// CodeMirror version 3.13 // // CodeMirror is the only global var we claim window.CodeMirror = (function() {

"use strict";

// BROWSER SNIFFING

// Crude, but necessary to handle a number of hard-to-feature-detect
// bugs and behavior differences.
var gecko = /gecko\/\d/i.test(navigator.userAgent);
var ie = /MSIE \d/.test(navigator.userAgent);
var ie_lt8 = ie && (document.documentMode == null || document.documentMode < 8);
var ie_lt9 = ie && (document.documentMode == null || document.documentMode < 9);
var webkit = /WebKit\//.test(navigator.userAgent);
var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(navigator.userAgent);
var chrome = /Chrome\//.test(navigator.userAgent);
var opera = /Opera\//.test(navigator.userAgent);
var safari = /Apple Computer/.test(navigator.vendor);
var khtml = /KHTML\//.test(navigator.userAgent);
var mac_geLion = /Mac OS X 1\d\D([7-9]|\d\d)\D/.test(navigator.userAgent);
var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(navigator.userAgent);
var phantom = /PhantomJS/.test(navigator.userAgent);

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

var opera_version = opera && navigator.userAgent.match(/Version\/(\d*\.\d*)/);
if (opera_version) opera_version = Number(opera_version[1]);
// Some browsers use the wrong event properties to signal cmd/ctrl on OS X
var flipCtrlCmd = mac && (qtwebkit || opera && (opera_version == null || opera_version < 12.11));
var captureMiddleClick = gecko || (ie && !ie_lt9);

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

// CONSTRUCTOR

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

  this.options = options = options || {};
  // Determine effective options based on given values and defaults.
  for (var opt in defaults) if (!options.hasOwnProperty(opt) && defaults.hasOwnProperty(opt))
    options[opt] = defaults[opt];
  setGuttersForLineNumbers(options);

  var docStart = typeof options.value == "string" ? 0 : options.value.first;
  var display = this.display = makeDisplay(place, docStart);
  display.wrapper.CodeMirror = this;
  updateGutters(this);
  if (options.autofocus && !mobile) focusInput(this);

  this.state = {keyMaps: [],
                overlays: [],
                modeGen: 0,
                overwrite: false, focused: false,
                suppressEdits: false, pasteIncoming: false,
                draggingText: false,
                highlight: new Delayed()};

  themeChanged(this);
  if (options.lineWrapping)
    this.display.wrapper.className += " CodeMirror-wrap";

  var doc = options.value;
  if (typeof doc == "string") doc = new Doc(options.value, options.mode);
  operation(this, attachDoc)(this, doc);

  // Override magic textarea content restore that IE sometimes does
  // on our hidden textarea on reload
  if (ie) setTimeout(bind(resetInput, this, true), 20);

  registerEventHandlers(this);
  // IE throws unspecified error in certain cases, when
  // trying to access activeElement before onload
  var hasFocus; try { hasFocus = (document.activeElement == display.input); } catch(e) { }
  if (hasFocus || (options.autofocus && !mobile)) setTimeout(bind(onFocus, this), 20);
  else onBlur(this);

  operation(this, function() {
    for (var opt in optionHandlers)
      if (optionHandlers.propertyIsEnumerable(opt))
        optionHandlers[opt](this, options[opt], Init);
    for (var i = 0; i < initHooks.length; ++i) initHooks[i](this);
  })();
}

// DISPLAY CONSTRUCTOR

function makeDisplay(place, docStart) {
  var d = {};

  var input = d.input = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none; font-size: 4px;");
  if (webkit) input.style.width = "1000px";
  else input.setAttribute("wrap", "off");
  // if border: 0; -- iOS fails to open keyboard (issue #1287)
  if (ios) input.style.border = "1px solid black";
  input.setAttribute("autocorrect", "off"); input.setAttribute("autocapitalize", "off"); input.setAttribute("spellcheck", "false");

  // Wraps and hides input textarea
  d.inputDiv = elt("div", [input], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
  // The actual fake scrollbars.
  d.scrollbarH = elt("div", [elt("div", null, null, "height: 1px")], "CodeMirror-hscrollbar");
  d.scrollbarV = elt("div", [elt("div", null, null, "width: 1px")], "CodeMirror-vscrollbar");
  d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
  d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
  // DIVs containing the selection and the actual code
  d.lineDiv = elt("div", null, "CodeMirror-code");
  d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
  // Blinky cursor, and element used to ensure cursor fits at the end of a line
  d.cursor = elt("div", "\u00a0", "CodeMirror-cursor");
  // Secondary cursor, shown when on a 'jump' in bi-directional text
  d.otherCursor = elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor");
  // Used to measure text size
  d.measure = elt("div", null, "CodeMirror-measure");
  // Wraps everything that needs to exist inside the vertically-padded coordinate system
  d.lineSpace = elt("div", [d.measure, d.selectionDiv, d.lineDiv, d.cursor, d.otherCursor],
                       null, "position: relative; outline: none");
  // Moved around its parent to cover visible view
  d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
  // Set to the height of the text, causes scrolling
  d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
  // D is needed because behavior of elts with overflow: auto and padding is inconsistent across browsers
  d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerCutOff + "px; width: 1px;");
  // Will contain the gutters, if any
  d.gutters = elt("div", null, "CodeMirror-gutters");
  d.lineGutter = null;
  // Provides scrolling
  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.inputDiv, d.scrollbarH, d.scrollbarV,
                          d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
  // Work around IE7 z-index bug
  if (ie_lt8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
  if (place.appendChild) place.appendChild(d.wrapper); else place(d.wrapper);

  // Needed to hide big blue blinking cursor on Mobile Safari
  if (ios) input.style.width = "0px";
  if (!webkit) d.scroller.draggable = true;
  // Needed to handle Tab key in KHTML
  if (khtml) { d.inputDiv.style.height = "1px"; d.inputDiv.style.position = "absolute"; }
  // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
  else if (ie_lt8) d.scrollbarH.style.minWidth = d.scrollbarV.style.minWidth = "18px";

  // Current visible range (may be bigger than the view window).
  d.viewOffset = d.lastSizeC = 0;
  d.showingFrom = d.showingTo = docStart;

  // 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;
  // See readInput and resetInput
  d.prevInput = "";
  // Set to true when a non-horizontal-scrolling widget is added. As
  // an optimization, widget aligning is skipped when d is false.
  d.alignWidgets = false;
  // Flag that indicates whether we currently expect input to appear
  // (after some event like 'keypress' or 'input') and are polling
  // intensively.
  d.pollingFast = false;
  // Self-resetting timeout for the poller
  d.poll = new Delayed();

  d.cachedCharWidth = d.cachedTextHeight = null;
  d.measureLineCache = [];
  d.measureLineCachePos = 0;

  // Tracks when resetInput has punted to just putting a short
  // string instead of the (large) selection.
  d.inaccurateSelection = false;

  // 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;

  return d;
}

// STATE UPDATES

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

function loadMode(cm) {
  cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
  cm.doc.iter(function(line) {
    if (line.stateAfter) line.stateAfter = null;
    if (line.styles) line.styles = null;
  });
  cm.doc.frontier = cm.doc.first;
  startWorker(cm, 100);
  cm.state.modeGen++;
  if (cm.curOp) regChange(cm);
}

function wrappingChanged(cm) {
  if (cm.options.lineWrapping) {
    cm.display.wrapper.className += " CodeMirror-wrap";
    cm.display.sizer.style.minWidth = "";
  } else {
    cm.display.wrapper.className = cm.display.wrapper.className.replace(" CodeMirror-wrap", "");
    computeMaxLength(cm);
  }
  estimateLineHeights(cm);
  regChange(cm);
  clearCaches(cm);
  setTimeout(function(){updateScrollbars(cm);}, 100);
}

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

function keyMapChanged(cm) {
  var style = keyMap[cm.options.keyMap].style;
  cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-keymap-\S+/g, "") +
    (style ? " cm-keymap-" + style : "");
}

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);
}

function guttersChanged(cm) {
  updateGutters(cm);
  regChange(cm);
  setTimeout(function(){alignHorizontally(cm);}, 20);
}

function updateGutters(cm) {
  var gutters = cm.display.gutters, specs = cm.options.gutters;
  removeChildren(gutters);
  for (var i = 0; i < specs.length; ++i) {
    var gutterClass = specs[i];
    var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
    if (gutterClass == "CodeMirror-linenumbers") {
      cm.display.lineGutter = gElt;
      gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
    }
  }
  gutters.style.display = i ? "" : "none";
}

function lineLength(doc, line) {
  if (line.height == 0) return 0;
  var len = line.text.length, merged, cur = line;
  while (merged = collapsedSpanAtStart(cur)) {
    var found = merged.find();
    cur = getLine(doc, found.from.line);
    len += found.from.ch - found.to.ch;
  }
  cur = line;
  while (merged = collapsedSpanAtEnd(cur)) {
    var found = merged.find();
    len -= cur.text.length - found.from.ch;
    cur = getLine(doc, found.to.line);
    len += cur.text.length - found.to.ch;
  }
  return len;
}

function computeMaxLength(cm) {
  var d = cm.display, doc = cm.doc;
  d.maxLine = getLine(doc, doc.first);
  d.maxLineLength = lineLength(doc, d.maxLine);
  d.maxLineChanged = true;
  doc.iter(function(line) {
    var len = lineLength(doc, line);
    if (len > d.maxLineLength) {
      d.maxLineLength = len;
      d.maxLine = line;
    }
  });
}

// Make sure the gutters options contains the element
// "CodeMirror-linenumbers" when the lineNumbers option is true.
function setGuttersForLineNumbers(options) {
  var found = false;
  for (var i = 0; i < options.gutters.length; ++i) {
    if (options.gutters[i] == "CodeMirror-linenumbers") {
      if (options.lineNumbers) found = true;
      else options.gutters.splice(i--, 1);
    }
  }
  if (!found && options.lineNumbers)
    options.gutters.push("CodeMirror-linenumbers");
}

// SCROLLBARS

// Re-synchronize the fake scrollbars with the actual size of the
// content. Optionally force a scrollTop.
function updateScrollbars(cm) {
  var d = cm.display, docHeight = cm.doc.height;
  var totalHeight = docHeight + paddingVert(d);
  d.sizer.style.minHeight = d.heightForcer.style.top = totalHeight + "px";
  d.gutters.style.height = Math.max(totalHeight, d.scroller.clientHeight - scrollerCutOff) + "px";
  var scrollHeight = Math.max(totalHeight, d.scroller.scrollHeight);
  var needsH = d.scroller.scrollWidth > d.scroller.clientWidth;
  var needsV = scrollHeight > d.scroller.clientHeight;
  if (needsV) {
    d.scrollbarV.style.display = "block";
    d.scrollbarV.style.bottom = needsH ? scrollbarWidth(d.measure) + "px" : "0";
    d.scrollbarV.firstChild.style.height =
      (scrollHeight - d.scroller.clientHeight + d.scrollbarV.clientHeight) + "px";
  } else d.scrollbarV.style.display = "";
  if (needsH) {
    d.scrollbarH.style.display = "block";
    d.scrollbarH.style.right = needsV ? scrollbarWidth(d.measure) + "px" : "0";
    d.scrollbarH.firstChild.style.width =
      (d.scroller.scrollWidth - d.scroller.clientWidth + d.scrollbarH.clientWidth) + "px";
  } else d.scrollbarH.style.display = "";
  if (needsH && needsV) {
    d.scrollbarFiller.style.display = "block";
    d.scrollbarFiller.style.height = d.scrollbarFiller.style.width = scrollbarWidth(d.measure) + "px";
  } else d.scrollbarFiller.style.display = "";
  if (needsH && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
    d.gutterFiller.style.display = "block";
    d.gutterFiller.style.height = scrollbarWidth(d.measure) + "px";
    d.gutterFiller.style.width = d.gutters.offsetWidth + "px";
  } else d.gutterFiller.style.display = "";

  if (mac_geLion && scrollbarWidth(d.measure) === 0)
    d.scrollbarV.style.minWidth = d.scrollbarH.style.minHeight = mac_geMountainLion ? "18px" : "12px";
}

function visibleLines(display, doc, viewPort) {
  var top = display.scroller.scrollTop, height = display.wrapper.clientHeight;
  if (typeof viewPort == "number") top = viewPort;
  else if (viewPort) {top = viewPort.top; height = viewPort.bottom - viewPort.top;}
  top = Math.floor(top - paddingTop(display));
  var bottom = Math.ceil(top + height);
  return {from: lineAtHeight(doc, top), to: lineAtHeight(doc, bottom)};
}

