers && emitter._handlers[type] || noHandlers
 }

 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 = emitter._handlers, arr = map && map[type];
     if (arr) {
       var index = indexOf(arr, f);
       if (index > -1)
         { map[type] = arr.slice(0, index).concat(arr.slice(index + 1)); }
     }
   }
 }

 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); }
 }

 // 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 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]); } }
 }

 function hasHandler(emitter, type) {
   return getHandlers(emitter, type).length > 0
 }

 // 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);};
 }

 // 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; }
 }
 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; }
   }
   if (mac && e.ctrlKey && b == 1) { b = 3; }
   return b
 }

 // 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 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); }
   }
   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)
 }

 // 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 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;
   try {range = te.ownerDocument.selection.createRange();}
   catch(e) {}
   if (!range || range.parentElement() != te) { return false }
   return range.compareEndPoints("StartToEnd", range) != 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
 }

 // 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 defineMIME(mime, spec) {
   mimeModes[mime] = spec;
 }

 // 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"} }
 }

 // 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
 }

 // 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);
 }

 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
 }

 // 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}
 }

 function startState(mode, a1, a2) {
   return mode.startState ? mode.startState(a1, a2) : true
 }

 // STRING STREAM

 // Fed to the mode parsers, provides helper functions to make
 // parsers more succinct.

 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;
   }
   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
   }
 };
 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]
 }

 // 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
 }

 // 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; } }
 }

 // 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();
     }
   }
   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;
   }
   return n + i
 }

 function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size}

 function lineNumberFor(options, i) {
   return String(options.lineNumberFormatter(i + options.firstLineNumber))
 }

 // A Pos instance represents a position within the text.
 function Pos(line, ch, sticky) {
   if ( sticky === void 0 ) sticky = null;

   if (!(this instanceof Pos)) { return new Pos(line, ch, sticky) }
   this.line = line;
   this.ch = ch;
   this.sticky = sticky;
 }

 // 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 }

 function equalCursorPos(a, b) { return a.sticky == b.sticky && cmp(a, b) == 0 }

 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 }

 // 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
 }

 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}
 };

 Context.prototype.nextLine = function () {
   this.line++;
   if (this.maxLookAhead > 0) { this.maxLookAhead--; }
 };

 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) }
 };

 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
 };


 // 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;

   // 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;
   };

   for (var o = 0; o < cm.state.overlays.length; ++o) loop( o );

   return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null}
 }

 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 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);

   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
 }

 // 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 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) }
 }

 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.")
 }

 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))); }
   }
   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
 }

 // 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;
   }
 }

 // 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
 }

 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
     }
   }
   doc.highlightFrontier = Math.min(doc.highlightFrontier, start);
 }

 // Optimize some code when these features are not used.
 var sawReadOnlySpans = false, sawCollapsedSpans = false;

 function seeReadOnlySpans() {
   sawReadOnlySpans = true;
 }

 function seeCollapsedSpans() {
   sawCollapsedSpans = true;
 }

 // TEXTMARKER SPANS

 function MarkedSpan(marker, from, to) {
   this.marker = marker;
   this.from = from; this.to = to;
 }

 // 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 }
   } }
 }
 // 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
 }
 // Add a span to a line.
 function addMarkedSpan(line, span) {
   line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
   span.marker.attachLine(line);
 }

 // 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
 }

 // 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); }

   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
 }

 // 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
 }

 // 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;
 }

 // 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 }

 // 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
 }

 // 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) }

 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
 }

 // 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, from, to, marker) {
   var line = getLine(doc, lineNo);
   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 }
   } }
 }

 // 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
 }

 function visualLineEnd(line) {
   var merged;
   while (merged = collapsedSpanAtEnd(line))
     { line = merged.find(1, true).line; }
   return line
 }

 // 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
 }

 // 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)
 }

 // 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
 }

 // 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 }
   }
 }

 // Find the height above the given line.
 function heightAtLine(lineObj) {
   lineObj = visualLine(lineObj);

   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; }
   }
   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
 }

 // 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;
     }
   });
 }

 // LINE DATA STRUCTURE

 // Line objects. These hold state related to a line, including
 // highlighting info (the styles array).
 var Line = function(text, markedSpans, estimateHeight) {
   this.text = text;
   attachMarkedSpans(this, markedSpans);
   this.height = estimateHeight ? estimateHeight(this) : 1;
 };

 Line.prototype.lineNo = function () { return lineNo(this) };
 eventMixin(Line);

 // Change the content (text, markers) of a line. Automatically
 // invalidates cached information and tries to re-estimate the
 // line's height.
 function updateLine(line, text, markedSpans, estimateHeight) {
   line.text = text;
   if (line.stateAfter) { line.stateAfter = null; }
   if (line.styles) { line.styles = null; }
   if (line.order != null) { line.order = null; }
   detachMarkedSpans(line);
   attachMarkedSpans(line, markedSpans);
   var estHeight = estimateHeight ? estimateHeight(line) : 1;
   if (estHeight != line.height) { updateLineHeight(line, estHeight); }
 }

 // Detach a line from the document tree and its markers.
 function cleanUpLine(line) {
   line.parent = null;
   detachMarkedSpans(line);
 }

 // Convert a style as returned by a mode (either null, or a string
 // containing one or more styles) to a CSS style. This is cached,
 // and also looks for line-wide styles.
 var styleToClassCache = {}, styleToClassCacheWithMode = {};
 function interpretTokenStyle(style, options) {
   if (!style || /^\s*$/.test(style)) { return null }
   var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache;
   return cache[style] ||
     (cache[style] = style.replace(/\S+/g, "cm-$&"))
 }

 // Render the DOM representation of the text of a line. Also builds
 // up a 'line map', which points at the DOM nodes that represent
 // specific stretches of text, and is used by the measuring code.
 // The returned object contains the DOM node, this map, and
 // information about line-wide styles that were set by the mode.
 function buildLineContent(cm, lineView) {
   // The padding-right forces the element to have a 'border', which
   // is needed on Webkit to be able to get line-level bounding
   // rectangles for it (in measureChar).
   var content = eltP("span", null, null, webkit ? "padding-right: .1px" : null);
   var builder = {pre: eltP("pre", [content], "CodeMirror-line"), content: content,
                  col: 0, pos: 0, cm: cm,
                  trailingSpace: false,
                  splitSpaces: cm.getOption("lineWrapping")};
   lineView.measure = {};

   // Iterate over the logical lines that make up this visual line.
   for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {
     var line = i ? lineView.rest[i - 1] : lineView.line, order = (void 0);
     builder.pos = 0;
     builder.addToken = buildToken;
     // Optionally wire in some hacks into the token-rendering
     // algorithm, to deal with browser quirks.
     if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line, cm.doc.direction)))
       { builder.addToken = buildTokenBadBidi(builder.addToken, order); }
     builder.map = [];
     var allowFrontierUpdate = lineView != cm.display.externalMeasured && lineNo(line);
     insertLineContent(line, builder, getLineStyles(cm, line, allowFrontierUpdate));
     if (line.styleClasses) {
       if (line.styleClasses.bgClass)
         { builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || ""); }
       if (line.styleClasses.textClass)
         { builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || ""); }
     }

     // Ensure at least a single node is present, for measuring.
     if (builder.map.length == 0)
       { builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure))); }

     // Store the map and a cache object for the current logical line
     if (i == 0) {
       lineView.measure.map = builder.map;
       lineView.measure.cache = {};
     } else {
 (lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map)
       ;(lineView.measure.caches || (lineView.measure.caches = [])).push({});
     }
   }

   // See issue #2901
   if (webkit) {
     var last = builder.content.lastChild;
     if (/\bcm-tab\b/.test(last.className) || (last.querySelector && last.querySelector(".cm-tab")))
       { builder.content.className = "cm-tab-wrap-hack"; }
   }

   signal(cm, "renderLine", cm, lineView.line, builder.pre);
   if (builder.pre.className)
     { builder.textClass = joinClasses(builder.pre.className, builder.textClass || ""); }

   return builder
 }

 function defaultSpecialCharPlaceholder(ch) {
   var token = elt("span", "\u2022", "cm-invalidchar");
   token.title = "\\u" + ch.charCodeAt(0).toString(16);
   token.setAttribute("aria-label", token.title);
   return token
 }

 // Build up the DOM representation for a single token, and add it to
 // the line map. Takes care to render special characters separately.
 function buildToken(builder, text, style, startStyle, endStyle, css, attributes) {
   if (!text) { return }
   var displayText = builder.splitSpaces ? splitSpaces(text, builder.trailingSpace) : text;
   var special = builder.cm.state.specialChars, mustWrap = false;
   var content;
   if (!special.test(text)) {
     builder.col += text.length;
     content = document.createTextNode(displayText);
     builder.map.push(builder.pos, builder.pos + text.length, content);
     if (ie && ie_version < 9) { mustWrap = true; }
     builder.pos += text.length;
   } else {
     content = document.createDocumentFragment();
     var pos = 0;
     while (true) {
       special.lastIndex = pos;
       var m = special.exec(text);
       var skipped = m ? m.index - pos : text.length - pos;
       if (skipped) {
         var txt = document.createTextNode(displayText.slice(pos, pos + skipped));
         if (ie && ie_version < 9) { content.appendChild(elt("span", [txt])); }
         else { content.appendChild(txt); }
         builder.map.push(builder.pos, builder.pos + skipped, txt);
         builder.col += skipped;
         builder.pos += skipped;
       }
       if (!m) { break }
       pos += skipped + 1;
       var txt$1 = (void 0);
       if (m[0] == "\t") {
         var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
         txt$1 = content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
         txt$1.setAttribute("role", "presentation");
         txt$1.setAttribute("cm-text", "\t");
         builder.col += tabWidth;
       } else if (m[0] == "\r" || m[0] == "\n") {
         txt$1 = content.appendChild(elt("span", m[0] == "\r" ? "\u240d" : "\u2424", "cm-invalidchar"));
         txt$1.setAttribute("cm-text", m[0]);
         builder.col += 1;
       } else {
         txt$1 = builder.cm.options.specialCharPlaceholder(m[0]);
         txt$1.setAttribute("cm-text", m[0]);
         if (ie && ie_version < 9) { content.appendChild(elt("span", [txt$1])); }
         else { content.appendChild(txt$1); }
         builder.col += 1;
       }
       builder.map.push(builder.pos, builder.pos + 1, txt$1);
       builder.pos++;
     }
   }
   builder.trailingSpace = displayText.charCodeAt(text.length - 1) == 32;
   if (style || startStyle || endStyle || mustWrap || css || attributes) {
     var fullStyle = style || "";
     if (startStyle) { fullStyle += startStyle; }
     if (endStyle) { fullStyle += endStyle; }
     var token = elt("span", [content], fullStyle, css);
     if (attributes) {
       for (var attr in attributes) { if (attributes.hasOwnProperty(attr) && attr != "style" && attr != "class")
         { token.setAttribute(attr, attributes[attr]); } }
     }
     return builder.content.appendChild(token)
   }
   builder.content.appendChild(content);
 }

 // Change some spaces to NBSP to prevent the browser from collapsing
 // trailing spaces at the end of a line when rendering text (issue #1362).
 function splitSpaces(text, trailingBefore) {
   if (text.length > 1 && !/  /.test(text)) { return text }
   var spaceBefore = trailingBefore, result = "";
   for (var i = 0; i < text.length; i++) {
     var ch = text.charAt(i);
     if (ch == " " && spaceBefore && (i == text.length - 1 || text.charCodeAt(i + 1) == 32))
       { ch = "\u00a0"; }
     result += ch;
     spaceBefore = ch == " ";
   }
   return result
 }

 // Work around nonsense dimensions being reported for stretches of
 // right-to-left text.
 function buildTokenBadBidi(inner, order) {
   return function (builder, text, style, startStyle, endStyle, css, attributes) {
     style = style ? style + " cm-force-border" : "cm-force-border";
     var start = builder.pos, end = start + text.length;
     for (;;) {
       // Find the part that overlaps with the start of this text
       var part = (void 0);
       for (var i = 0; i < order.length; i++) {
         part = order[i];
         if (part.to > start && part.from <= start) { break }
       }
       if (part.to >= end) { return inner(builder, text, style, startStyle, endStyle, css, attributes) }
       inner(builder, text.slice(0, part.to - start), style, startStyle, null, css, attributes);
       startStyle = null;
       text = text.slice(part.to - start);
       start = part.to;
     }
   }
 }

 function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
   var widget = !ignoreWidget && marker.widgetNode;
   if (widget) { builder.map.push(builder.pos, builder.pos + size, widget); }
   if (!ignoreWidget && builder.cm.display.input.needsContentAttribute) {
     if (!widget)
       { widget = builder.content.appendChild(document.createElement("span")); }
     widget.setAttribute("cm-marker", marker.id);
   }
   if (widget) {
     builder.cm.display.input.setUneditable(widget);
     builder.content.appendChild(widget);
   }
   builder.pos += size;
   builder.trailingSpace = false;
 }

 // Outputs a number of spans to make up a line, taking highlighting
 // and marked text into account.
 function insertLineContent(line, builder, styles) {
   var spans = line.markedSpans, allText = line.text, at = 0;
   if (!spans) {
     for (var i$1 = 1; i$1 < styles.length; i$1+=2)
       { builder.addToken(builder, allText.slice(at, at = styles[i$1]), interpretTokenStyle(styles[i$1+1], builder.cm.options)); }
     return
   }

   var len = allText.length, pos = 0, i = 1, text = "", style, css;
   var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, collapsed, attributes;
   for (;;) {
     if (nextChange == pos) { // Update current marker set
       spanStyle = spanEndStyle = spanStartStyle = css = "";
       attributes = null;
       collapsed = null; nextChange = Infinity;
       var foundBookmarks = [], endStyles = (void 0);
       for (var j = 0; j < spans.length; ++j) {
         var sp = spans[j], m = sp.marker;
         if (m.type == "bookmark" && sp.from == pos && m.widgetNode) {
           foundBookmarks.push(m);
         } else if (sp.from <= pos && (sp.to == null || sp.to > pos || m.collapsed && sp.to == pos && sp.from == pos)) {
           if (sp.to != null && sp.to != pos && nextChange > sp.to) {
             nextChange = sp.to;
             spanEndStyle = "";
           }
           if (m.className) { spanStyle += " " + m.className; }
           if (m.css) { css = (css ? css + ";" : "") + m.css; }
           if (m.startStyle && sp.from == pos) { spanStartStyle += " " + m.startStyle; }
           if (m.endStyle && sp.to == nextChange) { (endStyles || (endStyles = [])).push(m.endStyle, sp.to); }
           // support for the old title property
           // https://github.com/codemirror/CodeMirror/pull/5673
           if (m.title) { (attributes || (attributes = {})).title = m.title; }
           if (m.attributes) {
             for (var attr in m.attributes)
               { (attributes || (attributes = {}))[attr] = m.attributes[attr]; }
           }
           if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0))
             { collapsed = sp; }
         } else if (sp.from > pos && nextChange > sp.from) {
           nextChange = sp.from;
         }
       }
       if (endStyles) { for (var j$1 = 0; j$1 < endStyles.length; j$1 += 2)
         { if (endStyles[j$1 + 1] == nextChange) { spanEndStyle += " " + endStyles[j$1]; } } }

       if (!collapsed || collapsed.from == pos) { for (var j$2 = 0; j$2 < foundBookmarks.length; ++j$2)
         { buildCollapsedSpan(builder, 0, foundBookmarks[j$2]); } }
       if (collapsed && (collapsed.from || 0) == pos) {
         buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos,
                            collapsed.marker, collapsed.from == null);
         if (collapsed.to == null) { return }
         if (collapsed.to == pos) { collapsed = false; }
       }
     }
     if (pos >= len) { break }

     var upto = Math.min(len, nextChange);
     while (true) {
       if (text) {
         var end = pos + text.length;
         if (!collapsed) {
           var tokenText = end > upto ? text.slice(0, upto - pos) : text;
           builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,
                            spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", css, attributes);
         }
         if (end >= upto) {text = text.slice(upto - pos); pos = upto; break}
         pos = end;
         spanStartStyle = "";
       }
       text = allText.slice(at, at = styles[i++]);
       style = interpretTokenStyle(styles[i++], builder.cm.options);
     }
   }
 }


 // These objects are used to represent the visible (currently drawn)
 // part of the document. A LineView may correspond to multiple
 // logical lines, if those are connected by collapsed ranges.
 function LineView(doc, line, lineN) {
   // The starting line
   this.line = line;
   // Continuing lines, if any
   this.rest = visualLineContinued(line);
   // Number of logical lines in this visual line
   this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;
   this.node = this.text = null;
   this.hidden = lineIsHidden(doc, line);
 }

 // Create a range of LineView objects for the given lines.
 function buildViewArray(cm, from, to) {
   var array = [], nextPos;
   for (var pos = from; pos < to; pos = nextPos) {
     var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);
     nextPos = pos + view.size;
     array.push(view);
   }
   return array
 }

 var operationGroup = null;

 function pushOperation(op) {
   if (operationGroup) {
     operationGroup.ops.push(op);
   } else {
     op.ownsGroup = operationGroup = {
       ops: [op],
       delayedCallbacks: []
     };
   }
 }

 function fireCallbacksForOps(group) {
   // Calls delayed callbacks and cursorActivity handlers until no
   // new ones appear
   var callbacks = group.delayedCallbacks, i = 0;
   do {
     for (; i < callbacks.length; i++)
       { callbacks[i].call(null); }
     for (var j = 0; j < group.ops.length; j++) {
       var op = group.ops[j];
       if (op.cursorActivityHandlers)
         { while (op.cursorActivityCalled < op.cursorActivityHandlers.length)
           { op.cursorActivityHandlers[op.cursorActivityCalled++].call(null, op.cm); } }
     }
   } while (i < callbacks.length)
 }

 function finishOperation(op, endCb) {
   var group = op.ownsGroup;
   if (!group) { return }

   try { fireCallbacksForOps(group); }
   finally {
     operationGroup = null;
     endCb(group);
   }
 }

 var orphanDelayedCallbacks = null;

 // Often, we want to signal events at a point where we are in the
 // middle of some work, but don't want the handler to start calling
 // other methods on the editor, which might be in an inconsistent
 // state or simply not expect any other events to happen.
 // signalLater looks whether there are any handlers, and schedules
 // them to be executed when the last operation ends, or, if no
 // operation is active, when a timeout fires.
 function signalLater(emitter, type /*, values...*/) {
   var arr = getHandlers(emitter, type);
   if (!arr.length) { return }
   var args = Array.prototype.slice.call(arguments, 2), list;
   if (operationGroup) {
     list = operationGroup.delayedCallbacks;
   } else if (orphanDelayedCallbacks) {
     list = orphanDelayedCallbacks;
   } else {
     list = orphanDelayedCallbacks = [];
     setTimeout(fireOrphanDelayed, 0);
   }
   var loop = function ( i ) {
     list.push(function () { return arr[i].apply(null, args); });
   };

   for (var i = 0; i < arr.length; ++i)
     loop( i );
 }

 function fireOrphanDelayed() {
   var delayed = orphanDelayedCallbacks;
   orphanDelayedCallbacks = null;
   for (var i = 0; i < delayed.length; ++i) { delayed[i](); }
 }

 // When an aspect of a line changes, a string is added to
 // lineView.changes. This updates the relevant part of the line's
 // DOM structure.
 function updateLineForChanges(cm, lineView, lineN, dims) {
   for (var j = 0; j < lineView.changes.length; j++) {
     var type = lineView.changes[j];
     if (type == "text") { updateLineText(cm, lineView); }
     else if (type == "gutter") { updateLineGutter(cm, lineView, lineN, dims); }
     else if (type == "class") { updateLineClasses(cm, lineView); }
     else if (type == "widget") { updateLineWidgets(cm, lineView, dims); }
   }
   lineView.changes = null;
 }

 // Lines with gutter elements, widgets or a background class need to
 // be wrapped, and have the extra elements added to the wrapper div
 function ensureLineWrapped(lineView) {
   if (lineView.node == lineView.text) {
     lineView.node = elt("div", null, null, "position: relative");
     if (lineView.text.parentNode)
       { lineView.text.parentNode.replaceChild(lineView.node, lineView.text); }
     lineView.node.appendChild(lineView.text);
     if (ie && ie_version < 8) { lineView.node.style.zIndex = 2; }
   }
   return lineView.node
 }

 function updateLineBackground(cm, lineView) {
   var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;
   if (cls) { cls += " CodeMirror-linebackground"; }
   if (lineView.background) {
     if (cls) { lineView.background.className = cls; }
     else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }
   } else if (cls) {
     var wrap = ensureLineWrapped(lineView);
     lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);
     cm.display.input.setUneditable(lineView.background);
   }
 }

 // Wrapper around buildLineContent which will reuse the structure
 // in display.externalMeasured when possible.
 function getLineContent(cm, lineView) {
   var ext = cm.display.externalMeasured;
   if (ext && ext.line == lineView.line) {
     cm.display.externalMeasured = null;
     lineView.measure = ext.measure;
     return ext.built
   }
   return buildLineContent(cm, lineView)
 }

 // Redraw the line's text. Interacts with the background and text
 // classes because the mode may output tokens that influence these
 // classes.
 function updateLineText(cm, lineView) {
   var cls = lineView.text.className;
   var built = getLineContent(cm, lineView);
   if (lineView.text == lineView.node) { lineView.node = built.pre; }
   lineView.text.parentNode.replaceChild(built.pre, lineView.text);
   lineView.text = built.pre;
   if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
     lineView.bgClass = built.bgClass;
     lineView.textClass = built.textClass;
     updateLineClasses(cm, lineView);
   } else if (cls) {
     lineView.text.className = cls;
   }
 }

 function updateLineClasses(cm, lineView) {
   updateLineBackground(cm, lineView);
   if (lineView.line.wrapClass)
     { ensureLineWrapped(lineView).className = lineView.line.wrapClass; }
   else if (lineView.node != lineView.text)
     { lineView.node.className = ""; }
   var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;
   lineView.text.className = textClass || "";
 }

 function updateLineGutter(cm, lineView, lineN, dims) {
   if (lineView.gutter) {
     lineView.node.removeChild(lineView.gutter);
     lineView.gutter = null;
   }
   if (lineView.gutterBackground) {
     lineView.node.removeChild(lineView.gutterBackground);
     lineView.gutterBackground = null;
   }
   if (lineView.line.gutterClass) {
     var wrap = ensureLineWrapped(lineView);
     lineView.gutterBackground = elt("div", null, "CodeMirror-gutter-background " + lineView.line.gutterClass,
                                     ("left: " + (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px; width: " + (dims.gutterTotalWidth) + "px"));
     cm.display.input.setUneditable(lineView.gutterBackground);
     wrap.insertBefore(lineView.gutterBackground, lineView.text);
   }
   var markers = lineView.line.gutterMarkers;
   if (cm.options.lineNumbers || markers) {
     var wrap$1 = ensureLineWrapped(lineView);
     var gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", ("left: " + (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px"));
     cm.display.input.setUneditable(gutterWrap);
     wrap$1.insertBefore(gutterWrap, lineView.text);
     if (lineView.line.gutterClass)
       { gutterWrap.className += " " + lineView.line.gutterClass; }
     if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
       { lineView.lineNumber = gutterWrap.appendChild(
         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.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"))); }
     } }
   }
 }

 function updateLineWidgets(cm, lineView, dims) {
   if (lineView.alignable) { lineView.alignable = null; }
   var isWidget = classTest("CodeMirror-linewidget");
   for (var node = lineView.node.firstChild, next = (void 0); node; node = next) {
     next = node.nextSibling;
     if (isWidget.test(node.className)) { lineView.node.removeChild(node); }
   }
   insertLineWidgets(cm, lineView, dims);
 }

 // Build a line's DOM representation from scratch
 function buildLineElement(cm, lineView, lineN, dims) {
   var built = getLineContent(cm, lineView);
   lineView.text = lineView.node = built.pre;
   if (built.bgClass) { lineView.bgClass = built.bgClass; }
   if (built.textClass) { lineView.textClass = built.textClass; }

   updateLineClasses(cm, lineView);
   updateLineGutter(cm, lineView, lineN, dims);
   insertLineWidgets(cm, lineView, dims);
   return lineView.node
 }

 // A lineView may contain multiple logical lines (when merged by
 // collapsed spans). The widgets for all of them need to be drawn.
 function insertLineWidgets(cm, lineView, dims) {
   insertLineWidgetsFor(cm, lineView.line, lineView, dims, true);
   if (lineView.rest) { for (var i = 0; i < lineView.rest.length; i++)
     { insertLineWidgetsFor(cm, lineView.rest[i], lineView, dims, false); } }
 }

 function insertLineWidgetsFor(cm, line, lineView, dims, allowAbove) {
   if (!line.widgets) { return }
   var wrap = ensureLineWrapped(lineView);
   for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
     var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget" + (widget.className ? " " + widget.className : ""));
     if (!widget.handleMouseEvents) { node.setAttribute("cm-ignore-events", "true"); }
     positionLineWidget(widget, node, lineView, dims);
     cm.display.input.setUneditable(node);
     if (allowAbove && widget.above)
       { wrap.insertBefore(node, lineView.gutter || lineView.text); }
     else
       { wrap.appendChild(node); }
     signalLater(widget, "redraw");
   }
 }

 function positionLineWidget(widget, node, lineView, dims) {
   if (widget.noHScroll) {
 (lineView.alignable || (lineView.alignable = [])).push(node);
     var width = dims.wrapperWidth;
     node.style.left = dims.fixedPos + "px";
     if (!widget.coverGutter) {
       width -= dims.gutterTotalWidth;
       node.style.paddingLeft = dims.gutterTotalWidth + "px";
     }
     node.style.width = width + "px";
   }
   if (widget.coverGutter) {
     node.style.zIndex = 5;
     node.style.position = "relative";
     if (!widget.noHScroll) { node.style.marginLeft = -dims.gutterTotalWidth + "px"; }
   }
 }

 function widgetHeight(widget) {
   if (widget.height != null) { return widget.height }
   var cm = widget.doc.cm;
   if (!cm) { return 0 }
   if (!contains(document.body, widget.node)) {
     var parentStyle = "position: relative;";
     if (widget.coverGutter)
       { parentStyle += "margin-left: -" + cm.display.gutters.offsetWidth + "px;"; }
     if (widget.noHScroll)
       { parentStyle += "width: " + cm.display.wrapper.clientWidth + "px;"; }
     removeChildrenAndAdd(cm.display.measure, elt("div", [widget.node], null, parentStyle));
   }
   return widget.height = widget.node.parentNode.offsetHeight
 }

 // Return true when the given mouse event happened in a widget
 function eventInWidget(display, e) {
   for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
     if (!n || (n.nodeType == 1 && n.getAttribute("cm-ignore-events") == "true") ||
         (n.parentNode == display.sizer && n != display.mover))
       { return true }
   }
 }

 // POSITION MEASUREMENT

 function paddingTop(display) {return display.lineSpace.offsetTop}
 function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight}
 function paddingH(display) {
   if (display.cachedPaddingH) { return display.cachedPaddingH }
   var e = removeChildrenAndAdd(display.measure, elt("pre", "x", "CodeMirror-line-like"));
   var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;
   var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};
   if (!isNaN(data.left) && !isNaN(data.right)) { display.cachedPaddingH = data; }
   return data
 }

 function scrollGap(cm) { return scrollerGap - cm.display.nativeBarWidth }
 function displayWidth(cm) {
   return cm.display.scroller.clientWidth - scrollGap(cm) - cm.display.barWidth
 }
 function displayHeight(cm) {
   return cm.display.scroller.clientHeight - scrollGap(cm) - cm.display.barHeight
 }

 // Ensure the lineView.wrapping.heights array is populated. This is
 // an array of bottom offsets for the lines that make up a drawn
 // line. When lineWrapping is on, there might be more than one
 // height.
 function ensureLineHeights(cm, lineView, rect) {
   var wrapping = cm.options.lineWrapping;
   var curWidth = wrapping && displayWidth(cm);
   if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {
     var heights = lineView.measure.heights = [];
     if (wrapping) {
       lineView.measure.width = curWidth;
       var rects = lineView.text.firstChild.getClientRects();
       for (var i = 0; i < rects.length - 1; i++) {
         var cur = rects[i], next = rects[i + 1];
         if (Math.abs(cur.bottom - next.bottom) > 2)
           { heights.push((cur.bottom + next.top) / 2 - rect.top); }
       }
     }
     heights.push(rect.bottom - rect.top);
   }
 }

 // Find a line map (mapping character offsets to text nodes) and a
 // measurement cache for the given line number. (A line view might
 // contain multiple lines when collapsed ranges are present.)
 function mapFromLineView(lineView, line, lineN) {
   if (lineView.line == line)
     { return {map: lineView.measure.map, cache: lineView.measure.cache} }
   for (var i = 0; i < lineView.rest.length; i++)
     { if (lineView.rest[i] == line)
       { return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]} } }
   for (var i$1 = 0; i$1 < lineView.rest.length; i$1++)
     { if (lineNo(lineView.rest[i$1]) > lineN)
       { return {map: lineView.measure.maps[i$1], cache: lineView.measure.caches[i$1], before: true} } }
 }

 // Render a line into the hidden node display.externalMeasured. Used
 // when measurement is needed for a line that's not in the viewport.
 function updateExternalMeasurement(cm, line) {
   line = visualLine(line);
   var lineN = lineNo(line);
   var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
   view.lineN = lineN;
   var built = view.built = buildLineContent(cm, view);
   view.text = built.pre;
   removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
   return view
 }

 // Get a {top, bottom, left, right} box (in line-local coordinates)
 // for a given character.
 function measureChar(cm, line, ch, bias) {
   return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias)
 }

 // Find a line view that corresponds to the given line number.
 function findViewForLine(cm, lineN) {
   if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)
     { return cm.display.view[findViewIndex(cm, lineN)] }
   var ext = cm.display.externalMeasured;
   if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)
     { return ext }
 }

 // Measurement can be split in two steps, the set-up work that
 // applies to the whole line, and the measurement of the actual
 // character. Functions like coordsChar, that need to do a lot of
 // measurements in a row, can thus ensure that the set-up work is
 // only done once.
 function prepareMeasureForLine(cm, line) {
   var lineN = lineNo(line);
   var view = findViewForLine(cm, lineN);
   if (view && !view.text) {
     view = null;
   } else if (view && view.changes) {
     updateLineForChanges(cm, view, lineN, getDimensions(cm));
     cm.curOp.forceUpdate = true;
   }
   if (!view)
     { view = updateExternalMeasurement(cm, line); }

   var info = mapFromLineView(view, line, lineN);
   return {
     line: line, view: view, rect: null,
     map: info.map, cache: info.cache, before: info.before,
     hasHeights: false
   }
 }

 // Given a prepared measurement object, measures the position of an
 // actual character (or fetches it from the cache).
 function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
   if (prepared.before) { ch = -1; }
   var key = ch + (bias || ""), found;
   if (prepared.cache.hasOwnProperty(key)) {
     found = prepared.cache[key];
   } else {
     if (!prepared.rect)
       { prepared.rect = prepared.view.text.getBoundingClientRect(); }
     if (!prepared.hasHeights) {
       ensureLineHeights(cm, prepared.view, prepared.rect);
       prepared.hasHeights = true;
     }
     found = measureCharInner(cm, prepared, ch, bias);
     if (!found.bogus) { prepared.cache[key] = found; }
   }
   return {left: found.left, right: found.right,
           top: varHeight ? found.rtop : found.top,
           bottom: varHeight ? found.rbottom : found.bottom}
 }

 var nullRect = {left: 0, right: 0, top: 0, bottom: 0};

 function nodeAndOffsetInLineMap(map, ch, bias) {
   var node, start, end, collapse, mStart, mEnd;
   // First, search the line map for the text node corresponding to,
   // or closest to, the target character.
   for (var i = 0; i < map.length; i += 3) {
     mStart = map[i];
     mEnd = map[i + 1];
     if (ch < mStart) {
       start = 0; end = 1;
       collapse = "left";
     } else if (ch < mEnd) {
       start = ch - mStart;
       end = start + 1;
     } else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {
       end = mEnd - mStart;
       start = end - 1;
       if (ch >= mEnd) { collapse = "right"; }
     }
     if (start != null) {
       node = map[i + 2];
       if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))
         { collapse = bias; }
       if (bias == "left" && start == 0)
         { while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
           node = map[(i -= 3) + 2];
           collapse = "left";
         } }
       if (bias == "right" && start == mEnd - mStart)
         { while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
           node = map[(i += 3) + 2];
           collapse = "right";
         } }
       break
     }
   }
   return {node: node, start: start, end: end, collapse: collapse, coverStart: mStart, coverEnd: mEnd}
 }

 function getUsefulRect(rects, bias) {
   var rect = nullRect;
   if (bias == "left") { for (var i = 0; i < rects.length; i++) {
     if ((rect = rects[i]).left != rect.right) { break }
   } } else { for (var i$1 = rects.length - 1; i$1 >= 0; i$1--) {
     if ((rect = rects[i$1]).left != rect.right) { break }
   } }
   return rect
 }

 function measureCharInner(cm, prepared, ch, bias) {
   var place = nodeAndOffsetInLineMap(prepared.map, ch, bias);
   var node = place.node, start = place.start, end = place.end, collapse = place.collapse;

   var rect;
   if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.
     for (var i$1 = 0; i$1 < 4; i$1++) { // Retry a maximum of 4 times when nonsense rectangles are returned
       while (start && isExtendingChar(prepared.line.text.charAt(place.coverStart + start))) { --start; }
       while (place.coverStart + end < place.coverEnd && isExtendingChar(prepared.line.text.charAt(place.coverStart + end))) { ++end; }
       if (ie && ie_version < 9 && start == 0 && end == place.coverEnd - place.coverStart)
         { rect = node.parentNode.getBoundingClientRect(); }
       else
         { rect = getUsefulRect(range(node, start, end).getClientRects(), bias); }
       if (rect.left || rect.right || start == 0) { break }
       end = start;
       start = start - 1;
       collapse = "right";
     }
     if (ie && ie_version < 11) { rect = maybeUpdateRectForZooming(cm.display.measure, rect); }
   } else { // If it is a widget, simply get the box for the whole widget.
     if (start > 0) { collapse = bias = "right"; }
     var rects;
     if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)
       { rect = rects[bias == "right" ? rects.length - 1 : 0]; }
     else
       { rect = node.getBoundingClientRect(); }
   }
   if (ie && ie_version < 9 && !start && (!rect || !rect.left && !rect.right)) {
     var rSpan = node.parentNode.getClientRects()[0];
     if (rSpan)
       { rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom}; }
     else
       { rect = nullRect; }
   }

   var rtop = rect.top - prepared.rect.top, rbot = rect.bottom - prepared.rect.top;
   var mid = (rtop + rbot) / 2;
   var heights = prepared.view.measure.heights;
   var i = 0;
   for (; i < heights.length - 1; i++)
     { if (mid < heights[i]) { break } }
   var top = i ? heights[i - 1] : 0, bot = heights[i];
   var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,
                 right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,
                 top: top, bottom: bot};
   if (!rect.left && !rect.right) { result.bogus = true; }
   if (!cm.options.singleCursorHeightPerLine) { result.rtop = rtop; result.rbottom = rbot; }

   return result
 }

 // Work around problem with bounding client rects on ranges being
 // returned incorrectly when zoomed on IE10 and below.
 function maybeUpdateRectForZooming(measure, rect) {
   if (!window.screen || screen.logicalXDPI == null ||
       screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure))
     { return rect }
   var scaleX = screen.logicalXDPI / screen.deviceXDPI;
   var scaleY = screen.logicalYDPI / screen.deviceYDPI;
   return {left: rect.left * scaleX, right: rect.right * scaleX,
           top: rect.top * scaleY, bottom: rect.bottom * scaleY}
 }

 function clearLineMeasurementCacheFor(lineView) {
   if (lineView.measure) {
     lineView.measure.cache = {};
     lineView.measure.heights = null;
     if (lineView.rest) { for (var i = 0; i < lineView.rest.length; i++)
       { lineView.measure.caches[i] = {}; } }
   }
 }

 function clearLineMeasurementCache(cm) {
   cm.display.externalMeasure = null;
   removeChildren(cm.display.lineMeasure);
   for (var i = 0; i < cm.display.view.length; i++)
     { clearLineMeasurementCacheFor(cm.display.view[i]); }
 }

 function clearCaches(cm) {
   clearLineMeasurementCache(cm);
   cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;
   if (!cm.options.lineWrapping) { cm.display.maxLineChanged = true; }
   cm.display.lineNumChars = null;
 }

 function pageScrollX() {
   // Work around https://bugs.chromium.org/p/chromium/issues/detail?id=489206
   // which causes page_Offset and bounding client rects to use
   // different reference viewports and invalidate our calculations.
   if (chrome && android) { return -(document.body.getBoundingClientRect().left - parseInt(getComputedStyle(document.body).marginLeft)) }
   return window.pageXOffset || (document.documentElement || document.body).scrollLeft
 }
 function pageScrollY() {
   if (chrome && android) { return -(document.body.getBoundingClientRect().top - parseInt(getComputedStyle(document.body).marginTop)) }
   return window.pageYOffset || (document.documentElement || document.body).scrollTop
 }

 function widgetTopHeight(lineObj) {
   var height = 0;
   if (lineObj.widgets) { for (var i = 0; i < lineObj.widgets.length; ++i) { if (lineObj.widgets[i].above)
     { height += widgetHeight(lineObj.widgets[i]); } } }
   return height
 }