// LINE NUMBERS

function alignHorizontally(cm) {
  var display = cm.display;
  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, l = comp + "px";
  for (var n = display.lineDiv.firstChild; n; n = n.nextSibling) if (n.alignable) {
    for (var i = 0, a = n.alignable; i < a.length; ++i) a[i].style.left = l;
  }
  if (cm.options.fixedGutter)
    display.gutters.style.left = (comp + gutterW) + "px";
}

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);
    display.lineNumWidth = display.lineNumInnerWidth + padding;
    display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
    display.lineGutter.style.width = display.lineNumWidth + "px";
    return true;
  }
  return false;
}

function lineNumberFor(options, i) {
  return String(options.lineNumberFormatter(i + options.firstLineNumber));
}
function compensateForHScroll(display) {
  return getRect(display.scroller).left - getRect(display.sizer).left;
}

// DISPLAY DRAWING

function updateDisplay(cm, changes, viewPort) {
  var oldFrom = cm.display.showingFrom, oldTo = cm.display.showingTo, updated;
  var visible = visibleLines(cm.display, cm.doc, viewPort);
  for (;;) {
    if (!updateDisplayInner(cm, changes, visible)) break;
    updated = true;
    updateSelection(cm);
    updateScrollbars(cm);

    // Clip forced viewport to actual scrollable area
    if (viewPort)
      viewPort = Math.min(cm.display.scroller.scrollHeight - cm.display.scroller.clientHeight,
                          typeof viewPort == "number" ? viewPort : viewPort.top);
    visible = visibleLines(cm.display, cm.doc, viewPort);
    if (visible.from >= cm.display.showingFrom && visible.to <= cm.display.showingTo)
      break;
    changes = [];
  }

  if (updated) {
    signalLater(cm, "update", cm);
    if (cm.display.showingFrom != oldFrom || cm.display.showingTo != oldTo)
      signalLater(cm, "viewportChange", cm, cm.display.showingFrom, cm.display.showingTo);
  }
  return updated;
}

// Uses a set of changes plus the current scroll position to
// determine which DOM updates have to be made, and makes the
// updates.
function updateDisplayInner(cm, changes, visible) {
  var display = cm.display, doc = cm.doc;
  if (!display.wrapper.clientWidth) {
    display.showingFrom = display.showingTo = doc.first;
    display.viewOffset = 0;
    return;
  }

  // Bail out if the visible area is already rendered and nothing changed.
  if (changes.length == 0 &&
      visible.from > display.showingFrom && visible.to < display.showingTo)
    return;

  if (maybeUpdateLineNumberWidth(cm))
    changes = [{from: doc.first, to: doc.first + doc.size}];
  var gutterW = display.sizer.style.marginLeft = display.gutters.offsetWidth + "px";
  display.scrollbarH.style.left = cm.options.fixedGutter ? gutterW : "0";

  // Used to determine which lines need their line numbers updated
  var positionsChangedFrom = Infinity;
  if (cm.options.lineNumbers)
    for (var i = 0; i < changes.length; ++i)
      if (changes[i].diff) { positionsChangedFrom = changes[i].from; break; }

  var end = doc.first + doc.size;
  var from = Math.max(visible.from - cm.options.viewportMargin, doc.first);
  var to = Math.min(end, visible.to + cm.options.viewportMargin);
  if (display.showingFrom < from && from - display.showingFrom < 20) from = Math.max(doc.first, display.showingFrom);
  if (display.showingTo > to && display.showingTo - to < 20) to = Math.min(end, display.showingTo);
  if (sawCollapsedSpans) {
    from = lineNo(visualLine(doc, getLine(doc, from)));
    while (to < end && lineIsHidden(doc, getLine(doc, to))) ++to;
  }

  // Create a range of theoretically intact lines, and punch holes
  // in that using the change info.
  var intact = [{from: Math.max(display.showingFrom, doc.first),
                 to: Math.min(display.showingTo, end)}];
  if (intact[0].from >= intact[0].to) intact = [];
  else intact = computeIntact(intact, changes);
  // When merged lines are present, we might have to reduce the
  // intact ranges because changes in continued fragments of the
  // intact lines do require the lines to be redrawn.
  if (sawCollapsedSpans)
    for (var i = 0; i < intact.length; ++i) {
      var range = intact[i], merged;
      while (merged = collapsedSpanAtEnd(getLine(doc, range.to - 1))) {
        var newTo = merged.find().from.line;
        if (newTo > range.from) range.to = newTo;
        else { intact.splice(i--, 1); break; }
      }
    }

  // Clip off the parts that won't be visible
  var intactLines = 0;
  for (var i = 0; i < intact.length; ++i) {
    var range = intact[i];
    if (range.from < from) range.from = from;
    if (range.to > to) range.to = to;
    if (range.from >= range.to) intact.splice(i--, 1);
    else intactLines += range.to - range.from;
  }
  if (intactLines == to - from && from == display.showingFrom && to == display.showingTo) {
    updateViewOffset(cm);
    return;
  }
  intact.sort(function(a, b) {return a.from - b.from;});

  // Avoid crashing on IE's "unspecified error" when in iframes
  try {
    var focused = document.activeElement;
  } catch(e) {}
  if (intactLines < (to - from) * .7) display.lineDiv.style.display = "none";
  patchDisplay(cm, from, to, intact, positionsChangedFrom);
  display.lineDiv.style.display = "";
  if (focused && document.activeElement != focused && focused.offsetHeight) focused.focus();

  var different = from != display.showingFrom || to != display.showingTo ||
    display.lastSizeC != display.wrapper.clientHeight;
  // This is just a bogus formula that detects when the editor is
  // resized or the font size changes.
  if (different) display.lastSizeC = display.wrapper.clientHeight;
  display.showingFrom = from; display.showingTo = to;
  startWorker(cm, 100);

  var prevBottom = display.lineDiv.offsetTop;
  for (var node = display.lineDiv.firstChild, height; node; node = node.nextSibling) if (node.lineObj) {
    if (ie_lt8) {
      var bot = node.offsetTop + node.offsetHeight;
      height = bot - prevBottom;
      prevBottom = bot;
    } else {
      var box = getRect(node);
      height = box.bottom - box.top;
    }
    var diff = node.lineObj.height - height;
    if (height < 2) height = textHeight(display);
    if (diff > .001 || diff < -.001) {
      updateLineHeight(node.lineObj, height);
      var widgets = node.lineObj.widgets;
      if (widgets) for (var i = 0; i < widgets.length; ++i)
        widgets[i].height = widgets[i].node.offsetHeight;
    }
  }
  updateViewOffset(cm);

  return true;
}

function updateViewOffset(cm) {
  var off = cm.display.viewOffset = heightAtLine(cm, getLine(cm.doc, cm.display.showingFrom));
  // Position the mover div to align with the current virtual scroll position
  cm.display.mover.style.top = off + "px";
}

function computeIntact(intact, changes) {
  for (var i = 0, l = changes.length || 0; i < l; ++i) {
    var change = changes[i], intact2 = [], diff = change.diff || 0;
    for (var j = 0, l2 = intact.length; j < l2; ++j) {
      var range = intact[j];
      if (change.to <= range.from && change.diff) {
        intact2.push({from: range.from + diff, to: range.to + diff});
      } else if (change.to <= range.from || change.from >= range.to) {
        intact2.push(range);
      } else {
        if (change.from > range.from)
          intact2.push({from: range.from, to: change.from});
        if (change.to < range.to)
          intact2.push({from: change.to + diff, to: range.to + diff});
      }
    }
    intact = intact2;
  }
  return intact;
}

function getDimensions(cm) {
  var d = cm.display, left = {}, width = {};
  for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
    left[cm.options.gutters[i]] = n.offsetLeft;
    width[cm.options.gutters[i]] = n.offsetWidth;
  }
  return {fixedPos: compensateForHScroll(d),
          gutterTotalWidth: d.gutters.offsetWidth,
          gutterLeft: left,
          gutterWidth: width,
          wrapperWidth: d.wrapper.clientWidth};
}

function patchDisplay(cm, from, to, intact, updateNumbersFrom) {
  var dims = getDimensions(cm);
  var display = cm.display, lineNumbers = cm.options.lineNumbers;
  if (!intact.length && (!webkit || !cm.display.currentWheelTarget))
    removeChildren(display.lineDiv);
  var container = display.lineDiv, cur = container.firstChild;

  function rm(node) {
    var next = node.nextSibling;
    if (webkit && mac && cm.display.currentWheelTarget == node) {
      node.style.display = "none";
      node.lineObj = null;
    } else {
      node.parentNode.removeChild(node);
    }
    return next;
  }

  var nextIntact = intact.shift(), lineN = from;
  cm.doc.iter(from, to, function(line) {
    if (nextIntact && nextIntact.to == lineN) nextIntact = intact.shift();
    if (lineIsHidden(cm.doc, line)) {
      if (line.height != 0) updateLineHeight(line, 0);
      if (line.widgets && cur.previousSibling) for (var i = 0; i < line.widgets.length; ++i)
        if (line.widgets[i].showIfHidden) {
          var prev = cur.previousSibling;
          if (/pre/i.test(prev.nodeName)) {
            var wrap = elt("div", null, null, "position: relative");
            prev.parentNode.replaceChild(wrap, prev);
            wrap.appendChild(prev);
            prev = wrap;
          }
          var wnode = prev.appendChild(elt("div", [line.widgets[i].node], "CodeMirror-linewidget"));
          positionLineWidget(line.widgets[i], wnode, prev, dims);
        }
    } else if (nextIntact && nextIntact.from <= lineN && nextIntact.to > lineN) {
      // This line is intact. Skip to the actual node. Update its
      // line number if needed.
      while (cur.lineObj != line) cur = rm(cur);
      if (lineNumbers && updateNumbersFrom <= lineN && cur.lineNumber)
        setTextContent(cur.lineNumber, lineNumberFor(cm.options, lineN));
      cur = cur.nextSibling;
    } else {
      // For lines with widgets, make an attempt to find and reuse
      // the existing element, so that widgets aren't needlessly
      // removed and re-inserted into the dom
      if (line.widgets) for (var j = 0, search = cur, reuse; search && j < 20; ++j, search = search.nextSibling)
        if (search.lineObj == line && /div/i.test(search.nodeName)) { reuse = search; break; }
      // This line needs to be generated.
      var lineNode = buildLineElement(cm, line, lineN, dims, reuse);
      if (lineNode != reuse) {
        container.insertBefore(lineNode, cur);
      } else {
        while (cur != reuse) cur = rm(cur);
        cur = cur.nextSibling;
      }

      lineNode.lineObj = line;
    }
    ++lineN;
  });
  while (cur) cur = rm(cur);
}

function buildLineElement(cm, line, lineNo, dims, reuse) {
  var lineElement = lineContent(cm, line);
  var markers = line.gutterMarkers, display = cm.display, wrap;

  if (!cm.options.lineNumbers && !markers && !line.bgClass && !line.wrapClass && !line.widgets)
    return lineElement;

  // Lines with gutter elements, widgets or a background class need
  // to be wrapped again, and have the extra elements added to the
  // wrapper div

  if (reuse) {
    reuse.alignable = null;
    var isOk = true, widgetsSeen = 0;
    for (var n = reuse.firstChild, next; n; n = next) {
      next = n.nextSibling;
      if (!/\bCodeMirror-linewidget\b/.test(n.className)) {
        reuse.removeChild(n);
      } else {
        for (var i = 0, first = true; i < line.widgets.length; ++i) {
          var widget = line.widgets[i], isFirst = false;
          if (!widget.above) { isFirst = first; first = false; }
          if (widget.node == n.firstChild) {
            positionLineWidget(widget, n, reuse, dims);
            ++widgetsSeen;
            if (isFirst) reuse.insertBefore(lineElement, n);
            break;
          }
        }
        if (i == line.widgets.length) { isOk = false; break; }
      }
    }
    if (isOk && widgetsSeen == line.widgets.length) {
      wrap = reuse;
      reuse.className = line.wrapClass || "";
    }
  }
  if (!wrap) {
    wrap = elt("div", null, line.wrapClass, "position: relative");
    wrap.appendChild(lineElement);
  }
  // Kludge to make sure the styled element lies behind the selection (by z-index)
  if (line.bgClass)
    wrap.insertBefore(elt("div", null, line.bgClass + " CodeMirror-linebackground"), wrap.firstChild);
  if (cm.options.lineNumbers || markers) {
    var gutterWrap = wrap.insertBefore(elt("div", null, null, "position: absolute; left: " +
                                           (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px"),
                                       wrap.firstChild);
    if (cm.options.fixedGutter) (wrap.alignable || (wrap.alignable = [])).push(gutterWrap);
    if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
      wrap.lineNumber = gutterWrap.appendChild(
        elt("div", lineNumberFor(cm.options, lineNo),
            "CodeMirror-linenumber CodeMirror-gutter-elt",
            "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
            + display.lineNumInnerWidth + "px"));
    if (markers)
      for (var k = 0; k < cm.options.gutters.length; ++k) {
        var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
        if (found)
          gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
                                     dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
      }
  }
  if (ie_lt8) wrap.style.zIndex = 2;
  if (line.widgets && wrap != reuse) for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
    var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
    positionLineWidget(widget, node, wrap, dims);
    if (widget.above)
      wrap.insertBefore(node, cm.options.lineNumbers && line.height != 0 ? gutterWrap : lineElement);
    else
      wrap.appendChild(node);
    signalLater(widget, "redraw");
  }
  return wrap;
}

function positionLineWidget(widget, node, wrap, dims) {
  if (widget.noHScroll) {
    (wrap.alignable || (wrap.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";
  }
}

// SELECTION / CURSOR

function updateSelection(cm) {
  var display = cm.display;
  var collapsed = posEq(cm.doc.sel.from, cm.doc.sel.to);
  if (collapsed || cm.options.showCursorWhenSelecting)
    updateSelectionCursor(cm);
  else
    display.cursor.style.display = display.otherCursor.style.display = "none";
  if (!collapsed)
    updateSelectionRange(cm);
  else
    display.selectionDiv.style.display = "none";

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

// No selection, plain cursor
function updateSelectionCursor(cm) {
  var display = cm.display, pos = cursorCoords(cm, cm.doc.sel.head, "div");
  display.cursor.style.left = pos.left + "px";
  display.cursor.style.top = pos.top + "px";
  display.cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";
  display.cursor.style.display = "";

  if (pos.other) {
    display.otherCursor.style.display = "";
    display.otherCursor.style.left = pos.other.left + "px";
    display.otherCursor.style.top = pos.other.top + "px";
    display.otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
  } else { display.otherCursor.style.display = "none"; }
}

// Highlight selection
function updateSelectionRange(cm) {
  var display = cm.display, doc = cm.doc, sel = cm.doc.sel;
  var fragment = document.createDocumentFragment();
  var clientWidth = display.lineSpace.offsetWidth, pl = paddingLeft(cm.display);

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

  function drawForLine(line, fromArg, toArg, retTop) {
    var lineObj = getLine(doc, line);
    var lineLen = lineObj.text.length, rVal = retTop ? Infinity : -Infinity;
    function coords(ch) {
      return charCoords(cm, Pos(line, ch), "div", lineObj);
    }

    iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
      var leftPos = coords(from), rightPos, left, right;
      if (from == to) {
        rightPos = leftPos;
        left = right = leftPos.left;
      } else {
        rightPos = coords(to - 1);
        if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
        left = leftPos.left;
        right = rightPos.right;
      }
      if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
        add(left, leftPos.top, null, leftPos.bottom);
        left = pl;
        if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
      }
      if (toArg == null && to == lineLen) right = clientWidth;
      if (fromArg == null && from == 0) left = pl;
      rVal = retTop ? Math.min(rightPos.top, rVal) : Math.max(rightPos.bottom, rVal);
      if (left < pl + 1) left = pl;
      add(left, rightPos.top, right - left, rightPos.bottom);
    });
    return rVal;
  }

  if (sel.from.line == sel.to.line) {
    drawForLine(sel.from.line, sel.from.ch, sel.to.ch);
  } else {
    var fromObj = getLine(doc, sel.from.line);
    var cur = fromObj, merged, path = [sel.from.line, sel.from.ch], singleLine;
    while (merged = collapsedSpanAtEnd(cur)) {
      var found = merged.find();
      path.push(found.from.ch, found.to.line, found.to.ch);
      if (found.to.line == sel.to.line) {
        path.push(sel.to.ch);
        singleLine = true;
        break;
      }
      cur = getLine(doc, found.to.line);
    }

    // This is a single, merged line
    if (singleLine) {
      for (var i = 0; i < path.length; i += 3)
        drawForLine(path[i], path[i+1], path[i+2]);
    } else {
      var middleTop, middleBot, toObj = getLine(doc, sel.to.line);
      if (sel.from.ch)
        // Draw the first line of selection.
        middleTop = drawForLine(sel.from.line, sel.from.ch, null, false);
      else
        // Simply include it in the middle block.
        middleTop = heightAtLine(cm, fromObj) - display.viewOffset;

      if (!sel.to.ch)
        middleBot = heightAtLine(cm, toObj) - display.viewOffset;
      else
        middleBot = drawForLine(sel.to.line, collapsedSpanAtStart(toObj) ? null : 0, sel.to.ch, true);

      if (middleTop < middleBot) add(pl, middleTop, null, middleBot);
    }
  }

  removeChildrenAndAdd(display.selectionDiv, fragment);
  display.selectionDiv.style.display = "";
}

// Cursor-blinking
function restartBlink(cm) {
  if (!cm.state.focused) return;
  var display = cm.display;
  clearInterval(display.blinker);
  var on = true;
  display.cursor.style.visibility = display.otherCursor.style.visibility = "";
  display.blinker = setInterval(function() {
    display.cursor.style.visibility = display.otherCursor.style.visibility = (on = !on) ? "" : "hidden";
  }, cm.options.cursorBlinkRate);
}

// HIGHLIGHT WORKER

function startWorker(cm, time) {
  if (cm.doc.mode.startState && cm.doc.frontier < cm.display.showingTo)
    cm.state.highlight.set(time, bind(highlightWorker, cm));
}

function highlightWorker(cm) {
  var doc = cm.doc;
  if (doc.frontier < doc.first) doc.frontier = doc.first;
  if (doc.frontier >= cm.display.showingTo) return;
  var end = +new Date + cm.options.workTime;
  var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));
  var changed = [], prevChange;
  doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.showingTo + 500), function(line) {
    if (doc.frontier >= cm.display.showingFrom) { // Visible
      var oldStyles = line.styles;
      line.styles = highlightLine(cm, line, state);
      var ischange = !oldStyles || oldStyles.length != line.styles.length;
      for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
      if (ischange) {
        if (prevChange && prevChange.end == doc.frontier) prevChange.end++;
        else changed.push(prevChange = {start: doc.frontier, end: doc.frontier + 1});
      }
      line.stateAfter = copyState(doc.mode, state);
    } else {
      processLine(cm, line, state);
      line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
    }
    ++doc.frontier;
    if (+new Date > end) {
      startWorker(cm, cm.options.workDelay);
      return true;
    }
  });
  if (changed.length)
    operation(cm, function() {
      for (var i = 0; i < changed.length; ++i)
        regChange(this, changed[i].start, changed[i].end);
    })();
}

// 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) {
  var minindent, minline, doc = cm.doc;
  for (var search = n, lim = n - 100; search > lim; --search) {
    if (search <= doc.first) return doc.first;
    var line = getLine(doc, search - 1);
    if (line.stateAfter) return search;
    var indented = countColumn(line.text, null, cm.options.tabSize);
    if (minline == null || minindent > indented) {
      minline = search - 1;
      minindent = indented;
    }
  }
  return minline;
}

function getStateBefore(cm, n) {
  var doc = cm.doc, display = cm.display;
    if (!doc.mode.startState) return true;
  var pos = findStartLine(cm, n), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
  if (!state) state = startState(doc.mode);
  else state = copyState(doc.mode, state);
  doc.iter(pos, n, function(line) {
    processLine(cm, line, state);
    var save = pos == n - 1 || pos % 5 == 0 || pos >= display.showingFrom && pos < display.showingTo;
    line.stateAfter = save ? copyState(doc.mode, state) : null;
    ++pos;
  });
  return state;
}

// POSITION MEASUREMENT

function paddingTop(display) {return display.lineSpace.offsetTop;}
function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
function paddingLeft(display) {
  var e = removeChildrenAndAdd(display.measure, elt("pre", null, null, "text-align: left")).appendChild(elt("span", "x"));
  return e.offsetLeft;
}

function measureChar(cm, line, ch, data) {
  var dir = -1;
  data = data || measureLine(cm, line);

  for (var pos = ch;; pos += dir) {
    var r = data[pos];
    if (r) break;
    if (dir < 0 && pos == 0) dir = 1;
  }
  return {left: pos < ch ? r.right : r.left,
          right: pos > ch ? r.left : r.right,
          top: r.top, bottom: r.bottom};
}

function findCachedMeasurement(cm, line) {
  var cache = cm.display.measureLineCache;
  for (var i = 0; i < cache.length; ++i) {
    var memo = cache[i];
    if (memo.text == line.text && memo.markedSpans == line.markedSpans &&
        cm.display.scroller.clientWidth == memo.width &&
        memo.classes == line.textClass + "|" + line.bgClass + "|" + line.wrapClass)
      return memo;
  }
}

function clearCachedMeasurement(cm, line) {
  var exists = findCachedMeasurement(cm, line);
  if (exists) exists.text = exists.measure = exists.markedSpans = null;
}

function measureLine(cm, line) {
  // First look in the cache
  var cached = findCachedMeasurement(cm, line);
  if (cached) return cached.measure;

  // Failing that, recompute and store result in cache
  var measure = measureLineInner(cm, line);
  var cache = cm.display.measureLineCache;
  var memo = {text: line.text, width: cm.display.scroller.clientWidth,
              markedSpans: line.markedSpans, measure: measure,
              classes: line.textClass + "|" + line.bgClass + "|" + line.wrapClass};
  if (cache.length == 16) cache[++cm.display.measureLineCachePos % 16] = memo;
  else cache.push(memo);
  return measure;
}

function measureLineInner(cm, line) {
  var display = cm.display, measure = emptyArray(line.text.length);
  var pre = lineContent(cm, line, measure);