 // Converts a {top, bottom, left, right} box from line-local
 // coordinates into another coordinate system. Context may be one of
 // "line", "div" (display.lineDiv), "local"./null (editor), "window",
 // or "page".
 function intoCoordSystem(cm, lineObj, rect, context, includeWidgets) {
   if (!includeWidgets) {
     var height = widgetTopHeight(lineObj);
     rect.top += height; rect.bottom += height;
   }
   if (context == "line") { return rect }
   if (!context) { context = "local"; }
   var yOff = heightAtLine(lineObj);
   if (context == "local") { yOff += paddingTop(cm.display); }
   else { yOff -= cm.display.viewOffset; }
   if (context == "page" || context == "window") {
     var lOff = cm.display.lineSpace.getBoundingClientRect();
     yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
     var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
     rect.left += xOff; rect.right += xOff;
   }
   rect.top += yOff; rect.bottom += yOff;
   return rect
 }

 // Coverts a box from "div" coords to another coordinate system.
 // Context may be "window", "page", "div", or "local"./null.
 function fromCoordSystem(cm, coords, context) {
   if (context == "div") { return coords }
   var left = coords.left, top = coords.top;
   // First move into "page" coordinate system
   if (context == "page") {
     left -= pageScrollX();
     top -= pageScrollY();
   } else if (context == "local" || !context) {
     var localBox = cm.display.sizer.getBoundingClientRect();
     left += localBox.left;
     top += localBox.top;
   }

   var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();
   return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top}
 }

 function charCoords(cm, pos, context, lineObj, bias) {
   if (!lineObj) { lineObj = getLine(cm.doc, pos.line); }
   return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context)
 }

 // Returns a box for a given cursor position, which may have an
 // 'other' property containing the position of the secondary cursor
 // on a bidi boundary.
 // A cursor Pos(line, char, "before") is on the same visual line as `char - 1`
 // and after `char - 1` in writing order of `char - 1`
 // A cursor Pos(line, char, "after") is on the same visual line as `char`
 // and before `char` in writing order of `char`
 // Examples (upper-case letters are RTL, lower-case are LTR):
 //     Pos(0, 1, ...)
 //     before   after
 // ab     a|b     a|b
 // aB     a|B     aB|
 // Ab     |Ab     A|b
 // AB     B|A     B|A
 // Every position after the last character on a line is considered to stick
 // to the last character on the line.
 function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {
   lineObj = lineObj || getLine(cm.doc, pos.line);
   if (!preparedMeasure) { preparedMeasure = prepareMeasureForLine(cm, lineObj); }
   function get(ch, right) {
     var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left", varHeight);
     if (right) { m.left = m.right; } else { m.right = m.left; }
     return intoCoordSystem(cm, lineObj, m, context)
   }
   var order = getOrder(lineObj, cm.doc.direction), ch = pos.ch, sticky = pos.sticky;
   if (ch >= lineObj.text.length) {
     ch = lineObj.text.length;
     sticky = "before";
   } else if (ch <= 0) {
     ch = 0;
     sticky = "after";
   }
   if (!order) { return get(sticky == "before" ? ch - 1 : ch, sticky == "before") }

   function getBidi(ch, partPos, invert) {
     var part = order[partPos], right = part.level == 1;
     return get(invert ? ch - 1 : ch, right != invert)
   }
   var partPos = getBidiPartAt(order, ch, sticky);
   var other = bidiOther;
   var val = getBidi(ch, partPos, sticky == "before");
   if (other != null) { val.other = getBidi(ch, other, sticky != "before"); }
   return val
 }

 // Used to cheaply estimate the coordinates for a position. Used for
 // intermediate scroll updates.
 function estimateCoords(cm, pos) {
   var left = 0;
   pos = clipPos(cm.doc, pos);
   if (!cm.options.lineWrapping) { left = charWidth(cm.display) * pos.ch; }
   var lineObj = getLine(cm.doc, pos.line);
   var top = heightAtLine(lineObj) + paddingTop(cm.display);
   return {left: left, right: left, top: top, bottom: top + lineObj.height}
 }

 // Positions returned by coordsChar contain some extra information.
 // xRel is the relative x position of the input coordinates compared
 // to the found position (so xRel > 0 means the coordinates are to
 // the right of the character position, for example). When outside
 // is true, that means the coordinates lie outside the line's
 // vertical range.
 function PosWithInfo(line, ch, sticky, outside, xRel) {
   var pos = Pos(line, ch, sticky);
   pos.xRel = xRel;
   if (outside) { pos.outside = outside; }
   return pos
 }

 // Compute the character position closest to the given coordinates.
 // Input must be lineSpace-local ("div" coordinate system).
 function coordsChar(cm, x, y) {
   var doc = cm.doc;
   y += cm.display.viewOffset;
   if (y < 0) { return PosWithInfo(doc.first, 0, null, -1, -1) }
   var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
   if (lineN > last)
     { return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, null, 1, 1) }
   if (x < 0) { x = 0; }

   var lineObj = getLine(doc, lineN);
   for (;;) {
     var found = coordsCharInner(cm, lineObj, lineN, x, y);
     var collapsed = collapsedSpanAround(lineObj, found.ch + (found.xRel > 0 || found.outside > 0 ? 1 : 0));
     if (!collapsed) { return found }
     var rangeEnd = collapsed.find(1);
     if (rangeEnd.line == lineN) { return rangeEnd }
     lineObj = getLine(doc, lineN = rangeEnd.line);
   }
 }

 function wrappedLineExtent(cm, lineObj, preparedMeasure, y) {
   y -= widgetTopHeight(lineObj);
   var end = lineObj.text.length;
   var begin = findFirst(function (ch) { return measureCharPrepared(cm, preparedMeasure, ch - 1).bottom <= y; }, end, 0);
   end = findFirst(function (ch) { return measureCharPrepared(cm, preparedMeasure, ch).top > y; }, begin, end);
   return {begin: begin, end: end}
 }

 function wrappedLineExtentChar(cm, lineObj, preparedMeasure, target) {
   if (!preparedMeasure) { preparedMeasure = prepareMeasureForLine(cm, lineObj); }
   var targetTop = intoCoordSystem(cm, lineObj, measureCharPrepared(cm, preparedMeasure, target), "line").top;
   return wrappedLineExtent(cm, lineObj, preparedMeasure, targetTop)
 }

 // Returns true if the given side of a box is after the given
 // coordinates, in top-to-bottom, left-to-right order.
 function boxIsAfter(box, x, y, left) {
   return box.bottom <= y ? false : box.top > y ? true : (left ? box.left : box.right) > x
 }

 function coordsCharInner(cm, lineObj, lineNo, x, y) {
   // Move y into line-local coordinate space
   y -= heightAtLine(lineObj);
   var preparedMeasure = prepareMeasureForLine(cm, lineObj);
   // When directly calling `measureCharPrepared`, we have to adjust
   // for the widgets at this line.
   var widgetHeight = widgetTopHeight(lineObj);
   var begin = 0, end = lineObj.text.length, ltr = true;

   var order = getOrder(lineObj, cm.doc.direction);
   // If the line isn't plain left-to-right text, first figure out
   // which bidi section the coordinates fall into.
   if (order) {
     var part = (cm.options.lineWrapping ? coordsBidiPartWrapped : coordsBidiPart)
                  (cm, lineObj, lineNo, preparedMeasure, order, x, y);
     ltr = part.level != 1;
     // The awkward -1 offsets are needed because findFirst (called
     // on these below) will treat its first bound as inclusive,
     // second as exclusive, but we want to actually address the
     // characters in the part's range
     begin = ltr ? part.from : part.to - 1;
     end = ltr ? part.to : part.from - 1;
   }

   // A binary search to find the first character whose bounding box
   // starts after the coordinates. If we run across any whose box wrap
   // the coordinates, store that.
   var chAround = null, boxAround = null;
   var ch = findFirst(function (ch) {
     var box = measureCharPrepared(cm, preparedMeasure, ch);
     box.top += widgetHeight; box.bottom += widgetHeight;
     if (!boxIsAfter(box, x, y, false)) { return false }
     if (box.top <= y && box.left <= x) {
       chAround = ch;
       boxAround = box;
     }
     return true
   }, begin, end);

   var baseX, sticky, outside = false;
   // If a box around the coordinates was found, use that
   if (boxAround) {
     // Distinguish coordinates nearer to the left or right side of the box
     var atLeft = x - boxAround.left < boxAround.right - x, atStart = atLeft == ltr;
     ch = chAround + (atStart ? 0 : 1);
     sticky = atStart ? "after" : "before";
     baseX = atLeft ? boxAround.left : boxAround.right;
   } else {
     // (Adjust for extended bound, if necessary.)
     if (!ltr && (ch == end || ch == begin)) { ch++; }
     // To determine which side to associate with, get the box to the
     // left of the character and compare it's vertical position to the
     // coordinates
     sticky = ch == 0 ? "after" : ch == lineObj.text.length ? "before" :
       (measureCharPrepared(cm, preparedMeasure, ch - (ltr ? 1 : 0)).bottom + widgetHeight <= y) == ltr ?
       "after" : "before";
     // Now get accurate coordinates for this place, in order to get a
     // base X position
     var coords = cursorCoords(cm, Pos(lineNo, ch, sticky), "line", lineObj, preparedMeasure);
     baseX = coords.left;
     outside = y < coords.top ? -1 : y >= coords.bottom ? 1 : 0;
   }

   ch = skipExtendingChars(lineObj.text, ch, 1);
   return PosWithInfo(lineNo, ch, sticky, outside, x - baseX)
 }

 function coordsBidiPart(cm, lineObj, lineNo, preparedMeasure, order, x, y) {
   // Bidi parts are sorted left-to-right, and in a non-line-wrapping
   // situation, we can take this ordering to correspond to the visual
   // ordering. This finds the first part whose end is after the given
   // coordinates.
   var index = findFirst(function (i) {
     var part = order[i], ltr = part.level != 1;
     return boxIsAfter(cursorCoords(cm, Pos(lineNo, ltr ? part.to : part.from, ltr ? "before" : "after"),
                                    "line", lineObj, preparedMeasure), x, y, true)
   }, 0, order.length - 1);
   var part = order[index];
   // If this isn't the first part, the part's start is also after
   // the coordinates, and the coordinates aren't on the same line as
   // that start, move one part back.
   if (index > 0) {
     var ltr = part.level != 1;
     var start = cursorCoords(cm, Pos(lineNo, ltr ? part.from : part.to, ltr ? "after" : "before"),
                              "line", lineObj, preparedMeasure);
     if (boxIsAfter(start, x, y, true) && start.top > y)
       { part = order[index - 1]; }
   }
   return part
 }

 function coordsBidiPartWrapped(cm, lineObj, _lineNo, preparedMeasure, order, x, y) {
   // In a wrapped line, rtl text on wrapping boundaries can do things
   // that don't correspond to the ordering in our `order` array at
   // all, so a binary search doesn't work, and we want to return a
   // part that only spans one line so that the binary search in
   // coordsCharInner is safe. As such, we first find the extent of the
   // wrapped line, and then do a flat search in which we discard any
   // spans that aren't on the line.
   var ref = wrappedLineExtent(cm, lineObj, preparedMeasure, y);
   var begin = ref.begin;
   var end = ref.end;
   if (/\s/.test(lineObj.text.charAt(end - 1))) { end--; }
   var part = null, closestDist = null;
   for (var i = 0; i < order.length; i++) {
     var p = order[i];
     if (p.from >= end || p.to <= begin) { continue }
     var ltr = p.level != 1;
     var endX = measureCharPrepared(cm, preparedMeasure, ltr ? Math.min(end, p.to) - 1 : Math.max(begin, p.from)).right;
     // Weigh against spans ending before this, so that they are only
     // picked if nothing ends after
     var dist = endX < x ? x - endX + 1e9 : endX - x;
     if (!part || closestDist > dist) {
       part = p;
       closestDist = dist;
     }
   }
   if (!part) { part = order[order.length - 1]; }
   // Clip the part to the wrapped line.
   if (part.from < begin) { part = {from: begin, to: part.to, level: part.level}; }
   if (part.to > end) { part = {from: part.from, to: end, level: part.level}; }
   return part
 }

 var measureText;
 // Compute the default text height.
 function textHeight(display) {
   if (display.cachedTextHeight != null) { return display.cachedTextHeight }
   if (measureText == null) {
     measureText = elt("pre", null, "CodeMirror-line-like");
     // Measure a bunch of lines, for browsers that compute
     // fractional heights.
     for (var i = 0; i < 49; ++i) {
       measureText.appendChild(document.createTextNode("x"));
       measureText.appendChild(elt("br"));
     }
     measureText.appendChild(document.createTextNode("x"));
   }
   removeChildrenAndAdd(display.measure, measureText);
   var height = measureText.offsetHeight / 50;
   if (height > 3) { display.cachedTextHeight = height; }
   removeChildren(display.measure);
   return height || 1
 }

 // Compute the default character width.
 function charWidth(display) {
   if (display.cachedCharWidth != null) { return display.cachedCharWidth }
   var anchor = elt("span", "xxxxxxxxxx");
   var pre = elt("pre", [anchor], "CodeMirror-line-like");
   removeChildrenAndAdd(display.measure, pre);
   var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;
   if (width > 2) { display.cachedCharWidth = width; }
   return width || 10
 }

 // Do a bulk-read of the DOM positions and sizes needed to draw the
 // view, so that we don't interleave reading and writing to the DOM.
 function getDimensions(cm) {
   var d = cm.display, left = {}, width = {};
   var gutterLeft = d.gutters.clientLeft;
   for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
     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,
           gutterLeft: left,
           gutterWidth: width,
           wrapperWidth: d.wrapper.clientWidth}
 }

 // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
 // but using getBoundingClientRect to get a sub-pixel-accurate
 // result.
 function compensateForHScroll(display) {
   return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left
 }

 // Returns a function that estimates the height of a line, to use as
 // first approximation until the line becomes visible (and is thus
 // properly measurable).
 function estimateHeight(cm) {
   var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
   var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
   return function (line) {
     if (lineIsHidden(cm.doc, line)) { return 0 }

     var widgetsHeight = 0;
     if (line.widgets) { for (var i = 0; i < line.widgets.length; i++) {
       if (line.widgets[i].height) { widgetsHeight += line.widgets[i].height; }
     } }

     if (wrapping)
       { return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th }
     else
       { return widgetsHeight + th }
   }
 }

 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$1) { return null }
   var coords = coordsChar(cm, x, y), line;
   if (forRect && coords.xRel > 0 && (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;
 }

 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}
 }

 // 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)); }
   }
   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; }
   }
   return dirty
 }

 function updateSelection(cm) {
   cm.display.input.showSelection(cm.display.input.prepareSelection());
 }

 function prepareSelection(cm, primary) {
   if ( primary === void 0 ) primary = true;

   var doc = cm.doc, result = {};
   var curFragment = result.cursors = document.createDocumentFragment();
   var selFragment = result.selection = document.createDocumentFragment();

   for (var i = 0; i < doc.sel.ranges.length; i++) {
     if (!primary && i == doc.sel.primIndex) { continue }
     var range = doc.sel.ranges[i];
     if (range.from().line >= cm.display.viewTo || range.to().line < cm.display.viewFrom) { continue }
     var collapsed = range.empty();
     if (collapsed || cm.options.showCursorWhenSelecting)
       { drawSelectionCursor(cm, range.head, curFragment); }
     if (!collapsed)
       { drawSelectionRange(cm, range, selFragment); }
   }
   return result
 }

 // Draws a cursor for the given range
 function drawSelectionCursor(cm, head, output) {
   var pos = cursorCoords(cm, head, "div", null, null, !cm.options.singleCursorHeightPerLine);

   var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));
   cursor.style.left = pos.left + "px";
   cursor.style.top = pos.top + "px";
   cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";

   if (pos.other) {
     // Secondary cursor, shown when on a 'jump' in bi-directional text
     var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));
     otherCursor.style.display = "";
     otherCursor.style.left = pos.other.left + "px";
     otherCursor.style.top = pos.other.top + "px";
     otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
   }
 }

 function cmpCoords(a, b) { return a.top - b.top || a.left - b.left }

 // Draws the given range as a highlighted selection
 function drawSelectionRange(cm, range, output) {
   var display = cm.display, doc = cm.doc;
   var fragment = document.createDocumentFragment();
   var padding = paddingH(cm.display), leftSide = padding.left;
   var rightSide = Math.max(display.sizerWidth, displayWidth(cm) - display.sizer.offsetLeft) - padding.right;
   var docLTR = doc.direction == "ltr";

   function add(left, top, width, bottom) {
     if (top < 0) { top = 0; }
     top = Math.round(top);
     bottom = Math.round(bottom);
     fragment.appendChild(elt("div", null, "CodeMirror-selected", ("position: absolute; left: " + left + "px;\n                             top: " + top + "px; width: " + (width == null ? rightSide - left : width) + "px;\n                             height: " + (bottom - top) + "px")));
   }

   function drawForLine(line, fromArg, toArg) {
     var lineObj = getLine(doc, line);
     var lineLen = lineObj.text.length;
     var start, end;
     function coords(ch, bias) {
       return charCoords(cm, Pos(line, ch), "div", lineObj, bias)
     }

     function wrapX(pos, dir, side) {
       var extent = wrappedLineExtentChar(cm, lineObj, null, pos);
       var prop = (dir == "ltr") == (side == "after") ? "left" : "right";
       var ch = side == "after" ? extent.begin : extent.end - (/\s/.test(lineObj.text.charAt(extent.end - 1)) ? 2 : 1);
       return coords(ch, prop)[prop]
     }

     var order = getOrder(lineObj, doc.direction);
     iterateBidiSections(order, fromArg || 0, toArg == null ? lineLen : toArg, function (from, to, dir, i) {
       var ltr = dir == "ltr";
       var fromPos = coords(from, ltr ? "left" : "right");
       var toPos = coords(to - 1, ltr ? "right" : "left");

       var openStart = fromArg == null && from == 0, openEnd = toArg == null && to == lineLen;
       var first = i == 0, last = !order || i == order.length - 1;
       if (toPos.top - fromPos.top <= 3) { // Single line
         var openLeft = (docLTR ? openStart : openEnd) && first;
         var openRight = (docLTR ? openEnd : openStart) && last;
         var left = openLeft ? leftSide : (ltr ? fromPos : toPos).left;
         var right = openRight ? rightSide : (ltr ? toPos : fromPos).right;
         add(left, fromPos.top, right - left, fromPos.bottom);
       } else { // Multiple lines
         var topLeft, topRight, botLeft, botRight;
         if (ltr) {
           topLeft = docLTR && openStart && first ? leftSide : fromPos.left;
           topRight = docLTR ? rightSide : wrapX(from, dir, "before");
           botLeft = docLTR ? leftSide : wrapX(to, dir, "after");
           botRight = docLTR && openEnd && last ? rightSide : toPos.right;
         } else {
           topLeft = !docLTR ? leftSide : wrapX(from, dir, "before");
           topRight = !docLTR && openStart && first ? rightSide : fromPos.right;
           botLeft = !docLTR && openEnd && last ? leftSide : toPos.left;
           botRight = !docLTR ? rightSide : wrapX(to, dir, "after");
         }
         add(topLeft, fromPos.top, topRight - topLeft, fromPos.bottom);
         if (fromPos.bottom < toPos.top) { add(leftSide, fromPos.bottom, null, toPos.top); }
         add(botLeft, toPos.top, botRight - botLeft, toPos.bottom);
       }

       if (!start || cmpCoords(fromPos, start) < 0) { start = fromPos; }
       if (cmpCoords(toPos, start) < 0) { start = toPos; }
       if (!end || cmpCoords(fromPos, end) < 0) { end = fromPos; }
       if (cmpCoords(toPos, end) < 0) { end = toPos; }
     });
     return {start: start, end: end}
   }

   var sFrom = range.from(), sTo = range.to();
   if (sFrom.line == sTo.line) {
     drawForLine(sFrom.line, sFrom.ch, sTo.ch);
   } else {
     var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);
     var singleVLine = visualLine(fromLine) == visualLine(toLine);
     var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;
     var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;
     if (singleVLine) {
       if (leftEnd.top < rightStart.top - 2) {
         add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
         add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);
       } else {
         add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
       }
     }
     if (leftEnd.bottom < rightStart.top)
       { add(leftSide, leftEnd.bottom, null, rightStart.top); }
   }

   output.appendChild(fragment);
 }

 // Cursor-blinking
 function restartBlink(cm) {
   if (!cm.state.focused) { return }
   var display = cm.display;
   clearInterval(display.blinker);
   var on = true;
   display.cursorDiv.style.visibility = "";
   if (cm.options.cursorBlinkRate > 0)
     { display.blinker = setInterval(function () {
       if (!cm.hasFocus()) { onBlur(cm); }
       display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";
     }, cm.options.cursorBlinkRate); }
   else if (cm.options.cursorBlinkRate < 0)
     { display.cursorDiv.style.visibility = "hidden"; }
 }

 function ensureFocus(cm) {
   if (!cm.state.focused) { cm.display.input.focus(); onFocus(cm); }
 }

 function delayBlurEvent(cm) {
   cm.state.delayingBlurEvent = true;
   setTimeout(function () { if (cm.state.delayingBlurEvent) {
     cm.state.delayingBlurEvent = false;
     onBlur(cm);
   } }, 100);
 }

 function onFocus(cm, e) {
   if (cm.state.delayingBlurEvent) { cm.state.delayingBlurEvent = false; }

   if (cm.options.readOnly == "nocursor") { return }
   if (!cm.state.focused) {
     signal(cm, "focus", cm, e);
     cm.state.focused = true;
     addClass(cm.display.wrapper, "CodeMirror-focused");
     // This test prevents this from firing when a context
     // menu is closed (since the input reset would kill the
     // select-all detection hack)
     if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {
       cm.display.input.reset();
       if (webkit) { setTimeout(function () { return cm.display.input.reset(true); }, 20); } // Issue #1730
     }
     cm.display.input.receivedFocus();
   }
   restartBlink(cm);
 }
 function onBlur(cm, e) {
   if (cm.state.delayingBlurEvent) { return }

   if (cm.state.focused) {
     signal(cm, "blur", cm, e);
     cm.state.focused = false;
     rmClass(cm.display.wrapper, "CodeMirror-focused");
   }
   clearInterval(cm.display.blinker);
   setTimeout(function () { if (!cm.state.focused) { cm.display.shift = false; } }, 150);
 }

 // Read the actual heights of the rendered lines, and update their
 // stored heights to match.
 function updateHeightsInViewport(cm) {
   var display = cm.display;
   var prevBottom = display.lineDiv.offsetTop;
   for (var i = 0; i < display.view.length; i++) {
     var cur = display.view[i], wrapping = cm.options.lineWrapping;
     var height = (void 0), width = 0;
     if (cur.hidden) { continue }
     if (ie && ie_version < 8) {
       var bot = cur.node.offsetTop + cur.node.offsetHeight;
       height = bot - prevBottom;
       prevBottom = bot;
     } else {
       var box = cur.node.getBoundingClientRect();
       height = box.bottom - box.top;
       // Check that lines don't extend past the right of the current
       // editor width
       if (!wrapping && cur.text.firstChild)
         { width = cur.text.firstChild.getBoundingClientRect().right - box.left - 1; }
     }
     var diff = cur.line.height - height;
     if (diff > .005 || diff < -.005) {
       updateLineHeight(cur.line, height);
       updateWidgetHeight(cur.line);
       if (cur.rest) { for (var j = 0; j < cur.rest.length; j++)
         { updateWidgetHeight(cur.rest[j]); } }
     }
     if (width > cm.display.sizerWidth) {
       var chWidth = Math.ceil(width / charWidth(cm.display));
       if (chWidth > cm.display.maxLineLength) {
         cm.display.maxLineLength = chWidth;
         cm.display.maxLine = cur.line;
         cm.display.maxLineChanged = true;
       }
     }
   }
 }

 // Read and store the height of line widgets associated with the
 // given line.
 function updateWidgetHeight(line) {
   if (line.widgets) { for (var i = 0; i < line.widgets.length; ++i) {
     var w = line.widgets[i], parent = w.node.parentNode;
     if (parent) { w.height = parent.offsetHeight; }
   } }
 }

 // Compute the lines that are visible in a given viewport (defaults
 // the the current scroll position). viewport may contain top,
 // height, and ensure (see op.scrollToPos) properties.
 function visibleLines(display, doc, viewport) {
   var top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop;
   top = Math.floor(top - paddingTop(display));
   var bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight;

   var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);
   // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
   // forces those lines into the viewport (if possible).
   if (viewport && viewport.ensure) {
     var ensureFrom = viewport.ensure.from.line, ensureTo = viewport.ensure.to.line;
     if (ensureFrom < from) {
       from = ensureFrom;
       to = lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight);
     } else if (Math.min(ensureTo, doc.lastLine()) >= to) {
       from = lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight);
       to = ensureTo;
     }
   }
   return {from: from, to: Math.max(to, from + 1)}
 }

 // SCROLLING THINGS INTO VIEW

 // If an editor sits on the top or bottom of the window, partially
 // scrolled out of view, this ensures that the cursor is visible.
 function maybeScrollWindow(cm, rect) {
   if (signalDOMEvent(cm, "scrollCursorIntoView")) { return }

   var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;
   if (rect.top + box.top < 0) { doScroll = true; }
   else if (rect.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) { doScroll = false; }
   if (doScroll != null && !phantom) {
     var scrollNode = elt("div", "\u200b", null, ("position: absolute;\n                         top: " + (rect.top - display.viewOffset - paddingTop(cm.display)) + "px;\n                         height: " + (rect.bottom - rect.top + scrollGap(cm) + display.barHeight) + "px;\n                         left: " + (rect.left) + "px; width: " + (Math.max(2, rect.right - rect.left)) + "px;"));
     cm.display.lineSpace.appendChild(scrollNode);
     scrollNode.scrollIntoView(doScroll);
     cm.display.lineSpace.removeChild(scrollNode);
   }
 }

 // Scroll a given position into view (immediately), verifying that
 // it actually became visible (as line heights are accurately
 // measured, the position of something may 'drift' during drawing).
 function scrollPosIntoView(cm, pos, end, margin) {
   if (margin == null) { margin = 0; }
   var rect;
   if (!cm.options.lineWrapping && pos == end) {
     // Set pos and end to the cursor positions around the character pos sticks to
     // If pos.sticky == "before", that is around pos.ch - 1, otherwise around pos.ch
     // If pos == Pos(_, 0, "before"), pos and end are unchanged
     pos = pos.ch ? Pos(pos.line, pos.sticky == "before" ? pos.ch - 1 : pos.ch, "after") : pos;
     end = pos.sticky == "before" ? Pos(pos.line, pos.ch + 1, "before") : pos;
   }
   for (var limit = 0; limit < 5; limit++) {
     var changed = false;
     var coords = cursorCoords(cm, pos);
     var endCoords = !end || end == pos ? coords : cursorCoords(cm, end);
     rect = {left: Math.min(coords.left, endCoords.left),
             top: Math.min(coords.top, endCoords.top) - margin,
             right: Math.max(coords.left, endCoords.left),
             bottom: Math.max(coords.bottom, endCoords.bottom) + margin};
     var scrollPos = calculateScrollPos(cm, rect);
     var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
     if (scrollPos.scrollTop != null) {
       updateScrollTop(cm, scrollPos.scrollTop);
       if (Math.abs(cm.doc.scrollTop - startTop) > 1) { changed = true; }
     }
     if (scrollPos.scrollLeft != null) {
       setScrollLeft(cm, scrollPos.scrollLeft);
       if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) { changed = true; }
     }
     if (!changed) { break }
   }
   return rect
 }

 // Scroll a given set of coordinates into view (immediately).
 function scrollIntoView(cm, rect) {
   var scrollPos = calculateScrollPos(cm, rect);
   if (scrollPos.scrollTop != null) { updateScrollTop(cm, scrollPos.scrollTop); }
   if (scrollPos.scrollLeft != null) { setScrollLeft(cm, scrollPos.scrollLeft); }
 }

 // Calculate a new scroll position needed to scroll the given
 // rectangle into view. Returns an object with scrollTop and
 // scrollLeft properties. When these are undefined, the
 // vertical/horizontal position does not need to be adjusted.
 function calculateScrollPos(cm, rect) {
   var display = cm.display, snapMargin = textHeight(cm.display);
   if (rect.top < 0) { rect.top = 0; }
   var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop;
   var screen = displayHeight(cm), result = {};
   if (rect.bottom - rect.top > screen) { rect.bottom = rect.top + screen; }
   var docBottom = cm.doc.height + paddingVert(display);
   var atTop = rect.top < snapMargin, atBottom = rect.bottom > docBottom - snapMargin;
   if (rect.top < screentop) {
     result.scrollTop = atTop ? 0 : rect.top;
   } else if (rect.bottom > screentop + screen) {
     var newTop = Math.min(rect.top, (atBottom ? docBottom : rect.bottom) - screen);
     if (newTop != screentop) { result.scrollTop = newTop; }
   }

   var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft;
   var screenw = displayWidth(cm) - (cm.options.fixedGutter ? display.gutters.offsetWidth : 0);
   var tooWide = rect.right - rect.left > screenw;
   if (tooWide) { rect.right = rect.left + screenw; }
   if (rect.left < 10)
     { result.scrollLeft = 0; }
   else if (rect.left < screenleft)
     { result.scrollLeft = Math.max(0, rect.left - (tooWide ? 0 : 10)); }
   else if (rect.right > screenw + screenleft - 3)
     { result.scrollLeft = rect.right + (tooWide ? 0 : 10) - screenw; }
   return result
 }

 // Store a relative adjustment to the scroll position in the current
 // operation (to be applied when the operation finishes).
 function addToScrollTop(cm, top) {
   if (top == null) { return }
   resolveScrollToPos(cm);
   cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top;
 }

 // Make sure that at the end of the operation the current cursor is
 // shown.
 function ensureCursorVisible(cm) {
   resolveScrollToPos(cm);
   var cur = cm.getCursor();
   cm.curOp.scrollToPos = {from: cur, to: cur, margin: cm.options.cursorScrollMargin};
 }

 function scrollToCoords(cm, x, y) {
   if (x != null || y != null) { resolveScrollToPos(cm); }
   if (x != null) { cm.curOp.scrollLeft = x; }
   if (y != null) { cm.curOp.scrollTop = y; }
 }

 function scrollToRange(cm, range) {
   resolveScrollToPos(cm);
   cm.curOp.scrollToPos = range;
 }

 // When an operation has its scrollToPos property set, and another
 // scroll action is applied before the end of the operation, this
 // 'simulates' scrolling that position into view in a cheap way, so
 // that the effect of intermediate scroll commands is not ignored.
 function resolveScrollToPos(cm) {
   var range = cm.curOp.scrollToPos;
   if (range) {
     cm.curOp.scrollToPos = null;
     var from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to);
     scrollToCoordsRange(cm, from, to, range.margin);
   }
 }

 function scrollToCoordsRange(cm, from, to, margin) {
   var sPos = calculateScrollPos(cm, {
     left: Math.min(from.left, to.left),
     top: Math.min(from.top, to.top) - margin,
     right: Math.max(from.right, to.right),
     bottom: Math.max(from.bottom, to.bottom) + margin
   });
   scrollToCoords(cm, sPos.scrollLeft, sPos.scrollTop);
 }

 // Sync the scrollable area and scrollbars, ensure the viewport
 // covers the visible area.
 function updateScrollTop(cm, val) {
   if (Math.abs(cm.doc.scrollTop - val) < 2) { return }
   if (!gecko) { updateDisplaySimple(cm, {top: val}); }
   setScrollTop(cm, val, true);
   if (gecko) { updateDisplaySimple(cm); }
   startWorker(cm, 100);
 }

 function setScrollTop(cm, val, forceScroll) {
   val = Math.max(0, Math.min(cm.display.scroller.scrollHeight - cm.display.scroller.clientHeight, val));
   if (cm.display.scroller.scrollTop == val && !forceScroll) { return }
   cm.doc.scrollTop = val;
   cm.display.scrollbars.setScrollTop(val);
   if (cm.display.scroller.scrollTop != val) { cm.display.scroller.scrollTop = val; }
 }

 // Sync scroller and scrollbar, ensure the gutter elements are
 // aligned.
 function setScrollLeft(cm, val, isScroller, forceScroll) {
   val = Math.max(0, Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth));
   if ((isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) && !forceScroll) { return }
   cm.doc.scrollLeft = val;
   alignHorizontally(cm);
   if (cm.display.scroller.scrollLeft != val) { cm.display.scroller.scrollLeft = val; }
   cm.display.scrollbars.setScrollLeft(val);
 }

 // SCROLLBARS

 // Prepare DOM reads needed to update the scrollbars. Done in one
 // shot to minimize update/measure roundtrips.
 function measureForScrollbars(cm) {
   var d = cm.display, gutterW = d.gutters.offsetWidth;
   var docH = Math.round(cm.doc.height + paddingVert(cm.display));
   return {
     clientHeight: d.scroller.clientHeight,
     viewHeight: d.wrapper.clientHeight,
     scrollWidth: d.scroller.scrollWidth, clientWidth: d.scroller.clientWidth,
     viewWidth: d.wrapper.clientWidth,
     barLeft: cm.options.fixedGutter ? gutterW : 0,
     docHeight: docH,
     scrollHeight: docH + scrollGap(cm) + d.barHeight,
     nativeBarWidth: d.nativeBarWidth,
     gutterWidth: gutterW
   }
 }

 var NativeScrollbars = function(place, scroll, cm) {
   this.cm = cm;
   var vert = this.vert = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");
   var horiz = this.horiz = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");
   vert.tabIndex = horiz.tabIndex = -1;
   place(vert); place(horiz);

   on(vert, "scroll", function () {
     if (vert.clientHeight) { scroll(vert.scrollTop, "vertical"); }
   });
   on(horiz, "scroll", function () {
     if (horiz.clientWidth) { scroll(horiz.scrollLeft, "horizontal"); }
   });

   this.checkedZeroWidth = false;
   // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
   if (ie && ie_version < 8) { this.horiz.style.minHeight = this.vert.style.minWidth = "18px"; }
 };