  // IE does not cache element positions of inline elements between
  // calls to getBoundingClientRect. This makes the loop below,
  // which gathers the positions of all the characters on the line,
  // do an amount of layout work quadratic to the number of
  // characters. When line wrapping is off, we try to improve things
  // by first subdividing the line into a bunch of inline blocks, so
  // that IE can reuse most of the layout information from caches
  // for those blocks. This does interfere with line wrapping, so it
  // doesn't work when wrapping is on, but in that case the
  // situation is slightly better, since IE does cache line-wrapping
  // information and only recomputes per-line.
  if (ie && !ie_lt8 && !cm.options.lineWrapping && pre.childNodes.length > 100) {
    var fragment = document.createDocumentFragment();
    var chunk = 10, n = pre.childNodes.length;
    for (var i = 0, chunks = Math.ceil(n / chunk); i < chunks; ++i) {
      var wrap = elt("div", null, null, "display: inline-block");
      for (var j = 0; j < chunk && n; ++j) {
        wrap.appendChild(pre.firstChild);
        --n;
      }
      fragment.appendChild(wrap);
    }
    pre.appendChild(fragment);
  }

  removeChildrenAndAdd(display.measure, pre);

  var outer = getRect(display.lineDiv);
  var vranges = [], data = emptyArray(line.text.length), maxBot = pre.offsetHeight;
  // Work around an IE7/8 bug where it will sometimes have randomly
  // replaced our pre with a clone at this point.
  if (ie_lt9 && display.measure.first != pre)
    removeChildrenAndAdd(display.measure, pre);

  for (var i = 0, cur; i < measure.length; ++i) if (cur = measure[i]) {
    var size = getRect(cur);
    var top = Math.max(0, size.top - outer.top), bot = Math.min(size.bottom - outer.top, maxBot);
    for (var j = 0; j < vranges.length; j += 2) {
      var rtop = vranges[j], rbot = vranges[j+1];
      if (rtop > bot || rbot < top) continue;
      if (rtop <= top && rbot >= bot ||
          top <= rtop && bot >= rbot ||
          Math.min(bot, rbot) - Math.max(top, rtop) >= (bot - top) >> 1) {
        vranges[j] = Math.min(top, rtop);
        vranges[j+1] = Math.max(bot, rbot);
        break;
      }
    }
    if (j == vranges.length) vranges.push(top, bot);
    var right = size.right;
    if (cur.measureRight) right = getRect(cur.measureRight).left;
    data[i] = {left: size.left - outer.left, right: right - outer.left, top: j};
  }
  for (var i = 0, cur; i < data.length; ++i) if (cur = data[i]) {
    var vr = cur.top;
    cur.top = vranges[vr]; cur.bottom = vranges[vr+1];
  }

  return data;
}

function measureLineWidth(cm, line) {
  var hasBadSpan = false;
  if (line.markedSpans) for (var i = 0; i < line.markedSpans; ++i) {
    var sp = line.markedSpans[i];
    if (sp.collapsed && (sp.to == null || sp.to == line.text.length)) hasBadSpan = true;
  }
  var cached = !hasBadSpan && findCachedMeasurement(cm, line);
  if (cached) return measureChar(cm, line, line.text.length, cached.measure).right;

  var pre = lineContent(cm, line);
  var end = pre.appendChild(zeroWidthElement(cm.display.measure));
  removeChildrenAndAdd(cm.display.measure, pre);
  return getRect(end).right - getRect(cm.display.lineDiv).left;
}

function clearCaches(cm) {
  cm.display.measureLineCache.length = cm.display.measureLineCachePos = 0;
  cm.display.cachedCharWidth = cm.display.cachedTextHeight = null;
  if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
  cm.display.lineNumChars = null;
}

// Context is one of "line", "div" (display.lineDiv), "local"/null (editor), or "page"
function intoCoordSystem(cm, lineObj, rect, context) {
  if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
    var size = widgetHeight(lineObj.widgets[i]);
    rect.top += size; rect.bottom += size;
  }
  if (context == "line") return rect;
  if (!context) context = "local";
  var yOff = heightAtLine(cm, lineObj);
  if (context != "local") yOff -= cm.display.viewOffset;
  if (context == "page") {
    var lOff = getRect(cm.display.lineSpace);
    yOff += lOff.top + (window.pageYOffset || (document.documentElement || document.body).scrollTop);
    var xOff = lOff.left + (window.pageXOffset || (document.documentElement || document.body).scrollLeft);
    rect.left += xOff; rect.right += xOff;
  }
  rect.top += yOff; rect.bottom += yOff;
  return rect;
}

// Context may be "window", "page", "div", or "local"/null
// Result is in "div" coords
function fromCoordSystem(cm, coords, context) {
  if (context == "div") return coords;
  var left = coords.left, top = coords.top;
  if (context == "page") {
    left -= window.pageXOffset || (document.documentElement || document.body).scrollLeft;
    top -= window.pageYOffset || (document.documentElement || document.body).scrollTop;
  }
  var lineSpaceBox = getRect(cm.display.lineSpace);
  left -= lineSpaceBox.left;
  top -= lineSpaceBox.top;
  if (context == "local" || !context) {
    var editorBox = getRect(cm.display.wrapper);
    left += editorBox.left;
    top += editorBox.top;
  }
  return {left: left, top: top};
}

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

function cursorCoords(cm, pos, context, lineObj, measurement) {
  lineObj = lineObj || getLine(cm.doc, pos.line);
  if (!measurement) measurement = measureLine(cm, lineObj);
  function get(ch, right) {
    var m = measureChar(cm, lineObj, ch, measurement);
    if (right) m.left = m.right; else m.right = m.left;
    return intoCoordSystem(cm, lineObj, m, context);
  }
  function getBidi(ch, partPos) {
    var part = order[partPos], right = part.level % 2;
    if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
      part = order[--partPos];
      ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
      right = true;
    } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
      part = order[++partPos];
      ch = bidiLeft(part) - part.level % 2;
      right = false;
    }
    if (right && ch == part.to && ch > part.from) return get(ch - 1);
    return get(ch, right);
  }
  var order = getOrder(lineObj), ch = pos.ch;
  if (!order) return get(ch);
  var partPos = getBidiPartAt(order, ch);
  var val = getBidi(ch, partPos);
  if (bidiOther != null) val.other = getBidi(ch, bidiOther);
  return val;
}

function PosMaybeOutside(line, ch, outside) {
  var pos = new Pos(line, ch);
  if (outside) pos.outside = true;
  return pos;
}

// Coords must be lineSpace-local
function coordsChar(cm, x, y) {
  var doc = cm.doc;
  y += cm.display.viewOffset;
  if (y < 0) return PosMaybeOutside(doc.first, 0, true);
  var lineNo = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
  if (lineNo > last)
    return PosMaybeOutside(doc.first + doc.size - 1, getLine(doc, last).text.length, true);
  if (x < 0) x = 0;

  for (;;) {
    var lineObj = getLine(doc, lineNo);
    var found = coordsCharInner(cm, lineObj, lineNo, x, y);
    var merged = collapsedSpanAtEnd(lineObj);
    var mergedPos = merged && merged.find();
    if (merged && found.ch >= mergedPos.from.ch)
      lineNo = mergedPos.to.line;
    else
      return found;
  }
}

function coordsCharInner(cm, lineObj, lineNo, x, y) {
  var innerOff = y - heightAtLine(cm, lineObj);
  var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
  var measurement = measureLine(cm, lineObj);

  function getX(ch) {
    var sp = cursorCoords(cm, Pos(lineNo, ch), "line",
                          lineObj, measurement);
    wrongLine = true;
    if (innerOff > sp.bottom) return sp.left - adjust;
    else if (innerOff < sp.top) return sp.left + adjust;
    else wrongLine = false;
    return sp.left;
  }

  var bidi = getOrder(lineObj), dist = lineObj.text.length;
  var from = lineLeft(lineObj), to = lineRight(lineObj);
  var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;

  if (x > toX) return PosMaybeOutside(lineNo, to, toOutside);
  // Do a binary search between these bounds.
  for (;;) {
    if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
      var after = x - fromX < toX - x, ch = after ? from : to;
      while (isExtendingChar.test(lineObj.text.charAt(ch))) ++ch;
      var pos = PosMaybeOutside(lineNo, ch, after ? fromOutside : toOutside);
      pos.after = after;
      return pos;
    }
    var step = Math.ceil(dist / 2), middle = from + step;
    if (bidi) {
      middle = from;
      for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
    }
    var middleX = getX(middle);
    if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
    else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
  }
}

var measureText;
function textHeight(display) {
  if (display.cachedTextHeight != null) return display.cachedTextHeight;
  if (measureText == null) {
    measureText = elt("pre");
    // 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;
}

function charWidth(display) {
  if (display.cachedCharWidth != null) return display.cachedCharWidth;
  var anchor = elt("span", "x");
  var pre = elt("pre", [anchor]);
  removeChildrenAndAdd(display.measure, pre);
  var width = anchor.offsetWidth;
  if (width > 2) display.cachedCharWidth = width;
  return width || 10;
}

// OPERATIONS

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

var nextOpId = 0;
function startOperation(cm) {
  cm.curOp = {
    // An array of ranges of lines that have to be updated. See
    // updateDisplay.
    changes: [],
    updateInput: null,
    userSelChange: null,
    textChanged: null,
    selectionChanged: false,
    cursorActivity: false,
    updateMaxLine: false,
    updateScrollPos: false,
    id: ++nextOpId
  };
  if (!delayedCallbackDepth++) delayedCallbacks = [];
}

function endOperation(cm) {
  var op = cm.curOp, doc = cm.doc, display = cm.display;
  cm.curOp = null;

  if (op.updateMaxLine) computeMaxLength(cm);
  if (display.maxLineChanged && !cm.options.lineWrapping && display.maxLine) {
    var width = measureLineWidth(cm, display.maxLine);
    display.sizer.style.minWidth = Math.max(0, width + 3 + scrollerCutOff) + "px";
    display.maxLineChanged = false;
    var maxScrollLeft = Math.max(0, display.sizer.offsetLeft + display.sizer.offsetWidth - display.scroller.clientWidth);
    if (maxScrollLeft < doc.scrollLeft && !op.updateScrollPos)
      setScrollLeft(cm, Math.min(display.scroller.scrollLeft, maxScrollLeft), true);
  }
  var newScrollPos, updated;
  if (op.updateScrollPos) {
    newScrollPos = op.updateScrollPos;
  } else if (op.selectionChanged && display.scroller.clientHeight) { // don't rescroll if not visible
    var coords = cursorCoords(cm, doc.sel.head);
    newScrollPos = calculateScrollPos(cm, coords.left, coords.top, coords.left, coords.bottom);
  }
  if (op.changes.length || newScrollPos && newScrollPos.scrollTop != null) {
    updated = updateDisplay(cm, op.changes, newScrollPos && newScrollPos.scrollTop);
    if (cm.display.scroller.offsetHeight) cm.doc.scrollTop = cm.display.scroller.scrollTop;
  }
  if (!updated && op.selectionChanged) updateSelection(cm);
  if (op.updateScrollPos) {
    display.scroller.scrollTop = display.scrollbarV.scrollTop = doc.scrollTop = newScrollPos.scrollTop;
    display.scroller.scrollLeft = display.scrollbarH.scrollLeft = doc.scrollLeft = newScrollPos.scrollLeft;
    alignHorizontally(cm);
    if (op.scrollToPos)
      scrollPosIntoView(cm, clipPos(cm.doc, op.scrollToPos), op.scrollToPosMargin);
  } else if (newScrollPos) {
    scrollCursorIntoView(cm);
  }
  if (op.selectionChanged) restartBlink(cm);

  if (cm.state.focused && op.updateInput)
    resetInput(cm, op.userSelChange);

  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 = 0; i < unhidden.length; ++i)
    if (unhidden[i].lines.length) signal(unhidden[i], "unhide");

  var delayed;
  if (!--delayedCallbackDepth) {
    delayed = delayedCallbacks;
    delayedCallbacks = null;
  }
  if (op.textChanged)
    signal(cm, "change", cm, op.textChanged);
  if (op.cursorActivity) signal(cm, "cursorActivity", cm);
  if (delayed) for (var i = 0; i < delayed.length; ++i) delayed[i]();
}