 NativeScrollbars.prototype.update = function (measure) {
   var needsH = measure.scrollWidth > measure.clientWidth + 1;
   var needsV = measure.scrollHeight > measure.clientHeight + 1;
   var sWidth = measure.nativeBarWidth;

   if (needsV) {
     this.vert.style.display = "block";
     this.vert.style.bottom = needsH ? sWidth + "px" : "0";
     var totalHeight = measure.viewHeight - (needsH ? sWidth : 0);
     // A bug in IE8 can cause this value to be negative, so guard it.
     this.vert.firstChild.style.height =
       Math.max(0, measure.scrollHeight - measure.clientHeight + totalHeight) + "px";
   } else {
     this.vert.style.display = "";
     this.vert.firstChild.style.height = "0";
   }

   if (needsH) {
     this.horiz.style.display = "block";
     this.horiz.style.right = needsV ? sWidth + "px" : "0";
     this.horiz.style.left = measure.barLeft + "px";
     var totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0);
     this.horiz.firstChild.style.width =
       Math.max(0, measure.scrollWidth - measure.clientWidth + totalWidth) + "px";
   } else {
     this.horiz.style.display = "";
     this.horiz.firstChild.style.width = "0";
   }

   if (!this.checkedZeroWidth && measure.clientHeight > 0) {
     if (sWidth == 0) { this.zeroWidthHack(); }
     this.checkedZeroWidth = true;
   }

   return {right: needsV ? sWidth : 0, bottom: needsH ? sWidth : 0}
 };

 NativeScrollbars.prototype.setScrollLeft = function (pos) {
   if (this.horiz.scrollLeft != pos) { this.horiz.scrollLeft = pos; }
   if (this.disableHoriz) { this.enableZeroWidthBar(this.horiz, this.disableHoriz, "horiz"); }
 };

 NativeScrollbars.prototype.setScrollTop = function (pos) {
   if (this.vert.scrollTop != pos) { this.vert.scrollTop = pos; }
   if (this.disableVert) { this.enableZeroWidthBar(this.vert, this.disableVert, "vert"); }
 };

 NativeScrollbars.prototype.zeroWidthHack = function () {
   var w = mac && !mac_geMountainLion ? "12px" : "18px";
   this.horiz.style.height = this.vert.style.width = w;
   this.horiz.style.pointerEvents = this.vert.style.pointerEvents = "none";
   this.disableHoriz = new Delayed;
   this.disableVert = new Delayed;
 };

 NativeScrollbars.prototype.enableZeroWidthBar = function (bar, delay, type) {
   bar.style.pointerEvents = "auto";
   function maybeDisable() {
     // To find out whether the scrollbar is still visible, we
     // check whether the element under the pixel in the bottom
     // right corner of the scrollbar box is the scrollbar box
     // itself (when the bar is still visible) or its filler child
     // (when the bar is hidden). If it is still visible, we keep
     // it enabled, if it's hidden, we disable pointer events.
     var box = bar.getBoundingClientRect();
     var elt = type == "vert" ? document.elementFromPoint(box.right - 1, (box.top + box.bottom) / 2)
         : document.elementFromPoint((box.right + box.left) / 2, box.bottom - 1);
     if (elt != bar) { bar.style.pointerEvents = "none"; }
     else { delay.set(1000, maybeDisable); }
   }
   delay.set(1000, maybeDisable);
 };

 NativeScrollbars.prototype.clear = function () {
   var parent = this.horiz.parentNode;
   parent.removeChild(this.horiz);
   parent.removeChild(this.vert);
 };

 var NullScrollbars = function () {};

 NullScrollbars.prototype.update = function () { return {bottom: 0, right: 0} };
 NullScrollbars.prototype.setScrollLeft = function () {};
 NullScrollbars.prototype.setScrollTop = function () {};
 NullScrollbars.prototype.clear = function () {};

 function updateScrollbars(cm, measure) {
   if (!measure) { measure = measureForScrollbars(cm); }
   var startWidth = cm.display.barWidth, startHeight = cm.display.barHeight;
   updateScrollbarsInner(cm, measure);
   for (var i = 0; i < 4 && startWidth != cm.display.barWidth || startHeight != cm.display.barHeight; i++) {
     if (startWidth != cm.display.barWidth && cm.options.lineWrapping)
       { updateHeightsInViewport(cm); }
     updateScrollbarsInner(cm, measureForScrollbars(cm));
     startWidth = cm.display.barWidth; startHeight = cm.display.barHeight;
   }
 }

 // Re-synchronize the fake scrollbars with the actual size of the
 // content.
 function updateScrollbarsInner(cm, measure) {
   var d = cm.display;
   var sizes = d.scrollbars.update(measure);

   d.sizer.style.paddingRight = (d.barWidth = sizes.right) + "px";
   d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + "px";
   d.heightForcer.style.borderBottom = sizes.bottom + "px solid transparent";

   if (sizes.right && sizes.bottom) {
     d.scrollbarFiller.style.display = "block";
     d.scrollbarFiller.style.height = sizes.bottom + "px";
     d.scrollbarFiller.style.width = sizes.right + "px";
   } else { d.scrollbarFiller.style.display = ""; }
   if (sizes.bottom && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
     d.gutterFiller.style.display = "block";
     d.gutterFiller.style.height = sizes.bottom + "px";
     d.gutterFiller.style.width = measure.gutterWidth + "px";
   } else { d.gutterFiller.style.display = ""; }
 }

 var scrollbarModel = {"native": NativeScrollbars, "null": NullScrollbars};

 function initScrollbars(cm) {
   if (cm.display.scrollbars) {
     cm.display.scrollbars.clear();
     if (cm.display.scrollbars.addClass)
       { rmClass(cm.display.wrapper, cm.display.scrollbars.addClass); }
   }

   cm.display.scrollbars = new scrollbarModel[cm.options.scrollbarStyle](function (node) {
     cm.display.wrapper.insertBefore(node, cm.display.scrollbarFiller);
     // Prevent clicks in the scrollbars from killing focus
     on(node, "mousedown", function () {
       if (cm.state.focused) { setTimeout(function () { return cm.display.input.focus(); }, 0); }
     });
     node.setAttribute("cm-not-content", "true");
   }, function (pos, axis) {
     if (axis == "horizontal") { setScrollLeft(cm, pos); }
     else { updateScrollTop(cm, pos); }
   }, cm);
   if (cm.display.scrollbars.addClass)
     { addClass(cm.display.wrapper, cm.display.scrollbars.addClass); }
 }

 // Operations are used to wrap a series of changes to the editor
 // state in such a way that each change won't have to update the
 // cursor and display (which would be awkward, slow, and
 // error-prone). Instead, display updates are batched and then all
 // combined and executed at once.

 var nextOpId = 0;
 // Start a new operation.
 function startOperation(cm) {
   cm.curOp = {
     cm: cm,
     viewChanged: false,      // Flag that indicates that lines might need to be redrawn
     startHeight: cm.doc.height, // Used to detect need to update scrollbar
     forceUpdate: false,      // Used to force a redraw
     updateInput: 0,       // Whether to reset the input textarea
     typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
     changeObjs: null,        // Accumulated changes, for firing change events
     cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
     cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already
     selectionChanged: false, // Whether the selection needs to be redrawn
     updateMaxLine: false,    // Set when the widest line needs to be determined anew
     scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
     scrollToPos: null,       // Used to scroll to a specific position
     focus: false,
     id: ++nextOpId           // Unique ID
   };
   pushOperation(cm.curOp);
 }

 // Finish an operation, updating the display and signalling delayed events
 function endOperation(cm) {
   var op = cm.curOp;
   if (op) { finishOperation(op, function (group) {
     for (var i = 0; i < group.ops.length; i++)
       { group.ops[i].cm.curOp = null; }
     endOperations(group);
   }); }
 }

 // The DOM updates done when an operation finishes are batched so
 // that the minimum number of relayouts are required.
 function endOperations(group) {
   var ops = group.ops;
   for (var i = 0; i < ops.length; i++) // Read DOM
     { endOperation_R1(ops[i]); }
   for (var i$1 = 0; i$1 < ops.length; i$1++) // Write DOM (maybe)
     { endOperation_W1(ops[i$1]); }
   for (var i$2 = 0; i$2 < ops.length; i$2++) // Read DOM
     { endOperation_R2(ops[i$2]); }
   for (var i$3 = 0; i$3 < ops.length; i$3++) // Write DOM (maybe)
     { endOperation_W2(ops[i$3]); }
   for (var i$4 = 0; i$4 < ops.length; i$4++) // Read DOM
     { endOperation_finish(ops[i$4]); }
 }

 function endOperation_R1(op) {
   var cm = op.cm, display = cm.display;
   maybeClipScrollbars(cm);
   if (op.updateMaxLine) { findMaxLine(cm); }

   op.mustUpdate = op.viewChanged || op.forceUpdate || op.scrollTop != null ||
     op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
                        op.scrollToPos.to.line >= display.viewTo) ||
     display.maxLineChanged && cm.options.lineWrapping;
   op.update = op.mustUpdate &&
     new DisplayUpdate(cm, op.mustUpdate && {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate);
 }

 function endOperation_W1(op) {
   op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update);
 }

 function endOperation_R2(op) {
   var cm = op.cm, display = cm.display;
   if (op.updatedDisplay) { updateHeightsInViewport(cm); }

   op.barMeasure = measureForScrollbars(cm);

   // If the max line changed since it was last measured, measure it,
   // and ensure the document's width matches it.
   // updateDisplay_W2 will use these properties to do the actual resizing
   if (display.maxLineChanged && !cm.options.lineWrapping) {
     op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3;
     cm.display.sizerWidth = op.adjustWidthTo;
     op.barMeasure.scrollWidth =
       Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth);
     op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm));
   }

   if (op.updatedDisplay || op.selectionChanged)
     { op.preparedSelection = display.input.prepareSelection(); }
 }

 function endOperation_W2(op) {
   var cm = op.cm;

   if (op.adjustWidthTo != null) {
     cm.display.sizer.style.minWidth = op.adjustWidthTo + "px";
     if (op.maxScrollLeft < cm.doc.scrollLeft)
       { setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true); }
     cm.display.maxLineChanged = false;
   }

   var takeFocus = op.focus && op.focus == activeElt();
   if (op.preparedSelection)
     { cm.display.input.showSelection(op.preparedSelection, takeFocus); }
   if (op.updatedDisplay || op.startHeight != cm.doc.height)
     { updateScrollbars(cm, op.barMeasure); }
   if (op.updatedDisplay)
     { setDocumentHeight(cm, op.barMeasure); }

   if (op.selectionChanged) { restartBlink(cm); }

   if (cm.state.focused && op.updateInput)
     { cm.display.input.reset(op.typing); }
   if (takeFocus) { ensureFocus(op.cm); }
 }

 function endOperation_finish(op) {
   var cm = op.cm, display = cm.display, doc = cm.doc;

   if (op.updatedDisplay) { postUpdateDisplay(cm, op.update); }

   // Abort mouse wheel delta measurement, when scrolling explicitly
   if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))
     { display.wheelStartX = display.wheelStartY = null; }

   // Propagate the scroll position to the actual DOM scroller
   if (op.scrollTop != null) { setScrollTop(cm, op.scrollTop, op.forceScroll); }

   if (op.scrollLeft != null) { setScrollLeft(cm, op.scrollLeft, true, true); }
   // If we need to scroll a specific position into view, do so.
   if (op.scrollToPos) {
     var rect = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from),
                                  clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin);
     maybeScrollWindow(cm, rect);
   }

   // Fire events for markers that are hidden/unidden by editing or
   // undoing
   var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
   if (hidden) { for (var i = 0; i < hidden.length; ++i)
     { if (!hidden[i].lines.length) { signal(hidden[i], "hide"); } } }
   if (unhidden) { for (var i$1 = 0; i$1 < unhidden.length; ++i$1)
     { 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); }
   }
 }

 // HIGHLIGHT WORKER

 function startWorker(cm, time) {
   if (cm.doc.highlightFrontier < cm.display.viewTo)
     { cm.state.highlight.set(time, bind(highlightWorker, cm)); }
 }

 function highlightWorker(cm) {
   var doc = cm.doc;
   if (doc.highlightFrontier >= cm.display.viewTo) { return }
   var end = +new Date + cm.options.workTime;
   var context = getContextBefore(cm, doc.highlightFrontier);
   var changedLines = [];

   doc.iter(context.line, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function (line) {
     if (context.line >= cm.display.viewFrom) { // Visible
       var oldStyles = line.styles;
       var resetState = line.text.length > cm.options.maxHighlightLength ? copyState(doc.mode, context.state) : null;
       var highlighted = highlightLine(cm, line, context, true);
       if (resetState) { context.state = resetState; }
       line.styles = highlighted.styles;
       var oldCls = line.styleClasses, newCls = highlighted.classes;
       if (newCls) { line.styleClasses = newCls; }
       else if (oldCls) { line.styleClasses = null; }
       var ischange = !oldStyles || oldStyles.length != line.styles.length ||
         oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass);
       for (var i = 0; !ischange && i < oldStyles.length; ++i) { ischange = oldStyles[i] != line.styles[i]; }
       if (ischange) { changedLines.push(context.line); }
       line.stateAfter = context.save();
       context.nextLine();
     } else {
       if (line.text.length <= cm.options.maxHighlightLength)
         { processLine(cm, line.text, context); }
       line.stateAfter = context.line % 5 == 0 ? context.save() : null;
       context.nextLine();
     }
     if (+new Date > end) {
       startWorker(cm, cm.options.workDelay);
       return true
     }
   });
   doc.highlightFrontier = context.line;
   doc.modeFrontier = Math.max(doc.modeFrontier, context.line);
   if (changedLines.length) { runInOp(cm, function () {
     for (var i = 0; i < changedLines.length; i++)
       { regLineChange(cm, changedLines[i], "text"); }
   }); }
 }

 // DISPLAY DRAWING

 var DisplayUpdate = function(cm, viewport, force) {
   var display = cm.display;

   this.viewport = viewport;
   // Store some values that we'll need later (but don't want to force a relayout for)
   this.visible = visibleLines(display, cm.doc, viewport);
   this.editorIsHidden = !display.wrapper.offsetWidth;
   this.wrapperHeight = display.wrapper.clientHeight;
   this.wrapperWidth = display.wrapper.clientWidth;
   this.oldDisplayWidth = displayWidth(cm);
   this.force = force;
   this.dims = getDimensions(cm);
   this.events = [];
 };

 DisplayUpdate.prototype.signal = function (emitter, type) {
   if (hasHandler(emitter, type))
     { this.events.push(arguments); }
 };
 DisplayUpdate.prototype.finish = function () {
   for (var i = 0; i < this.events.length; i++)
     { signal.apply(null, this.events[i]); }
 };

 function maybeClipScrollbars(cm) {
   var display = cm.display;
   if (!display.scrollbarsClipped && display.scroller.offsetWidth) {
     display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth;
     display.heightForcer.style.height = scrollGap(cm) + "px";
     display.sizer.style.marginBottom = -display.nativeBarWidth + "px";
     display.sizer.style.borderRightWidth = scrollGap(cm) + "px";
     display.scrollbarsClipped = true;
   }
 }

 function selectionSnapshot(cm) {
   if (cm.hasFocus()) { return null }
   var active = activeElt();
   if (!active || !contains(cm.display.lineDiv, active)) { return null }
   var result = {activeElt: active};
   if (window.getSelection) {
     var sel = window.getSelection();
     if (sel.anchorNode && sel.extend && contains(cm.display.lineDiv, sel.anchorNode)) {
       result.anchorNode = sel.anchorNode;
       result.anchorOffset = sel.anchorOffset;
       result.focusNode = sel.focusNode;
       result.focusOffset = sel.focusOffset;
     }
   }
   return result
 }

 function restoreSelection(snapshot) {
   if (!snapshot || !snapshot.activeElt || snapshot.activeElt == activeElt()) { return }
   snapshot.activeElt.focus();
   if (!/^(INPUT|TEXTAREA)$/.test(snapshot.activeElt.nodeName) &&
       snapshot.anchorNode && contains(document.body, snapshot.anchorNode) && contains(document.body, snapshot.focusNode)) {
     var sel = window.getSelection(), range = document.createRange();
     range.setEnd(snapshot.anchorNode, snapshot.anchorOffset);
     range.collapse(false);
     sel.removeAllRanges();
     sel.addRange(range);
     sel.extend(snapshot.focusNode, snapshot.focusOffset);
   }
 }

 // Does the actual updating of the line display. Bails out
 // (returning false) when there is nothing to be done and forced is
 // false.
 function updateDisplayIfNeeded(cm, update) {
   var display = cm.display, doc = cm.doc;

   if (update.editorIsHidden) {
     resetView(cm);
     return false
   }

   // Bail out if the visible area is already rendered and nothing changed.
   if (!update.force &&
       update.visible.from >= display.viewFrom && update.visible.to <= display.viewTo &&
       (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
       display.renderedView == display.view && countDirtyView(cm) == 0)
     { return false }

   if (maybeUpdateLineNumberWidth(cm)) {
     resetView(cm);
     update.dims = getDimensions(cm);
   }

   // Compute a suitable new viewport (from & to)
   var end = doc.first + doc.size;
   var from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first);
   var to = Math.min(end, update.visible.to + cm.options.viewportMargin);
   if (display.viewFrom < from && from - display.viewFrom < 20) { from = Math.max(doc.first, display.viewFrom); }
   if (display.viewTo > to && display.viewTo - to < 20) { to = Math.min(end, display.viewTo); }
   if (sawCollapsedSpans) {
     from = visualLineNo(cm.doc, from);
     to = visualLineEndNo(cm.doc, to);
   }

   var different = from != display.viewFrom || to != display.viewTo ||
     display.lastWrapHeight != update.wrapperHeight || display.lastWrapWidth != update.wrapperWidth;
   adjustView(cm, from, to);

   display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));
   // Position the mover div to align with the current scroll position
   cm.display.mover.style.top = display.viewOffset + "px";

   var toUpdate = countDirtyView(cm);
   if (!different && toUpdate == 0 && !update.force && display.renderedView == display.view &&
       (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo))
     { return false }

   // For big changes, we hide the enclosing element during the
   // update, since that speeds up the operations on most browsers.
   var selSnapshot = selectionSnapshot(cm);
   if (toUpdate > 4) { display.lineDiv.style.display = "none"; }
   patchDisplay(cm, display.updateLineNumbers, update.dims);
   if (toUpdate > 4) { display.lineDiv.style.display = ""; }
   display.renderedView = display.view;
   // There might have been a widget with a focused element that got
   // hidden or updated, if so re-focus it.
   restoreSelection(selSnapshot);

   // Prevent selection and cursors from interfering with the scroll
   // width and height.
   removeChildren(display.cursorDiv);
   removeChildren(display.selectionDiv);
   display.gutters.style.height = display.sizer.style.minHeight = 0;

   if (different) {
     display.lastWrapHeight = update.wrapperHeight;
     display.lastWrapWidth = update.wrapperWidth;
     startWorker(cm, 400);
   }

   display.updateLineNumbers = null;

   return true
 }

 function postUpdateDisplay(cm, update) {
   var viewport = update.viewport;

   for (var first = true;; first = false) {
     if (!first || !cm.options.lineWrapping || update.oldDisplayWidth == displayWidth(cm)) {
       // Clip forced viewport to actual scrollable area.
       if (viewport && viewport.top != null)
         { viewport = {top: Math.min(cm.doc.height + paddingVert(cm.display) - displayHeight(cm), viewport.top)}; }
       // Updated line heights might result in the drawn area not
       // actually covering the viewport. Keep looping until it does.
       update.visible = visibleLines(cm.display, cm.doc, viewport);
       if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo)
         { break }
     } else if (first) {
       update.visible = visibleLines(cm.display, cm.doc, viewport);
     }
     if (!updateDisplayIfNeeded(cm, update)) { break }
     updateHeightsInViewport(cm);
     var barMeasure = measureForScrollbars(cm);
     updateSelection(cm);
     updateScrollbars(cm, barMeasure);
     setDocumentHeight(cm, barMeasure);
     update.force = false;
   }

   update.signal(cm, "update", cm);
   if (cm.display.viewFrom != cm.display.reportedViewFrom || cm.display.viewTo != cm.display.reportedViewTo) {
     update.signal(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);
     cm.display.reportedViewFrom = cm.display.viewFrom; cm.display.reportedViewTo = cm.display.viewTo;
   }
 }

 function updateDisplaySimple(cm, viewport) {
   var update = new DisplayUpdate(cm, viewport);
   if (updateDisplayIfNeeded(cm, update)) {
     updateHeightsInViewport(cm);
     postUpdateDisplay(cm, update);
     var barMeasure = measureForScrollbars(cm);
     updateSelection(cm);
     updateScrollbars(cm, barMeasure);
     setDocumentHeight(cm, barMeasure);
     update.finish();
   }
 }

 // Sync the actual display DOM structure with display.view, removing
 // nodes for lines that are no longer in view, and creating the ones
 // that are not there yet, and updating the ones that are out of
 // date.
 function patchDisplay(cm, updateNumbersFrom, dims) {
   var display = cm.display, lineNumbers = cm.options.lineNumbers;
   var container = display.lineDiv, cur = container.firstChild;

   function rm(node) {
     var next = node.nextSibling;
     // Works around a throw-scroll bug in OS X Webkit
     if (webkit && mac && cm.display.currentWheelTarget == node)
       { node.style.display = "none"; }
     else
       { node.parentNode.removeChild(node); }
     return next
   }

   var view = display.view, lineN = display.viewFrom;
   // Loop over the elements in the view, syncing cur (the DOM nodes
   // in display.lineDiv) with the view as we go.
   for (var i = 0; i < view.length; i++) {
     var lineView = view[i];
     if (lineView.hidden) ; else if (!lineView.node || lineView.node.parentNode != container) { // Not drawn yet
       var node = buildLineElement(cm, lineView, lineN, dims);
       container.insertBefore(node, cur);
     } else { // Already drawn
       while (cur != lineView.node) { cur = rm(cur); }
       var updateNumber = lineNumbers && updateNumbersFrom != null &&
         updateNumbersFrom <= lineN && lineView.lineNumber;
       if (lineView.changes) {
         if (indexOf(lineView.changes, "gutter") > -1) { updateNumber = false; }
         updateLineForChanges(cm, lineView, lineN, dims);
       }
       if (updateNumber) {
         removeChildren(lineView.lineNumber);
         lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));
       }
       cur = lineView.node.nextSibling;
     }
     lineN += lineView.size;
   }
   while (cur) { cur = rm(cur); }
 }

 function updateGutterSpace(display) {
   var width = display.gutters.offsetWidth;
   display.sizer.style.marginLeft = width + "px";
 }

 function setDocumentHeight(cm, measure) {
   cm.display.sizer.style.minHeight = measure.docHeight + "px";
   cm.display.heightForcer.style.top = measure.docHeight + "px";
   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 renderGutters(display) {
   var gutters = display.gutters, specs = display.gutterSpecs;
   removeChildren(gutters);
   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 = specs.length ? "" : "none";
   updateGutterSpace(display);
 }

 function updateGutters(cm) {
   renderGutters(cm.display);
   regChange(cm);
   alignHorizontally(cm);
 }

 // 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
 // unstandardized between browsers and even browser versions, and
 // generally horribly unpredictable, this code starts by measuring
 // the scroll effect that the first few mouse wheel events have,
 // and, from that, detects the way it can convert deltas to pixel
 // offsets afterwards.
 //
 // The reason we want to know the amount a wheel event will scroll
 // is that it gives us a chance to update the display before the
 // actual scrolling happens, reducing flickering.

 var wheelSamples = 0, wheelPixelsPerUnit = null;
 // Fill in a browser-detected starting value on browsers where we
 // know one. These don't have to be accurate -- the result of them
 // being wrong would just be a slight flicker on the first wheel
 // scroll (if it is large enough).
 if (ie) { wheelPixelsPerUnit = -.53; }
 else if (gecko) { wheelPixelsPerUnit = 15; }
 else if (chrome) { wheelPixelsPerUnit = -.7; }
 else if (safari) { wheelPixelsPerUnit = -1/3; }

 function wheelEventDelta(e) {
   var dx = e.wheelDeltaX, dy = e.wheelDeltaY;
   if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) { dx = e.detail; }
   if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) { dy = e.detail; }
   else if (dy == null) { dy = e.wheelDelta; }
   return {x: dx, y: dy}
 }
 function wheelEventPixels(e) {
   var delta = wheelEventDelta(e);
   delta.x *= wheelPixelsPerUnit;
   delta.y *= wheelPixelsPerUnit;
   return delta
 }

 function onScrollWheel(cm, e) {
   var delta = wheelEventDelta(e), dx = delta.x, dy = delta.y;

   var display = cm.display, scroll = display.scroller;
   // Quit if there's nothing to scroll here
   var canScrollX = scroll.scrollWidth > scroll.clientWidth;
   var canScrollY = scroll.scrollHeight > scroll.clientHeight;
   if (!(dx && canScrollX || dy && canScrollY)) { return }

   // Webkit browsers on OS X abort momentum scrolls when the target
   // of the scroll event is removed from the scrollable element.
   // This hack (see related code in patchDisplay) makes sure the
   // element is kept around.
   if (dy && mac && webkit) {
     outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
       for (var i = 0; i < view.length; i++) {
         if (view[i].node == cur) {
           cm.display.currentWheelTarget = cur;
           break outer
         }
       }
     }
   }

   // On some browsers, horizontal scrolling will cause redraws to
   // happen before the gutter has been realigned, causing it to
   // wriggle around in a most unseemly way. When we have an
   // estimated pixels/delta value, we just handle horizontal
   // scrolling entirely here. It'll be slightly off from native, but
   // better than glitching out.
   if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {
     if (dy && canScrollY)
       { updateScrollTop(cm, Math.max(0, scroll.scrollTop + dy * wheelPixelsPerUnit)); }
     setScrollLeft(cm, Math.max(0, scroll.scrollLeft + dx * wheelPixelsPerUnit));
     // Only prevent default scrolling if vertical scrolling is
     // actually possible. Otherwise, it causes vertical scroll
     // jitter on OSX trackpads when deltaX is small and deltaY
     // is large (issue #3579)
     if (!dy || (dy && canScrollY))
       { e_preventDefault(e); }
     display.wheelStartX = null; // Abort measurement, if in progress
     return
   }

   // 'Project' the visible viewport to cover the area that is being
   // scrolled into view (if we know enough to estimate it).
   if (dy && wheelPixelsPerUnit != null) {
     var pixels = dy * wheelPixelsPerUnit;
     var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;
     if (pixels < 0) { top = Math.max(0, top + pixels - 50); }
     else { bot = Math.min(cm.doc.height, bot + pixels + 50); }
     updateDisplaySimple(cm, {top: top, bottom: bot});
   }

   if (wheelSamples < 20) {
     if (display.wheelStartX == null) {
       display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;
       display.wheelDX = dx; display.wheelDY = dy;
       setTimeout(function () {
         if (display.wheelStartX == null) { return }
         var movedX = scroll.scrollLeft - display.wheelStartX;
         var movedY = scroll.scrollTop - display.wheelStartY;
         var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
           (movedX && display.wheelDX && movedX / display.wheelDX);
         display.wheelStartX = display.wheelStartY = null;
         if (!sample) { return }
         wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);
         ++wheelSamples;
       }, 200);
     } else {
       display.wheelDX += dx; display.wheelDY += dy;
     }
   }
 }

 // Selection objects are immutable. A new one is created every time
 // the selection changes. A selection is one or more non-overlapping
 // (and non-touching) ranges, sorted, and an integer that indicates
 // which one is the primary selection (the one that's scrolled into
 // view, that getCursor returns, etc).
 var Selection = function(ranges, primIndex) {
   this.ranges = ranges;
   this.primIndex = primIndex;
 };

 Selection.prototype.primary = function () { return this.ranges[this.primIndex] };

 Selection.prototype.equals = function (other) {
   if (other == this) { return true }
   if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) { return false }
   for (var i = 0; i < this.ranges.length; i++) {
     var here = this.ranges[i], there = other.ranges[i];
     if (!equalCursorPos(here.anchor, there.anchor) || !equalCursorPos(here.head, there.head)) { return false }
   }
   return true
 };

 Selection.prototype.deepCopy = function () {
   var out = [];
   for (var i = 0; i < this.ranges.length; i++)
     { out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head)); }
   return new Selection(out, this.primIndex)
 };

 Selection.prototype.somethingSelected = function () {
   for (var i = 0; i < this.ranges.length; i++)
     { if (!this.ranges[i].empty()) { return true } }
   return false
 };

 Selection.prototype.contains = function (pos, end) {
   if (!end) { end = pos; }
   for (var i = 0; i < this.ranges.length; i++) {
     var range = this.ranges[i];
     if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)
       { return i }
   }
   return -1
 };

 var Range = function(anchor, head) {
   this.anchor = anchor; this.head = head;
 };

 Range.prototype.from = function () { return minPos(this.anchor, this.head) };
 Range.prototype.to = function () { return maxPos(this.anchor, this.head) };
 Range.prototype.empty = function () { return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch };

 // Take an unsorted, potentially overlapping set of ranges, and
 // build a selection out of it. 'Consumes' ranges array (modifying
 // it).
 function normalizeSelection(cm, ranges, primIndex) {
   var mayTouch = cm && cm.options.selectionsMayTouch;
   var prim = ranges[primIndex];
   ranges.sort(function (a, b) { return cmp(a.from(), b.from()); });
   primIndex = indexOf(ranges, prim);
   for (var i = 1; i < ranges.length; i++) {
     var cur = ranges[i], prev = ranges[i - 1];
     var diff = cmp(prev.to(), cur.from());
     if (mayTouch && !cur.empty() ? diff > 0 : diff >= 0) {
       var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());
       var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;
       if (i <= primIndex) { --primIndex; }
       ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));
     }
   }
   return new Selection(ranges, primIndex)
 }

 function simpleSelection(anchor, head) {
   return new Selection([new Range(anchor, head || anchor)], 0)
 }

 // Compute the position of the end of a change (its 'to' property
 // refers to the pre-change end).
 function changeEnd(change) {
   if (!change.text) { return change.to }
   return Pos(change.from.line + change.text.length - 1,
              lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0))
 }

 // Adjust a position to refer to the post-change position of the
 // same text, or the end of the change if the change covers it.
 function adjustForChange(pos, change) {
   if (cmp(pos, change.from) < 0) { return pos }
   if (cmp(pos, change.to) <= 0) { return changeEnd(change) }

   var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
   if (pos.line == change.to.line) { ch += changeEnd(change).ch - change.to.ch; }
   return Pos(line, ch)
 }

 function computeSelAfterChange(doc, change) {
   var out = [];
   for (var i = 0; i < doc.sel.ranges.length; i++) {
     var range = doc.sel.ranges[i];
     out.push(new Range(adjustForChange(range.anchor, change),
                        adjustForChange(range.head, change)));
   }
   return normalizeSelection(doc.cm, out, doc.sel.primIndex)
 }

 function offsetPos(pos, old, nw) {
   if (pos.line == old.line)
     { return Pos(nw.line, pos.ch - old.ch + nw.ch) }
   else
     { return Pos(nw.line + (pos.line - old.line), pos.ch) }
 }

 // Used by replaceSelections to allow moving the selection to the
 // start or around the replaced test. Hint may be "start" or "around".
 function computeReplacedSel(doc, changes, hint) {
   var out = [];
   var oldPrev = Pos(doc.first, 0), newPrev = oldPrev;
   for (var i = 0; i < changes.length; i++) {
     var change = changes[i];
     var from = offsetPos(change.from, oldPrev, newPrev);
     var to = offsetPos(changeEnd(change), oldPrev, newPrev);
     oldPrev = change.to;
     newPrev = to;
     if (hint == "around") {
       var range = doc.sel.ranges[i], inv = cmp(range.head, range.anchor) < 0;
       out[i] = new Range(inv ? to : from, inv ? from : to);
     } else {
       out[i] = new Range(from, from);
     }
   }
   return new Selection(out, doc.sel.primIndex)
 }

 // Used to get the editor into a consistent state again when options change.

 function loadMode(cm) {
   cm.doc.mode = getMode(cm.options, cm.doc.modeOption);
   resetModeState(cm);
 }

 function resetModeState(cm) {
   cm.doc.iter(function (line) {
     if (line.stateAfter) { line.stateAfter = null; }
     if (line.styles) { line.styles = null; }
   });
   cm.doc.modeFrontier = cm.doc.highlightFrontier = cm.doc.first;
   startWorker(cm, 100);
   cm.state.modeGen++;
   if (cm.curOp) { regChange(cm); }
 }

 // DOCUMENT DATA STRUCTURE

 // By default, updates that start and end at the beginning of a line
 // are treated specially, in order to make the association of line
 // widgets and marker elements with the text behave more intuitive.
 function isWholeLineUpdate(doc, change) {
   return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == "" &&
     (!doc.cm || doc.cm.options.wholeLineUpdateBefore)
 }

 // Perform a change on the document data structure.
 function updateDoc(doc, change, markedSpans, estimateHeight) {
   function spansFor(n) {return markedSpans ? markedSpans[n] : null}
   function update(line, text, spans) {
     updateLine(line, text, spans, estimateHeight);
     signalLater(line, "change", line, change);
   }
   function linesFor(start, end) {
     var result = [];
     for (var i = start; i < end; ++i)
       { result.push(new Line(text[i], spansFor(i), estimateHeight)); }
     return result
   }

   var from = change.from, to = change.to, text = change.text;
   var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);
   var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;

   // Adjust the line structure
   if (change.full) {
     doc.insert(0, linesFor(0, text.length));
     doc.remove(text.length, doc.size - text.length);
   } else if (isWholeLineUpdate(doc, change)) {
     // This is a whole-line replace. Treated specially to make
     // sure line objects move the way they are supposed to.
     var added = linesFor(0, text.length - 1);
     update(lastLine, lastLine.text, lastSpans);
     if (nlines) { doc.remove(from.line, nlines); }
     if (added.length) { doc.insert(from.line, added); }
   } else if (firstLine == lastLine) {
     if (text.length == 1) {
       update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);
     } else {
       var added$1 = linesFor(1, text.length - 1);
       added$1.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));
       update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
       doc.insert(from.line + 1, added$1);
     }
   } else if (text.length == 1) {
     update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));
     doc.remove(from.line + 1, nlines);
   } else {
     update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
     update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);
     var added$2 = linesFor(1, text.length - 1);
     if (nlines > 1) { doc.remove(from.line + 1, nlines - 1); }
     doc.insert(from.line + 1, added$2);
   }

   signalLater(doc, "change", doc, change);
 }

 // Call f for all linked documents.
 function linkedDocs(doc, f, sharedHistOnly) {
   function propagate(doc, skip, sharedHist) {
     if (doc.linked) { for (var i = 0; i < doc.linked.length; ++i) {
       var rel = doc.linked[i];
       if (rel.doc == skip) { continue }
       var shared = sharedHist && rel.sharedHist;
       if (sharedHistOnly && !shared) { continue }
       f(rel.doc, shared);
       propagate(rel.doc, doc, shared);
     } }
   }
   propagate(doc, null, true);
 }

 // Attach a document to an editor.
 function attachDoc(cm, doc) {
   if (doc.cm) { throw new Error("This document is already in use.") }
   cm.doc = doc;
   doc.cm = cm;
   estimateLineHeights(cm);
   loadMode(cm);
   setDirectionClass(cm);
   if (!cm.options.lineWrapping) { findMaxLine(cm); }
   cm.options.mode = doc.modeOption;
   regChange(cm);
 }

 function setDirectionClass(cm) {
 (cm.doc.direction == "rtl" ? addClass : rmClass)(cm.display.lineDiv, "CodeMirror-rtl");
 }

 function directionChanged(cm) {
   runInOp(cm, function () {
     setDirectionClass(cm);
     regChange(cm);
   });
 }

 function History(startGen) {
   // Arrays of change events and selections. Doing something adds an
   // event to done and clears undo. Undoing moves events from done
   // to undone, redoing moves them in the other direction.
   this.done = []; this.undone = [];
   this.undoDepth = Infinity;
   // Used to track when changes can be merged into a single undo
   // event
   this.lastModTime = this.lastSelTime = 0;
   this.lastOp = this.lastSelOp = null;
   this.lastOrigin = this.lastSelOrigin = null;
   // Used by the isClean() method
   this.generation = this.maxGeneration = startGen || 1;
 }

 // Create a history change event from an updateDoc-style change
 // object.
 function historyChangeFromChange(doc, change) {
   var histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)};
   attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);
   linkedDocs(doc, function (doc) { return attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1); }, true);
   return histChange
 }

 // Pop all selection events off the end of a history array. Stop at
 // a change event.
 function clearSelectionEvents(array) {
   while (array.length) {
     var last = lst(array);
     if (last.ranges) { array.pop(); }
     else { break }
   }
 }

 // Find the top change event in the history. Pop off selection
 // events that are in the way.
 function lastChangeEvent(hist, force) {
   if (force) {
     clearSelectionEvents(hist.done);
     return lst(hist.done)
   } else if (hist.done.length && !lst(hist.done).ranges) {
     return lst(hist.done)
   } else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
     hist.done.pop();
     return lst(hist.done)
   }
 }

 // Register a change in the history. Merges changes that are within
 // a single operation, or are close together with an origin that
 // allows merging (starting with "+") into a single event.
 function addChangeToHistory(doc, change, selAfter, opId) {
   var hist = doc.history;
   hist.undone.length = 0;
   var time = +new Date, cur;
   var last;

   if ((hist.lastOp == opId ||
        hist.lastOrigin == change.origin && change.origin &&
        ((change.origin.charAt(0) == "+" && hist.lastModTime > time - (doc.cm ? doc.cm.options.historyEventDelay : 500)) ||
         change.origin.charAt(0) == "*")) &&
       (cur = lastChangeEvent(hist, hist.lastOp == opId))) {
     // Merge this change into the last event
     last = lst(cur.changes);
     if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
       // Optimized case for simple insertion -- don't want to add
       // new changesets for every character typed
       last.to = changeEnd(change);
     } else {
       // Add new sub-event
       cur.changes.push(historyChangeFromChange(doc, change));
     }
   } else {
     // Can not be merged, start a new event.
     var before = lst(hist.done);
     if (!before || !before.ranges)
       { pushSelectionToHistory(doc.sel, hist.done); }
     cur = {changes: [historyChangeFromChange(doc, change)],
            generation: hist.generation};
     hist.done.push(cur);
     while (hist.done.length > hist.undoDepth) {
       hist.done.shift();
       if (!hist.done[0].ranges) { hist.done.shift(); }
     }
   }
   hist.done.push(selAfter);
   hist.generation = ++hist.maxGeneration;
   hist.lastModTime = hist.lastSelTime = time;
   hist.lastOp = hist.lastSelOp = opId;
   hist.lastOrigin = hist.lastSelOrigin = change.origin;

   if (!last) { signal(doc, "historyAdded"); }
 }

 function selectionEventCanBeMerged(doc, origin, prev, sel) {
   var ch = origin.charAt(0);
   return ch == "*" ||
     ch == "+" &&
     prev.ranges.length == sel.ranges.length &&
     prev.somethingSelected() == sel.somethingSelected() &&
     new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500)
 }

 // Called whenever the selection changes, sets the new selection as
 // the pending selection in the history, and pushes the old pending
 // selection into the 'done' array when it was significantly
 // different (in number of selected ranges, emptiness, or time).
 function addSelectionToHistory(doc, sel, opId, options) {
   var hist = doc.history, origin = options && options.origin;

   // A new event is started when the previous origin does not match
   // the current, or the origins don't allow matching. Origins
   // starting with * are always merged, those starting with + are
   // merged when similar and close together in time.
   if (opId == hist.lastSelOp ||
       (origin && hist.lastSelOrigin == origin &&
        (hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||
         selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))
     { hist.done[hist.done.length - 1] = sel; }
   else
     { pushSelectionToHistory(sel, hist.done); }

   hist.lastSelTime = +new Date;
   hist.lastSelOrigin = origin;
   hist.lastSelOp = opId;
   if (options && options.clearRedo !== false)
     { clearSelectionEvents(hist.undone); }
 }

 function pushSelectionToHistory(sel, dest) {
   var top = lst(dest);
   if (!(top && top.ranges && top.equals(sel)))
     { dest.push(sel); }
 }

 // Used to store marked span information in the history.
 function attachLocalSpans(doc, change, from, to) {
   var existing = change["spans_" + doc.id], n = 0;
   doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function (line) {
     if (line.markedSpans)
       { (existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans; }
     ++n;
   });
 }

 // When un/re-doing restores text containing marked spans, those
 // that have been explicitly cleared should not be restored.
 function removeClearedSpans(spans) {
   if (!spans) { return null }
   var out;
   for (var i = 0; i < spans.length; ++i) {
     if (spans[i].marker.explicitlyCleared) { if (!out) { out = spans.slice(0, i); } }
     else if (out) { out.push(spans[i]); }
   }
   return !out ? spans : out.length ? out : null
 }

 // Retrieve and filter the old marked spans stored in a change event.
 function getOldSpans(doc, change) {
   var found = change["spans_" + doc.id];
   if (!found) { return null }
   var nw = [];
   for (var i = 0; i < change.text.length; ++i)
     { nw.push(removeClearedSpans(found[i])); }
   return nw
 }

 // Used for un/re-doing changes from the history. Combines the
 // result of computing the existing spans with the set of spans that
 // existed in the history (so that deleting around a span and then
 // undoing brings back the span).
 function mergeOldSpans(doc, change) {
   var old = getOldSpans(doc, change);
   var stretched = stretchSpansOverChange(doc, change);
   if (!old) { return stretched }
   if (!stretched) { return old }

   for (var i = 0; i < old.length; ++i) {
     var oldCur = old[i], stretchCur = stretched[i];
     if (oldCur && stretchCur) {
       spans: for (var j = 0; j < stretchCur.length; ++j) {
         var span = stretchCur[j];
         for (var k = 0; k < oldCur.length; ++k)
           { if (oldCur[k].marker == span.marker) { continue spans } }
         oldCur.push(span);
       }
     } else if (stretchCur) {
       old[i] = stretchCur;
     }
   }
   return old
 }

 // Used both to provide a JSON-safe object in .getHistory, and, when
 // detaching a document, to split the history in two
 function copyHistoryArray(events, newGroup, instantiateSel) {
   var copy = [];
   for (var i = 0; i < events.length; ++i) {
     var event = events[i];
     if (event.ranges) {
       copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event);
       continue
     }
     var changes = event.changes, newChanges = [];
     copy.push({changes: newChanges});
     for (var j = 0; j < changes.length; ++j) {
       var change = changes[j], m = (void 0);
       newChanges.push({from: change.from, to: change.to, text: change.text});
       if (newGroup) { for (var prop in change) { if (m = prop.match(/^spans_(\d+)$/)) {
         if (indexOf(newGroup, Number(m[1])) > -1) {
           lst(newChanges)[prop] = change[prop];
           delete change[prop];
         }
       } } }
     }
   }
   return copy
 }

 // The 'scroll' parameter given to many of these indicated whether
 // the new cursor position should be scrolled into view after
 // modifying the selection.

 // If shift is held or the extend flag is set, extends a range to
 // include a given position (and optionally a second position).
 // Otherwise, simply returns the range between the given positions.
 // Used for cursor motion and such.
 function extendRange(range, head, other, extend) {
   if (extend) {
     var anchor = range.anchor;
     if (other) {
       var posBefore = cmp(head, anchor) < 0;
       if (posBefore != (cmp(other, anchor) < 0)) {
         anchor = head;
         head = other;
       } else if (posBefore != (cmp(head, other) < 0)) {
         head = other;
       }
     }
     return new Range(anchor, head)
   } else {
     return new Range(other || head, head)
   }
 }

 // Extend the primary selection range, discard the rest.
 function extendSelection(doc, head, other, options, extend) {
   if (extend == null) { extend = doc.cm && (doc.cm.display.shift || doc.extend); }
   setSelection(doc, new Selection([extendRange(doc.sel.primary(), head, other, extend)], 0), options);
 }

 // Extend all selections (pos is an array of selections with length
 // equal the number of selections)
 function extendSelections(doc, heads, options) {
   var out = [];
   var extend = doc.cm && (doc.cm.display.shift || doc.extend);
   for (var i = 0; i < doc.sel.ranges.length; i++)
     { out[i] = extendRange(doc.sel.ranges[i], heads[i], null, extend); }
   var newSel = normalizeSelection(doc.cm, out, doc.sel.primIndex);
   setSelection(doc, newSel, options);
 }

 // Updates a single range in the selection.
 function replaceOneSelection(doc, i, range, options) {
   var ranges = doc.sel.ranges.slice(0);
   ranges[i] = range;
   setSelection(doc, normalizeSelection(doc.cm, ranges, doc.sel.primIndex), options);
 }

 // Reset the selection to a single range.
 function setSimpleSelection(doc, anchor, head, options) {
   setSelection(doc, simpleSelection(anchor, head), options);
 }

 // Give beforeSelectionChange handlers a change to influence a
 // selection update.
 function filterSelectionChange(doc, sel, options) {
   var obj = {
     ranges: sel.ranges,
     update: function(ranges) {
       this.ranges = [];
       for (var i = 0; i < ranges.length; i++)
         { this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),
                                    clipPos(doc, ranges[i].head)); }
     },
     origin: options && options.origin
   };
   signal(doc, "beforeSelectionChange", doc, obj);
   if (doc.cm) { signal(doc.cm, "beforeSelectionChange", doc.cm, obj); }
   if (obj.ranges != sel.ranges) { return normalizeSelection(doc.cm, obj.ranges, obj.ranges.length - 1) }
   else { return sel }
 }

 function setSelectionReplaceHistory(doc, sel, options) {
   var done = doc.history.done, last = lst(done);
   if (last && last.ranges) {
     done[done.length - 1] = sel;
     setSelectionNoUndo(doc, sel, options);
   } else {
     setSelection(doc, sel, options);
   }
 }

 // Set a new selection.
 function setSelection(doc, sel, options) {
   setSelectionNoUndo(doc, sel, options);
   addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);
 }

 function setSelectionNoUndo(doc, sel, options) {
   if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))
     { sel = filterSelectionChange(doc, sel, options); }

   var bias = options && options.bias ||
     (cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1);
   setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));

   if (!(options && options.scroll === false) && doc.cm)
     { ensureCursorVisible(doc.cm); }
 }

 function setSelectionInner(doc, sel) {
   if (sel.equals(doc.sel)) { return }

   doc.sel = sel;

   if (doc.cm) {
     doc.cm.curOp.updateInput = 1;
     doc.cm.curOp.selectionChanged = true;
     signalCursorActivity(doc.cm);
   }
   signalLater(doc, "cursorActivity", doc);
 }

 // Verify that the selection does not partially select any atomic
 // marked ranges.
 function reCheckSelection(doc) {
   setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false));
 }

 // Return a selection that does not partially select any atomic
 // ranges.
 function skipAtomicInSelection(doc, sel, bias, mayClear) {
   var out;
   for (var i = 0; i < sel.ranges.length; i++) {
     var range = sel.ranges[i];
     var old = sel.ranges.length == doc.sel.ranges.length && doc.sel.ranges[i];
     var newAnchor = skipAtomic(doc, range.anchor, old && old.anchor, bias, mayClear);
     var newHead = skipAtomic(doc, range.head, old && old.head, bias, mayClear);
     if (out || newAnchor != range.anchor || newHead != range.head) {
       if (!out) { out = sel.ranges.slice(0, i); }
       out[i] = new Range(newAnchor, newHead);
     }
   }
   return out ? normalizeSelection(doc.cm, out, sel.primIndex) : sel
 }

 function skipAtomicInner(doc, pos, oldPos, dir, mayClear) {
   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;

     // 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) {
           if (!line.markedSpans) { break }
           else {--i; continue}
         }
       }
       if (!m.atomic) { continue }

       if (oldPos) {
         var near = m.find(dir < 0 ? 1 : -1), diff = (void 0);
         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 ? preventCursorLeft : preventCursorRight)
         { far = movePos(doc, far, dir, far.line == pos.line ? line : null); }
       return far ? skipAtomicInner(doc, far, pos, dir, mayClear) : null
     }
   } }
   return pos
 }

 // Ensure a given position is not inside an atomic range.
 function skipAtomic(doc, pos, oldPos, bias, mayClear) {
   var dir = bias || 1;
   var found = skipAtomicInner(doc, pos, oldPos, dir, mayClear) ||
       (!mayClear && skipAtomicInner(doc, pos, oldPos, dir, true)) ||
       skipAtomicInner(doc, pos, oldPos, -dir, mayClear) ||
       (!mayClear && skipAtomicInner(doc, pos, oldPos, -dir, true));
   if (!found) {
     doc.cantEdit = true;
     return Pos(doc.first, 0)
   }
   return found
 }

 function movePos(doc, pos, dir, line) {
   if (dir < 0 && pos.ch == 0) {
     if (pos.line > doc.first) { return clipPos(doc, Pos(pos.line - 1)) }
     else { return null }
   } else if (dir > 0 && pos.ch == (line || getLine(doc, pos.line)).text.length) {
     if (pos.line < doc.first + doc.size - 1) { return Pos(pos.line + 1, 0) }
     else { return null }
   } else {
     return new Pos(pos.line, pos.ch + dir)
   }
 }

 function selectAll(cm) {
   cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll);
 }

 // UPDATING

 // Allow "beforeChange" event handlers to influence a change
 function filterChange(doc, change, update) {
   var obj = {
     canceled: false,
     from: change.from,
     to: change.to,
     text: change.text,
     origin: change.origin,
     cancel: function () { return obj.canceled = true; }
   };
   if (update) { obj.update = function (from, to, text, origin) {
     if (from) { obj.from = clipPos(doc, from); }
     if (to) { obj.to = clipPos(doc, to); }
     if (text) { obj.text = text; }
     if (origin !== undefined) { obj.origin = origin; }
   }; }
   signal(doc, "beforeChange", doc, obj);
   if (doc.cm) { signal(doc.cm, "beforeChange", doc.cm, obj); }

   if (obj.canceled) {
     if (doc.cm) { doc.cm.curOp.updateInput = 2; }
     return null
   }
   return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin}
 }

 // Apply a change to a document, and add it to the document's
 // history, and propagating it to all linked documents.
 function makeChange(doc, change, ignoreReadOnly) {
   if (doc.cm) {
     if (!doc.cm.curOp) { return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly) }
     if (doc.cm.state.suppressEdits) { return }
   }

   if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
     change = filterChange(doc, change, true);
     if (!change) { return }
   }

   // Possibly split or suppress the update based on the presence
   // of read-only spans in its range.
   var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);
   if (split) {
     for (var i = split.length - 1; i >= 0; --i)
       { makeChangeInner(doc, {from: split[i].from, to: split[i].to, text: i ? [""] : change.text, origin: change.origin}); }
   } else {
     makeChangeInner(doc, change);
   }
 }

 function makeChangeInner(doc, change) {
   if (change.text.length == 1 && change.text[0] == "" && cmp(change.from, change.to) == 0) { return }
   var selAfter = computeSelAfterChange(doc, change);
   addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);

   makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));
   var rebased = [];

   linkedDocs(doc, function (doc, sharedHist) {
     if (!sharedHist && indexOf(rebased, doc.history) == -1) {
       rebaseHist(doc.history, change);
       rebased.push(doc.history);
     }
     makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));
   });
 }

 // Revert a change stored in a document's history.
 function makeChangeFromHistory(doc, type, allowSelectionOnly) {
   var suppress = doc.cm && doc.cm.state.suppressEdits;
   if (suppress && !allowSelectionOnly) { return }

   var hist = doc.history, event, selAfter = doc.sel;
   var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;

   // Verify that there is a useable event (so that ctrl-z won't
   // needlessly clear selection events)
   var i = 0;
   for (; i < source.length; i++) {
     event = source[i];
     if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges)
       { break }
   }
   if (i == source.length) { return }
   hist.lastOrigin = hist.lastSelOrigin = null;

   for (;;) {
     event = source.pop();
     if (event.ranges) {
       pushSelectionToHistory(event, dest);
       if (allowSelectionOnly && !event.equals(doc.sel)) {
         setSelection(doc, event, {clearRedo: false});
         return
       }
       selAfter = event;
     } else if (suppress) {
       source.push(event);
       return
     } else { break }
   }

   // Build up a reverse change object to add to the opposite history
   // stack (redo when undoing, and vice versa).
   var antiChanges = [];
   pushSelectionToHistory(selAfter, dest);
   dest.push({changes: antiChanges, generation: hist.generation});
   hist.generation = event.generation || ++hist.maxGeneration;

   var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");

   var loop = function ( i ) {
     var change = event.changes[i];
     change.origin = type;
     if (filter && !filterChange(doc, change, false)) {
       source.length = 0;
       return {}
     }

     antiChanges.push(historyChangeFromChange(doc, change));

     var after = i ? computeSelAfterChange(doc, change) : lst(source);
     makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));
     if (!i && doc.cm) { doc.cm.scrollIntoView({from: change.from, to: changeEnd(change)}); }
     var rebased = [];

     // Propagate to the linked documents
     linkedDocs(doc, function (doc, sharedHist) {
       if (!sharedHist && indexOf(rebased, doc.history) == -1) {
         rebaseHist(doc.history, change);
         rebased.push(doc.history);
       }
       makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));
     });
   };

   for (var i$1 = event.changes.length - 1; i$1 >= 0; --i$1) {
     var returned = loop( i$1 );

     if ( returned ) return returned.v;
   }
 }

 // Sub-views need their line numbers shifted when text is added
 // above or below them in the parent document.
 function shiftDoc(doc, distance) {
   if (distance == 0) { return }
   doc.first += distance;
   doc.sel = new Selection(map(doc.sel.ranges, function (range) { return new Range(
     Pos(range.anchor.line + distance, range.anchor.ch),
     Pos(range.head.line + distance, range.head.ch)
   ); }), doc.sel.primIndex);
   if (doc.cm) {
     regChange(doc.cm, doc.first, doc.first - distance, distance);
     for (var d = doc.cm.display, l = d.viewFrom; l < d.viewTo; l++)
       { regLineChange(doc.cm, l, "gutter"); }
   }
 }

 // More lower-level change function, handling only a single document
 // (not linked ones).
 function makeChangeSingleDoc(doc, change, selAfter, spans) {
   if (doc.cm && !doc.cm.curOp)
     { return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans) }

   if (change.to.line < doc.first) {
     shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));
     return
   }
   if (change.from.line > doc.lastLine()) { return }

   // Clip the change to the size of this doc
   if (change.from.line < doc.first) {
     var shift = change.text.length - 1 - (doc.first - change.from.line);
     shiftDoc(doc, shift);
     change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),
               text: [lst(change.text)], origin: change.origin};
   }
   var last = doc.lastLine();
   if (change.to.line > last) {
     change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),
               text: [change.text[0]], origin: change.origin};
   }

   change.removed = getBetween(doc, change.from, change.to);

   if (!selAfter) { selAfter = computeSelAfterChange(doc, change); }
   if (doc.cm) { makeChangeSingleDocInEditor(doc.cm, change, spans); }
   else { updateDoc(doc, change, spans); }
   setSelectionNoUndo(doc, selAfter, sel_dontScroll);

   if (doc.cantEdit && skipAtomic(doc, Pos(doc.firstLine(), 0)))
     { doc.cantEdit = false; }
 }

 // Handle the interaction of a change to a document with the editor
 // that this document is part of.
 function makeChangeSingleDocInEditor(cm, change, spans) {
   var doc = cm.doc, display = cm.display, from = change.from, to = change.to;

   var recomputeMaxLength = false, checkWidthStart = from.line;
   if (!cm.options.lineWrapping) {
     checkWidthStart = lineNo(visualLine(getLine(doc, from.line)));
     doc.iter(checkWidthStart, to.line + 1, function (line) {
       if (line == display.maxLine) {
         recomputeMaxLength = true;
         return true
       }
     });
   }

   if (doc.sel.contains(change.from, change.to) > -1)
     { signalCursorActivity(cm); }

   updateDoc(doc, change, spans, estimateHeight(cm));

   if (!cm.options.lineWrapping) {
     doc.iter(checkWidthStart, from.line + change.text.length, function (line) {
       var len = lineLength(line);
       if (len > display.maxLineLength) {
         display.maxLine = line;
         display.maxLineLength = len;
         display.maxLineChanged = true;
         recomputeMaxLength = false;
       }
     });
     if (recomputeMaxLength) { cm.curOp.updateMaxLine = true; }
   }

   retreatFrontier(doc, from.line);
   startWorker(cm, 400);

   var lendiff = change.text.length - (to.line - from.line) - 1;
   // Remember that these lines changed, for updating the display
   if (change.full)
     { regChange(cm); }
   else if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change))
     { regLineChange(cm, from.line, "text"); }
   else
     { regChange(cm, from.line, to.line + 1, lendiff); }

   var changesHandler = hasHandler(cm, "changes"), changeHandler = hasHandler(cm, "change");
   if (changeHandler || changesHandler) {
     var obj = {
       from: from, to: to,
       text: change.text,
       removed: change.removed,
       origin: change.origin
     };
     if (changeHandler) { signalLater(cm, "change", cm, obj); }
     if (changesHandler) { (cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj); }
   }
   cm.display.selForContextMenu = null;
 }

 function replaceRange(doc, code, from, to, origin) {
   var assign;

   if (!to) { to = from; }
   if (cmp(to, from) < 0) { (assign = [to, from], from = assign[0], to = assign[1]); }
   if (typeof code == "string") { code = doc.splitLines(code); }
   makeChange(doc, {from: from, to: to, text: code, origin: origin});
 }

 // Rebasing/resetting history to deal with externally-sourced changes

 function rebaseHistSelSingle(pos, from, to, diff) {
   if (to < pos.line) {
     pos.line += diff;
   } else if (from < pos.line) {
     pos.line = from;
     pos.ch = 0;
   }
 }

 // Tries to rebase an array of history events given a change in the
 // document. If the change touches the same lines as the event, the
 // event, and everything 'behind' it, is discarded. If the change is
 // before the event, the event's positions are updated. Uses a
 // copy-on-write scheme for the positions, to avoid having to
 // reallocate them all on every rebase, but also avoid problems with
 // shared position objects being unsafely updated.
 function rebaseHistArray(array, from, to, diff) {
   for (var i = 0; i < array.length; ++i) {
     var sub = array[i], ok = true;
     if (sub.ranges) {
       if (!sub.copied) { sub = array[i] = sub.deepCopy(); sub.copied = true; }
       for (var j = 0; j < sub.ranges.length; j++) {
         rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff);
         rebaseHistSelSingle(sub.ranges[j].head, from, to, diff);
       }
       continue
     }
     for (var j$1 = 0; j$1 < sub.changes.length; ++j$1) {
       var cur = sub.changes[j$1];
       if (to < cur.from.line) {
         cur.from = Pos(cur.from.line + diff, cur.from.ch);
         cur.to = Pos(cur.to.line + diff, cur.to.ch);
       } else if (from <= cur.to.line) {
         ok = false;
         break
       }
     }
     if (!ok) {
       array.splice(0, i + 1);
       i = 0;
     }
   }
 }

 function rebaseHist(hist, change) {
   var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
   rebaseHistArray(hist.done, from, to, diff);
   rebaseHistArray(hist.undone, from, to, diff);
 }

 // Utility for applying a change to a line by handle or number,
 // returning the number and optionally registering the line as
 // changed.
 function changeLine(doc, handle, changeType, op) {
   var no = handle, line = handle;
   if (typeof handle == "number") { line = getLine(doc, clipLine(doc, handle)); }
   else { no = lineNo(handle); }
   if (no == null) { return null }
   if (op(line, no) && doc.cm) { regLineChange(doc.cm, no, changeType); }
   return line
 }

 // The document is represented as a BTree consisting of leaves, with
 // chunk of lines in them, and branches, with up to ten leaves or
 // other branch nodes below them. The top node is always a branch
 // node, and is the document object itself (meaning it has
 // additional methods and properties).
 //
 // All nodes have parent links. The tree is used both to go from
 // line numbers to line objects, and to go from objects to numbers.
 // It also indexes by height, and is used to convert between height
 // and line object, and to find the total height of the document.
 //
 // See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html

 function LeafChunk(lines) {
   this.lines = lines;
   this.parent = null;
   var height = 0;
   for (var i = 0; i < lines.length; ++i) {
     lines[i].parent = this;
     height += lines[i].height;
   }
   this.height = height;
 }

 LeafChunk.prototype = {
   chunkSize: function() { return this.lines.length },

   // Remove the n lines at offset 'at'.
   removeInner: function(at, n) {
     for (var i = at, e = at + n; i < e; ++i) {
       var line = this.lines[i];
       this.height -= line.height;
       cleanUpLine(line);
       signalLater(line, "delete");
     }
     this.lines.splice(at, n);
   },

   // Helper used to collapse a small branch into a single leaf.
   collapse: function(lines) {
     lines.push.apply(lines, this.lines);
   },

   // Insert the given array of lines at offset 'at', count them as
   // having the given height.
   insertInner: function(at, lines, height) {
     this.height += height;
     this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
     for (var i = 0; i < lines.length; ++i) { lines[i].parent = this; }
   },

   // Used to iterate over a part of the tree.
   iterN: function(at, n, op) {
     for (var e = at + n; at < e; ++at)
       { if (op(this.lines[at])) { return true } }
   }
 };

 function BranchChunk(children) {
   this.children = children;
   var size = 0, height = 0;
   for (var i = 0; i < children.length; ++i) {
     var ch = children[i];
     size += ch.chunkSize(); height += ch.height;
     ch.parent = this;
   }
   this.size = size;
   this.height = height;
   this.parent = null;
 }

 BranchChunk.prototype = {
   chunkSize: function() { return this.size },

   removeInner: function(at, n) {
     this.size -= n;
     for (var i = 0; i < this.children.length; ++i) {
       var child = this.children[i], sz = child.chunkSize();
       if (at < sz) {
         var rm = Math.min(n, sz - at), oldHeight = child.height;
         child.removeInner(at, rm);
         this.height -= oldHeight - child.height;
         if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }
         if ((n -= rm) == 0) { break }
         at = 0;
       } else { at -= sz; }
     }
     // If the result is smaller than 25 lines, ensure that it is a
     // single leaf node.
     if (this.size - n < 25 &&
         (this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {
       var lines = [];
       this.collapse(lines);
       this.children = [new LeafChunk(lines)];
       this.children[0].parent = this;
     }
   },

   collapse: function(lines) {
     for (var i = 0; i < this.children.length; ++i) { this.children[i].collapse(lines); }
   },

   insertInner: function(at, lines, height) {
     this.size += lines.length;
     this.height += height;
     for (var i = 0; i < this.children.length; ++i) {
       var child = this.children[i], sz = child.chunkSize();
       if (at <= sz) {
         child.insertInner(at, lines, height);
         if (child.lines && child.lines.length > 50) {
           // To avoid memory thrashing when child.lines is huge (e.g. first view of a large file), it's never spliced.
           // Instead, small slices are taken. They're taken in order because sequential memory accesses are fastest.
           var remaining = child.lines.length % 25 + 25;
           for (var pos = remaining; pos < child.lines.length;) {
             var leaf = new LeafChunk(child.lines.slice(pos, pos += 25));
             child.height -= leaf.height;
             this.children.splice(++i, 0, leaf);
             leaf.parent = this;
           }
           child.lines = child.lines.slice(0, remaining);
           this.maybeSpill();
         }
         break
       }
       at -= sz;
     }
   },

   // When a node has grown, check whether it should be split.
   maybeSpill: function() {
     if (this.children.length <= 10) { return }
     var me = this;
     do {
       var spilled = me.children.splice(me.children.length - 5, 5);
       var sibling = new BranchChunk(spilled);
       if (!me.parent) { // Become the parent node
         var copy = new BranchChunk(me.children);
         copy.parent = me;
         me.children = [copy, sibling];
         me = copy;
      } else {
         me.size -= sibling.size;
         me.height -= sibling.height;
         var myIndex = indexOf(me.parent.children, me);
         me.parent.children.splice(myIndex + 1, 0, sibling);
       }
       sibling.parent = me.parent;
     } while (me.children.length > 10)
     me.parent.maybeSpill();
   },

   iterN: function(at, n, op) {
     for (var i = 0; i < this.children.length; ++i) {
       var child = this.children[i], sz = child.chunkSize();
       if (at < sz) {
         var used = Math.min(n, sz - at);
         if (child.iterN(at, used, op)) { return true }
         if ((n -= used) == 0) { break }
         at = 0;
       } else { at -= sz; }
     }
   }
 };

 // Line widgets are block elements displayed above or below a line.

 var LineWidget = function(doc, node, options) {
   if (options) { for (var opt in options) { if (options.hasOwnProperty(opt))
     { this[opt] = options[opt]; } } }
   this.doc = doc;
   this.node = node;
 };

 LineWidget.prototype.clear = function () {
   var cm = this.doc.cm, ws = this.line.widgets, line = this.line, no = lineNo(line);
   if (no == null || !ws) { return }
   for (var i = 0; i < ws.length; ++i) { if (ws[i] == this) { ws.splice(i--, 1); } }
   if (!ws.length) { line.widgets = null; }
   var height = widgetHeight(this);
   updateLineHeight(line, Math.max(0, line.height - height));
   if (cm) {
     runInOp(cm, function () {
       adjustScrollWhenAboveVisible(cm, line, -height);
       regLineChange(cm, no, "widget");
     });
     signalLater(cm, "lineWidgetCleared", cm, this, no);
   }
 };

 LineWidget.prototype.changed = function () {
     var this$1 = this;

   var oldH = this.height, cm = this.doc.cm, line = this.line;
   this.height = null;
   var diff = widgetHeight(this) - oldH;
   if (!diff) { return }
   if (!lineIsHidden(this.doc, line)) { updateLineHeight(line, line.height + diff); }
   if (cm) {
     runInOp(cm, function () {
       cm.curOp.forceUpdate = true;
       adjustScrollWhenAboveVisible(cm, line, diff);
       signalLater(cm, "lineWidgetChanged", cm, this$1, lineNo(line));
     });
   }
 };
 eventMixin(LineWidget);

 function adjustScrollWhenAboveVisible(cm, line, diff) {
   if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop))
     { addToScrollTop(cm, diff); }
 }

 function addLineWidget(doc, handle, node, options) {
   var widget = new LineWidget(doc, node, options);
   var cm = doc.cm;
   if (cm && widget.noHScroll) { cm.display.alignWidgets = true; }
   changeLine(doc, handle, "widget", function (line) {
     var widgets = line.widgets || (line.widgets = []);
     if (widget.insertAt == null) { widgets.push(widget); }
     else { widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget); }
     widget.line = line;
     if (cm && !lineIsHidden(doc, line)) {
       var aboveVisible = heightAtLine(line) < doc.scrollTop;
       updateLineHeight(line, line.height + widgetHeight(widget));
       if (aboveVisible) { addToScrollTop(cm, widget.height); }
       cm.curOp.forceUpdate = true;
     }
     return true
   });
   if (cm) { signalLater(cm, "lineWidgetAdded", cm, widget, typeof handle == "number" ? handle : lineNo(handle)); }
   return widget
 }

 // TEXTMARKERS

 // Created with markText and setBookmark methods. A TextMarker is a
 // handle that can be used to clear or find a marked position in the
 // document. Line objects hold arrays (markedSpans) containing
 // {from, to, marker} object pointing to such marker objects, and
 // indicating that such a marker is present on that line. Multiple
 // lines may point to the same marker when it spans across lines.
 // The spans will have null for their from/to properties when the
 // marker continues beyond the start/end of the line. Markers have
 // links back to the lines they currently touch.