// Wraps a function in an operation. Returns the wrapped function.
function operation(cm1, f) {
  return function() {
    var cm = cm1 || this, withOp = !cm.curOp;
    if (withOp) startOperation(cm);
    try { var result = f.apply(cm, arguments); }
    finally { if (withOp) endOperation(cm); }
    return result;
  };
}
function docOperation(f) {
  return function() {
    var withOp = this.cm && !this.cm.curOp, result;
    if (withOp) startOperation(this.cm);
    try { result = f.apply(this, arguments); }
    finally { if (withOp) endOperation(this.cm); }
    return result;
  };
}
function runInOp(cm, f) {
  var withOp = !cm.curOp, result;
  if (withOp) startOperation(cm);
  try { result = f(); }
  finally { if (withOp) endOperation(cm); }
  return result;
}

function regChange(cm, from, to, lendiff) {
  if (from == null) from = cm.doc.first;
  if (to == null) to = cm.doc.first + cm.doc.size;
  cm.curOp.changes.push({from: from, to: to, diff: lendiff});
}

// INPUT HANDLING

function slowPoll(cm) {
  if (cm.display.pollingFast) return;
  cm.display.poll.set(cm.options.pollInterval, function() {
    readInput(cm);
    if (cm.state.focused) slowPoll(cm);
  });
}

function fastPoll(cm) {
  var missed = false;
  cm.display.pollingFast = true;
  function p() {
    var changed = readInput(cm);
    if (!changed && !missed) {missed = true; cm.display.poll.set(60, p);}
    else {cm.display.pollingFast = false; slowPoll(cm);}
  }
  cm.display.poll.set(20, p);
}

// prevInput is a hack to work with IME. If we reset the textarea
// on every change, that breaks IME. So we look for changes
// compared to the previous content instead. (Modern browsers have
// events that indicate IME taking place, but these are not widely
// supported or compatible enough yet to rely on.)
function readInput(cm) {
  var input = cm.display.input, prevInput = cm.display.prevInput, doc = cm.doc, sel = doc.sel;
  if (!cm.state.focused || hasSelection(input) || isReadOnly(cm)) return false;
  var text = input.value;
  if (text == prevInput && posEq(sel.from, sel.to)) return false;
  if (ie && !ie_lt9 && cm.display.inputHasSelection === text) {
    resetInput(cm, true);
    return false;
  }

  var withOp = !cm.curOp;
  if (withOp) startOperation(cm);
  sel.shift = false;
  var same = 0, l = Math.min(prevInput.length, text.length);
  while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
  var from = sel.from, to = sel.to;
  if (same < prevInput.length)
    from = Pos(from.line, from.ch - (prevInput.length - same));
  else if (cm.state.overwrite && posEq(from, to) && !cm.state.pasteIncoming)
    to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + (text.length - same)));
  var updateInput = cm.curOp.updateInput;
  makeChange(cm.doc, {from: from, to: to, text: splitLines(text.slice(same)),
                      origin: cm.state.pasteIncoming ? "paste" : "+input"}, "end");

  cm.curOp.updateInput = updateInput;
  if (text.length > 1000 || text.indexOf("\n") > -1) input.value = cm.display.prevInput = "";
  else cm.display.prevInput = text;
  if (withOp) endOperation(cm);
  cm.state.pasteIncoming = false;
  return true;
}

function resetInput(cm, user) {
  var minimal, selected, doc = cm.doc;
  if (!posEq(doc.sel.from, doc.sel.to)) {
    cm.display.prevInput = "";
    minimal = hasCopyEvent &&
      (doc.sel.to.line - doc.sel.from.line > 100 || (selected = cm.getSelection()).length > 1000);
    var content = minimal ? "-" : selected || cm.getSelection();
    cm.display.input.value = content;
    if (cm.state.focused) selectInput(cm.display.input);
    if (ie && !ie_lt9) cm.display.inputHasSelection = content;
  } else if (user) {
    cm.display.prevInput = cm.display.input.value = "";
    if (ie && !ie_lt9) cm.display.inputHasSelection = null;
  }
  cm.display.inaccurateSelection = minimal;
}

function focusInput(cm) {
  if (cm.options.readOnly != "nocursor" && (!mobile || document.activeElement != cm.display.input))
    cm.display.input.focus();
}

function isReadOnly(cm) {
  return cm.options.readOnly || cm.doc.cantEdit;
}

// EVENT HANDLERS

function registerEventHandlers(cm) {
  var d = cm.display;
  on(d.scroller, "mousedown", operation(cm, onMouseDown));
  if (ie)
    on(d.scroller, "dblclick", operation(cm, function(e) {
      var pos = posFromMouse(cm, e);
      if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
      e_preventDefault(e);
      var word = findWordAt(getLine(cm.doc, pos.line).text, pos);
      extendSelection(cm.doc, word.from, word.to);
    }));
  else
    on(d.scroller, "dblclick", e_preventDefault);
  on(d.lineSpace, "selectstart", function(e) {
    if (!eventInWidget(d, e)) e_preventDefault(e);
  });
  // Gecko browsers fire contextmenu *after* opening the menu, at
  // which point we can't mess with it anymore. Context menu is
  // handled in onMouseDown for Gecko.
  if (!captureMiddleClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});

  on(d.scroller, "scroll", function() {
    if (d.scroller.clientHeight) {
      setScrollTop(cm, d.scroller.scrollTop);
      setScrollLeft(cm, d.scroller.scrollLeft, true);
      signal(cm, "scroll", cm);
    }
  });
  on(d.scrollbarV, "scroll", function() {
    if (d.scroller.clientHeight) setScrollTop(cm, d.scrollbarV.scrollTop);
  });
  on(d.scrollbarH, "scroll", function() {
    if (d.scroller.clientHeight) setScrollLeft(cm, d.scrollbarH.scrollLeft);
  });

  on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
  on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});

  function reFocus() { if (cm.state.focused) setTimeout(bind(focusInput, cm), 0); }
  on(d.scrollbarH, "mousedown", reFocus);
  on(d.scrollbarV, "mousedown", reFocus);
  // Prevent wrapper from ever scrolling
  on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });

  function onResize() {
    // Might be a text scaling operation, clear size caches.
    d.cachedCharWidth = d.cachedTextHeight = null;
    clearCaches(cm);
    runInOp(cm, bind(regChange, cm));
  }
  on(window, "resize", onResize);
  // Above handler holds on to the editor and its data structures.
  // Here we poll to unregister it when the editor is no longer in
  // the document, so that it can be garbage-collected.
  function unregister() {
    for (var p = d.wrapper.parentNode; p && p != document.body; p = p.parentNode) {}
    if (p) setTimeout(unregister, 5000);
    else off(window, "resize", onResize);
  }
  setTimeout(unregister, 5000);

  on(d.input, "keyup", operation(cm, function(e) {
    if (cm.options.onKeyEvent && cm.options.onKeyEvent(cm, addStop(e))) return;
    if (e.keyCode == 16) cm.doc.sel.shift = false;
  }));
  on(d.input, "input", bind(fastPoll, cm));
  on(d.input, "keydown", operation(cm, onKeyDown));
  on(d.input, "keypress", operation(cm, onKeyPress));
  on(d.input, "focus", bind(onFocus, cm));
  on(d.input, "blur", bind(onBlur, cm));

  function drag_(e) {
    if (cm.options.onDragEvent && cm.options.onDragEvent(cm, addStop(e))) return;
    e_stop(e);
  }
  if (cm.options.dragDrop) {
    on(d.scroller, "dragstart", function(e){onDragStart(cm, e);});
    on(d.scroller, "dragenter", drag_);
    on(d.scroller, "dragover", drag_);
    on(d.scroller, "drop", operation(cm, onDrop));
  }
  on(d.scroller, "paste", function(e){
    if (eventInWidget(d, e)) return;
    focusInput(cm);
    fastPoll(cm);
  });
  on(d.input, "paste", function() {
    cm.state.pasteIncoming = true;
    fastPoll(cm);
  });

  function prepareCopy() {
    if (d.inaccurateSelection) {
      d.prevInput = "";
      d.inaccurateSelection = false;
      d.input.value = cm.getSelection();
      selectInput(d.input);
    }
  }
  on(d.input, "cut", prepareCopy);
  on(d.input, "copy", prepareCopy);

  // Needed to handle Tab key in KHTML
  if (khtml) on(d.sizer, "mouseup", function() {
      if (document.activeElement == d.input) d.input.blur();
      focusInput(cm);
  });
}

function eventInWidget(display, e) {
  for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
    if (!n) return true;
    if (/\bCodeMirror-(?:line)?widget\b/.test(n.className) ||
        n.parentNode == display.sizer && n != display.mover) return true;
  }
}

function posFromMouse(cm, e, liberal) {
  var display = cm.display;
  if (!liberal) {
    var target = e_target(e);
    if (target == display.scrollbarH || target == display.scrollbarH.firstChild ||
        target == display.scrollbarV || target == display.scrollbarV.firstChild ||
        target == display.scrollbarFiller || target == display.gutterFiller) return null;
  }
  var x, y, space = getRect(display.lineSpace);
  // Fails unpredictably on IE[67] when mouse is dragged around quickly.
  try { x = e.clientX; y = e.clientY; } catch (e) { return null; }
  return coordsChar(cm, x - space.left, y - space.top);
}

var lastClick, lastDoubleClick;
function onMouseDown(e) {
  var cm = this, display = cm.display, doc = cm.doc, sel = doc.sel;
  sel.shift = e.shiftKey;

  if (eventInWidget(display, e)) {
    if (!webkit) {
      display.scroller.draggable = false;
      setTimeout(function(){display.scroller.draggable = true;}, 100);
    }
    return;
  }
  if (clickInGutter(cm, e)) return;
  var start = posFromMouse(cm, e);

  switch (e_button(e)) {
  case 3:
    if (captureMiddleClick) onContextMenu.call(cm, cm, e);
    return;
  case 2:
    if (start) extendSelection(cm.doc, start);
    setTimeout(bind(focusInput, cm), 20);
    e_preventDefault(e);
    return;
  }
  // For button 1, if it was clicked inside the editor
  // (posFromMouse returning non-null), we have to adjust the
  // selection.
  if (!start) {if (e_target(e) == display.scroller) e_preventDefault(e); return;}

  if (!cm.state.focused) onFocus(cm);

  var now = +new Date, type = "single";
  if (lastDoubleClick && lastDoubleClick.time > now - 400 && posEq(lastDoubleClick.pos, start)) {
    type = "triple";
    e_preventDefault(e);
    setTimeout(bind(focusInput, cm), 20);
    selectLine(cm, start.line);
  } else if (lastClick && lastClick.time > now - 400 && posEq(lastClick.pos, start)) {
    type = "double";
    lastDoubleClick = {time: now, pos: start};
    e_preventDefault(e);
    var word = findWordAt(getLine(doc, start.line).text, start);
    extendSelection(cm.doc, word.from, word.to);
  } else { lastClick = {time: now, pos: start}; }

  var last = start;
  if (cm.options.dragDrop && dragAndDrop && !isReadOnly(cm) && !posEq(sel.from, sel.to) &&
      !posLess(start, sel.from) && !posLess(sel.to, start) && type == "single") {
    var dragEnd = operation(cm, function(e2) {
      if (webkit) display.scroller.draggable = false;
      cm.state.draggingText = false;
      off(document, "mouseup", dragEnd);
      off(display.scroller, "drop", dragEnd);
      if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
        e_preventDefault(e2);
        extendSelection(cm.doc, start);
        focusInput(cm);
      }
    });
    // Let the drag handler handle this.
    if (webkit) display.scroller.draggable = true;
    cm.state.draggingText = dragEnd;
    // IE's approach to draggable
    if (display.scroller.dragDrop) display.scroller.dragDrop();
    on(document, "mouseup", dragEnd);
    on(display.scroller, "drop", dragEnd);
    return;
  }
  e_preventDefault(e);
  if (type == "single") extendSelection(cm.doc, clipPos(doc, start));

  var startstart = sel.from, startend = sel.to, lastPos = start;

  function doSelect(cur) {
    if (posEq(lastPos, cur)) return;
    lastPos = cur;

    if (type == "single") {
      extendSelection(cm.doc, clipPos(doc, start), cur);
      return;
    }