 // Collapsed markers have unique ids, in order to be able to order
 // them, which is needed for uniquely determining an outer marker
 // when they overlap (they may nest, but not partially overlap).
 var nextMarkerId = 0;

 var TextMarker = function(doc, type) {
   this.lines = [];
   this.type = type;
   this.doc = doc;
   this.id = ++nextMarkerId;
 };

 // Clear the marker.
 TextMarker.prototype.clear = function () {
   if (this.explicitlyCleared) { return }
   var cm = this.doc.cm, withOp = cm && !cm.curOp;
   if (withOp) { startOperation(cm); }
   if (hasHandler(this, "clear")) {
     var found = this.find();
     if (found) { signalLater(this, "clear", found.from, found.to); }
   }
   var min = null, max = null;
   for (var i = 0; i < this.lines.length; ++i) {
     var line = this.lines[i];
     var span = getMarkedSpanFor(line.markedSpans, this);
     if (cm && !this.collapsed) { regLineChange(cm, lineNo(line), "text"); }
     else if (cm) {
       if (span.to != null) { max = lineNo(line); }
       if (span.from != null) { min = lineNo(line); }
     }
     line.markedSpans = removeMarkedSpan(line.markedSpans, span);
     if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm)
       { updateLineHeight(line, textHeight(cm.display)); }
   }
   if (cm && this.collapsed && !cm.options.lineWrapping) { for (var i$1 = 0; i$1 < this.lines.length; ++i$1) {
     var visual = visualLine(this.lines[i$1]), len = lineLength(visual);
     if (len > cm.display.maxLineLength) {
       cm.display.maxLine = visual;
       cm.display.maxLineLength = len;
       cm.display.maxLineChanged = true;
     }
   } }

   if (min != null && cm && this.collapsed) { regChange(cm, min, max + 1); }
   this.lines.length = 0;
   this.explicitlyCleared = true;
   if (this.atomic && this.doc.cantEdit) {
     this.doc.cantEdit = false;
     if (cm) { reCheckSelection(cm.doc); }
   }
   if (cm) { signalLater(cm, "markerCleared", cm, this, min, max); }
   if (withOp) { endOperation(cm); }
   if (this.parent) { this.parent.clear(); }
 };

 // Find the position of the marker in the document. Returns a {from,
 // to} object by default. Side can be passed to get a specific side
 // -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the
 // Pos objects returned contain a line object, rather than a line
 // number (used to prevent looking up the same line twice).
 TextMarker.prototype.find = function (side, lineObj) {
   if (side == null && this.type == "bookmark") { side = 1; }
   var from, to;
   for (var i = 0; i < this.lines.length; ++i) {
     var line = this.lines[i];
     var span = getMarkedSpanFor(line.markedSpans, this);
     if (span.from != null) {
       from = Pos(lineObj ? line : lineNo(line), span.from);
       if (side == -1) { return from }
     }
     if (span.to != null) {
       to = Pos(lineObj ? line : lineNo(line), span.to);
       if (side == 1) { return to }
     }
   }
   return from && {from: from, to: to}
 };

 // Signals that the marker's widget changed, and surrounding layout
 // should be recomputed.
 TextMarker.prototype.changed = function () {
     var this$1 = this;

   var pos = this.find(-1, true), widget = this, cm = this.doc.cm;
   if (!pos || !cm) { return }
   runInOp(cm, function () {
     var line = pos.line, lineN = lineNo(pos.line);
     var view = findViewForLine(cm, lineN);
     if (view) {
       clearLineMeasurementCacheFor(view);
       cm.curOp.selectionChanged = cm.curOp.forceUpdate = true;
     }
     cm.curOp.updateMaxLine = true;
     if (!lineIsHidden(widget.doc, line) && widget.height != null) {
       var oldHeight = widget.height;
       widget.height = null;
       var dHeight = widgetHeight(widget) - oldHeight;
       if (dHeight)
         { updateLineHeight(line, line.height + dHeight); }
     }
     signalLater(cm, "markerChanged", cm, this$1);
   });
 };

 TextMarker.prototype.attachLine = function (line) {
   if (!this.lines.length && this.doc.cm) {
     var op = this.doc.cm.curOp;
     if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)
       { (op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this); }
   }
   this.lines.push(line);
 };

 TextMarker.prototype.detachLine = function (line) {
   this.lines.splice(indexOf(this.lines, line), 1);
   if (!this.lines.length && this.doc.cm) {
     var op = this.doc.cm.curOp
     ;(op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);
   }
 };
 eventMixin(TextMarker);

 // Create a marker, wire it up to the right lines, and
 function markText(doc, from, to, options, type) {
   // Shared markers (across linked documents) are handled separately
   // (markTextShared will call out to this again, once per
   // document).
   if (options && options.shared) { return markTextShared(doc, from, to, options, type) }
   // Ensure we are in an operation.
   if (doc.cm && !doc.cm.curOp) { return operation(doc.cm, markText)(doc, from, to, options, type) }

   var marker = new TextMarker(doc, type), diff = cmp(from, to);
   if (options) { copyObj(options, marker, false); }
   // Don't connect empty markers unless clearWhenEmpty is false
   if (diff > 0 || diff == 0 && marker.clearWhenEmpty !== false)
     { return marker }
   if (marker.replacedWith) {
     // Showing up as a widget implies collapsed (widget replaces text)
     marker.collapsed = true;
     marker.widgetNode = eltP("span", [marker.replacedWith], "CodeMirror-widget");
     if (!options.handleMouseEvents) { marker.widgetNode.setAttribute("cm-ignore-events", "true"); }
     if (options.insertLeft) { marker.widgetNode.insertLeft = true; }
   }
   if (marker.collapsed) {
     if (conflictingCollapsedRange(doc, from.line, from, to, marker) ||
         from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))
       { throw new Error("Inserting collapsed marker partially overlapping an existing one") }
     seeCollapsedSpans();
   }

   if (marker.addToHistory)
     { addChangeToHistory(doc, {from: from, to: to, origin: "markText"}, doc.sel, NaN); }

   var curLine = from.line, cm = doc.cm, updateMaxLine;
   doc.iter(curLine, to.line + 1, function (line) {
     if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine)
       { updateMaxLine = true; }
     if (marker.collapsed && curLine != from.line) { updateLineHeight(line, 0); }
     addMarkedSpan(line, new MarkedSpan(marker,
                                        curLine == from.line ? from.ch : null,
                                        curLine == to.line ? to.ch : null));
     ++curLine;
   });
   // lineIsHidden depends on the presence of the spans, so needs a second pass
   if (marker.collapsed) { doc.iter(from.line, to.line + 1, function (line) {
     if (lineIsHidden(doc, line)) { updateLineHeight(line, 0); }
   }); }

   if (marker.clearOnEnter) { on(marker, "beforeCursorEnter", function () { return marker.clear(); }); }

   if (marker.readOnly) {
     seeReadOnlySpans();
     if (doc.history.done.length || doc.history.undone.length)
       { doc.clearHistory(); }
   }
   if (marker.collapsed) {
     marker.id = ++nextMarkerId;
     marker.atomic = true;
   }
   if (cm) {
     // Sync editor state
     if (updateMaxLine) { cm.curOp.updateMaxLine = true; }
     if (marker.collapsed)
       { regChange(cm, from.line, to.line + 1); }
     else if (marker.className || marker.startStyle || marker.endStyle || marker.css ||
              marker.attributes || marker.title)
       { for (var i = from.line; i <= to.line; i++) { regLineChange(cm, i, "text"); } }
     if (marker.atomic) { reCheckSelection(cm.doc); }
     signalLater(cm, "markerAdded", cm, marker);
   }
   return marker
 }

 // SHARED TEXTMARKERS

 // A shared marker spans multiple linked documents. It is
 // implemented as a meta-marker-object controlling multiple normal
 // markers.
 var SharedTextMarker = function(markers, primary) {
   this.markers = markers;
   this.primary = primary;
   for (var i = 0; i < markers.length; ++i)
     { markers[i].parent = this; }
 };

 SharedTextMarker.prototype.clear = function () {
   if (this.explicitlyCleared) { return }
   this.explicitlyCleared = true;
   for (var i = 0; i < this.markers.length; ++i)
     { this.markers[i].clear(); }
   signalLater(this, "clear");
 };

 SharedTextMarker.prototype.find = function (side, lineObj) {
   return this.primary.find(side, lineObj)
 };
 eventMixin(SharedTextMarker);

 function markTextShared(doc, from, to, options, type) {
   options = copyObj(options);
   options.shared = false;
   var markers = [markText(doc, from, to, options, type)], primary = markers[0];
   var widget = options.widgetNode;
   linkedDocs(doc, function (doc) {
     if (widget) { options.widgetNode = widget.cloneNode(true); }
     markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));
     for (var i = 0; i < doc.linked.length; ++i)
       { if (doc.linked[i].isParent) { return } }
     primary = lst(markers);
   });
   return new SharedTextMarker(markers, primary)
 }

 function findSharedMarkers(doc) {
   return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())), function (m) { return m.parent; })
 }

 function copySharedMarkers(doc, markers) {
   for (var i = 0; i < markers.length; i++) {
     var marker = markers[i], pos = marker.find();
     var mFrom = doc.clipPos(pos.from), mTo = doc.clipPos(pos.to);
     if (cmp(mFrom, mTo)) {
       var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type);
       marker.markers.push(subMark);
       subMark.parent = marker;
     }
   }
 }

 function detachSharedMarkers(markers) {
   var loop = function ( i ) {
     var marker = markers[i], linked = [marker.primary.doc];
     linkedDocs(marker.primary.doc, function (d) { return linked.push(d); });
     for (var j = 0; j < marker.markers.length; j++) {
       var subMarker = marker.markers[j];
       if (indexOf(linked, subMarker.doc) == -1) {
         subMarker.parent = null;
         marker.markers.splice(j--, 1);
       }
     }
   };

   for (var i = 0; i < markers.length; i++) loop( i );
 }

 var nextDocId = 0;
 var Doc = function(text, mode, firstLine, lineSep, direction) {
   if (!(this instanceof Doc)) { return new Doc(text, mode, firstLine, lineSep, direction) }
   if (firstLine == null) { firstLine = 0; }

   BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);
   this.first = firstLine;
   this.scrollTop = this.scrollLeft = 0;
   this.cantEdit = false;
   this.cleanGeneration = 1;
   this.modeFrontier = this.highlightFrontier = firstLine;
   var start = Pos(firstLine, 0);
   this.sel = simpleSelection(start);
   this.history = new History(null);
   this.id = ++nextDocId;
   this.modeOption = mode;
   this.lineSep = lineSep;
   this.direction = (direction == "rtl") ? "rtl" : "ltr";
   this.extend = false;

   if (typeof text == "string") { text = this.splitLines(text); }
   updateDoc(this, {from: start, to: start, text: text});
   setSelection(this, simpleSelection(start), sel_dontScroll);
 };

 Doc.prototype = createObj(BranchChunk.prototype, {
   constructor: Doc,
   // Iterate over the document. Supports two forms -- with only one
   // argument, it calls that for each line in the document. With
   // three, it iterates over the range given by the first two (with
   // the second being non-inclusive).
   iter: function(from, to, op) {
     if (op) { this.iterN(from - this.first, to - from, op); }
     else { this.iterN(this.first, this.first + this.size, from); }
   },

   // Non-public interface for adding and removing lines.
   insert: function(at, lines) {
     var height = 0;
     for (var i = 0; i < lines.length; ++i) { height += lines[i].height; }
     this.insertInner(at - this.first, lines, height);
   },
   remove: function(at, n) { this.removeInner(at - this.first, n); },

   // From here, the methods are part of the public interface. Most
   // are also available from CodeMirror (editor) instances.

   getValue: function(lineSep) {
     var lines = getLines(this, this.first, this.first + this.size);
     if (lineSep === false) { return lines }
     return lines.join(lineSep || this.lineSeparator())
   },
   setValue: docMethodOp(function(code) {
     var top = Pos(this.first, 0), last = this.first + this.size - 1;
     makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),
                       text: this.splitLines(code), origin: "setValue", full: true}, true);
     if (this.cm) { scrollToCoords(this.cm, 0, 0); }
     setSelection(this, simpleSelection(top), sel_dontScroll);
   }),
   replaceRange: function(code, from, to, origin) {
     from = clipPos(this, from);
     to = to ? clipPos(this, to) : from;
     replaceRange(this, code, from, to, origin);
   },
   getRange: function(from, to, lineSep) {
     var lines = getBetween(this, clipPos(this, from), clipPos(this, to));
     if (lineSep === false) { return lines }
     return lines.join(lineSep || this.lineSeparator())
   },

   getLine: function(line) {var l = this.getLineHandle(line); return l && l.text},

   getLineHandle: function(line) {if (isLine(this, line)) { return getLine(this, line) }},
   getLineNumber: function(line) {return lineNo(line)},

   getLineHandleVisualStart: function(line) {
     if (typeof line == "number") { line = getLine(this, line); }
     return visualLine(line)
   },

   lineCount: function() {return this.size},
   firstLine: function() {return this.first},
   lastLine: function() {return this.first + this.size - 1},

   clipPos: function(pos) {return clipPos(this, pos)},

   getCursor: function(start) {
     var range = this.sel.primary(), pos;
     if (start == null || start == "head") { pos = range.head; }
     else if (start == "anchor") { pos = range.anchor; }
     else if (start == "end" || start == "to" || start === false) { pos = range.to(); }
     else { pos = range.from(); }
     return pos
   },
   listSelections: function() { return this.sel.ranges },
   somethingSelected: function() {return this.sel.somethingSelected()},

   setCursor: docMethodOp(function(line, ch, options) {
     setSimpleSelection(this, clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line), null, options);
   }),
   setSelection: docMethodOp(function(anchor, head, options) {
     setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options);
   }),
   extendSelection: docMethodOp(function(head, other, options) {
     extendSelection(this, clipPos(this, head), other && clipPos(this, other), options);
   }),
   extendSelections: docMethodOp(function(heads, options) {
     extendSelections(this, clipPosArray(this, heads), options);
   }),
   extendSelectionsBy: docMethodOp(function(f, options) {
     var heads = map(this.sel.ranges, f);
     extendSelections(this, clipPosArray(this, heads), options);
   }),
   setSelections: docMethodOp(function(ranges, primary, options) {
     if (!ranges.length) { return }
     var out = [];
     for (var i = 0; i < ranges.length; i++)
       { out[i] = new Range(clipPos(this, ranges[i].anchor),
                          clipPos(this, ranges[i].head)); }
     if (primary == null) { primary = Math.min(ranges.length - 1, this.sel.primIndex); }
     setSelection(this, normalizeSelection(this.cm, out, primary), options);
   }),
   addSelection: docMethodOp(function(anchor, head, options) {
     var ranges = this.sel.ranges.slice(0);
     ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)));
     setSelection(this, normalizeSelection(this.cm, ranges, ranges.length - 1), options);
   }),

   getSelection: function(lineSep) {
     var ranges = this.sel.ranges, lines;
     for (var i = 0; i < ranges.length; i++) {
       var sel = getBetween(this, ranges[i].from(), ranges[i].to());
       lines = lines ? lines.concat(sel) : sel;
     }
     if (lineSep === false) { return lines }
     else { return lines.join(lineSep || this.lineSeparator()) }
   },
   getSelections: function(lineSep) {
     var parts = [], ranges = this.sel.ranges;
     for (var i = 0; i < ranges.length; i++) {
       var sel = getBetween(this, ranges[i].from(), ranges[i].to());
       if (lineSep !== false) { sel = sel.join(lineSep || this.lineSeparator()); }
       parts[i] = sel;
     }
     return parts
   },
   replaceSelection: function(code, collapse, origin) {
     var dup = [];
     for (var i = 0; i < this.sel.ranges.length; i++)
       { dup[i] = code; }
     this.replaceSelections(dup, collapse, origin || "+input");
   },
   replaceSelections: docMethodOp(function(code, collapse, origin) {
     var changes = [], sel = this.sel;
     for (var i = 0; i < sel.ranges.length; i++) {
       var range = sel.ranges[i];
       changes[i] = {from: range.from(), to: range.to(), text: this.splitLines(code[i]), origin: origin};
     }
     var newSel = collapse && collapse != "end" && computeReplacedSel(this, changes, collapse);
     for (var i$1 = changes.length - 1; i$1 >= 0; i$1--)
       { makeChange(this, changes[i$1]); }
     if (newSel) { setSelectionReplaceHistory(this, newSel); }
     else if (this.cm) { ensureCursorVisible(this.cm); }
   }),
   undo: docMethodOp(function() {makeChangeFromHistory(this, "undo");}),
   redo: docMethodOp(function() {makeChangeFromHistory(this, "redo");}),
   undoSelection: docMethodOp(function() {makeChangeFromHistory(this, "undo", true);}),
   redoSelection: docMethodOp(function() {makeChangeFromHistory(this, "redo", true);}),

   setExtending: function(val) {this.extend = val;},
   getExtending: function() {return this.extend},

   historySize: function() {
     var hist = this.history, done = 0, undone = 0;
     for (var i = 0; i < hist.done.length; i++) { if (!hist.done[i].ranges) { ++done; } }
     for (var i$1 = 0; i$1 < hist.undone.length; i$1++) { if (!hist.undone[i$1].ranges) { ++undone; } }
     return {undo: done, redo: undone}
   },
   clearHistory: function() {
     var this$1 = this;

     this.history = new History(this.history.maxGeneration);
     linkedDocs(this, function (doc) { return doc.history = this$1.history; }, true);
   },

   markClean: function() {
     this.cleanGeneration = this.changeGeneration(true);
   },
   changeGeneration: function(forceSplit) {
     if (forceSplit)
       { this.history.lastOp = this.history.lastSelOp = this.history.lastOrigin = null; }
     return this.history.generation
   },
   isClean: function (gen) {
     return this.history.generation == (gen || this.cleanGeneration)
   },

   getHistory: function() {
     return {done: copyHistoryArray(this.history.done),
             undone: copyHistoryArray(this.history.undone)}
   },
   setHistory: function(histData) {
     var hist = this.history = new History(this.history.maxGeneration);
     hist.done = copyHistoryArray(histData.done.slice(0), null, true);
     hist.undone = copyHistoryArray(histData.undone.slice(0), null, true);
   },

   setGutterMarker: docMethodOp(function(line, gutterID, value) {
     return changeLine(this, line, "gutter", function (line) {
       var markers = line.gutterMarkers || (line.gutterMarkers = {});
       markers[gutterID] = value;
       if (!value && isEmpty(markers)) { line.gutterMarkers = null; }
       return true
     })
   }),

   clearGutter: docMethodOp(function(gutterID) {
     var this$1 = this;

     this.iter(function (line) {
       if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
         changeLine(this$1, line, "gutter", function () {
           line.gutterMarkers[gutterID] = null;
           if (isEmpty(line.gutterMarkers)) { line.gutterMarkers = null; }
           return true
         });
       }
     });
   }),

   lineInfo: function(line) {
     var n;
     if (typeof line == "number") {
       if (!isLine(this, line)) { return null }
       n = line;
       line = getLine(this, line);
       if (!line) { return null }
     } else {
       n = lineNo(line);
       if (n == null) { return null }
     }
     return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,
             textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,
             widgets: line.widgets}
   },

   addLineClass: docMethodOp(function(handle, where, cls) {
     return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function (line) {
       var prop = where == "text" ? "textClass"
                : where == "background" ? "bgClass"
                : where == "gutter" ? "gutterClass" : "wrapClass";
       if (!line[prop]) { line[prop] = cls; }
       else if (classTest(cls).test(line[prop])) { return false }
       else { line[prop] += " " + cls; }
       return true
     })
   }),
   removeLineClass: docMethodOp(function(handle, where, cls) {
     return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function (line) {
       var prop = where == "text" ? "textClass"
                : where == "background" ? "bgClass"
                : where == "gutter" ? "gutterClass" : "wrapClass";
       var cur = line[prop];
       if (!cur) { return false }
       else if (cls == null) { line[prop] = null; }
       else {
         var found = cur.match(classTest(cls));
         if (!found) { return false }
         var end = found.index + found[0].length;
         line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;
       }
       return true
     })
   }),

   addLineWidget: docMethodOp(function(handle, node, options) {
     return addLineWidget(this, handle, node, options)
   }),
   removeLineWidget: function(widget) { widget.clear(); },

   markText: function(from, to, options) {
     return markText(this, clipPos(this, from), clipPos(this, to), options, options && options.type || "range")
   },
   setBookmark: function(pos, options) {
     var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
                     insertLeft: options && options.insertLeft,
                     clearWhenEmpty: false, shared: options && options.shared,
                     handleMouseEvents: options && options.handleMouseEvents};
     pos = clipPos(this, pos);
     return markText(this, pos, pos, realOpts, "bookmark")
   },
   findMarksAt: function(pos) {
     pos = clipPos(this, pos);
     var markers = [], spans = getLine(this, pos.line).markedSpans;
     if (spans) { for (var i = 0; i < spans.length; ++i) {
       var span = spans[i];
       if ((span.from == null || span.from <= pos.ch) &&
           (span.to == null || span.to >= pos.ch))
         { markers.push(span.marker.parent || span.marker); }
     } }
     return markers
   },
   findMarks: function(from, to, filter) {
     from = clipPos(this, from); to = clipPos(this, to);
     var found = [], lineNo = from.line;
     this.iter(from.line, to.line + 1, function (line) {
       var spans = line.markedSpans;
       if (spans) { for (var i = 0; i < spans.length; i++) {
         var span = spans[i];
         if (!(span.to != null && lineNo == from.line && from.ch >= span.to ||
               span.from == null && lineNo != from.line ||
               span.from != null && lineNo == to.line && span.from >= to.ch) &&
             (!filter || filter(span.marker)))
           { found.push(span.marker.parent || span.marker); }
       } }
       ++lineNo;
     });
     return found
   },
   getAllMarks: function() {
     var markers = [];
     this.iter(function (line) {
       var sps = line.markedSpans;
       if (sps) { for (var i = 0; i < sps.length; ++i)
         { if (sps[i].from != null) { markers.push(sps[i].marker); } } }
     });
     return markers
   },

   posFromIndex: function(off) {
     var ch, lineNo = this.first, sepSize = this.lineSeparator().length;
     this.iter(function (line) {
       var sz = line.text.length + sepSize;
       if (sz > off) { ch = off; return true }
       off -= sz;
       ++lineNo;
     });
     return clipPos(this, Pos(lineNo, ch))
   },
   indexFromPos: function (coords) {
     coords = clipPos(this, coords);
     var index = coords.ch;
     if (coords.line < this.first || coords.ch < 0) { return 0 }
     var sepSize = this.lineSeparator().length;
     this.iter(this.first, coords.line, function (line) { // iter aborts when callback returns a truthy value
       index += line.text.length + sepSize;
     });
     return index
   },

   copy: function(copyHistory) {
     var doc = new Doc(getLines(this, this.first, this.first + this.size),
                       this.modeOption, this.first, this.lineSep, this.direction);
     doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
     doc.sel = this.sel;
     doc.extend = false;
     if (copyHistory) {
       doc.history.undoDepth = this.history.undoDepth;
       doc.setHistory(this.getHistory());
     }
     return doc
   },

   linkedDoc: function(options) {
     if (!options) { options = {}; }
     var from = this.first, to = this.first + this.size;
     if (options.from != null && options.from > from) { from = options.from; }
     if (options.to != null && options.to < to) { to = options.to; }
     var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from, this.lineSep, this.direction);
     if (options.sharedHist) { copy.history = this.history
     ; }(this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});
     copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];
     copySharedMarkers(copy, findSharedMarkers(this));
     return copy
   },
   unlinkDoc: function(other) {
     if (other instanceof CodeMirror) { other = other.doc; }
     if (this.linked) { for (var i = 0; i < this.linked.length; ++i) {
       var link = this.linked[i];
       if (link.doc != other) { continue }
       this.linked.splice(i, 1);
       other.unlinkDoc(this);
       detachSharedMarkers(findSharedMarkers(this));
       break
     } }
     // If the histories were shared, split them again
     if (other.history == this.history) {
       var splitIds = [other.id];
       linkedDocs(other, function (doc) { return splitIds.push(doc.id); }, true);
       other.history = new History(null);
       other.history.done = copyHistoryArray(this.history.done, splitIds);
       other.history.undone = copyHistoryArray(this.history.undone, splitIds);
     }
   },
   iterLinkedDocs: function(f) {linkedDocs(this, f);},

   getMode: function() {return this.mode},
   getEditor: function() {return this.cm},

   splitLines: function(str) {
     if (this.lineSep) { return str.split(this.lineSep) }
     return splitLinesAuto(str)
   },
   lineSeparator: function() { return this.lineSep || "\n" },

   setDirection: docMethodOp(function (dir) {
     if (dir != "rtl") { dir = "ltr"; }
     if (dir == this.direction) { return }
     this.direction = dir;
     this.iter(function (line) { return line.order = null; });
     if (this.cm) { directionChanged(this.cm); }
   })
 });

 // Public alias.
 Doc.prototype.eachLine = Doc.prototype.iter;

 // Kludge to work around strange IE behavior where it'll sometimes
 // re-fire a series of drag-related events right after the drop (#1551)
 var lastDrop = 0;

 function onDrop(e) {
   var cm = this;
   clearDragCursor(cm);
   if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e))
     { return }
   e_preventDefault(e);
   if (ie) { lastDrop = +new Date; }
   var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
   if (!pos || cm.isReadOnly()) { return }
   // Might be a file drop, in which case we simply extract the text
   // and insert it.
   if (files && files.length && window.FileReader && window.File) {
     var n = files.length, text = Array(n), read = 0;
     var markAsReadAndPasteIfAllFilesAreRead = function () {
       if (++read == n) {
         operation(cm, function () {
           pos = clipPos(cm.doc, pos);
           var change = {from: pos, to: pos,
                         text: cm.doc.splitLines(
                             text.filter(function (t) { return t != null; }).join(cm.doc.lineSeparator())),
                         origin: "paste"};
           makeChange(cm.doc, change);
           setSelectionReplaceHistory(cm.doc, simpleSelection(clipPos(cm.doc, pos), clipPos(cm.doc, changeEnd(change))));
         })();
       }
     };
     var readTextFromFile = function (file, i) {
       if (cm.options.allowDropFileTypes &&
           indexOf(cm.options.allowDropFileTypes, file.type) == -1) {
         markAsReadAndPasteIfAllFilesAreRead();
         return
       }
       var reader = new FileReader;
       reader.onerror = function () { return markAsReadAndPasteIfAllFilesAreRead(); };
       reader.onload = function () {
         var content = reader.result;
         if (/[\x00-\x08\x0e-\x1f]{2}/.test(content)) {
           markAsReadAndPasteIfAllFilesAreRead();
           return
         }
         text[i] = content;
         markAsReadAndPasteIfAllFilesAreRead();
       };
       reader.readAsText(file);
     };
     for (var i = 0; i < files.length; i++) { readTextFromFile(files[i], i); }
   } else { // Normal drop
     // Don't do a replace if the drop happened inside of the selected text.
     if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {
       cm.state.draggingText(e);
       // Ensure the editor is re-focused
       setTimeout(function () { return cm.display.input.focus(); }, 20);
       return
     }
     try {
       var text$1 = e.dataTransfer.getData("Text");
       if (text$1) {
         var selected;
         if (cm.state.draggingText && !cm.state.draggingText.copy)
           { selected = cm.listSelections(); }
         setSelectionNoUndo(cm.doc, simpleSelection(pos, pos));
         if (selected) { for (var i$1 = 0; i$1 < selected.length; ++i$1)
           { replaceRange(cm.doc, "", selected[i$1].anchor, selected[i$1].head, "drag"); } }
         cm.replaceSelection(text$1, "around", "paste");
         cm.display.input.focus();
       }
     }
     catch(e$1){}
   }
 }

 function onDragStart(cm, e) {
   if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return }
   if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) { return }

   e.dataTransfer.setData("Text", cm.getSelection());
   e.dataTransfer.effectAllowed = "copyMove";

   // Use dummy image instead of default browsers image.
   // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
   if (e.dataTransfer.setDragImage && !safari) {
     var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
     img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
     if (presto) {
       img.width = img.height = 1;
       cm.display.wrapper.appendChild(img);
       // Force a relayout, or Opera won't use our image for some obscure reason
       img._top = img.offsetTop;
     }
     e.dataTransfer.setDragImage(img, 0, 0);
     if (presto) { img.parentNode.removeChild(img); }
   }
 }

 function onDragOver(cm, e) {
   var pos = posFromMouse(cm, e);
   if (!pos) { return }
   var frag = document.createDocumentFragment();
   drawSelectionCursor(cm, pos, frag);
   if (!cm.display.dragCursor) {
     cm.display.dragCursor = elt("div", null, "CodeMirror-cursors CodeMirror-dragcursors");
     cm.display.lineSpace.insertBefore(cm.display.dragCursor, cm.display.cursorDiv);
   }
   removeChildrenAndAdd(cm.display.dragCursor, frag);
 }

 function clearDragCursor(cm) {
   if (cm.display.dragCursor) {
     cm.display.lineSpace.removeChild(cm.display.dragCursor);
     cm.display.dragCursor = null;
   }
 }

 // These must be handled carefully, because naively registering a
 // handler for each editor will cause the editors to never be
 // garbage collected.

 function forEachCodeMirror(f) {
   if (!document.getElementsByClassName) { return }
   var byClass = document.getElementsByClassName("CodeMirror"), editors = [];
   for (var i = 0; i < byClass.length; i++) {
     var cm = byClass[i].CodeMirror;
     if (cm) { editors.push(cm); }
   }
   if (editors.length) { editors[0].operation(function () {
     for (var i = 0; i < editors.length; i++) { f(editors[i]); }
   }); }
 }

 var globalsRegistered = false;
 function ensureGlobalHandlers() {
   if (globalsRegistered) { return }
   registerGlobalHandlers();
   globalsRegistered = true;
 }
 function registerGlobalHandlers() {
   // When the window resizes, we need to refresh active editors.
   var resizeTimer;
   on(window, "resize", function () {
     if (resizeTimer == null) { resizeTimer = setTimeout(function () {
       resizeTimer = null;
       forEachCodeMirror(onResize);
     }, 100); }
   });
   // When the window loses focus, we want to show the editor as blurred
   on(window, "blur", function () { return forEachCodeMirror(onBlur); });
 }
 // Called when the window resizes
 function onResize(cm) {
   var d = cm.display;
   // Might be a text scaling operation, clear size caches.
   d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
   d.scrollbarsClipped = false;
   cm.setSize();
 }

 var keyNames = {
   3: "Pause", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",
   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: "/", 145: "ScrollLock",
   173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
   221: "]", 222: "'", 224: "Mod", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",
   63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"
 };

 // Number keys
 for (var i = 0; i < 10; i++) { keyNames[i + 48] = keyNames[i + 96] = String(i); }
 // Alphabetic keys
 for (var i$1 = 65; i$1 <= 90; i$1++) { keyNames[i$1] = String.fromCharCode(i$1); }
 // Function keys
 for (var i$2 = 1; i$2 <= 12; i$2++) { keyNames[i$2 + 111] = keyNames[i$2 + 63235] = "F" + i$2; }

 var keyMap = {};

 keyMap.basic = {
   "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
   "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
   "Delete": "delCharAfter", "Backspace": "delCharBefore", "Shift-Backspace": "delCharBefore",
   "Tab": "defaultTab", "Shift-Tab": "indentAuto",
   "Enter": "newlineAndIndent", "Insert": "toggleOverwrite",
   "Esc": "singleSelection"
 };
 // Note that the save and find-related commands aren't defined by
 // default. User code or addons can define them. Unknown commands
 // are simply ignored.
 keyMap.pcDefault = {
   "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
   "Ctrl-Home": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Up": "goLineUp", "Ctrl-Down": "goLineDown",
   "Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
   "Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",
   "Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",
   "Ctrl-[": "indentLess", "Ctrl-]": "indentMore",
   "Ctrl-U": "undoSelection", "Shift-Ctrl-U": "redoSelection", "Alt-U": "redoSelection",
   "fallthrough": "basic"
 };
 // Very basic readline/emacs-style bindings, which are standard on Mac.
 keyMap.emacsy = {
   "Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",
   "Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",
   "Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",
   "Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars",
   "Ctrl-O": "openLine"
 };
 keyMap.macDefault = {
   "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
   "Cmd-Home": "goDocStart", "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
   "Alt-Right": "goGroupRight", "Cmd-Left": "goLineLeft", "Cmd-Right": "goLineRight", "Alt-Backspace": "delGroupBefore",
   "Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",
   "Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",
   "Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delWrappedLineLeft", "Cmd-Delete": "delWrappedLineRight",
   "Cmd-U": "undoSelection", "Shift-Cmd-U": "redoSelection", "Ctrl-Up": "goDocStart", "Ctrl-Down": "goDocEnd",
   "fallthrough": ["basic", "emacsy"]
 };
 keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;

 // KEYMAP DISPATCH

 function normalizeKeyName(name) {
   var parts = name.split(/-(?!$)/);
   name = parts[parts.length - 1];
   var alt, ctrl, shift, cmd;
   for (var i = 0; i < parts.length - 1; i++) {
     var mod = parts[i];
     if (/^(cmd|meta|m)$/i.test(mod)) { cmd = true; }
     else if (/^a(lt)?$/i.test(mod)) { alt = true; }
     else if (/^(c|ctrl|control)$/i.test(mod)) { ctrl = true; }
     else if (/^s(hift)?$/i.test(mod)) { shift = true; }
     else { throw new Error("Unrecognized modifier name: " + mod) }
   }
   if (alt) { name = "Alt-" + name; }
   if (ctrl) { name = "Ctrl-" + name; }
   if (cmd) { name = "Cmd-" + name; }
   if (shift) { name = "Shift-" + name; }
   return name
 }

 // This is a kludge to keep keymaps mostly working as raw objects
 // (backwards compatibility) while at the same time support features
 // like normalization and multi-stroke key bindings. It compiles a
 // new normalized keymap, and then updates the old object to reflect
 // this.
 function normalizeKeyMap(keymap) {
   var copy = {};
   for (var keyname in keymap) { if (keymap.hasOwnProperty(keyname)) {
     var value = keymap[keyname];
     if (/^(name|fallthrough|(de|at)tach)$/.test(keyname)) { continue }
     if (value == "...") { delete keymap[keyname]; continue }

     var keys = map(keyname.split(" "), normalizeKeyName);
     for (var i = 0; i < keys.length; i++) {
       var val = (void 0), name = (void 0);
       if (i == keys.length - 1) {
         name = keys.join(" ");
         val = value;
       } else {
         name = keys.slice(0, i + 1).join(" ");
         val = "...";
       }
       var prev = copy[name];
       if (!prev) { copy[name] = val; }
       else if (prev != val) { throw new Error("Inconsistent bindings for " + name) }
     }
     delete keymap[keyname];
   } }
   for (var prop in copy) { keymap[prop] = copy[prop]; }
   return keymap
 }

 function lookupKey(key, map, handle, context) {
   map = getKeyMap(map);
   var found = map.call ? map.call(key, context) : map[key];
   if (found === false) { return "nothing" }
   if (found === "...") { return "multi" }
   if (found != null && handle(found)) { return "handled" }

   if (map.fallthrough) {
     if (Object.prototype.toString.call(map.fallthrough) != "[object Array]")
       { return lookupKey(key, map.fallthrough, handle, context) }
     for (var i = 0; i < map.fallthrough.length; i++) {
       var result = lookupKey(key, map.fallthrough[i], handle, context);
       if (result) { return result }
     }
   }
 }

 // Modifier key presses don't count as 'real' key presses for the
 // purpose of keymap fallthrough.
 function isModifierKey(value) {
   var name = typeof value == "string" ? value : keyNames[value.keyCode];
   return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod"
 }

 function addModifierNames(name, event, noShift) {
   var base = name;
   if (event.altKey && base != "Alt") { name = "Alt-" + name; }
   if ((flipCtrlCmd ? event.metaKey : event.ctrlKey) && base != "Ctrl") { name = "Ctrl-" + name; }
   if ((flipCtrlCmd ? event.ctrlKey : event.metaKey) && base != "Mod") { name = "Cmd-" + name; }
   if (!noShift && event.shiftKey && base != "Shift") { name = "Shift-" + name; }
   return name
 }

 // Look up the name of a key as indicated by an event object.
 function keyName(event, noShift) {
   if (presto && event.keyCode == 34 && event["char"]) { return false }
   var name = keyNames[event.keyCode];
   if (name == null || event.altGraphKey) { return false }
   // Ctrl-ScrollLock has keyCode 3, same as Ctrl-Pause,
   // so we'll use event.code when available (Chrome 48+, FF 38+, Safari 10.1+)
   if (event.keyCode == 3 && event.code) { name = event.code; }
   return addModifierNames(name, event, noShift)
 }

 function getKeyMap(val) {
   return typeof val == "string" ? keyMap[val] : val
 }

 // Helper for deleting text near the selection(s), used to implement
 // backspace, delete, and similar functionality.
 function deleteNearSelection(cm, compute) {
   var ranges = cm.doc.sel.ranges, kill = [];
   // Build up a set of ranges to kill first, merging overlapping
   // ranges.
   for (var i = 0; i < ranges.length; i++) {
     var toKill = compute(ranges[i]);
     while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {
       var replaced = kill.pop();
       if (cmp(replaced.from, toKill.from) < 0) {
         toKill.from = replaced.from;
         break
       }
     }
     kill.push(toKill);
   }
   // Next, remove those actual ranges.
   runInOp(cm, function () {
     for (var i = kill.length - 1; i >= 0; i--)
       { replaceRange(cm.doc, "", kill[i].from, kill[i].to, "+delete"); }
     ensureCursorVisible(cm);
   });
 }

 function moveCharLogically(line, ch, dir) {
   var target = skipExtendingChars(line.text, ch + dir, dir);
   return target < 0 || target > line.text.length ? null : target
 }

 function moveLogically(line, start, dir) {
   var ch = moveCharLogically(line, start.ch, dir);
   return ch == null ? null : new Pos(start.line, ch, dir < 0 ? "after" : "before")
 }

 function endOfLine(visually, cm, lineObj, lineNo, dir) {
   if (visually) {
     if (cm.doc.direction == "rtl") { dir = -dir; }
     var order = getOrder(lineObj, cm.doc.direction);
     if (order) {
       var part = dir < 0 ? lst(order) : order[0];
       var moveInStorageOrder = (dir < 0) == (part.level == 1);
       var sticky = moveInStorageOrder ? "after" : "before";
       var ch;
       // With a wrapped rtl chunk (possibly spanning multiple bidi parts),
       // it could be that the last bidi part is not on the last visual line,
       // since visual lines contain content order-consecutive chunks.
       // Thus, in rtl, we are looking for the first (content-order) character
       // in the rtl chunk that is on the last line (that is, the same line
       // as the last (content-order) character).
       if (part.level > 0 || cm.doc.direction == "rtl") {
         var prep = prepareMeasureForLine(cm, lineObj);
         ch = dir < 0 ? lineObj.text.length - 1 : 0;
         var targetTop = measureCharPrepared(cm, prep, ch).top;
         ch = findFirst(function (ch) { return measureCharPrepared(cm, prep, ch).top == targetTop; }, (dir < 0) == (part.level == 1) ? part.from : part.to - 1, ch);
         if (sticky == "before") { ch = moveCharLogically(lineObj, ch, 1); }
       } else { ch = dir < 0 ? part.to : part.from; }
       return new Pos(lineNo, ch, sticky)
     }
   }
   return new Pos(lineNo, dir < 0 ? lineObj.text.length : 0, dir < 0 ? "before" : "after")
 }

 function moveVisually(cm, line, start, dir) {
   var bidi = getOrder(line, cm.doc.direction);
   if (!bidi) { return moveLogically(line, start, dir) }
   if (start.ch >= line.text.length) {
     start.ch = line.text.length;
     start.sticky = "before";
   } else if (start.ch <= 0) {
     start.ch = 0;
     start.sticky = "after";
   }
   var partPos = getBidiPartAt(bidi, start.ch, start.sticky), part = bidi[partPos];
   if (cm.doc.direction == "ltr" && part.level % 2 == 0 && (dir > 0 ? part.to > start.ch : part.from < start.ch)) {
     // Case 1: We move within an ltr part in an ltr editor. Even with wrapped lines,
     // nothing interesting happens.
     return moveLogically(line, start, dir)
   }

   var mv = function (pos, dir) { return moveCharLogically(line, pos instanceof Pos ? pos.ch : pos, dir); };
   var prep;
   var getWrappedLineExtent = function (ch) {
     if (!cm.options.lineWrapping) { return {begin: 0, end: line.text.length} }
     prep = prep || prepareMeasureForLine(cm, line);
     return wrappedLineExtentChar(cm, line, prep, ch)
   };
   var wrappedLineExtent = getWrappedLineExtent(start.sticky == "before" ? mv(start, -1) : start.ch);

   if (cm.doc.direction == "rtl" || part.level == 1) {
     var moveInStorageOrder = (part.level == 1) == (dir < 0);
     var ch = mv(start, moveInStorageOrder ? 1 : -1);
     if (ch != null && (!moveInStorageOrder ? ch >= part.from && ch >= wrappedLineExtent.begin : ch <= part.to && ch <= wrappedLineExtent.end)) {
       // Case 2: We move within an rtl part or in an rtl editor on the same visual line
       var sticky = moveInStorageOrder ? "before" : "after";
       return new Pos(start.line, ch, sticky)
     }
   }