    startstart = clipPos(doc, startstart);
    startend = clipPos(doc, startend);
    if (type == "double") {
      var word = findWordAt(getLine(doc, cur.line).text, cur);
      if (posLess(cur, startstart)) extendSelection(cm.doc, word.from, startend);
      else extendSelection(cm.doc, startstart, word.to);
    } else if (type == "triple") {
      if (posLess(cur, startstart)) extendSelection(cm.doc, startend, clipPos(doc, Pos(cur.line, 0)));
      else extendSelection(cm.doc, startstart, clipPos(doc, Pos(cur.line + 1, 0)));
    }
  }

  var editorSize = getRect(display.wrapper);
  // 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);
    if (!cur) return;
    if (!posEq(cur, last)) {
      if (!cm.state.focused) onFocus(cm);
      last = cur;
      doSelect(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) {
    counter = Infinity;
    var cur = posFromMouse(cm, e);
    if (cur) doSelect(cur);
    e_preventDefault(e);
    focusInput(cm);
    off(document, "mousemove", move);
    off(document, "mouseup", up);
  }

  var move = operation(cm, function(e) {
    if (!ie && !e_button(e)) done(e);
    else extend(e);
  });
  var up = operation(cm, done);
  on(document, "mousemove", move);
  on(document, "mouseup", up);
}

function onDrop(e) {
  var cm = this;
  if (eventInWidget(cm.display, e) || (cm.options.onDragEvent && cm.options.onDragEvent(cm, addStop(e))))
    return;
  e_preventDefault(e);
  var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
  if (!pos || isReadOnly(cm)) return;
  if (files && files.length && window.FileReader && window.File) {
    var n = files.length, text = Array(n), read = 0;
    var loadFile = function(file, i) {
      var reader = new FileReader;
      reader.onload = function() {
        text[i] = reader.result;
        if (++read == n) {
          pos = clipPos(cm.doc, pos);
          makeChange(cm.doc, {from: pos, to: pos, text: splitLines(text.join("\n")), origin: "paste"}, "around");
        }
      };
      reader.readAsText(file);
    };
    for (var i = 0; i < n; ++i) loadFile(files[i], i);
  } else {
    // Don't do a replace if the drop happened inside of the selected text.
    if (cm.state.draggingText && !(posLess(pos, cm.doc.sel.from) || posLess(cm.doc.sel.to, pos))) {
      cm.state.draggingText(e);
      // Ensure the editor is re-focused
      setTimeout(bind(focusInput, cm), 20);
      return;
    }
    try {
      var text = e.dataTransfer.getData("Text");
      if (text) {
        var curFrom = cm.doc.sel.from, curTo = cm.doc.sel.to;
        setSelection(cm.doc, pos, pos);
        if (cm.state.draggingText) replaceRange(cm.doc, "", curFrom, curTo, "paste");
        cm.replaceSelection(text, null, "paste");
        focusInput(cm);
        onFocus(cm);
      }
    }
    catch(e){}
  }
}

function clickInGutter(cm, e) {
  var display = cm.display;
  try { var mX = e.clientX, mY = e.clientY; }
  catch(e) { return false; }

  if (mX >= Math.floor(getRect(display.gutters).right)) return false;
  e_preventDefault(e);
  if (!hasHandler(cm, "gutterClick")) return true;

  var lineBox = getRect(display.lineDiv);
  if (mY > lineBox.bottom) return true;
  mY -= lineBox.top - display.viewOffset;

  for (var i = 0; i < cm.options.gutters.length; ++i) {
    var g = display.gutters.childNodes[i];
    if (g && getRect(g).right >= mX) {
      var line = lineAtHeight(cm.doc, mY);
      var gutter = cm.options.gutters[i];
      signalLater(cm, "gutterClick", cm, line, gutter, e);
      break;
    }
  }
  return true;
}

function onDragStart(cm, e) {
  if (ie && !cm.state.draggingText) { e_stop(e); return; }
  if (eventInWidget(cm.display, e)) return;

  var txt = cm.getSelection();
  e.dataTransfer.setData("Text", txt);

  // 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) {
    var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
    if (opera) {
      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;
    }
    if (safari) {
      if (cm.display.dragImg) {
        img = cm.display.dragImg;
      } else {
        cm.display.dragImg = img;
        img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
        cm.display.wrapper.appendChild(img);
      }
    }
    e.dataTransfer.setDragImage(img, 0, 0);
    if (opera) img.parentNode.removeChild(img);
  }
}

function setScrollTop(cm, val) {
  if (Math.abs(cm.doc.scrollTop - val) < 2) return;
  cm.doc.scrollTop = val;
  if (!gecko) updateDisplay(cm, [], val);
  if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
  if (cm.display.scrollbarV.scrollTop != val) cm.display.scrollbarV.scrollTop = val;
  if (gecko) updateDisplay(cm, []);
}
function setScrollLeft(cm, val, isScroller) {
  if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;
  val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);
  cm.doc.scrollLeft = val;
  alignHorizontally(cm);
  if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;
  if (cm.display.scrollbarH.scrollLeft != val) cm.display.scrollbarH.scrollLeft = val;
}

// 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 onScrollWheel(cm, 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;

  var display = cm.display, scroll = display.scroller;
  // Quit if there's nothing to scroll here
  if (!(dx && scroll.scrollWidth > scroll.clientWidth ||
        dy && scroll.scrollHeight > scroll.clientHeight)) 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) {
    for (var cur = e.target; cur != scroll; cur = cur.parentNode) {
      if (cur.lineObj) {
        cm.display.currentWheelTarget = cur;
        break;
      }
    }
  }

  // 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 && !opera && wheelPixelsPerUnit != null) {
    if (dy)
      setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));
    setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));
    e_preventDefault(e);
    display.wheelStartX = null; // Abort measurement, if in progress
    return;
  }

  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);
    updateDisplay(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;
    }
  }
}

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
  if (cm.display.pollingFast && readInput(cm)) cm.display.pollingFast = false;
  var doc = cm.doc, prevShift = doc.sel.shift, done = false;
  try {
    if (isReadOnly(cm)) cm.state.suppressEdits = true;
    if (dropShift) doc.sel.shift = false;
    done = bound(cm) != Pass;
  } finally {
    doc.sel.shift = prevShift;
    cm.state.suppressEdits = false;
  }
  return done;
}

function allKeyMaps(cm) {
  var maps = cm.state.keyMaps.slice(0);
  if (cm.options.extraKeys) maps.push(cm.options.extraKeys);
  maps.push(cm.options.keyMap);
  return maps;
}

var maybeTransition;
function handleKeyBinding(cm, e) {
  // Handle auto keymap transitions
  var startMap = getKeyMap(cm.options.keyMap), next = startMap.auto;
  clearTimeout(maybeTransition);
  if (next && !isModifierKey(e)) maybeTransition = setTimeout(function() {
    if (getKeyMap(cm.options.keyMap) == startMap)
      cm.options.keyMap = (next.call ? next.call(null, cm) : next);
  }, 50);

  var name = keyName(e, true), handled = false;
  if (!name) return false;
  var keymaps = allKeyMaps(cm);

  if (e.shiftKey) {
    // 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-'.
    handled = lookupKey("Shift-" + name, keymaps, function(b) {return doHandleBinding(cm, b, true);})
           || lookupKey(name, keymaps, function(b) {
                if (typeof b == "string" && /^go[A-Z]/.test(b)) return doHandleBinding(cm, b);
              });
  } else {
    handled = lookupKey(name, keymaps, function(b) { return doHandleBinding(cm, b); });
  }
  if (handled == "stop") handled = false;

  if (handled) {
    e_preventDefault(e);
    restartBlink(cm);
    if (ie_lt9) { e.oldKeyCode = e.keyCode; e.keyCode = 0; }
  }
  return handled;
}

function handleCharBinding(cm, e, ch) {
  var handled = lookupKey("'" + ch + "'", allKeyMaps(cm),
                          function(b) { return doHandleBinding(cm, b, true); });
  if (handled) {
    e_preventDefault(e);
    restartBlink(cm);
  }
  return handled;
}

var lastStoppedKey = null;
function onKeyDown(e) {
  var cm = this;
  if (!cm.state.focused) onFocus(cm);
  if (ie && e.keyCode == 27) { e.returnValue = false; }
  if (cm.options.onKeyEvent && cm.options.onKeyEvent(cm, addStop(e))) return;
  var code = e.keyCode;
  // IE does strange things with escape.
  cm.doc.sel.shift = code == 16 || e.shiftKey;
  // First give onKeyEvent option a chance to handle this.
  var handled = handleKeyBinding(cm, e);
  if (opera) {
    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("");
  }
}

function onKeyPress(e) {
  var cm = this;
  if (cm.options.onKeyEvent && cm.options.onKeyEvent(cm, addStop(e))) return;
  var keyCode = e.keyCode, charCode = e.charCode;
  if (opera && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
  if (((opera && (!e.which || e.which < 10)) || khtml) && handleKeyBinding(cm, e)) return;
  var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
  if (this.options.electricChars && this.doc.mode.electricChars &&
      this.options.smartIndent && !isReadOnly(this) &&
      this.doc.mode.electricChars.indexOf(ch) > -1)
    setTimeout(operation(cm, function() {indentLine(cm, cm.doc.sel.to.line, "smart");}), 75);
  if (handleCharBinding(cm, e, ch)) return;
  if (ie && !ie_lt9) cm.display.inputHasSelection = null;
  fastPoll(cm);
}

function onFocus(cm) {
  if (cm.options.readOnly == "nocursor") return;
  if (!cm.state.focused) {
    signal(cm, "focus", cm);
    cm.state.focused = true;
    if (cm.display.wrapper.className.search(/\bCodeMirror-focused\b/) == -1)
      cm.display.wrapper.className += " CodeMirror-focused";
    resetInput(cm, true);
  }
  slowPoll(cm);
  restartBlink(cm);
}
function onBlur(cm) {
  if (cm.state.focused) {
    signal(cm, "blur", cm);
    cm.state.focused = false;
    cm.display.wrapper.className = cm.display.wrapper.className.replace(" CodeMirror-focused", "");
  }
  clearInterval(cm.display.blinker);
  setTimeout(function() {if (!cm.state.focused) cm.doc.sel.shift = false;}, 150);
}

var detectingSelectAll;
function onContextMenu(cm, e) {
  var display = cm.display, sel = cm.doc.sel;
  if (eventInWidget(display, e)) return;

  var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
  if (!pos || opera) return; // Opera is difficult.
  if (posEq(sel.from, sel.to) || posLess(pos, sel.from) || !posLess(pos, sel.to))
    operation(cm, setSelection)(cm.doc, pos, pos);

  var oldCSS = display.input.style.cssText;
  display.inputDiv.style.position = "absolute";
  display.input.style.cssText = "position: fixed; width: 30px; height: 30px; top: " + (e.clientY - 5) +
    "px; left: " + (e.clientX - 5) + "px; z-index: 1000; background: white; outline: none;" +
    "border-width: 0; outline: none; overflow: hidden; opacity: .05; -ms-opacity: .05; filter: alpha(opacity=5);";
  focusInput(cm);
  resetInput(cm, true);
  // Adds "Select all" to context menu in FF
  if (posEq(sel.from, sel.to)) display.input.value = display.prevInput = " ";

  function prepareSelectAllHack() {
    if (display.input.selectionStart != null) {
      var extval = display.input.value = " " + (posEq(sel.from, sel.to) ? "" : display.input.value);
      display.prevInput = " ";
      display.input.selectionStart = 1; display.input.selectionEnd = extval.length;
    }
  }
  function rehide() {
    display.inputDiv.style.position = "relative";
    display.input.style.cssText = oldCSS;
    if (ie_lt9) display.scrollbarV.scrollTop = display.scroller.scrollTop = scrollPos;
    slowPoll(cm);