   // Case 3: Could not move within this bidi part in this visual line, so leave
   // the current bidi part

   var searchInVisualLine = function (partPos, dir, wrappedLineExtent) {
     var getRes = function (ch, moveInStorageOrder) { return moveInStorageOrder
       ? new Pos(start.line, mv(ch, 1), "before")
       : new Pos(start.line, ch, "after"); };

     for (; partPos >= 0 && partPos < bidi.length; partPos += dir) {
       var part = bidi[partPos];
       var moveInStorageOrder = (dir > 0) == (part.level != 1);
       var ch = moveInStorageOrder ? wrappedLineExtent.begin : mv(wrappedLineExtent.end, -1);
       if (part.from <= ch && ch < part.to) { return getRes(ch, moveInStorageOrder) }
       ch = moveInStorageOrder ? part.from : mv(part.to, -1);
       if (wrappedLineExtent.begin <= ch && ch < wrappedLineExtent.end) { return getRes(ch, moveInStorageOrder) }
     }
   };

   // Case 3a: Look for other bidi parts on the same visual line
   var res = searchInVisualLine(partPos + dir, dir, wrappedLineExtent);
   if (res) { return res }

   // Case 3b: Look for other bidi parts on the next visual line
   var nextCh = dir > 0 ? wrappedLineExtent.end : mv(wrappedLineExtent.begin, -1);
   if (nextCh != null && !(dir > 0 && nextCh == line.text.length)) {
     res = searchInVisualLine(dir > 0 ? 0 : bidi.length - 1, dir, getWrappedLineExtent(nextCh));
     if (res) { return res }
   }

   // Case 4: Nowhere to move
   return null
 }

 // Commands are parameter-less actions that can be performed on an
 // editor, mostly used for keybindings.
 var commands = {
   selectAll: selectAll,
   singleSelection: function (cm) { return cm.setSelection(cm.getCursor("anchor"), cm.getCursor("head"), sel_dontScroll); },
   killLine: function (cm) { return deleteNearSelection(cm, function (range) {
     if (range.empty()) {
       var len = getLine(cm.doc, range.head.line).text.length;
       if (range.head.ch == len && range.head.line < cm.lastLine())
         { return {from: range.head, to: Pos(range.head.line + 1, 0)} }
       else
         { return {from: range.head, to: Pos(range.head.line, len)} }
     } else {
       return {from: range.from(), to: range.to()}
     }
   }); },
   deleteLine: function (cm) { return deleteNearSelection(cm, function (range) { return ({
     from: Pos(range.from().line, 0),
     to: clipPos(cm.doc, Pos(range.to().line + 1, 0))
   }); }); },
   delLineLeft: function (cm) { return deleteNearSelection(cm, function (range) { return ({
     from: Pos(range.from().line, 0), to: range.from()
   }); }); },
   delWrappedLineLeft: function (cm) { return deleteNearSelection(cm, function (range) {
     var top = cm.charCoords(range.head, "div").top + 5;
     var leftPos = cm.coordsChar({left: 0, top: top}, "div");
     return {from: leftPos, to: range.from()}
   }); },
   delWrappedLineRight: function (cm) { return deleteNearSelection(cm, function (range) {
     var top = cm.charCoords(range.head, "div").top + 5;
     var rightPos = cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
     return {from: range.from(), to: rightPos }
   }); },
   undo: function (cm) { return cm.undo(); },
   redo: function (cm) { return cm.redo(); },
   undoSelection: function (cm) { return cm.undoSelection(); },
   redoSelection: function (cm) { return cm.redoSelection(); },
   goDocStart: function (cm) { return cm.extendSelection(Pos(cm.firstLine(), 0)); },
   goDocEnd: function (cm) { return cm.extendSelection(Pos(cm.lastLine())); },
   goLineStart: function (cm) { return cm.extendSelectionsBy(function (range) { return lineStart(cm, range.head.line); },
     {origin: "+move", bias: 1}
   ); },
   goLineStartSmart: function (cm) { return cm.extendSelectionsBy(function (range) { return lineStartSmart(cm, range.head); },
     {origin: "+move", bias: 1}
   ); },
   goLineEnd: function (cm) { return cm.extendSelectionsBy(function (range) { return lineEnd(cm, range.head.line); },
     {origin: "+move", bias: -1}
   ); },
   goLineRight: function (cm) { return cm.extendSelectionsBy(function (range) {
     var top = cm.cursorCoords(range.head, "div").top + 5;
     return cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div")
   }, sel_move); },
   goLineLeft: function (cm) { return cm.extendSelectionsBy(function (range) {
     var top = cm.cursorCoords(range.head, "div").top + 5;
     return cm.coordsChar({left: 0, top: top}, "div")
   }, sel_move); },
   goLineLeftSmart: function (cm) { return cm.extendSelectionsBy(function (range) {
     var top = cm.cursorCoords(range.head, "div").top + 5;
     var pos = cm.coordsChar({left: 0, top: top}, "div");
     if (pos.ch < cm.getLine(pos.line).search(/\S/)) { return lineStartSmart(cm, range.head) }
     return pos
   }, sel_move); },
   goLineUp: function (cm) { return cm.moveV(-1, "line"); },
   goLineDown: function (cm) { return cm.moveV(1, "line"); },
   goPageUp: function (cm) { return cm.moveV(-1, "page"); },
   goPageDown: function (cm) { return cm.moveV(1, "page"); },
   goCharLeft: function (cm) { return cm.moveH(-1, "char"); },
   goCharRight: function (cm) { return cm.moveH(1, "char"); },
   goColumnLeft: function (cm) { return cm.moveH(-1, "column"); },
   goColumnRight: function (cm) { return cm.moveH(1, "column"); },
   goWordLeft: function (cm) { return cm.moveH(-1, "word"); },
   goGroupRight: function (cm) { return cm.moveH(1, "group"); },
   goGroupLeft: function (cm) { return cm.moveH(-1, "group"); },
   goWordRight: function (cm) { return cm.moveH(1, "word"); },
   delCharBefore: function (cm) { return cm.deleteH(-1, "codepoint"); },
   delCharAfter: function (cm) { return cm.deleteH(1, "char"); },
   delWordBefore: function (cm) { return cm.deleteH(-1, "word"); },
   delWordAfter: function (cm) { return cm.deleteH(1, "word"); },
   delGroupBefore: function (cm) { return cm.deleteH(-1, "group"); },
   delGroupAfter: function (cm) { return cm.deleteH(1, "group"); },
   indentAuto: function (cm) { return cm.indentSelection("smart"); },
   indentMore: function (cm) { return cm.indentSelection("add"); },
   indentLess: function (cm) { return cm.indentSelection("subtract"); },
   insertTab: function (cm) { return cm.replaceSelection("\t"); },
   insertSoftTab: function (cm) {
     var spaces = [], ranges = cm.listSelections(), tabSize = cm.options.tabSize;
     for (var i = 0; i < ranges.length; i++) {
       var pos = ranges[i].from();
       var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize);
       spaces.push(spaceStr(tabSize - col % tabSize));
     }
     cm.replaceSelections(spaces);
   },
   defaultTab: function (cm) {
     if (cm.somethingSelected()) { cm.indentSelection("add"); }
     else { cm.execCommand("insertTab"); }
   },
   // Swap the two chars left and right of each selection's head.
   // Move cursor behind the two swapped characters afterwards.
   //
   // Doesn't consider line feeds a character.
   // Doesn't scan more than one line above to find a character.
   // Doesn't do anything on an empty line.
   // Doesn't do anything with non-empty selections.
   transposeChars: function (cm) { return runInOp(cm, function () {
     var ranges = cm.listSelections(), newSel = [];
     for (var i = 0; i < ranges.length; i++) {
       if (!ranges[i].empty()) { continue }
       var cur = ranges[i].head, line = getLine(cm.doc, cur.line).text;
       if (line) {
         if (cur.ch == line.length) { cur = new Pos(cur.line, cur.ch - 1); }
         if (cur.ch > 0) {
           cur = new Pos(cur.line, cur.ch + 1);
           cm.replaceRange(line.charAt(cur.ch - 1) + line.charAt(cur.ch - 2),
                           Pos(cur.line, cur.ch - 2), cur, "+transpose");
         } else if (cur.line > cm.doc.first) {
           var prev = getLine(cm.doc, cur.line - 1).text;
           if (prev) {
             cur = new Pos(cur.line, 1);
             cm.replaceRange(line.charAt(0) + cm.doc.lineSeparator() +
                             prev.charAt(prev.length - 1),
                             Pos(cur.line - 1, prev.length - 1), cur, "+transpose");
           }
         }
       }
       newSel.push(new Range(cur, cur));
     }
     cm.setSelections(newSel);
   }); },
   newlineAndIndent: function (cm) { return runInOp(cm, function () {
     var sels = cm.listSelections();
     for (var i = sels.length - 1; i >= 0; i--)
       { cm.replaceRange(cm.doc.lineSeparator(), sels[i].anchor, sels[i].head, "+input"); }
     sels = cm.listSelections();
     for (var i$1 = 0; i$1 < sels.length; i$1++)
       { cm.indentLine(sels[i$1].from().line, null, true); }
     ensureCursorVisible(cm);
   }); },
   openLine: function (cm) { return cm.replaceSelection("\n", "start"); },
   toggleOverwrite: function (cm) { return cm.toggleOverwrite(); }
 };


 function lineStart(cm, lineN) {
   var line = getLine(cm.doc, lineN);
   var visual = visualLine(line);
   if (visual != line) { lineN = lineNo(visual); }
   return endOfLine(true, cm, visual, lineN, 1)
 }
 function lineEnd(cm, lineN) {
   var line = getLine(cm.doc, lineN);
   var visual = visualLineEnd(line);
   if (visual != line) { lineN = lineNo(visual); }
   return endOfLine(true, cm, line, lineN, -1)
 }
 function lineStartSmart(cm, pos) {
   var start = lineStart(cm, pos.line);
   var line = getLine(cm.doc, start.line);
   var order = getOrder(line, cm.doc.direction);
   if (!order || order[0].level == 0) {
     var firstNonWS = Math.max(start.ch, line.text.search(/\S/));
     var inWS = pos.line == start.line && pos.ch <= firstNonWS && pos.ch;
     return Pos(start.line, inWS ? 0 : firstNonWS, start.sticky)
   }
   return start
 }

 // Run a handler that was bound to a key.
 function doHandleBinding(cm, bound, dropShift) {
   if (typeof bound == "string") {
     bound = commands[bound];
     if (!bound) { return false }
   }
   // Ensure previous input has been read, so that the handler sees a
   // consistent view of the document
   cm.display.input.ensurePolled();
   var prevShift = cm.display.shift, done = false;
   try {
     if (cm.isReadOnly()) { cm.state.suppressEdits = true; }
     if (dropShift) { cm.display.shift = false; }
     done = bound(cm) != Pass;
   } finally {
     cm.display.shift = prevShift;
     cm.state.suppressEdits = false;
   }
   return done
 }

 function lookupKeyForEditor(cm, name, handle) {
   for (var i = 0; i < cm.state.keyMaps.length; i++) {
     var result = lookupKey(name, cm.state.keyMaps[i], handle, cm);
     if (result) { return result }
   }
   return (cm.options.extraKeys && lookupKey(name, cm.options.extraKeys, handle, cm))
     || lookupKey(name, cm.options.keyMap, handle, cm)
 }

 // Note that, despite the name, this function is also used to check
 // for bound mouse clicks.

 var stopSeq = new Delayed;

 function dispatchKey(cm, name, e, handle) {
   var seq = cm.state.keySeq;
   if (seq) {
     if (isModifierKey(name)) { return "handled" }
     if (/\'$/.test(name))
       { cm.state.keySeq = null; }
     else
       { stopSeq.set(50, function () {
         if (cm.state.keySeq == seq) {
           cm.state.keySeq = null;
           cm.display.input.reset();
         }
       }); }
     if (dispatchKeyInner(cm, seq + " " + name, e, handle)) { return true }
   }
   return dispatchKeyInner(cm, name, e, handle)
 }

 function dispatchKeyInner(cm, name, e, handle) {
   var result = lookupKeyForEditor(cm, name, handle);

   if (result == "multi")
     { cm.state.keySeq = name; }
   if (result == "handled")
     { signalLater(cm, "keyHandled", cm, name, e); }

   if (result == "handled" || result == "multi") {
     e_preventDefault(e);
     restartBlink(cm);
   }

   return !!result
 }

 // Handle a key from the keydown event.
 function handleKeyBinding(cm, e) {
   var name = keyName(e, true);
   if (!name) { return false }

   if (e.shiftKey && !cm.state.keySeq) {
     // First try to resolve full name (including 'Shift-'). Failing
     // that, see if there is a cursor-motion command (starting with
     // 'go') bound to the keyname without 'Shift-'.
     return dispatchKey(cm, "Shift-" + name, e, function (b) { return doHandleBinding(cm, b, true); })
         || dispatchKey(cm, name, e, function (b) {
              if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)
                { return doHandleBinding(cm, b) }
            })
   } else {
     return dispatchKey(cm, name, e, function (b) { return doHandleBinding(cm, b); })
   }
 }

 // Handle a key from the keypress event
 function handleCharBinding(cm, e, ch) {
   return dispatchKey(cm, "'" + ch + "'", e, function (b) { return doHandleBinding(cm, b, true); })
 }

 var lastStoppedKey = null;
 function onKeyDown(e) {
   var cm = this;
   if (e.target && e.target != cm.display.input.getField()) { return }
   cm.curOp.focus = activeElt();
   if (signalDOMEvent(cm, e)) { return }
   // IE does strange things with escape.
   if (ie && ie_version < 11 && e.keyCode == 27) { e.returnValue = false; }
   var code = e.keyCode;
   cm.display.shift = code == 16 || e.shiftKey;
   var handled = handleKeyBinding(cm, e);
   if (presto) {
     lastStoppedKey = handled ? code : null;
     // Opera has no cut event... we try to at least catch the key combo
     if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))
       { cm.replaceSelection("", null, "cut"); }
   }
   if (gecko && !mac && !handled && code == 46 && e.shiftKey && !e.ctrlKey && document.execCommand)
     { document.execCommand("cut"); }

   // Turn mouse into crosshair when Alt is held on Mac.
   if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className))
     { showCrossHair(cm); }
 }

 function showCrossHair(cm) {
   var lineDiv = cm.display.lineDiv;
   addClass(lineDiv, "CodeMirror-crosshair");

   function up(e) {
     if (e.keyCode == 18 || !e.altKey) {
       rmClass(lineDiv, "CodeMirror-crosshair");
       off(document, "keyup", up);
       off(document, "mouseover", up);
     }
   }
   on(document, "keyup", up);
   on(document, "mouseover", up);
 }

 function onKeyUp(e) {
   if (e.keyCode == 16) { this.doc.sel.shift = false; }
   signalDOMEvent(this, e);
 }

 function onKeyPress(e) {
   var cm = this;
   if (e.target && e.target != cm.display.input.getField()) { return }
   if (eventInWidget(cm.display, e) || signalDOMEvent(cm, e) || e.ctrlKey && !e.altKey || mac && e.metaKey) { return }
   var keyCode = e.keyCode, charCode = e.charCode;
   if (presto && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return}
   if ((presto && (!e.which || e.which < 10)) && handleKeyBinding(cm, e)) { return }
   var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
   // Some browsers fire keypress events for backspace
   if (ch == "\x08") { return }
   if (handleCharBinding(cm, e, ch)) { return }
   cm.display.input.onKeyPress(e);
 }

 var DOUBLECLICK_DELAY = 400;

 var PastClick = function(time, pos, button) {
   this.time = time;
   this.pos = pos;
   this.button = button;
 };

 PastClick.prototype.compare = function (time, pos, button) {
   return this.time + DOUBLECLICK_DELAY > time &&
     cmp(pos, this.pos) == 0 && button == this.button
 };

 var lastClick, lastDoubleClick;
 function clickRepeat(pos, button) {
   var now = +new Date;
   if (lastDoubleClick && lastDoubleClick.compare(now, pos, button)) {
     lastClick = lastDoubleClick = null;
     return "triple"
   } else if (lastClick && lastClick.compare(now, pos, button)) {
     lastDoubleClick = new PastClick(now, pos, button);
     lastClick = null;
     return "double"
   } else {
     lastClick = new PastClick(now, pos, button);
     lastDoubleClick = null;
     return "single"
   }
 }

 // A mouse down can be a single click, double click, triple click,
 // start of selection drag, start of text drag, new cursor
 // (ctrl-click), rectangle drag (alt-drag), or xwin
 // middle-click-paste. Or it might be a click on something we should
 // not interfere with, such as a scrollbar or widget.
 function onMouseDown(e) {
   var cm = this, display = cm.display;
   if (signalDOMEvent(cm, e) || display.activeTouch && display.input.supportsTouch()) { return }
   display.input.ensurePolled();
   display.shift = e.shiftKey;

   if (eventInWidget(display, e)) {
     if (!webkit) {
       // Briefly turn off draggability, to allow widgets to do
       // normal dragging things.
       display.scroller.draggable = false;
       setTimeout(function () { return display.scroller.draggable = true; }, 100);
     }
     return
   }
   if (clickInGutter(cm, e)) { return }
   var pos = posFromMouse(cm, e), button = e_button(e), repeat = pos ? clickRepeat(pos, button) : "single";
   window.focus();

   // #3261: make sure, that we're not starting a second selection
   if (button == 1 && cm.state.selectingText)
     { cm.state.selectingText(e); }

   if (pos && handleMappedButton(cm, button, pos, repeat, e)) { return }

   if (button == 1) {
     if (pos) { leftButtonDown(cm, pos, repeat, e); }
     else if (e_target(e) == display.scroller) { e_preventDefault(e); }
   } else if (button == 2) {
     if (pos) { extendSelection(cm.doc, pos); }
     setTimeout(function () { return display.input.focus(); }, 20);
   } else if (button == 3) {
     if (captureRightClick) { cm.display.input.onContextMenu(e); }
     else { delayBlurEvent(cm); }
   }
 }

 function handleMappedButton(cm, button, pos, repeat, event) {
   var name = "Click";
   if (repeat == "double") { name = "Double" + name; }
   else if (repeat == "triple") { name = "Triple" + name; }
   name = (button == 1 ? "Left" : button == 2 ? "Middle" : "Right") + name;

   return dispatchKey(cm,  addModifierNames(name, event), event, function (bound) {
     if (typeof bound == "string") { bound = commands[bound]; }
     if (!bound) { return false }
     var done = false;
     try {
       if (cm.isReadOnly()) { cm.state.suppressEdits = true; }
       done = bound(cm, pos) != Pass;
     } finally {
       cm.state.suppressEdits = false;
     }
     return done
   })
 }

 function configureMouse(cm, repeat, event) {
   var option = cm.getOption("configureMouse");
   var value = option ? option(cm, repeat, event) : {};
   if (value.unit == null) {
     var rect = chromeOS ? event.shiftKey && event.metaKey : event.altKey;
     value.unit = rect ? "rectangle" : repeat == "single" ? "char" : repeat == "double" ? "word" : "line";
   }
   if (value.extend == null || cm.doc.extend) { value.extend = cm.doc.extend || event.shiftKey; }
   if (value.addNew == null) { value.addNew = mac ? event.metaKey : event.ctrlKey; }
   if (value.moveOnDrag == null) { value.moveOnDrag = !(mac ? event.altKey : event.ctrlKey); }
   return value
 }

 function leftButtonDown(cm, pos, repeat, event) {
   if (ie) { setTimeout(bind(ensureFocus, cm), 0); }
   else { cm.curOp.focus = activeElt(); }

   var behavior = configureMouse(cm, repeat, event);

   var sel = cm.doc.sel, contained;
   if (cm.options.dragDrop && dragAndDrop && !cm.isReadOnly() &&
       repeat == "single" && (contained = sel.contains(pos)) > -1 &&
       (cmp((contained = sel.ranges[contained]).from(), pos) < 0 || pos.xRel > 0) &&
       (cmp(contained.to(), pos) > 0 || pos.xRel < 0))
     { leftButtonStartDrag(cm, event, pos, behavior); }
   else
     { leftButtonSelect(cm, event, pos, behavior); }
 }

 // Start a text drag. When it ends, see if any dragging actually
 // happen, and treat as a click if it didn't.
 function leftButtonStartDrag(cm, event, pos, behavior) {
   var display = cm.display, moved = false;
   var dragEnd = operation(cm, function (e) {
     if (webkit) { display.scroller.draggable = false; }
     cm.state.draggingText = false;
     off(display.wrapper.ownerDocument, "mouseup", dragEnd);
     off(display.wrapper.ownerDocument, "mousemove", mouseMove);
     off(display.scroller, "dragstart", dragStart);
     off(display.scroller, "drop", dragEnd);
     if (!moved) {
       e_preventDefault(e);
       if (!behavior.addNew)
         { extendSelection(cm.doc, pos, null, null, behavior.extend); }
       // Work around unexplainable focus problem in IE9 (#2127) and Chrome (#3081)
       if ((webkit && !safari) || ie && ie_version == 9)
         { setTimeout(function () {display.wrapper.ownerDocument.body.focus({preventScroll: true}); display.input.focus();}, 20); }
       else
         { display.input.focus(); }
     }
   });
   var mouseMove = function(e2) {
     moved = moved || Math.abs(event.clientX - e2.clientX) + Math.abs(event.clientY - e2.clientY) >= 10;
   };
   var dragStart = function () { return moved = true; };
   // Let the drag handler handle this.
   if (webkit) { display.scroller.draggable = true; }
   cm.state.draggingText = dragEnd;
   dragEnd.copy = !behavior.moveOnDrag;
   // IE's approach to draggable
   if (display.scroller.dragDrop) { display.scroller.dragDrop(); }
   on(display.wrapper.ownerDocument, "mouseup", dragEnd);
   on(display.wrapper.ownerDocument, "mousemove", mouseMove);
   on(display.scroller, "dragstart", dragStart);
   on(display.scroller, "drop", dragEnd);

   delayBlurEvent(cm);
   setTimeout(function () { return display.input.focus(); }, 20);
 }

 function rangeForUnit(cm, pos, unit) {
   if (unit == "char") { return new Range(pos, pos) }
   if (unit == "word") { return cm.findWordAt(pos) }
   if (unit == "line") { return new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0))) }
   var result = unit(cm, pos);
   return new Range(result.from, result.to)
 }

 // Normal selection, as opposed to text dragging.
 function leftButtonSelect(cm, event, start, behavior) {
   var display = cm.display, doc = cm.doc;
   e_preventDefault(event);

   var ourRange, ourIndex, startSel = doc.sel, ranges = startSel.ranges;
   if (behavior.addNew && !behavior.extend) {
     ourIndex = doc.sel.contains(start);
     if (ourIndex > -1)
       { ourRange = ranges[ourIndex]; }
     else
       { ourRange = new Range(start, start); }
   } else {
     ourRange = doc.sel.primary();
     ourIndex = doc.sel.primIndex;
   }

   if (behavior.unit == "rectangle") {
     if (!behavior.addNew) { ourRange = new Range(start, start); }
     start = posFromMouse(cm, event, true, true);
     ourIndex = -1;
   } else {
     var range = rangeForUnit(cm, start, behavior.unit);
     if (behavior.extend)
       { ourRange = extendRange(ourRange, range.anchor, range.head, behavior.extend); }
     else
       { ourRange = range; }
   }

   if (!behavior.addNew) {
     ourIndex = 0;
     setSelection(doc, new Selection([ourRange], 0), sel_mouse);
     startSel = doc.sel;
   } else if (ourIndex == -1) {
     ourIndex = ranges.length;
     setSelection(doc, normalizeSelection(cm, ranges.concat([ourRange]), ourIndex),
                  {scroll: false, origin: "*mouse"});
   } else if (ranges.length > 1 && ranges[ourIndex].empty() && behavior.unit == "char" && !behavior.extend) {
     setSelection(doc, normalizeSelection(cm, ranges.slice(0, ourIndex).concat(ranges.slice(ourIndex + 1)), 0),
                  {scroll: false, origin: "*mouse"});
     startSel = doc.sel;
   } else {
     replaceOneSelection(doc, ourIndex, ourRange, sel_mouse);
   }

   var lastPos = start;
   function extendTo(pos) {
     if (cmp(lastPos, pos) == 0) { return }
     lastPos = pos;

     if (behavior.unit == "rectangle") {
       var ranges = [], tabSize = cm.options.tabSize;
       var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize);
       var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize);
       var left = Math.min(startCol, posCol), right = Math.max(startCol, posCol);
       for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line));
            line <= end; line++) {
         var text = getLine(doc, line).text, leftPos = findColumn(text, left, tabSize);
         if (left == right)
           { ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos))); }
         else if (text.length > leftPos)
           { ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize)))); }
       }
       if (!ranges.length) { ranges.push(new Range(start, start)); }
       setSelection(doc, normalizeSelection(cm, startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex),
                    {origin: "*mouse", scroll: false});
       cm.scrollIntoView(pos);
     } else {
       var oldRange = ourRange;
       var range = rangeForUnit(cm, pos, behavior.unit);
       var anchor = oldRange.anchor, head;
       if (cmp(range.anchor, anchor) > 0) {
         head = range.head;
         anchor = minPos(oldRange.from(), range.anchor);
       } else {
         head = range.anchor;
         anchor = maxPos(oldRange.to(), range.head);
       }
       var ranges$1 = startSel.ranges.slice(0);
       ranges$1[ourIndex] = bidiSimplify(cm, new Range(clipPos(doc, anchor), head));
       setSelection(doc, normalizeSelection(cm, ranges$1, ourIndex), sel_mouse);
     }
   }

   var editorSize = display.wrapper.getBoundingClientRect();
   // Used to ensure timeout re-tries don't fire when another extend
   // happened in the meantime (clearTimeout isn't reliable -- at
   // least on Chrome, the timeouts still happen even when cleared,
   // if the clear happens after their scheduled firing time).
   var counter = 0;

   function extend(e) {
     var curCount = ++counter;
     var cur = posFromMouse(cm, e, true, behavior.unit == "rectangle");
     if (!cur) { return }
     if (cmp(cur, lastPos) != 0) {
       cm.curOp.focus = activeElt();
       extendTo(cur);
       var visible = visibleLines(display, doc);
       if (cur.line >= visible.to || cur.line < visible.from)
         { setTimeout(operation(cm, function () {if (counter == curCount) { extend(e); }}), 150); }
     } else {
       var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;
       if (outside) { setTimeout(operation(cm, function () {
         if (counter != curCount) { return }
         display.scroller.scrollTop += outside;
         extend(e);
       }), 50); }
     }
   }

   function done(e) {
     cm.state.selectingText = false;
     counter = Infinity;
     // 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;
   }

   var move = operation(cm, function (e) {
     if (e.buttons === 0 || !e_button(e)) { done(e); }
     else { extend(e); }
   });
   var up = operation(cm, done);
   cm.state.selectingText = up;
   on(display.wrapper.ownerDocument, "mousemove", move);
   on(display.wrapper.ownerDocument, "mouseup", up);
 }

 // Used when mouse-selecting to adjust the anchor to the proper side
 // of a bidi jump depending on the visual position of the head.
 function bidiSimplify(cm, range) {
   var anchor = range.anchor;
   var head = range.head;
   var anchorLine = getLine(cm.doc, anchor.line);
   if (cmp(anchor, head) == 0 && anchor.sticky == head.sticky) { return range }
   var order = getOrder(anchorLine);
   if (!order) { return range }
   var index = getBidiPartAt(order, anchor.ch, anchor.sticky), part = order[index];
   if (part.from != anchor.ch && part.to != anchor.ch) { return range }
   var boundary = index + ((part.from == anchor.ch) == (part.level != 1) ? 0 : 1);
   if (boundary == 0 || boundary == order.length) { return range }

   // Compute the relative visual position of the head compared to the
   // anchor (<0 is to the left, >0 to the right)
   var leftSide;
   if (head.line != anchor.line) {
     leftSide = (head.line - anchor.line) * (cm.doc.direction == "ltr" ? 1 : -1) > 0;
   } else {
     var headIndex = getBidiPartAt(order, head.ch, head.sticky);
     var dir = headIndex - index || (head.ch - anchor.ch) * (part.level == 1 ? -1 : 1);
     if (headIndex == boundary - 1 || headIndex == boundary)
       { leftSide = dir < 0; }
     else
       { leftSide = dir > 0; }
   }

   var usePart = order[boundary + (leftSide ? -1 : 0)];
   var from = leftSide == (usePart.level == 1);
   var ch = from ? usePart.from : usePart.to, sticky = from ? "after" : "before";
   return anchor.ch == ch && anchor.sticky == sticky ? range : new Range(new Pos(anchor.line, ch, sticky), head)
 }


 // Determines whether an event happened in the gutter, and fires the
 // handlers for the corresponding event.
 function gutterEvent(cm, e, type, prevent) {
   var mX, mY;
   if (e.touches) {
     mX = e.touches[0].clientX;
     mY = e.touches[0].clientY;
   } else {
     try { mX = e.clientX; mY = e.clientY; }
     catch(e$1) { return false }
   }
   if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) { return false }
   if (prevent) { e_preventDefault(e); }

   var display = cm.display;
   var lineBox = display.lineDiv.getBoundingClientRect();

   if (mY > lineBox.bottom || !hasHandler(cm, type)) { return e_defaultPrevented(e) }
   mY -= lineBox.top - display.viewOffset;

   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.display.gutterSpecs[i];
       signal(cm, type, cm, line, gutter.className, e);
       return e_defaultPrevented(e)
     }
   }
 }

 function clickInGutter(cm, e) {
   return gutterEvent(cm, e, "gutterClick", true)
 }

 // CONTEXT MENU HANDLING

 // To make the context menu work, we need to briefly unhide the
 // textarea (making it as unobtrusive as possible) to let the
 // right-click take effect on it.
 function onContextMenu(cm, e) {
   if (eventInWidget(cm.display, e) || contextMenuInGutter(cm, e)) { return }
   if (signalDOMEvent(cm, e, "contextmenu")) { return }
   if (!captureRightClick) { cm.display.input.onContextMenu(e); }
 }

 function contextMenuInGutter(cm, e) {
   if (!hasHandler(cm, "gutterContextMenu")) { return false }
   return gutterEvent(cm, e, "gutterContextMenu", false)
 }

 function themeChanged(cm) {
   cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
     cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
   clearCaches(cm);
 }

 var Init = {toString: function(){return "CodeMirror.Init"}};

 var defaults = {};
 var optionHandlers = {};

 function defineOptions(CodeMirror) {
   var optionHandlers = CodeMirror.optionHandlers;

   function option(name, deflt, handle, notOnInit) {
     CodeMirror.defaults[name] = deflt;
     if (handle) { optionHandlers[name] =
       notOnInit ? function (cm, val, old) {if (old != Init) { handle(cm, val, old); }} : handle; }
   }

   CodeMirror.defineOption = option;

   // Passed to option handlers when there is no old value.
   CodeMirror.Init = Init;

   // These two are, on init, called from the constructor because they
   // have to be initialized before the editor can start at all.
   option("value", "", function (cm, val) { return cm.setValue(val); }, true);
   option("mode", null, function (cm, val) {
     cm.doc.modeOption = val;
     loadMode(cm);
   }, true);

   option("indentUnit", 2, loadMode, true);
   option("indentWithTabs", false);
   option("smartIndent", true);
   option("tabSize", 4, function (cm) {
     resetModeState(cm);
     clearCaches(cm);
     regChange(cm);
   }, true);

   option("lineSeparator", null, function (cm, val) {
     cm.doc.lineSep = val;
     if (!val) { return }
     var newBreaks = [], lineNo = cm.doc.first;
     cm.doc.iter(function (line) {
       for (var pos = 0;;) {
         var found = line.text.indexOf(val, pos);
         if (found == -1) { break }
         pos = found + val.length;
         newBreaks.push(Pos(lineNo, found));
       }
       lineNo++;
     });
     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-\u200c\u200e\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(); }
   });
   option("specialCharPlaceholder", defaultSpecialCharPlaceholder, function (cm) { return cm.refresh(); }, true);
   option("electricChars", true);
   option("inputStyle", mobile ? "contenteditable" : "textarea", function () {
     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);
     updateGutters(cm);
   }, true);
   option("keyMap", "default", function (cm, val, old) {
     var next = getKeyMap(val);
     var prev = old != Init && getKeyMap(old);
     if (prev && prev.detach) { prev.detach(cm, next); }
     if (next.attach) { next.attach(cm, prev || null); }
   });
   option("extraKeys", null);
   option("configureMouse", null);

   option("lineWrapping", false, wrappingChanged, true);
   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";
     cm.refresh();
   }, true);
   option("coverGutterNextToScrollbar", false, function (cm) { return updateScrollbars(cm); }, true);
   option("scrollbarStyle", "native", function (cm) {
     initScrollbars(cm);
     updateScrollbars(cm);
     cm.display.scrollbars.setScrollTop(cm.doc.scrollTop);
     cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft);
   }, true);
   option("lineNumbers", false, function (cm, val) {
     cm.display.gutterSpecs = getGutters(cm.options.gutters, val);
     updateGutters(cm);
   }, true);
   option("firstLineNumber", 1, updateGutters, true);
   option("lineNumberFormatter", function (integer) { return integer; }, updateGutters, true);
   option("showCursorWhenSelecting", false, updateSelection, true);

   option("resetSelectionOnContextMenu", true);
   option("lineWiseCopyCut", true);
   option("pasteLinesPerSelection", true);
   option("selectionsMayTouch", false);

   option("readOnly", false, function (cm, val) {
     if (val == "nocursor") {
       onBlur(cm);
       cm.display.input.blur();
     }
     cm.display.input.readOnlyChanged(val);
   });

   option("screenReaderLabel", null, function (cm, val) {
     val = (val === '') ? null : val;
     cm.display.input.screenReaderLabelChanged(val);
   });

   option("disableInput", false, function (cm, val) {if (!val) { cm.display.input.reset(); }}, true);
   option("dragDrop", true, dragDropChanged);
   option("allowDropFileTypes", null);

   option("cursorBlinkRate", 530);
   option("cursorScrollMargin", 0);
   option("cursorHeight", 1, updateSelection, true);
   option("singleCursorHeightPerLine", true, updateSelection, true);
   option("workTime", 100);
   option("workDelay", 100);
   option("flattenSpans", true, resetModeState, true);
   option("addModeClass", false, resetModeState, true);
   option("pollInterval", 100);
   option("undoDepth", 200, function (cm, val) { return cm.doc.history.undoDepth = val; });
   option("historyEventDelay", 1250);
   option("viewportMargin", 10, function (cm) { return cm.refresh(); }, true);
   option("maxHighlightLength", 10000, resetModeState, true);
   option("moveInputWithCursor", true, function (cm, val) {
     if (!val) { cm.display.input.resetPosition(); }
   });

   option("tabindex", null, function (cm, val) { return cm.display.input.getField().tabIndex = val || ""; });
   option("autofocus", null);
   option("direction", "ltr", function (cm, val) { return cm.doc.setDirection(val); }, true);
   option("phrases", null);
 }

 function dragDropChanged(cm, value, old) {
   var wasOn = old && old != Init;
   if (!value != !wasOn) {
     var funcs = cm.display.dragFunctions;
     var toggle = value ? on : off;
     toggle(cm.display.scroller, "dragstart", funcs.start);
     toggle(cm.display.scroller, "dragenter", funcs.enter);
     toggle(cm.display.scroller, "dragover", funcs.over);
     toggle(cm.display.scroller, "dragleave", funcs.leave);
     toggle(cm.display.scroller, "drop", funcs.drop);
   }
 }

 function wrappingChanged(cm) {
   if (cm.options.lineWrapping) {
     addClass(cm.display.wrapper, "CodeMirror-wrap");
     cm.display.sizer.style.minWidth = "";
     cm.display.sizerWidth = null;
   } else {
     rmClass(cm.display.wrapper, "CodeMirror-wrap");
     findMaxLine(cm);
   }
   estimateLineHeights(cm);
   regChange(cm);
   clearCaches(cm);
   setTimeout(function () { return updateScrollbars(cm); }, 100);
 }

 // A CodeMirror instance represents an editor. This is the object
 // that user code is usually dealing with.

 function CodeMirror(place, options) {
   var this$1 = this;

   if (!(this instanceof CodeMirror)) { return new CodeMirror(place, options) }

   this.options = options = options ? copyObj(options) : {};
   // Determine effective options based on given values and defaults.
   copyObj(defaults, options, false);

   var doc = options.value;
   if (typeof doc == "string") { doc = new Doc(doc, options.mode, null, options.lineSeparator, options.direction); }
   else if (options.mode) { doc.modeOption = options.mode; }
   this.doc = doc;

   var input = new CodeMirror.inputStyles[options.inputStyle](this);
   var display = this.display = new Display(place, doc, input, options);
   display.wrapper.CodeMirror = this;
   themeChanged(this);
   if (options.lineWrapping)
     { this.display.wrapper.className += " CodeMirror-wrap"; }
   initScrollbars(this);

   this.state = {
     keyMaps: [],  // stores maps added by addKeyMap
     overlays: [], // highlighting overlays, as added by addOverlay
     modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info
     overwrite: false,
     delayingBlurEvent: false,
     focused: false,
     suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
     pasteIncoming: -1, cutIncoming: -1, // help recognize paste/cut edits in input.poll
     selectingText: false,
     draggingText: false,
     highlight: new Delayed(), // stores highlight worker timeout
     keySeq: null,  // Unfinished key sequence
     specialChars: null
   };

   if (options.autofocus && !mobile) { display.input.focus(); }

   // Override magic textarea content restore that IE sometimes does
   // on our hidden textarea on reload
   if (ie && ie_version < 11) { setTimeout(function () { return this$1.display.input.reset(true); }, 20); }

   registerEventHandlers(this);
   ensureGlobalHandlers();

   startOperation(this);
   this.curOp.forceUpdate = true;
   attachDoc(this, doc);

   if ((options.autofocus && !mobile) || this.hasFocus())
     { setTimeout(function () {
       if (this$1.hasFocus() && !this$1.state.focused) { onFocus(this$1); }
     }, 20); }
   else
     { onBlur(this); }

   for (var opt in optionHandlers) { if (optionHandlers.hasOwnProperty(opt))
     { optionHandlers[opt](this, options[opt], Init); } }
   maybeUpdateLineNumberWidth(this);
   if (options.finishInit) { options.finishInit(this); }
   for (var i = 0; i < initHooks.length; ++i) { initHooks[i](this); }
   endOperation(this);
   // Suppress optimizelegibility in Webkit, since it breaks text
   // measuring on line wrapping boundaries.
   if (webkit && options.lineWrapping &&
       getComputedStyle(display.lineDiv).textRendering == "optimizelegibility")
     { display.lineDiv.style.textRendering = "auto"; }
 }

 // The default configuration options.
 CodeMirror.defaults = defaults;
 // Functions to run when options are changed.
 CodeMirror.optionHandlers = optionHandlers;

 // Attach the necessary event handlers when initializing the editor
 function registerEventHandlers(cm) {
   var d = cm.display;
   on(d.scroller, "mousedown", operation(cm, onMouseDown));
   // Older IE's will not fire a second mousedown for a double click
   if (ie && ie_version < 11)
     { on(d.scroller, "dblclick", operation(cm, function (e) {
       if (signalDOMEvent(cm, e)) { return }
       var pos = posFromMouse(cm, e);
       if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) { return }
       e_preventDefault(e);
       var word = cm.findWordAt(pos);
       extendSelection(cm.doc, word.anchor, word.head);
     })); }
   else
     { on(d.scroller, "dblclick", function (e) { return signalDOMEvent(cm, e) || e_preventDefault(e); }); }
   // Some browsers fire contextmenu *after* opening the menu, at
   // which point we can't mess with it anymore. Context menu is
   // handled in onMouseDown for these browsers.
   on(d.scroller, "contextmenu", function (e) { return onContextMenu(cm, e); });
   on(d.input.getField(), "contextmenu", function (e) {
     if (!d.scroller.contains(e.target)) { onContextMenu(cm, e); }
   });

   // Used to suppress mouse event handling when a touch happens
   var touchFinished, prevTouch = {end: 0};
   function finishTouch() {
     if (d.activeTouch) {
       touchFinished = setTimeout(function () { return d.activeTouch = null; }, 1000);
       prevTouch = d.activeTouch;
       prevTouch.end = +new Date;
     }
   }
   function isMouseLikeTouchEvent(e) {
     if (e.touches.length != 1) { return false }
     var touch = e.touches[0];
     return touch.radiusX <= 1 && touch.radiusY <= 1
   }
   function farAway(touch, other) {
     if (other.left == null) { return true }
     var dx = other.left - touch.left, dy = other.top - touch.top;
     return dx * dx + dy * dy > 20 * 20
   }
   on(d.scroller, "touchstart", function (e) {
     if (!signalDOMEvent(cm, e) && !isMouseLikeTouchEvent(e) && !clickInGutter(cm, e)) {
       d.input.ensurePolled();
       clearTimeout(touchFinished);
       var now = +new Date;
       d.activeTouch = {start: now, moved: false,
                        prev: now - prevTouch.end <= 300 ? prevTouch : null};
       if (e.touches.length == 1) {
         d.activeTouch.left = e.touches[0].pageX;
         d.activeTouch.top = e.touches[0].pageY;
       }
     }
   });
   on(d.scroller, "touchmove", function () {
     if (d.activeTouch) { d.activeTouch.moved = true; }
   });
   on(d.scroller, "touchend", function (e) {
     var touch = d.activeTouch;
     if (touch && !eventInWidget(d, e) && touch.left != null &&
         !touch.moved && new Date - touch.start < 300) {
       var pos = cm.coordsChar(d.activeTouch, "page"), range;
       if (!touch.prev || farAway(touch, touch.prev)) // Single tap
         { range = new Range(pos, pos); }
       else if (!touch.prev.prev || farAway(touch, touch.prev.prev)) // Double tap
         { range = cm.findWordAt(pos); }
       else // Triple tap
         { range = new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0))); }
       cm.setSelection(range.anchor, range.head);
       cm.focus();
       e_preventDefault(e);
     }
     finishTouch();
   });
   on(d.scroller, "touchcancel", finishTouch);

   // Sync scrolling between fake scrollbars and real scrollable
   // area, ensure viewport is updated when scrolling.
   on(d.scroller, "scroll", function () {
     if (d.scroller.clientHeight) {
       updateScrollTop(cm, d.scroller.scrollTop);
       setScrollLeft(cm, d.scroller.scrollLeft, true);
       signal(cm, "scroll", cm);
     }
   });

   // Listen to wheel events in order to try and update the viewport on time.
   on(d.scroller, "mousewheel", function (e) { return onScrollWheel(cm, e); });
   on(d.scroller, "DOMMouseScroll", function (e) { return onScrollWheel(cm, e); });

   // Prevent wrapper from ever scrolling
   on(d.wrapper, "scroll", function () { return d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });

   d.dragFunctions = {
     enter: function (e) {if (!signalDOMEvent(cm, e)) { e_stop(e); }},
     over: function (e) {if (!signalDOMEvent(cm, e)) { onDragOver(cm, e); e_stop(e); }},
     start: function (e) { return onDragStart(cm, e); },
     drop: operation(cm, onDrop),
     leave: function (e) {if (!signalDOMEvent(cm, e)) { clearDragCursor(cm); }}
   };

   var inp = d.input.getField();
   on(inp, "keyup", function (e) { return onKeyUp.call(cm, e); });
   on(inp, "keydown", operation(cm, onKeyDown));
   on(inp, "keypress", operation(cm, onKeyPress));
   on(inp, "focus", function (e) { return onFocus(cm, e); });
   on(inp, "blur", function (e) { return onBlur(cm, e); });
 }

 var initHooks = [];
 CodeMirror.defineInitHook = function (f) { return initHooks.push(f); };

 // Indent the given line. The how parameter can be "smart",
 // "add"/null, "subtract", or "prev". When aggressive is false
 // (typically set to true for forced single-line indents), empty
 // lines are not indented, and places where the mode returns Pass
 // are left alone.
 function indentLine(cm, n, how, aggressive) {
   var doc = cm.doc, state;
   if (how == null) { how = "add"; }
   if (how == "smart") {
     // Fall back to "prev" when the mode doesn't have an indentation
     // method.
     if (!doc.mode.indent) { how = "prev"; }
     else { state = getContextBefore(cm, n).state; }
   }

   var tabSize = cm.options.tabSize;
   var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
   if (line.stateAfter) { line.stateAfter = null; }
   var curSpaceString = line.text.match(/^\s*/)[0], indentation;
   if (!aggressive && !/\S/.test(line.text)) {
     indentation = 0;
     how = "not";
   } else if (how == "smart") {
     indentation = doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
     if (indentation == Pass || indentation > 150) {
       if (!aggressive) { return }
       how = "prev";
     }
   }
   if (how == "prev") {
     if (n > doc.first) { indentation = countColumn(getLine(doc, n-1).text, null, tabSize); }
     else { indentation = 0; }
   } else if (how == "add") {
     indentation = curSpace + cm.options.indentUnit;
   } else if (how == "subtract") {
     indentation = curSpace - cm.options.indentUnit;
   } else if (typeof how == "number") {
     indentation = curSpace + how;
   }
   indentation = Math.max(0, indentation);

   var indentString = "", pos = 0;
   if (cm.options.indentWithTabs)
     { for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";} }
   if (pos < indentation) { indentString += spaceStr(indentation - pos); }

   if (indentString != curSpaceString) {
     replaceRange(doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
     line.stateAfter = null;
     return true
   } else {
     // Ensure that, if the cursor was in the whitespace at the start
     // of the line, it is moved to the end of that space.
     for (var i$1 = 0; i$1 < doc.sel.ranges.length; i$1++) {
       var range = doc.sel.ranges[i$1];
       if (range.head.line == n && range.head.ch < curSpaceString.length) {
         var pos$1 = Pos(n, curSpaceString.length);
         replaceOneSelection(doc, i$1, new Range(pos$1, pos$1));
         break
       }
     }
   }
 }

 // This will be set to a {lineWise: bool, text: [string]} object, so
 // that, when pasting, we know what kind of selections the copied
 // text was made out of.
 var lastCopied = null;

 function setLastCopied(newLastCopied) {
   lastCopied = newLastCopied;
 }

 function applyTextInput(cm, inserted, deleted, sel, origin) {
   var doc = cm.doc;
   cm.display.shift = false;
   if (!sel) { sel = doc.sel; }

   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) {
     if (lastCopied && lastCopied.text.join("\n") == inserted) {
       if (sel.ranges.length % lastCopied.text.length == 0) {
         multiPaste = [];
         for (var i = 0; i < lastCopied.text.length; i++)
           { multiPaste.push(doc.splitLines(lastCopied.text[i])); }
       }
     } else if (textLines.length == sel.ranges.length && cm.options.pasteLinesPerSelection) {
       multiPaste = map(textLines, function (l) { return [l]; });
     }
   }

   var updateInput = cm.curOp.updateInput;
   // Normal behavior is to insert the new text into every selection
   for (var i$1 = sel.ranges.length - 1; i$1 >= 0; i$1--) {
     var range = sel.ranges[i$1];
     var from = range.from(), to = range.to();
     if (range.empty()) {
       if (deleted && deleted > 0) // Handle deletion
         { from = Pos(from.line, from.ch - deleted); }
       else if (cm.state.overwrite && !paste) // Handle overwrite
         { to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length)); }
       else if (paste && lastCopied && lastCopied.lineWise && lastCopied.text.join("\n") == textLines.join("\n"))
         { 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 > recent ? "cut" : "+input")};
     makeChange(cm.doc, changeEvent);
     signalLater(cm, "inputRead", cm, changeEvent);
   }
   if (inserted && !paste)
     { triggerElectric(cm, inserted); }

   ensureCursorVisible(cm);
   if (cm.curOp.updateInput < 2) { cm.curOp.updateInput = updateInput; }
   cm.curOp.typing = true;
   cm.state.pasteIncoming = cm.state.cutIncoming = -1;
 }

 function handlePaste(e, cm) {
   var pasted = e.clipboardData && e.clipboardData.getData("Text");
   if (pasted) {
     e.preventDefault();
     if (!cm.isReadOnly() && !cm.options.disableInput)
       { runInOp(cm, function () { return applyTextInput(cm, pasted, 0, null, "paste"); }); }
     return true
   }
 }

 function triggerElectric(cm, inserted) {
   // When an 'electric' character is inserted, immediately trigger a reindent
   if (!cm.options.electricChars || !cm.options.smartIndent) { return }
   var sel = cm.doc.sel;

   for (var i = sel.ranges.length - 1; i >= 0; i--) {
     var range = sel.ranges[i];
     if (range.head.ch > 100 || (i && sel.ranges[i - 1].head.line == range.head.line)) { continue }
     var mode = cm.getModeAt(range.head);
     var indented = false;
     if (mode.electricChars) {
       for (var j = 0; j < mode.electricChars.length; j++)
         { if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
           indented = indentLine(cm, range.head.line, "smart");
           break
         } }
     } else if (mode.electricInput) {
       if (mode.electricInput.test(getLine(cm.doc, range.head.line).text.slice(0, range.head.ch)))
         { indented = indentLine(cm, range.head.line, "smart"); }
     }
     if (indented) { signalLater(cm, "electricInput", cm, range.head.line); }
   }
 }

 function copyableRanges(cm) {
   var text = [], ranges = [];
   for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
     var line = cm.doc.sel.ranges[i].head.line;
     var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};
     ranges.push(lineRange);
     text.push(cm.getRange(lineRange.anchor, lineRange.head));
   }
   return {text: text, ranges: ranges}
 }

 function disableBrowserMagic(field, spellcheck, autocorrect, autocapitalize) {
   field.setAttribute("autocorrect", autocorrect ? "" : "off");
   field.setAttribute("autocapitalize", autocapitalize ? "" : "off");
   field.setAttribute("spellcheck", !!spellcheck);
 }

 function hiddenTextarea() {
   var te = elt("textarea", null, null, "position: absolute; bottom: -1em; padding: 0; width: 1px; height: 1em; outline: none");
   var div = elt("div", [te], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
   // The textarea is kept positioned near the cursor to prevent the
   // fact that it'll be scrolled into view on input from scrolling
   // our fake cursor out of view. On webkit, when wrap=off, paste is
   // very slow. So make the area wide instead.
   if (webkit) { te.style.width = "1000px"; }
   else { te.setAttribute("wrap", "off"); }
   // If border: 0; -- iOS fails to open keyboard (issue #1287)
   if (ios) { te.style.border = "1px solid black"; }
   disableBrowserMagic(te);
   return div
 }

 // The publicly visible API. Note that methodOp(f) means
 // 'wrap f in an operation, performed on its `this` parameter'.

 // This is not the complete set of editor methods. Most of the
 // methods defined on the Doc type are also injected into
 // CodeMirror.prototype, for backwards compatibility and
 // convenience.

 function addEditorMethods(CodeMirror) {
   var optionHandlers = CodeMirror.optionHandlers;

   var helpers = CodeMirror.helpers = {};

   CodeMirror.prototype = {
     constructor: CodeMirror,
     focus: function(){window.focus(); this.display.input.focus();},

     setOption: function(option, value) {
       var options = this.options, old = options[option];
       if (options[option] == value && option != "mode") { return }
       options[option] = value;
       if (optionHandlers.hasOwnProperty(option))
         { operation(this, optionHandlers[option])(this, value, old); }
       signal(this, "optionChange", this, option);
     },

     getOption: function(option) {return this.options[option]},
     getDoc: function() {return this.doc},

     addKeyMap: function(map, bottom) {
       this.state.keyMaps[bottom ? "push" : "unshift"](getKeyMap(map));
     },
     removeKeyMap: function(map) {
       var maps = this.state.keyMaps;
       for (var i = 0; i < maps.length; ++i)
         { if (maps[i] == map || maps[i].name == map) {
           maps.splice(i, 1);
           return true
         } }
     },

     addOverlay: methodOp(function(spec, options) {
       var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);
       if (mode.startState) { throw new Error("Overlays may not be stateful.") }
       insertSorted(this.state.overlays,
                    {mode: mode, modeSpec: spec, opaque: options && options.opaque,
                     priority: (options && options.priority) || 0},
                    function (overlay) { return overlay.priority; });
       this.state.modeGen++;
       regChange(this);
     }),
     removeOverlay: methodOp(function(spec) {
       var overlays = this.state.overlays;
       for (var i = 0; i < overlays.length; ++i) {
         var cur = overlays[i].modeSpec;
         if (cur == spec || typeof spec == "string" && cur.name == spec) {
           overlays.splice(i, 1);
           this.state.modeGen++;
           regChange(this);
           return
         }
       }
     }),

     indentLine: methodOp(function(n, dir, aggressive) {
       if (typeof dir != "string" && typeof dir != "number") {
         if (dir == null) { dir = this.options.smartIndent ? "smart" : "prev"; }
         else { dir = dir ? "add" : "subtract"; }
       }
       if (isLine(this.doc, n)) { indentLine(this, n, dir, aggressive); }
     }),
     indentSelection: methodOp(function(how) {
       var ranges = this.doc.sel.ranges, end = -1;
       for (var i = 0; i < ranges.length; i++) {
         var range = ranges[i];
         if (!range.empty()) {
           var from = range.from(), to = range.to();
           var start = Math.max(end, from.line);
           end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1;
           for (var j = start; j < end; ++j)
             { indentLine(this, j, how); }
           var newRanges = this.doc.sel.ranges;
           if (from.ch == 0 && ranges.length == newRanges.length && newRanges[i].from().ch > 0)
             { replaceOneSelection(this.doc, i, new Range(from, newRanges[i].to()), sel_dontScroll); }
         } else if (range.head.line > end) {
           indentLine(this, range.head.line, how, true);
           end = range.head.line;
           if (i == this.doc.sel.primIndex) { ensureCursorVisible(this); }
         }
       }
     }),

     // Fetch the parser token for a given character. Useful for hacks
     // that want to inspect the mode state (say, for completion).
     getTokenAt: function(pos, precise) {
       return takeToken(this, pos, precise)
     },

     getLineTokens: function(line, precise) {
       return takeToken(this, Pos(line), precise, true)
     },

     getTokenTypeAt: function(pos) {
       pos = clipPos(this.doc, pos);
       var styles = getLineStyles(this, getLine(this.doc, pos.line));
       var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;
       var type;
       if (ch == 0) { type = styles[2]; }
       else { for (;;) {
         var mid = (before + after) >> 1;
         if ((mid ? styles[mid * 2 - 1] : 0) >= ch) { after = mid; }
         else if (styles[mid * 2 + 1] < ch) { before = mid + 1; }
         else { type = styles[mid * 2 + 2]; break }
       } }
       var cut = type ? type.indexOf("overlay ") : -1;
       return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1)
     },

     getModeAt: function(pos) {
       var mode = this.doc.mode;
       if (!mode.innerMode) { return mode }
       return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode
     },

     getHelper: function(pos, type) {
       return this.getHelpers(pos, type)[0]
     },

     getHelpers: function(pos, type) {
       var found = [];
       if (!helpers.hasOwnProperty(type)) { return found }
       var help = helpers[type], mode = this.getModeAt(pos);
       if (typeof mode[type] == "string") {
         if (help[mode[type]]) { found.push(help[mode[type]]); }
       } else if (mode[type]) {
         for (var i = 0; i < mode[type].length; i++) {
           var val = help[mode[type][i]];
           if (val) { found.push(val); }
         }
       } else if (mode.helperType && help[mode.helperType]) {
         found.push(help[mode.helperType]);
       } else if (help[mode.name]) {
         found.push(help[mode.name]);
       }
       for (var i$1 = 0; i$1 < help._global.length; i$1++) {
         var cur = help._global[i$1];
         if (cur.pred(mode, this) && indexOf(found, cur.val) == -1)
           { found.push(cur.val); }
       }
       return found
     },

     getStateAfter: function(line, precise) {
       var doc = this.doc;
       line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);
       return getContextBefore(this, line + 1, precise).state
     },

     cursorCoords: function(start, mode) {
       var pos, range = this.doc.sel.primary();
       if (start == null) { pos = range.head; }
       else if (typeof start == "object") { pos = clipPos(this.doc, start); }
       else { pos = start ? range.from() : range.to(); }
       return cursorCoords(this, pos, mode || "page")
     },

     charCoords: function(pos, mode) {
       return charCoords(this, clipPos(this.doc, pos), mode || "page")
     },

     coordsChar: function(coords, mode) {
       coords = fromCoordSystem(this, coords, mode || "page");
       return coordsChar(this, coords.left, coords.top)
     },

     lineAtHeight: function(height, mode) {
       height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;
       return lineAtHeight(this.doc, height + this.display.viewOffset)
     },
     heightAtLine: function(line, mode, includeWidgets) {
       var end = false, lineObj;
       if (typeof line == "number") {
         var last = this.doc.first + this.doc.size - 1;
         if (line < this.doc.first) { line = this.doc.first; }
         else if (line > last) { line = last; end = true; }
         lineObj = getLine(this.doc, line);
       } else {
         lineObj = line;
       }
       return intoCoordSystem(this, lineObj, {top: 0, left: 0}, mode || "page", includeWidgets || end).top +
         (end ? this.doc.height - heightAtLine(lineObj) : 0)
     },

     defaultTextHeight: function() { return textHeight(this.display) },
     defaultCharWidth: function() { return charWidth(this.display) },

     getViewport: function() { return {from: this.display.viewFrom, to: this.display.viewTo}},

     addWidget: function(pos, node, scroll, vert, horiz) {
       var display = this.display;
       pos = cursorCoords(this, clipPos(this.doc, pos));
       var top = pos.bottom, left = pos.left;
       node.style.position = "absolute";
       node.setAttribute("cm-ignore-events", "true");
       this.display.input.setUneditable(node);
       display.sizer.appendChild(node);
       if (vert == "over") {
         top = pos.top;
       } else if (vert == "above" || vert == "near") {
         var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
         hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);
         // Default to positioning above (if specified and possible); otherwise default to positioning below
         if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)
           { top = pos.top - node.offsetHeight; }
         else if (pos.bottom + node.offsetHeight <= vspace)
           { top = pos.bottom; }
         if (left + node.offsetWidth > hspace)
           { left = hspace - node.offsetWidth; }
       }
       node.style.top = top + "px";
       node.style.left = node.style.right = "";
       if (horiz == "right") {
         left = display.sizer.clientWidth - node.offsetWidth;
         node.style.right = "0px";
       } else {
         if (horiz == "left") { left = 0; }
         else if (horiz == "middle") { left = (display.sizer.clientWidth - node.offsetWidth) / 2; }
         node.style.left = left + "px";
       }
       if (scroll)
         { scrollIntoView(this, {left: left, top: top, right: left + node.offsetWidth, bottom: top + node.offsetHeight}); }
     },

     triggerOnKeyDown: methodOp(onKeyDown),
     triggerOnKeyPress: methodOp(onKeyPress),
     triggerOnKeyUp: onKeyUp,
     triggerOnMouseDown: methodOp(onMouseDown),

     execCommand: function(cmd) {
       if (commands.hasOwnProperty(cmd))
         { return commands[cmd].call(null, this) }
     },

     triggerElectric: methodOp(function(text) { triggerElectric(this, text); }),

     findPosH: function(from, amount, unit, visually) {
       var dir = 1;
       if (amount < 0) { dir = -1; amount = -amount; }
       var cur = clipPos(this.doc, from);
       for (var i = 0; i < amount; ++i) {
         cur = findPosH(this.doc, cur, dir, unit, visually);
         if (cur.hitSide) { break }
       }
       return cur
     },

     moveH: methodOp(function(dir, unit) {
       var this$1 = this;

       this.extendSelectionsBy(function (range) {
         if (this$1.display.shift || this$1.doc.extend || range.empty())
           { return findPosH(this$1.doc, range.head, dir, unit, this$1.options.rtlMoveVisually) }
         else
           { return dir < 0 ? range.from() : range.to() }
       }, sel_move);
     }),

     deleteH: methodOp(function(dir, unit) {
       var sel = this.doc.sel, doc = this.doc;
       if (sel.somethingSelected())
         { doc.replaceSelection("", null, "+delete"); }
       else
         { deleteNearSelection(this, function (range) {
           var other = findPosH(doc, range.head, dir, unit, false);
           return dir < 0 ? {from: other, to: range.head} : {from: range.head, to: other}
         }); }
     }),

     findPosV: function(from, amount, unit, goalColumn) {
       var dir = 1, x = goalColumn;
       if (amount < 0) { dir = -1; amount = -amount; }
       var cur = clipPos(this.doc, from);
       for (var i = 0; i < amount; ++i) {
         var coords = cursorCoords(this, cur, "div");
         if (x == null) { x = coords.left; }
         else { coords.left = x; }
         cur = findPosV(this, coords, dir, unit);
         if (cur.hitSide) { break }
       }
       return cur
     },

     moveV: methodOp(function(dir, unit) {
       var this$1 = this;

       var doc = this.doc, goals = [];
       var collapse = !this.display.shift && !doc.extend && doc.sel.somethingSelected();
       doc.extendSelectionsBy(function (range) {
         if (collapse)
           { return dir < 0 ? range.from() : range.to() }
         var headPos = cursorCoords(this$1, range.head, "div");
         if (range.goalColumn != null) { headPos.left = range.goalColumn; }
         goals.push(headPos.left);
         var pos = findPosV(this$1, headPos, dir, unit);
         if (unit == "page" && range == doc.sel.primary())
           { addToScrollTop(this$1, charCoords(this$1, pos, "div").top - headPos.top); }
         return pos
       }, sel_move);
       if (goals.length) { for (var i = 0; i < doc.sel.ranges.length; i++)
         { doc.sel.ranges[i].goalColumn = goals[i]; } }
     }),

     // Find the word at the given position (as returned by coordsChar).
     findWordAt: function(pos) {
       var doc = this.doc, line = getLine(doc, pos.line).text;
       var start = pos.ch, end = pos.ch;
       if (line) {
         var helper = this.getHelper(pos, "wordChars");
         if ((pos.sticky == "before" || end == line.length) && start) { --start; } else { ++end; }
         var startChar = line.charAt(start);
         var check = isWordChar(startChar, helper)
           ? function (ch) { return isWordChar(ch, helper); }
           : /\s/.test(startChar) ? function (ch) { return /\s/.test(ch); }
           : function (ch) { return (!/\s/.test(ch) && !isWordChar(ch)); };
         while (start > 0 && check(line.charAt(start - 1))) { --start; }
         while (end < line.length && check(line.charAt(end))) { ++end; }
       }
       return new Range(Pos(pos.line, start), Pos(pos.line, end))
     },

     toggleOverwrite: function(value) {
       if (value != null && value == this.state.overwrite) { return }
       if (this.state.overwrite = !this.state.overwrite)
         { addClass(this.display.cursorDiv, "CodeMirror-overwrite"); }
       else
         { rmClass(this.display.cursorDiv, "CodeMirror-overwrite"); }

       signal(this, "overwriteToggle", this, this.state.overwrite);
     },
     hasFocus: function() { return this.display.input.getField() == activeElt() },
     isReadOnly: function() { return !!(this.options.readOnly || this.doc.cantEdit) },

     scrollTo: methodOp(function (x, y) { scrollToCoords(this, x, y); }),
     getScrollInfo: function() {
       var scroller = this.display.scroller;
       return {left: scroller.scrollLeft, top: scroller.scrollTop,
               height: scroller.scrollHeight - scrollGap(this) - this.display.barHeight,
               width: scroller.scrollWidth - scrollGap(this) - this.display.barWidth,
               clientHeight: displayHeight(this), clientWidth: displayWidth(this)}
     },

     scrollIntoView: methodOp(function(range, margin) {
       if (range == null) {
         range = {from: this.doc.sel.primary().head, to: null};
         if (margin == null) { margin = this.options.cursorScrollMargin; }
       } else if (typeof range == "number") {
         range = {from: Pos(range, 0), to: null};
       } else if (range.from == null) {
         range = {from: range, to: null};
       }
       if (!range.to) { range.to = range.from; }
       range.margin = margin || 0;

       if (range.from.line != null) {
         scrollToRange(this, range);
       } else {
         scrollToCoordsRange(this, range.from, range.to, range.margin);
       }
     }),

     setSize: methodOp(function(width, height) {
       var this$1 = this;

       var interpret = function (val) { return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val; };
       if (width != null) { this.display.wrapper.style.width = interpret(width); }
       if (height != null) { this.display.wrapper.style.height = interpret(height); }
       if (this.options.lineWrapping) { clearLineMeasurementCache(this); }
       var lineNo = this.display.viewFrom;
       this.doc.iter(lineNo, this.display.viewTo, function (line) {
         if (line.widgets) { for (var i = 0; i < line.widgets.length; i++)
           { if (line.widgets[i].noHScroll) { regLineChange(this$1, lineNo, "widget"); break } } }
         ++lineNo;
       });
       this.curOp.forceUpdate = true;
       signal(this, "refresh", this);
     }),

     operation: function(f){return runInOp(this, f)},
     startOperation: function(){return startOperation(this)},
     endOperation: function(){return endOperation(this)},

     refresh: methodOp(function() {
       var oldHeight = this.display.cachedTextHeight;
       regChange(this);
       this.curOp.forceUpdate = true;
       clearCaches(this);
       scrollToCoords(this, this.doc.scrollLeft, this.doc.scrollTop);
       updateGutterSpace(this.display);
       if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5 || this.options.lineWrapping)
         { estimateLineHeights(this); }
       signal(this, "refresh", this);
     }),

     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();
       scrollToCoords(this, doc.scrollLeft, doc.scrollTop);
       this.curOp.forceScroll = true;
       signalLater(this, "swapDoc", this, old);
       return old
     }),

     phrase: function(phraseText) {
       var phrases = this.options.phrases;
       return phrases && Object.prototype.hasOwnProperty.call(phrases, phraseText) ? phrases[phraseText] : phraseText
     },

     getInputField: function(){return this.display.input.getField()},
     getWrapperElement: function(){return this.display.wrapper},
     getScrollerElement: function(){return this.display.scroller},
     getGutterElement: function(){return this.display.gutters}
   };
   eventMixin(CodeMirror);

   CodeMirror.registerHelper = function(type, name, value) {
     if (!helpers.hasOwnProperty(type)) { helpers[type] = CodeMirror[type] = {_global: []}; }
     helpers[type][name] = value;
   };
   CodeMirror.registerGlobalHelper = function(type, name, predicate, value) {
     CodeMirror.registerHelper(type, name, value);
     helpers[type]._global.push({pred: predicate, val: value});
   };
 }

 // Used for horizontal relative motion. Dir is -1 or 1 (left or
 // right), unit can be "codepoint", "char", "column" (like char, but
 // doesn't cross line boundaries), "word" (across next word), or
 // "group" (to the start of next group of word or
 // non-word-non-whitespace chars). The visually param controls
 // whether, in right-to-left text, direction 1 means to move towards
 // the next index in the string, or towards the character to the right
 // of the current position. The resulting position will have a
 // hitSide=true property if it reached the end of the document.
 function findPosH(doc, pos, dir, unit, visually) {
   var oldPos = pos;
   var origDir = dir;
   var lineObj = getLine(doc, pos.line);
   var lineDir = visually && doc.direction == "rtl" ? -dir : dir;
   function findNextLine() {
     var l = pos.line + lineDir;
     if (l < doc.first || l >= doc.first + doc.size) { return false }
     pos = new Pos(l, pos.ch, pos.sticky);
     return lineObj = getLine(doc, l)
   }
   function moveOnce(boundToLine) {
     var next;
     if (unit == "codepoint") {
       var ch = lineObj.text.charCodeAt(pos.ch + (unit > 0 ? 0 : -1));
       if (isNaN(ch)) { next = null; }
       else { next = new Pos(pos.line, Math.max(0, Math.min(lineObj.text.length, pos.ch + dir * (ch >= 0xD800 && ch < 0xDC00 ? 2 : 1))),
                           -dir); }
     } else if (visually) {
       next = moveVisually(doc.cm, lineObj, pos, dir);
     } else {
       next = moveLogically(lineObj, pos, dir);
     }
     if (next == null) {
       if (!boundToLine && findNextLine())
         { pos = endOfLine(visually, doc.cm, lineObj, pos.line, lineDir); }
       else
         { return false }
     } else {
       pos = next;
     }
     return true
   }

   if (unit == "char" || unit == "codepoint") {
     moveOnce();
   } else if (unit == "column") {
     moveOnce(true);
   } else if (unit == "word" || unit == "group") {
     var sawType = null, group = unit == "group";
     var helper = doc.cm && doc.cm.getHelper(pos, "wordChars");
     for (var first = true;; first = false) {
       if (dir < 0 && !moveOnce(!first)) { break }
       var cur = lineObj.text.charAt(pos.ch) || "\n";
       var type = isWordChar(cur, helper) ? "w"
         : group && cur == "\n" ? "n"
         : !group || /\s/.test(cur) ? null
         : "p";
       if (group && !first && !type) { type = "s"; }
       if (sawType && sawType != type) {
         if (dir < 0) {dir = 1; moveOnce(); pos.sticky = "after";}
         break
       }

       if (type) { sawType = type; }
       if (dir > 0 && !moveOnce(!first)) { break }
     }
   }
   var result = skipAtomic(doc, pos, oldPos, origDir, true);
   if (equalCursorPos(oldPos, result)) { result.hitSide = true; }
   return result
 }

 // For relative vertical movement. Dir may be -1 or 1. Unit can be
 // "page" or "line". The resulting position will have a hitSide=true
 // property if it reached the end of the document.
 function findPosV(cm, pos, dir, unit) {
   var doc = cm.doc, x = pos.left, y;
   if (unit == "page") {
     var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);
     var moveAmount = Math.max(pageSize - .5 * textHeight(cm.display), 3);
     y = (dir > 0 ? pos.bottom : pos.top) + dir * moveAmount;

   } else if (unit == "line") {
     y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
   }
   var target;
   for (;;) {
     target = coordsChar(cm, x, y);
     if (!target.outside) { break }
     if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break }
     y += dir * 5;
   }
   return target
 }

 // CONTENTEDITABLE INPUT STYLE

 var ContentEditableInput = function(cm) {
   this.cm = cm;
   this.lastAnchorNode = this.lastAnchorOffset = this.lastFocusNode = this.lastFocusOffset = null;
   this.polling = new Delayed();
   this.composing = null;
   this.gracePeriod = false;
   this.readDOMTimeout = null;
 };