    // Try to detect the user choosing select-all
    if (display.input.selectionStart != null) {
      if (!ie || ie_lt9) prepareSelectAllHack();
      clearTimeout(detectingSelectAll);
      var i = 0, poll = function(){
        if (display.prevInput == " " && display.input.selectionStart == 0)
          operation(cm, commands.selectAll)(cm);
        else if (i++ < 10) detectingSelectAll = setTimeout(poll, 500);
        else resetInput(cm);
      };
      detectingSelectAll = setTimeout(poll, 200);
    }
  }

  if (ie && !ie_lt9) prepareSelectAllHack();
  if (captureMiddleClick) {
    e_stop(e);
    var mouseup = function() {
      off(window, "mouseup", mouseup);
      setTimeout(rehide, 20);
    };
    on(window, "mouseup", mouseup);
  } else {
    setTimeout(rehide, 50);
  }
}

// UPDATING

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));
}

// Make sure a position will be valid after the given change.
function clipPostChange(doc, change, pos) {
  if (!posLess(change.from, pos)) return clipPos(doc, pos);
  var diff = (change.text.length - 1) - (change.to.line - change.from.line);
  if (pos.line > change.to.line + diff) {
    var preLine = pos.line - diff, lastLine = doc.first + doc.size - 1;
    if (preLine > lastLine) return Pos(lastLine, getLine(doc, lastLine).text.length);
    return clipToLen(pos, getLine(doc, preLine).text.length);
  }
  if (pos.line == change.to.line + diff)
    return clipToLen(pos, lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0) +
                     getLine(doc, change.to.line).text.length - change.to.ch);
  var inside = pos.line - change.from.line;
  return clipToLen(pos, change.text[inside].length + (inside ? 0 : change.from.ch));
}

// Hint can be null|"end"|"start"|"around"|{anchor,head}
function computeSelAfterChange(doc, change, hint) {
  if (hint && typeof hint == "object") // Assumed to be {anchor, head} object
    return {anchor: clipPostChange(doc, change, hint.anchor),
            head: clipPostChange(doc, change, hint.head)};

  if (hint == "start") return {anchor: change.from, head: change.from};

  var end = changeEnd(change);
  if (hint == "around") return {anchor: change.from, head: end};
  if (hint == "end") return {anchor: end, head: end};

  // hint is null, leave the selection alone as much as possible
  var adjustPos = function(pos) {
    if (posLess(pos, change.from)) return pos;
    if (!posLess(change.to, pos)) return end;

    var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
    if (pos.line == change.to.line) ch += end.ch - change.to.ch;
    return Pos(line, ch);
  };
  return {anchor: adjustPos(doc.sel.anchor), head: adjustPos(doc.sel.head)};
}

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

  if (obj.canceled) return null;
  return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};
}

// Replace the range from from to to by the strings in replacement.
// change is a {from, to, text [, origin]} object
function makeChange(doc, change, selUpdate, ignoreReadOnly) {
  if (doc.cm) {
    if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, selUpdate, ignoreReadOnly);
    if (doc.cm.state.suppressEdits) return;
  }

  if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
    change = filterChange(doc, change);
    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 >= 1; --i)
      makeChangeNoReadonly(doc, {from: split[i].from, to: split[i].to, text: [""]});
    if (split.length)
      makeChangeNoReadonly(doc, {from: split[0].from, to: split[0].to, text: change.text}, selUpdate);
  } else {
    makeChangeNoReadonly(doc, change, selUpdate);
  }
}

function makeChangeNoReadonly(doc, change, selUpdate) {
  var selAfter = computeSelAfterChange(doc, change, selUpdate);
  addToHistory(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));
  });
}

function makeChangeFromHistory(doc, type) {
  if (doc.cm && doc.cm.state.suppressEdits) return;

  var hist = doc.history;
  var event = (type == "undo" ? hist.done : hist.undone).pop();
  if (!event) return;
  hist.dirtyCounter += type == "undo" ? -1 : 1;

  var anti = {changes: [], anchorBefore: event.anchorAfter, headBefore: event.headAfter,
              anchorAfter: event.anchorBefore, headAfter: event.headBefore};
  (type == "undo" ? hist.undone : hist.done).push(anti);

  for (var i = event.changes.length - 1; i >= 0; --i) {
    var change = event.changes[i];
    change.origin = type;
    anti.changes.push(historyChangeFromChange(doc, change));

    var after = i ? computeSelAfterChange(doc, change, null)
                  : {anchor: event.anchorBefore, head: event.headBefore};
    makeChangeSingleDoc(doc, change, after, mergeOldSpans(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, mergeOldSpans(doc, change));
    });
  }
}

function shiftDoc(doc, distance) {
  function shiftPos(pos) {return Pos(pos.line + distance, pos.ch);}
  doc.first += distance;
  if (doc.cm) regChange(doc.cm, doc.first, doc.first, distance);
  doc.sel.head = shiftPos(doc.sel.head); doc.sel.anchor = shiftPos(doc.sel.anchor);
  doc.sel.from = shiftPos(doc.sel.from); doc.sel.to = shiftPos(doc.sel.to);
}

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, null);
  if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans, selAfter);
  else updateDoc(doc, change, spans, selAfter);
}

function makeChangeSingleDocInEditor(cm, change, spans, selAfter) {
  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(doc, getLine(doc, from.line)));
    doc.iter(checkWidthStart, to.line + 1, function(line) {
      if (line == display.maxLine) {
        recomputeMaxLength = true;
        return true;
      }
    });
  }

  if (!posLess(doc.sel.head, change.from) && !posLess(change.to, doc.sel.head))
    cm.curOp.cursorActivity = true;

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

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

  // Adjust frontier, schedule worker
  doc.frontier = Math.min(doc.frontier, from.line);
  startWorker(cm, 400);

  var lendiff = change.text.length - (to.line - from.line) - 1;
  // Remember that these lines changed, for updating the display
  regChange(cm, from.line, to.line + 1, lendiff);

  if (hasHandler(cm, "change")) {
    var changeObj = {from: from, to: to,
                     text: change.text,
                     removed: change.removed,
                     origin: change.origin};
    if (cm.curOp.textChanged) {
      for (var cur = cm.curOp.textChanged; cur.next; cur = cur.next) {}
      cur.next = changeObj;
    } else cm.curOp.textChanged = changeObj;
  }
}

function replaceRange(doc, code, from, to, origin) {
  if (!to) to = from;
  if (posLess(to, from)) { var tmp = to; to = from; from = tmp; }
  if (typeof code == "string") code = splitLines(code);
  makeChange(doc, {from: from, to: to, text: code, origin: origin}, null);
}

// POSITION OBJECT

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

function posEq(a, b) {return a.line == b.line && a.ch == b.ch;}
function posLess(a, b) {return a.line < b.line || (a.line == b.line && a.ch < b.ch);}
function copyPos(x) {return Pos(x.line, x.ch);}

// SELECTION

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

// If shift is held, this will move the selection anchor. Otherwise,
// it'll set the whole selection.
function extendSelection(doc, pos, other, bias) {
  if (doc.sel.shift || doc.sel.extend) {
    var anchor = doc.sel.anchor;
    if (other) {
      var posBefore = posLess(pos, anchor);
      if (posBefore != posLess(other, anchor)) {
        anchor = pos;
        pos = other;
      } else if (posBefore != posLess(pos, other)) {
        pos = other;
      }
    }
    setSelection(doc, anchor, pos, bias);
  } else {
    setSelection(doc, pos, other || pos, bias);
  }
  if (doc.cm) doc.cm.curOp.userSelChange = true;
}

function filterSelectionChange(doc, anchor, head) {
  var obj = {anchor: anchor, head: head};
  signal(doc, "beforeSelectionChange", doc, obj);
  if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
  obj.anchor = clipPos(doc, obj.anchor); obj.head = clipPos(doc, obj.head);
  return obj;
}

// Update the selection. Last two args are only used by
// updateDoc, since they have to be expressed in the line
// numbers before the update.
function setSelection(doc, anchor, head, bias, checkAtomic) {
  if (!checkAtomic && hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange")) {
    var filtered = filterSelectionChange(doc, anchor, head);
    head = filtered.head;
    anchor = filtered.anchor;
  }

  var sel = doc.sel;
  sel.goalColumn = null;
  // Skip over atomic spans.
  if (checkAtomic || !posEq(anchor, sel.anchor))
    anchor = skipAtomic(doc, anchor, bias, checkAtomic != "push");
  if (checkAtomic || !posEq(head, sel.head))
    head = skipAtomic(doc, head, bias, checkAtomic != "push");

  if (posEq(sel.anchor, anchor) && posEq(sel.head, head)) return;

  sel.anchor = anchor; sel.head = head;
  var inv = posLess(head, anchor);
  sel.from = inv ? head : anchor;
  sel.to = inv ? anchor : head;

  if (doc.cm)
    doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged =
      doc.cm.curOp.cursorActivity = true;

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

function reCheckSelection(cm) {
  setSelection(cm.doc, cm.doc.sel.from, cm.doc.sel.to, null, "push");
}

function skipAtomic(doc, pos, bias, mayClear) {
  var flipped = false, curPos = pos;
  var dir = bias || 1;
  doc.cantEdit = false;
  search: for (;;) {
    var line = getLine(doc, curPos.line);
    if (line.markedSpans) {
      for (var i = 0; i < line.markedSpans.length; ++i) {
        var sp = line.markedSpans[i], m = sp.marker;
        if ((sp.from == null || (m.inclusiveLeft ? sp.from <= curPos.ch : sp.from < curPos.ch)) &&
            (sp.to == null || (m.inclusiveRight ? sp.to >= curPos.ch : sp.to > curPos.ch))) {
          if (mayClear) {
            signal(m, "beforeCursorEnter");
            if (m.explicitlyCleared) {
              if (!line.markedSpans) break;
              else {--i; continue;}
            }
          }
          if (!m.atomic) continue;
          var newPos = m.find()[dir < 0 ? "from" : "to"];
          if (posEq(newPos, curPos)) {
            newPos.ch += dir;
            if (newPos.ch < 0) {
              if (newPos.line > doc.first) newPos = clipPos(doc, Pos(newPos.line - 1));
              else newPos = null;
            } else if (newPos.ch > line.text.length) {
              if (newPos.line < doc.first + doc.size - 1) newPos = Pos(newPos.line + 1, 0);
              else newPos = null;
            }
            if (!newPos) {
              if (flipped) {
                // Driven in a corner -- no valid cursor position found at all
                // -- try again *with* clearing, if we didn't already
                if (!mayClear) return skipAtomic(doc, pos, bias, true);
                // Otherwise, turn off editing until further notice, and return the start of the doc
                doc.cantEdit = true;
                return Pos(doc.first, 0);
              }
              flipped = true; newPos = pos; dir = -dir;
            }
          }
          curPos = newPos;
          continue search;
        }
      }
    }
    return curPos;
  }
}