 ContentEditableInput.prototype.init = function (display) {
     var this$1 = this;

   var input = this, cm = input.cm;
   var div = input.div = display.lineDiv;
   disableBrowserMagic(div, cm.options.spellcheck, cm.options.autocorrect, cm.options.autocapitalize);

   function belongsToInput(e) {
     for (var t = e.target; t; t = t.parentNode) {
       if (t == div) { return true }
       if (/\bCodeMirror-(?:line)?widget\b/.test(t.className)) { break }
     }
     return false
   }

   on(div, "paste", function (e) {
     if (!belongsToInput(e) || signalDOMEvent(cm, e) || handlePaste(e, cm)) { return }
     // IE doesn't fire input events, so we schedule a read for the pasted content in this way
     if (ie_version <= 11) { setTimeout(operation(cm, function () { return this$1.updateFromDOM(); }), 20); }
   });

   on(div, "compositionstart", function (e) {
     this$1.composing = {data: e.data, done: false};
   });
   on(div, "compositionupdate", function (e) {
     if (!this$1.composing) { this$1.composing = {data: e.data, done: false}; }
   });
   on(div, "compositionend", function (e) {
     if (this$1.composing) {
       if (e.data != this$1.composing.data) { this$1.readFromDOMSoon(); }
       this$1.composing.done = true;
     }
   });

   on(div, "touchstart", function () { return input.forceCompositionEnd(); });

   on(div, "input", function () {
     if (!this$1.composing) { this$1.readFromDOMSoon(); }
   });

   function onCopyCut(e) {
     if (!belongsToInput(e) || signalDOMEvent(cm, e)) { return }
     if (cm.somethingSelected()) {
       setLastCopied({lineWise: false, text: cm.getSelections()});
       if (e.type == "cut") { cm.replaceSelection("", null, "cut"); }
     } else if (!cm.options.lineWiseCopyCut) {
       return
     } else {
       var ranges = copyableRanges(cm);
       setLastCopied({lineWise: true, text: ranges.text});
       if (e.type == "cut") {
         cm.operation(function () {
           cm.setSelections(ranges.ranges, 0, sel_dontScroll);
           cm.replaceSelection("", null, "cut");
         });
       }
     }
     if (e.clipboardData) {
       e.clipboardData.clearData();
       var content = lastCopied.text.join("\n");
       // iOS exposes the clipboard API, but seems to discard content inserted into it
       e.clipboardData.setData("Text", content);
       if (e.clipboardData.getData("Text") == content) {
         e.preventDefault();
         return
       }
     }
     // Old-fashioned briefly-focus-a-textarea hack
     var kludge = hiddenTextarea(), te = kludge.firstChild;
     cm.display.lineSpace.insertBefore(kludge, cm.display.lineSpace.firstChild);
     te.value = lastCopied.text.join("\n");
     var hadFocus = document.activeElement;
     selectInput(te);
     setTimeout(function () {
       cm.display.lineSpace.removeChild(kludge);
       hadFocus.focus();
       if (hadFocus == div) { input.showPrimarySelection(); }
     }, 50);
   }
   on(div, "copy", onCopyCut);
   on(div, "cut", onCopyCut);
 };

 ContentEditableInput.prototype.screenReaderLabelChanged = function (label) {
   // Label for screenreaders, accessibility
   if(label) {
     this.div.setAttribute('aria-label', label);
   } else {
     this.div.removeAttribute('aria-label');
   }
 };

 ContentEditableInput.prototype.prepareSelection = function () {
   var result = prepareSelection(this.cm, false);
   result.focus = document.activeElement == this.div;
   return result
 };

 ContentEditableInput.prototype.showSelection = function (info, takeFocus) {
   if (!info || !this.cm.display.view.length) { return }
   if (info.focus || takeFocus) { this.showPrimarySelection(); }
   this.showMultipleSelections(info);
 };

 ContentEditableInput.prototype.getSelection = function () {
   return this.cm.display.wrapper.ownerDocument.getSelection()
 };

 ContentEditableInput.prototype.showPrimarySelection = function () {
   var sel = this.getSelection(), cm = this.cm, prim = cm.doc.sel.primary();
   var from = prim.from(), to = prim.to();

   if (cm.display.viewTo == cm.display.viewFrom || from.line >= cm.display.viewTo || to.line < cm.display.viewFrom) {
     sel.removeAllRanges();
     return
   }

   var curAnchor = domToPos(cm, sel.anchorNode, sel.anchorOffset);
   var curFocus = domToPos(cm, sel.focusNode, sel.focusOffset);
   if (curAnchor && !curAnchor.bad && curFocus && !curFocus.bad &&
       cmp(minPos(curAnchor, curFocus), from) == 0 &&
       cmp(maxPos(curAnchor, curFocus), to) == 0)
     { return }

   var view = cm.display.view;
   var start = (from.line >= cm.display.viewFrom && posToDOM(cm, from)) ||
       {node: view[0].measure.map[2], offset: 0};
   var end = to.line < cm.display.viewTo && posToDOM(cm, to);
   if (!end) {
     var measure = view[view.length - 1].measure;
     var map = measure.maps ? measure.maps[measure.maps.length - 1] : measure.map;
     end = {node: map[map.length - 1], offset: map[map.length - 2] - map[map.length - 3]};
   }

   if (!start || !end) {
     sel.removeAllRanges();
     return
   }

   var old = sel.rangeCount && sel.getRangeAt(0), rng;
   try { rng = range(start.node, start.offset, end.offset, end.node); }
   catch(e) {} // Our model of the DOM might be outdated, in which case the range we try to set can be impossible
   if (rng) {
     if (!gecko && cm.state.focused) {
       sel.collapse(start.node, start.offset);
       if (!rng.collapsed) {
         sel.removeAllRanges();
         sel.addRange(rng);
       }
     } else {
       sel.removeAllRanges();
       sel.addRange(rng);
     }
     if (old && sel.anchorNode == null) { sel.addRange(old); }
     else if (gecko) { this.startGracePeriod(); }
   }
   this.rememberSelection();
 };

 ContentEditableInput.prototype.startGracePeriod = function () {
     var this$1 = this;

   clearTimeout(this.gracePeriod);
   this.gracePeriod = setTimeout(function () {
     this$1.gracePeriod = false;
     if (this$1.selectionChanged())
       { this$1.cm.operation(function () { return this$1.cm.curOp.selectionChanged = true; }); }
   }, 20);
 };

 ContentEditableInput.prototype.showMultipleSelections = function (info) {
   removeChildrenAndAdd(this.cm.display.cursorDiv, info.cursors);
   removeChildrenAndAdd(this.cm.display.selectionDiv, info.selection);
 };

 ContentEditableInput.prototype.rememberSelection = function () {
   var sel = this.getSelection();
   this.lastAnchorNode = sel.anchorNode; this.lastAnchorOffset = sel.anchorOffset;
   this.lastFocusNode = sel.focusNode; this.lastFocusOffset = sel.focusOffset;
 };

 ContentEditableInput.prototype.selectionInEditor = function () {
   var sel = this.getSelection();
   if (!sel.rangeCount) { return false }
   var node = sel.getRangeAt(0).commonAncestorContainer;
   return contains(this.div, node)
 };

 ContentEditableInput.prototype.focus = function () {
   if (this.cm.options.readOnly != "nocursor") {
     if (!this.selectionInEditor() || document.activeElement != this.div)
       { this.showSelection(this.prepareSelection(), true); }
     this.div.focus();
   }
 };
 ContentEditableInput.prototype.blur = function () { this.div.blur(); };
 ContentEditableInput.prototype.getField = function () { return this.div };

 ContentEditableInput.prototype.supportsTouch = function () { return true };

 ContentEditableInput.prototype.receivedFocus = function () {
   var input = this;
   if (this.selectionInEditor())
     { this.pollSelection(); }
   else
     { runInOp(this.cm, function () { return input.cm.curOp.selectionChanged = true; }); }

   function poll() {
     if (input.cm.state.focused) {
       input.pollSelection();
       input.polling.set(input.cm.options.pollInterval, poll);
     }
   }
   this.polling.set(this.cm.options.pollInterval, poll);
 };

 ContentEditableInput.prototype.selectionChanged = function () {
   var sel = this.getSelection();
   return sel.anchorNode != this.lastAnchorNode || sel.anchorOffset != this.lastAnchorOffset ||
     sel.focusNode != this.lastFocusNode || sel.focusOffset != this.lastFocusOffset
 };

 ContentEditableInput.prototype.pollSelection = function () {
   if (this.readDOMTimeout != null || this.gracePeriod || !this.selectionChanged()) { return }
   var sel = this.getSelection(), cm = this.cm;
   // On Android Chrome (version 56, at least), backspacing into an
   // uneditable block element will put the cursor in that element,
   // and then, because it's not editable, hide the virtual keyboard.
   // 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.display.gutterSpecs.length && isInGutter(sel.anchorNode)) {
     this.cm.triggerOnKeyDown({type: "keydown", keyCode: 8, preventDefault: Math.abs});
     this.blur();
     this.focus();
     return
   }
   if (this.composing) { return }
   this.rememberSelection();
   var anchor = domToPos(cm, sel.anchorNode, sel.anchorOffset);
   var head = domToPos(cm, sel.focusNode, sel.focusOffset);
   if (anchor && head) { runInOp(cm, function () {
     setSelection(cm.doc, simpleSelection(anchor, head), sel_dontScroll);
     if (anchor.bad || head.bad) { cm.curOp.selectionChanged = true; }
   }); }
 };

 ContentEditableInput.prototype.pollContent = function () {
   if (this.readDOMTimeout != null) {
     clearTimeout(this.readDOMTimeout);
     this.readDOMTimeout = null;
   }

   var cm = this.cm, display = cm.display, sel = cm.doc.sel.primary();
   var from = sel.from(), to = sel.to();
   if (from.ch == 0 && from.line > cm.firstLine())
     { from = Pos(from.line - 1, getLine(cm.doc, from.line - 1).length); }
   if (to.ch == getLine(cm.doc, to.line).text.length && to.line < cm.lastLine())
     { to = Pos(to.line + 1, 0); }
   if (from.line < display.viewFrom || to.line > display.viewTo - 1) { return false }

   var fromIndex, fromLine, fromNode;
   if (from.line == display.viewFrom || (fromIndex = findViewIndex(cm, from.line)) == 0) {
     fromLine = lineNo(display.view[0].line);
     fromNode = display.view[0].node;
   } else {
     fromLine = lineNo(display.view[fromIndex].line);
     fromNode = display.view[fromIndex - 1].node.nextSibling;
   }
   var toIndex = findViewIndex(cm, to.line);
   var toLine, toNode;
   if (toIndex == display.view.length - 1) {
     toLine = display.viewTo - 1;
     toNode = display.lineDiv.lastChild;
   } else {
     toLine = lineNo(display.view[toIndex + 1].line) - 1;
     toNode = display.view[toIndex + 1].node.previousSibling;
   }

   if (!fromNode) { return false }
   var newText = cm.doc.splitLines(domTextBetween(cm, fromNode, toNode, fromLine, toLine));
   var oldText = getBetween(cm.doc, Pos(fromLine, 0), Pos(toLine, getLine(cm.doc, toLine).text.length));
   while (newText.length > 1 && oldText.length > 1) {
     if (lst(newText) == lst(oldText)) { newText.pop(); oldText.pop(); toLine--; }
     else if (newText[0] == oldText[0]) { newText.shift(); oldText.shift(); fromLine++; }
     else { break }
   }

   var cutFront = 0, cutEnd = 0;
   var newTop = newText[0], oldTop = oldText[0], maxCutFront = Math.min(newTop.length, oldTop.length);
   while (cutFront < maxCutFront && newTop.charCodeAt(cutFront) == oldTop.charCodeAt(cutFront))
     { ++cutFront; }
   var newBot = lst(newText), oldBot = lst(oldText);
   var maxCutEnd = Math.min(newBot.length - (newText.length == 1 ? cutFront : 0),
                            oldBot.length - (oldText.length == 1 ? cutFront : 0));
   while (cutEnd < maxCutEnd &&
          newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1))
     { ++cutEnd; }
   // Try to move start of change to start of selection if ambiguous
   if (newText.length == 1 && oldText.length == 1 && fromLine == from.line) {
     while (cutFront && cutFront > from.ch &&
            newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1)) {
       cutFront--;
       cutEnd++;
     }
   }

   newText[newText.length - 1] = newBot.slice(0, newBot.length - cutEnd).replace(/^\u200b+/, "");
   newText[0] = newText[0].slice(cutFront).replace(/\u200b+$/, "");

   var chFrom = Pos(fromLine, cutFront);
   var chTo = Pos(toLine, oldText.length ? lst(oldText).length - cutEnd : 0);
   if (newText.length > 1 || newText[0] || cmp(chFrom, chTo)) {
     replaceRange(cm.doc, newText, chFrom, chTo, "+input");
     return true
   }
 };

 ContentEditableInput.prototype.ensurePolled = function () {
   this.forceCompositionEnd();
 };
 ContentEditableInput.prototype.reset = function () {
   this.forceCompositionEnd();
 };
 ContentEditableInput.prototype.forceCompositionEnd = function () {
   if (!this.composing) { return }
   clearTimeout(this.readDOMTimeout);
   this.composing = null;
   this.updateFromDOM();
   this.div.blur();
   this.div.focus();
 };
 ContentEditableInput.prototype.readFromDOMSoon = function () {
     var this$1 = this;

   if (this.readDOMTimeout != null) { return }
   this.readDOMTimeout = setTimeout(function () {
     this$1.readDOMTimeout = null;
     if (this$1.composing) {
       if (this$1.composing.done) { this$1.composing = null; }
       else { return }
     }
     this$1.updateFromDOM();
   }, 80);
 };

 ContentEditableInput.prototype.updateFromDOM = function () {
     var this$1 = this;

   if (this.cm.isReadOnly() || !this.pollContent())
     { runInOp(this.cm, function () { return regChange(this$1.cm); }); }
 };

 ContentEditableInput.prototype.setUneditable = function (node) {
   node.contentEditable = "false";
 };

 ContentEditableInput.prototype.onKeyPress = function (e) {
   if (e.charCode == 0 || this.composing) { return }
   e.preventDefault();
   if (!this.cm.isReadOnly())
     { operation(this.cm, applyTextInput)(this.cm, String.fromCharCode(e.charCode == null ? e.keyCode : e.charCode), 0); }
 };

 ContentEditableInput.prototype.readOnlyChanged = function (val) {
   this.div.contentEditable = String(val != "nocursor");
 };

 ContentEditableInput.prototype.onContextMenu = function () {};
 ContentEditableInput.prototype.resetPosition = function () {};

 ContentEditableInput.prototype.needsContentAttribute = true;

 function posToDOM(cm, pos) {
   var view = findViewForLine(cm, pos.line);
   if (!view || view.hidden) { return null }
   var line = getLine(cm.doc, pos.line);
   var info = mapFromLineView(view, line, pos.line);

   var order = getOrder(line, cm.doc.direction), side = "left";
   if (order) {
     var partPos = getBidiPartAt(order, pos.ch);
     side = partPos % 2 ? "right" : "left";
   }
   var result = nodeAndOffsetInLineMap(info.map, pos.ch, side);
   result.offset = result.collapse == "right" ? result.end : result.start;
   return result
 }

 function isInGutter(node) {
   for (var scan = node; scan; scan = scan.parentNode)
     { if (/CodeMirror-gutter-wrapper/.test(scan.className)) { return true } }
   return false
 }

 function badPos(pos, bad) { if (bad) { pos.bad = true; } return pos }

 function domTextBetween(cm, from, to, fromLine, toLine) {
   var text = "", closing = false, lineSep = cm.doc.lineSeparator(), extraLinebreak = false;
   function recognizeMarker(id) { return function (marker) { return marker.id == id; } }
   function close() {
     if (closing) {
       text += lineSep;
       if (extraLinebreak) { text += lineSep; }
       closing = extraLinebreak = false;
     }
   }
   function addText(str) {
     if (str) {
       close();
       text += str;
     }
   }
   function walk(node) {
     if (node.nodeType == 1) {
       var cmText = node.getAttribute("cm-text");
       if (cmText) {
         addText(cmText);
         return
       }
       var markerID = node.getAttribute("cm-marker"), range;
       if (markerID) {
         var found = cm.findMarks(Pos(fromLine, 0), Pos(toLine + 1, 0), recognizeMarker(+markerID));
         if (found.length && (range = found[0].find(0)))
           { addText(getBetween(cm.doc, range.from, range.to).join(lineSep)); }
         return
       }
       if (node.getAttribute("contenteditable") == "false") { return }
       var isBlock = /^(pre|div|p|li|table|br)$/i.test(node.nodeName);
       if (!/^br$/i.test(node.nodeName) && node.textContent.length == 0) { return }

       if (isBlock) { close(); }
       for (var i = 0; i < node.childNodes.length; i++)
         { walk(node.childNodes[i]); }

       if (/^(pre|p)$/i.test(node.nodeName)) { extraLinebreak = true; }
       if (isBlock) { closing = true; }
     } else if (node.nodeType == 3) {
       addText(node.nodeValue.replace(/\u200b/g, "").replace(/\u00a0/g, " "));
     }
   }
   for (;;) {
     walk(from);
     if (from == to) { break }
     from = from.nextSibling;
     extraLinebreak = false;
   }
   return text
 }

 function domToPos(cm, node, offset) {
   var lineNode;
   if (node == cm.display.lineDiv) {
     lineNode = cm.display.lineDiv.childNodes[offset];
     if (!lineNode) { return badPos(cm.clipPos(Pos(cm.display.viewTo - 1)), true) }
     node = null; offset = 0;
   } else {
     for (lineNode = node;; lineNode = lineNode.parentNode) {
       if (!lineNode || lineNode == cm.display.lineDiv) { return null }
       if (lineNode.parentNode && lineNode.parentNode == cm.display.lineDiv) { break }
     }
   }
   for (var i = 0; i < cm.display.view.length; i++) {
     var lineView = cm.display.view[i];
     if (lineView.node == lineNode)
       { return locateNodeInLineView(lineView, node, offset) }
   }
 }

 function locateNodeInLineView(lineView, node, offset) {
   var wrapper = lineView.text.firstChild, bad = false;
   if (!node || !contains(wrapper, node)) { return badPos(Pos(lineNo(lineView.line), 0), true) }
   if (node == wrapper) {
     bad = true;
     node = wrapper.childNodes[offset];
     offset = 0;
     if (!node) {
       var line = lineView.rest ? lst(lineView.rest) : lineView.line;
       return badPos(Pos(lineNo(line), line.text.length), bad)
     }
   }

   var textNode = node.nodeType == 3 ? node : null, topNode = node;
   if (!textNode && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
     textNode = node.firstChild;
     if (offset) { offset = textNode.nodeValue.length; }
   }
   while (topNode.parentNode != wrapper) { topNode = topNode.parentNode; }
   var measure = lineView.measure, maps = measure.maps;

   function find(textNode, topNode, offset) {
     for (var i = -1; i < (maps ? maps.length : 0); i++) {
       var map = i < 0 ? measure.map : maps[i];
       for (var j = 0; j < map.length; j += 3) {
         var curNode = map[j + 2];
         if (curNode == textNode || curNode == topNode) {
           var line = lineNo(i < 0 ? lineView.line : lineView.rest[i]);
           var ch = map[j] + offset;
           if (offset < 0 || curNode != textNode) { ch = map[j + (offset ? 1 : 0)]; }
           return Pos(line, ch)
         }
       }
     }
   }
   var found = find(textNode, topNode, offset);
   if (found) { return badPos(found, bad) }

   // FIXME this is all really shaky. might handle the few cases it needs to handle, but likely to cause problems
   for (var after = topNode.nextSibling, dist = textNode ? textNode.nodeValue.length - offset : 0; after; after = after.nextSibling) {
     found = find(after, after.firstChild, 0);
     if (found)
       { return badPos(Pos(found.line, found.ch - dist), bad) }
     else
       { dist += after.textContent.length; }
   }
   for (var before = topNode.previousSibling, dist$1 = offset; before; before = before.previousSibling) {
     found = find(before, before.firstChild, -1);
     if (found)
       { return badPos(Pos(found.line, found.ch + dist$1), bad) }
     else
       { dist$1 += before.textContent.length; }
   }
 }

 // TEXTAREA INPUT STYLE

 var TextareaInput = function(cm) {
   this.cm = cm;
   // See input.poll and input.reset
   this.prevInput = "";

   // Flag that indicates whether we expect input to appear real soon
   // now (after some event like 'keypress' or 'input') and are
   // polling intensively.
   this.pollingFast = false;
   // Self-resetting timeout for the poller
   this.polling = new Delayed();
   // Used to work around IE issue with selection being forgotten when focus moves away from textarea
   this.hasSelection = false;
   this.composing = null;
 };

 TextareaInput.prototype.init = function (display) {
     var this$1 = this;

   var input = this, cm = this.cm;
   this.createField(display);
   var te = this.textarea;

   display.wrapper.insertBefore(this.wrapper, display.wrapper.firstChild);

   // Needed to hide big blue blinking cursor on Mobile Safari (doesn't seem to work in iOS 8 anymore)
   if (ios) { te.style.width = "0px"; }

   on(te, "input", function () {
     if (ie && ie_version >= 9 && this$1.hasSelection) { this$1.hasSelection = null; }
     input.poll();
   });

   on(te, "paste", function (e) {
     if (signalDOMEvent(cm, e) || handlePaste(e, cm)) { return }

     cm.state.pasteIncoming = +new Date;
     input.fastPoll();
   });

   function prepareCopyCut(e) {
     if (signalDOMEvent(cm, e)) { return }
     if (cm.somethingSelected()) {
       setLastCopied({lineWise: false, text: cm.getSelections()});
     } else if (!cm.options.lineWiseCopyCut) {
       return
     } else {
       var ranges = copyableRanges(cm);
       setLastCopied({lineWise: true, text: ranges.text});
       if (e.type == "cut") {
         cm.setSelections(ranges.ranges, null, sel_dontScroll);
       } else {
         input.prevInput = "";
         te.value = ranges.text.join("\n");
         selectInput(te);
       }
     }
     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 }
     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)
   on(display.lineSpace, "selectstart", function (e) {
     if (!eventInWidget(display, e)) { e_preventDefault(e); }
   });

   on(te, "compositionstart", function () {
     var start = cm.getCursor("from");
     if (input.composing) { input.composing.range.clear(); }
     input.composing = {
       start: start,
       range: cm.markText(start, cm.getCursor("to"), {className: "CodeMirror-composing"})
     };
   });
   on(te, "compositionend", function () {
     if (input.composing) {
       input.poll();
       input.composing.range.clear();
       input.composing = null;
     }
   });
 };

 TextareaInput.prototype.createField = function (_display) {
   // Wraps and hides input textarea
   this.wrapper = hiddenTextarea();
   // The semihidden textarea that is focused when the editor is
   // focused, and receives input.
   this.textarea = this.wrapper.firstChild;
 };

 TextareaInput.prototype.screenReaderLabelChanged = function (label) {
   // Label for screenreaders, accessibility
   if(label) {
     this.textarea.setAttribute('aria-label', label);
   } else {
     this.textarea.removeAttribute('aria-label');
   }
 };

 TextareaInput.prototype.prepareSelection = function () {
   // Redraw the selection and/or cursor
   var cm = this.cm, display = cm.display, doc = cm.doc;
   var result = prepareSelection(cm);

   // Move the hidden textarea near the cursor to prevent scrolling artifacts
   if (cm.options.moveInputWithCursor) {
     var headPos = cursorCoords(cm, doc.sel.primary().head, "div");
     var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();
     result.teTop = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
                                         headPos.top + lineOff.top - wrapOff.top));
     result.teLeft = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
                                          headPos.left + lineOff.left - wrapOff.left));
   }

   return result
 };

 TextareaInput.prototype.showSelection = function (drawn) {
   var cm = this.cm, display = cm.display;
   removeChildrenAndAdd(display.cursorDiv, drawn.cursors);
   removeChildrenAndAdd(display.selectionDiv, drawn.selection);
   if (drawn.teTop != null) {
     this.wrapper.style.top = drawn.teTop + "px";
     this.wrapper.style.left = drawn.teLeft + "px";
   }
 };

 // Reset the input to correspond to the selection (or to be empty,
 // when not typing and nothing is selected)
 TextareaInput.prototype.reset = function (typing) {
   if (this.contextMenuPending || this.composing) { return }
   var cm = this.cm;
   if (cm.somethingSelected()) {
     this.prevInput = "";
     var content = cm.getSelection();
     this.textarea.value = content;
     if (cm.state.focused) { selectInput(this.textarea); }
     if (ie && ie_version >= 9) { this.hasSelection = content; }
   } else if (!typing) {
     this.prevInput = this.textarea.value = "";
     if (ie && ie_version >= 9) { this.hasSelection = null; }
   }
 };

 TextareaInput.prototype.getField = function () { return this.textarea };

 TextareaInput.prototype.supportsTouch = function () { return false };

 TextareaInput.prototype.focus = function () {
   if (this.cm.options.readOnly != "nocursor" && (!mobile || activeElt() != this.textarea)) {
     try { this.textarea.focus(); }
     catch (e) {} // IE8 will throw if the textarea is display: none or not in DOM
   }
 };

 TextareaInput.prototype.blur = function () { this.textarea.blur(); };

 TextareaInput.prototype.resetPosition = function () {
   this.wrapper.style.top = this.wrapper.style.left = 0;
 };

 TextareaInput.prototype.receivedFocus = function () { this.slowPoll(); };

 // Poll for input changes, using the normal rate of polling. This
 // runs as long as the editor is focused.
 TextareaInput.prototype.slowPoll = function () {
     var this$1 = this;

   if (this.pollingFast) { return }
   this.polling.set(this.cm.options.pollInterval, function () {
     this$1.poll();
     if (this$1.cm.state.focused) { this$1.slowPoll(); }
   });
 };

 // When an event has just come in that is likely to add or change
 // something in the input textarea, we poll faster, to ensure that
 // the change appears on the screen quickly.
 TextareaInput.prototype.fastPoll = function () {
   var missed = false, input = this;
   input.pollingFast = true;
   function p() {
     var changed = input.poll();
     if (!changed && !missed) {missed = true; input.polling.set(60, p);}
     else {input.pollingFast = false; input.slowPoll();}
   }
   input.polling.set(20, p);
 };

 // Read input from the textarea, and update the document to match.
 // When something is selected, it is present in the textarea, and
 // selected (unless it is huge, in which case a placeholder is
 // used). When nothing is selected, the cursor sits after previously
 // seen text (can be empty), which is stored in prevInput (we must
 // not reset the textarea when typing, because that breaks IME).
 TextareaInput.prototype.poll = function () {
     var this$1 = this;

   var cm = this.cm, input = this.textarea, prevInput = this.prevInput;
   // Since this is called a *lot*, try to bail out as cheaply as
   // possible when it is clear that nothing happened. hasSelection
   // will be the case when there is a lot of text in the textarea,
   // in which case reading its value would be expensive.
   if (this.contextMenuPending || !cm.state.focused ||
       (hasSelection(input) && !prevInput && !this.composing) ||
       cm.isReadOnly() || cm.options.disableInput || cm.state.keySeq)
     { return false }

   var text = input.value;
   // If nothing changed, bail.
   if (text == prevInput && !cm.somethingSelected()) { return false }
   // Work around nonsensical selection resetting in IE9/10, and
   // inexplicable appearance of private area unicode characters on
   // some key combos in Mac (#2689).
   if (ie && ie_version >= 9 && this.hasSelection === text ||
       mac && /[\uf700-\uf7ff]/.test(text)) {
     cm.display.input.reset();
     return false
   }

   if (cm.doc.sel == cm.display.selForContextMenu) {
     var first = text.charCodeAt(0);
     if (first == 0x200b && !prevInput) { prevInput = "\u200b"; }
     if (first == 0x21da) { this.reset(); return this.cm.execCommand("undo") }
   }
   // Find the part of the input that is actually new
   var same = 0, l = Math.min(prevInput.length, text.length);
   while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) { ++same; }

   runInOp(cm, function () {
     applyTextInput(cm, text.slice(same), prevInput.length - same,
                    null, this$1.composing ? "*compose" : null);

     // Don't leave long text in the textarea, since it makes further polling slow
     if (text.length > 1000 || text.indexOf("\n") > -1) { input.value = this$1.prevInput = ""; }
     else { this$1.prevInput = text; }

     if (this$1.composing) {
       this$1.composing.range.clear();
       this$1.composing.range = cm.markText(this$1.composing.start, cm.getCursor("to"),
                                          {className: "CodeMirror-composing"});
     }
   });
   return true
 };

 TextareaInput.prototype.ensurePolled = function () {
   if (this.pollingFast && this.poll()) { this.pollingFast = false; }
 };

 TextareaInput.prototype.onKeyPress = function () {
   if (ie && ie_version >= 9) { this.hasSelection = null; }
   this.fastPoll();
 };

 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.

   // Reset the current text selection only if the click is done outside of the selection
   // and 'resetSelectionOnContextMenu' option is true.
   var reset = cm.options.resetSelectionOnContextMenu;
   if (reset && cm.doc.sel.contains(pos) == -1)
     { operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll); }

   var oldCSS = te.style.cssText, oldWrapperCSS = input.wrapper.style.cssText;
   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)
   display.input.focus();
   if (webkit) { window.scrollTo(null, oldScrollY); }
   display.input.reset();
   // Adds "Select all" to context menu in FF
   if (!cm.somethingSelected()) { te.value = input.prevInput = " "; }
   input.contextMenuPending = rehide;
   display.selForContextMenu = cm.doc.sel;
   clearTimeout(display.detectingSelectAll);

   // Select-all will be greyed out if there's nothing to select, so
   // this adds a zero-width space so that we can later check whether
   // it got selected.
   function prepareSelectAllHack() {
     if (te.selectionStart != null) {
       var selected = cm.somethingSelected();
       var extval = "\u200b" + (selected ? te.value : "");
       te.value = "\u21da"; // Used to catch context-menu undo
       te.value = extval;
       input.prevInput = selected ? "" : "\u200b";
       te.selectionStart = 1; te.selectionEnd = extval.length;
       // Re-set this, in case some other handler touched the
       // selection in the meantime.
       display.selForContextMenu = cm.doc.sel;
     }
   }
   function rehide() {
     if (input.contextMenuPending != rehide) { return }
     input.contextMenuPending = false;
     input.wrapper.style.cssText = oldWrapperCSS;
     te.style.cssText = oldCSS;
     if (ie && ie_version < 9) { display.scrollbars.setScrollTop(display.scroller.scrollTop = scrollPos); }

     // Try to detect the user choosing select-all
     if (te.selectionStart != null) {
       if (!ie || (ie && ie_version < 9)) { prepareSelectAllHack(); }
       var i = 0, poll = function () {
         if (display.selForContextMenu == cm.doc.sel && te.selectionStart == 0 &&
             te.selectionEnd > 0 && input.prevInput == "\u200b") {
           operation(cm, selectAll)(cm);
         } else if (i++ < 10) {
           display.detectingSelectAll = setTimeout(poll, 500);
         } else {
           display.selForContextMenu = null;
           display.input.reset();
         }
       };
       display.detectingSelectAll = setTimeout(poll, 200);
     }
   }

   if (ie && ie_version >= 9) { prepareSelectAllHack(); }
   if (captureRightClick) {
     e_stop(e);
     var mouseup = function () {
       off(window, "mouseup", mouseup);
       setTimeout(rehide, 20);
     };
     on(window, "mouseup", mouseup);
   } else {
     setTimeout(rehide, 50);
   }
 };

 TextareaInput.prototype.readOnlyChanged = function (val) {
   if (!val) { this.reset(); }
   this.textarea.disabled = val == "nocursor";
   this.textarea.readOnly = !!val;
 };

 TextareaInput.prototype.setUneditable = function () {};

 TextareaInput.prototype.needsContentAttribute = false;

 function fromTextArea(textarea, options) {
   options = options ? copyObj(options) : {};
   options.value = textarea.value;
   if (!options.tabindex && textarea.tabIndex)
     { options.tabindex = textarea.tabIndex; }
   if (!options.placeholder && textarea.placeholder)
     { options.placeholder = textarea.placeholder; }
   // Set autofocus to true if this textarea is focused, or if it has
   // autofocus and no other element is focused.
   if (options.autofocus == null) {
     var hasFocus = activeElt();
     options.autofocus = hasFocus == textarea ||
       textarea.getAttribute("autofocus") != null && hasFocus == document.body;
   }

   function save() {textarea.value = cm.getValue();}

   var realSubmit;
   if (textarea.form) {
     on(textarea.form, "submit", save);
     // Deplorable hack to make the submit method do the right thing.
     if (!options.leaveSubmitMethodAlone) {
       var form = textarea.form;
       realSubmit = form.submit;
       try {
         var wrappedSubmit = form.submit = function () {
           save();
           form.submit = realSubmit;
           form.submit();
           form.submit = wrappedSubmit;
         };
       } catch(e) {}
     }
   }

   options.finishInit = function (cm) {
     cm.save = save;
     cm.getTextArea = function () { return textarea; };
     cm.toTextArea = function () {
       cm.toTextArea = isNaN; // Prevent this from being ran twice
       save();
       textarea.parentNode.removeChild(cm.getWrapperElement());
       textarea.style.display = "";
       if (textarea.form) {
         off(textarea.form, "submit", save);
         if (!options.leaveSubmitMethodAlone && typeof textarea.form.submit == "function")
           { textarea.form.submit = realSubmit; }
       }
     };
   };

   textarea.style.display = "none";
   var cm = CodeMirror(function (node) { return textarea.parentNode.insertBefore(node, textarea.nextSibling); },
     options);
   return cm
 }

 function addLegacyProps(CodeMirror) {
   CodeMirror.off = off;
   CodeMirror.on = on;
   CodeMirror.wheelEventPixels = wheelEventPixels;
   CodeMirror.Doc = Doc;
   CodeMirror.splitLines = splitLinesAuto;
   CodeMirror.countColumn = countColumn;
   CodeMirror.findColumn = findColumn;
   CodeMirror.isWordChar = isWordCharBasic;
   CodeMirror.Pass = Pass;
   CodeMirror.signal = signal;
   CodeMirror.Line = Line;
   CodeMirror.changeEnd = changeEnd;
   CodeMirror.scrollbarModel = scrollbarModel;
   CodeMirror.Pos = Pos;
   CodeMirror.cmpPos = cmp;
   CodeMirror.modes = modes;
   CodeMirror.mimeModes = mimeModes;
   CodeMirror.resolveMode = resolveMode;
   CodeMirror.getMode = getMode;
   CodeMirror.modeExtensions = modeExtensions;
   CodeMirror.extendMode = extendMode;
   CodeMirror.copyState = copyState;
   CodeMirror.startState = startState;
   CodeMirror.innerMode = innerMode;
   CodeMirror.commands = commands;
   CodeMirror.keyMap = keyMap;
   CodeMirror.keyName = keyName;
   CodeMirror.isModifierKey = isModifierKey;
   CodeMirror.lookupKey = lookupKey;
   CodeMirror.normalizeKeyMap = normalizeKeyMap;
   CodeMirror.StringStream = StringStream;
   CodeMirror.SharedTextMarker = SharedTextMarker;
   CodeMirror.TextMarker = TextMarker;
   CodeMirror.LineWidget = LineWidget;
   CodeMirror.e_preventDefault = e_preventDefault;
   CodeMirror.e_stopPropagation = e_stopPropagation;
   CodeMirror.e_stop = e_stop;
   CodeMirror.addClass = addClass;
   CodeMirror.contains = contains;
   CodeMirror.rmClass = rmClass;
   CodeMirror.keyNames = keyNames;
 }

 // EDITOR CONSTRUCTOR

 defineOptions(CodeMirror);

 addEditorMethods(CodeMirror);

 // Set up methods on CodeMirror's prototype to redirect to the editor's document.
 var dontDelegate = "iter insert remove copy getEditor constructor".split(" ");
 for (var prop in Doc.prototype) { if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)
   { CodeMirror.prototype[prop] = (function(method) {
     return function() {return method.apply(this.doc, arguments)}
   })(Doc.prototype[prop]); } }

 eventMixin(Doc);
 CodeMirror.inputStyles = {"textarea": TextareaInput, "contenteditable": ContentEditableInput};

 // 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.)
 CodeMirror.defineMode = function(name/*, mode, …*/) {
   if (!CodeMirror.defaults.mode && name != "null") { CodeMirror.defaults.mode = name; }
   defineMode.apply(this, arguments);
 };

 CodeMirror.defineMIME = defineMIME;

 // Minimal default mode.
 CodeMirror.defineMode("null", function () { return ({token: function (stream) { return stream.skipToEnd(); }}); });
 CodeMirror.defineMIME("text/plain", "null");

 // EXTENSIONS

 CodeMirror.defineExtension = function (name, func) {
   CodeMirror.prototype[name] = func;
 };
 CodeMirror.defineDocExtension = function (name, func) {
   Doc.prototype[name] = func;
 };

 CodeMirror.fromTextArea = fromTextArea;

 addLegacyProps(CodeMirror);

 CodeMirror.version = "5.58.1";

 return CodeMirror;

})));