// SCROLLING

function scrollCursorIntoView(cm) {
  var coords = scrollPosIntoView(cm, cm.doc.sel.head, cm.options.cursorScrollMargin);
  if (!cm.state.focused) return;
  var display = cm.display, box = getRect(display.sizer), doScroll = null, pTop = paddingTop(cm.display);
  if (coords.top + pTop + box.top < 0) doScroll = true;
  else if (coords.bottom + pTop + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
  if (doScroll != null && !phantom) {
    var hidden = display.cursor.style.display == "none";
    if (hidden) {
      display.cursor.style.display = "";
      display.cursor.style.left = coords.left + "px";
      display.cursor.style.top = (coords.top - display.viewOffset) + "px";
    }
    display.cursor.scrollIntoView(doScroll);
    if (hidden) display.cursor.style.display = "none";
  }
}

function scrollPosIntoView(cm, pos, margin) {
  if (margin == null) margin = 0;
  for (;;) {
    var changed = false, coords = cursorCoords(cm, pos);
    var scrollPos = calculateScrollPos(cm, coords.left, coords.top - margin, coords.left, coords.bottom + margin);
    var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
    if (scrollPos.scrollTop != null) {
      setScrollTop(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) return coords;
  }
}

function scrollIntoView(cm, x1, y1, x2, y2) {
  var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);
  if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);
  if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);
}

function calculateScrollPos(cm, x1, y1, x2, y2) {
  var display = cm.display, pt = paddingTop(display);
  y1 += pt; y2 += pt;
  if (y1 < 0) y1 = 0;
  var screen = display.scroller.clientHeight - scrollerCutOff, screentop = display.scroller.scrollTop, result = {};
  var docBottom = cm.doc.height + paddingVert(display);
  var atTop = y1 < pt + 10, atBottom = y2 + pt > docBottom - 10;
  if (y1 < screentop) {
    result.scrollTop = atTop ? 0 : y1;
  } else if (y2 > screentop + screen) {
    var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);
    if (newTop != screentop) result.scrollTop = newTop;
  }

  var screenw = display.scroller.clientWidth - scrollerCutOff, screenleft = display.scroller.scrollLeft;
  x1 += display.gutters.offsetWidth; x2 += display.gutters.offsetWidth;
  var gutterw = display.gutters.offsetWidth;
  var atLeft = x1 < gutterw + 10;
  if (x1 < screenleft + gutterw || atLeft) {
    if (atLeft) x1 = 0;
    result.scrollLeft = Math.max(0, x1 - 10 - gutterw);
  } else if (x2 > screenw + screenleft - 3) {
    result.scrollLeft = x2 + 10 - screenw;
  }
  return result;
}

function updateScrollPos(cm, left, top) {
  cm.curOp.updateScrollPos = {scrollLeft: left == null ? cm.doc.scrollLeft : left,
                              scrollTop: top == null ? cm.doc.scrollTop : top};
}

function addToScrollPos(cm, left, top) {
  var pos = cm.curOp.updateScrollPos || (cm.curOp.updateScrollPos = {scrollLeft: cm.doc.scrollLeft, scrollTop: cm.doc.scrollTop});
  var scroll = cm.display.scroller;
  pos.scrollTop = Math.max(0, Math.min(scroll.scrollHeight - scroll.clientHeight, pos.scrollTop + top));
  pos.scrollLeft = Math.max(0, Math.min(scroll.scrollWidth - scroll.clientWidth, pos.scrollLeft + left));
}

// API UTILITIES

function indentLine(cm, n, how, aggressive) {
  var doc = cm.doc;
  if (!how) how = "add";
  if (how == "smart") {
    if (!cm.doc.mode.indent) how = "prev";
    else var state = getStateBefore(cm, n);
  }

  var tabSize = cm.options.tabSize;
  var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
  var curSpaceString = line.text.match(/^\s*/)[0], indentation;
  if (how == "smart") {
    indentation = cm.doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
    if (indentation == Pass) {
      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;
  }
  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(cm.doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
  line.stateAfter = null;
}

function changeLine(cm, handle, op) {
  var no = handle, line = handle, doc = cm.doc;
  if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));
  else no = lineNo(handle);
  if (no == null) return null;
  if (op(line, no)) regChange(cm, no, no + 1);
  else return null;
  return line;
}

function findPosH(doc, pos, dir, unit, visually) {
  var line = pos.line, ch = pos.ch, origDir = dir;
  var lineObj = getLine(doc, line);
  var possible = true;
  function findNextLine() {
    var l = line + dir;
    if (l < doc.first || l >= doc.first + doc.size) return (possible = false);
    line = l;
    return lineObj = getLine(doc, l);
  }
  function moveOnce(boundToLine) {
    var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
    if (next == null) {
      if (!boundToLine && findNextLine()) {
        if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
        else ch = dir < 0 ? lineObj.text.length : 0;
      } else return (possible = false);
    } else ch = next;
    return true;
  }

  if (unit == "char") moveOnce();
  else if (unit == "column") moveOnce(true);
  else if (unit == "word" || unit == "group") {
    var sawType = null, group = unit == "group";
    for (var first = true;; first = false) {
      if (dir < 0 && !moveOnce(!first)) break;
      var cur = lineObj.text.charAt(ch) || "\n";
      var type = isWordChar(cur) ? "w"
        : !group ? null
        : /\s/.test(cur) ? null
        : "p";
      if (sawType && sawType != type) {
        if (dir < 0) {dir = 1; moveOnce();}
        break;
      }
      if (type) sawType = type;
      if (dir > 0 && !moveOnce(!first)) break;
    }
  }
  var result = skipAtomic(doc, Pos(line, ch), origDir, true);
  if (!possible) result.hitSide = true;
  return result;
}

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);
    y = pos.top + dir * (pageSize - (dir < 0 ? 1.5 : .5) * textHeight(cm.display));
  } else if (unit == "line") {
    y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
  }
  for (;;) {
    var 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;
}

function findWordAt(line, pos) {
  var start = pos.ch, end = pos.ch;
  if (line) {
    if (pos.after === false || end == line.length) --start; else ++end;
    var startChar = line.charAt(start);
    var check = isWordChar(startChar) ? isWordChar
      : /\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 {from: Pos(pos.line, start), to: Pos(pos.line, end)};
}

function selectLine(cm, line) {
  extendSelection(cm.doc, Pos(line, 0), clipPos(cm.doc, Pos(line + 1, 0)));
}

// PROTOTYPE

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

CodeMirror.prototype = {
  constructor: CodeMirror,
  focus: function(){window.focus(); focusInput(this); onFocus(this); fastPoll(this);},

  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);
  },

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

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

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

  indentLine: operation(null, function(n, dir, aggressive) {
    if (typeof dir != "string") {
      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: operation(null, function(how) {
    var sel = this.doc.sel;
    if (posEq(sel.from, sel.to)) return indentLine(this, sel.from.line, how);
    var e = sel.to.line - (sel.to.ch ? 0 : 1);
    for (var i = sel.from.line; i <= e; ++i) indentLine(this, i, how);
  }),

  // Fetch the parser token for a given character. Useful for hacks
  // that want to inspect the mode state (say, for completion).
  getTokenAt: function(pos) {
    var doc = this.doc;
    pos = clipPos(doc, pos);
    var state = getStateBefore(this, pos.line), mode = this.doc.mode;
    var line = getLine(doc, pos.line);
    var stream = new StringStream(line.text, this.options.tabSize);
    while (stream.pos < pos.ch && !stream.eol()) {
      stream.start = stream.pos;
      var style = mode.token(stream, state);
    }
    return {start: stream.start,
            end: stream.pos,
            string: stream.current(),
            className: style || null, // Deprecated, use 'type' instead
            type: style || null,
            state: state};
  },

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

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

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

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

  clearGutter: operation(null, function(gutterID) {
    var cm = this, doc = cm.doc, i = doc.first;
    doc.iter(function(line) {
      if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
        line.gutterMarkers[gutterID] = null;
        regChange(cm, i, i + 1);
        if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;
      }
      ++i;
    });
  }),

  addLineClass: operation(null, function(handle, where, cls) {
    return changeLine(this, handle, function(line) {
      var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
      if (!line[prop]) line[prop] = cls;
      else if (new RegExp("\\b" + cls + "\\b").test(line[prop])) return false;
      else line[prop] += " " + cls;
      return true;
    });
  }),

  removeLineClass: operation(null, function(handle, where, cls) {
    return changeLine(this, handle, function(line) {
      var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
      var cur = line[prop];
      if (!cur) return false;
      else if (cls == null) line[prop] = null;
      else {
        var upd = cur.replace(new RegExp("^" + cls + "\\b\\s*|\\s*\\b" + cls + "\\b"), "");
        if (upd == cur) return false;
        line[prop] = upd || null;
      }
      return true;
    });
  }),

  addLineWidget: operation(null, function(handle, node, options) {
    return addLineWidget(this, handle, node, options);
  }),

  removeLineWidget: function(widget) { widget.clear(); },

  lineInfo: function(line) {
    if (typeof line == "number") {
      if (!isLine(this.doc, line)) return null;
      var n = line;
      line = getLine(this.doc, line);
      if (!line) return null;
    } else {
      var 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};
  },

  getViewport: function() { return {from: this.display.showingFrom, to: this.display.showingTo};},

  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";
    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 + paddingTop(display)) + "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, top, left + node.offsetWidth, top + node.offsetHeight);
  },

  triggerOnKeyDown: operation(null, onKeyDown),

  execCommand: function(cmd) {return commands[cmd](this);},

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

  moveH: operation(null, function(dir, unit) {
    var sel = this.doc.sel, pos;
    if (sel.shift || sel.extend || posEq(sel.from, sel.to))
      pos = findPosH(this.doc, sel.head, dir, unit, this.options.rtlMoveVisually);
    else
      pos = dir < 0 ? sel.from : sel.to;
    extendSelection(this.doc, pos, pos, dir);
  }),

  deleteH: operation(null, function(dir, unit) {
    var sel = this.doc.sel;
    if (!posEq(sel.from, sel.to)) replaceRange(this.doc, "", sel.from, sel.to, "+delete");
    else replaceRange(this.doc, "", sel.from, findPosH(this.doc, sel.head, dir, unit, false), "+delete");
    this.curOp.userSelChange = true;
  }),

  findPosV: function(from, amount, unit, goalColumn) {
    var dir = 1, x = goalColumn;
    if (amount < 0) { dir = -1; amount = -amount; }
    for (var i = 0, cur = clipPos(this.doc, from); 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: operation(null, function(dir, unit) {
    var sel = this.doc.sel;
    var pos = cursorCoords(this, sel.head, "div");
    if (sel.goalColumn != null) pos.left = sel.goalColumn;
    var target = findPosV(this, pos, dir, unit);

    if (unit == "page") addToScrollPos(this, 0, charCoords(this, target, "div").top - pos.top);
    extendSelection(this.doc, target, target, dir);
    sel.goalColumn = pos.left;
  }),

  toggleOverwrite: function(value) {
    if (value != null && value == this.state.overwrite) return;
    if (this.state.overwrite = !this.state.overwrite)
      this.display.cursor.className += " CodeMirror-overwrite";
    else
      this.display.cursor.className = this.display.cursor.className.replace(" CodeMirror-overwrite", "");
  },
  hasFocus: function() { return this.state.focused; },

  scrollTo: operation(null, function(x, y) {
    updateScrollPos(this, x, y);
  }),
  getScrollInfo: function() {
    var scroller = this.display.scroller, co = scrollerCutOff;
    return {left: scroller.scrollLeft, top: scroller.scrollTop,
            height: scroller.scrollHeight - co, width: scroller.scrollWidth - co,
            clientHeight: scroller.clientHeight - co, clientWidth: scroller.clientWidth - co};
  },

  scrollIntoView: operation(null, function(pos, margin) {
    if (typeof pos == "number") pos = Pos(pos, 0);
    if (!margin) margin = 0;
    var coords = pos;

    if (!pos || pos.line != null) {
      this.curOp.scrollToPos = pos ? clipPos(this.doc, pos) : this.doc.sel.head;
      this.curOp.scrollToPosMargin = margin;
      coords = cursorCoords(this, this.curOp.scrollToPos);
    }
    var sPos = calculateScrollPos(this, coords.left, coords.top - margin, coords.right, coords.bottom + margin);
    updateScrollPos(this, sPos.scrollLeft, sPos.scrollTop);
  }),

  setSize: function(width, height) {
    function interpret(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);
    this.refresh();
  },

  on: function(type, f) {on(this, type, f);},
  off: function(type, f) {off(this, type, f);},

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

  refresh: operation(null, function() {
    clearCaches(this);
    updateScrollPos(this, this.doc.scrollLeft, this.doc.scrollTop);
    regChange(this);
  }),

  swapDoc: operation(null, function(doc) {
    var old = this.doc;
    old.cm = null;
    attachDoc(this, doc);
    clearCaches(this);
    resetInput(this, true);
    updateScrollPos(this, doc.scrollLeft, doc.scrollTop);
    return old;
  }),

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

// OPTION DEFAULTS

var optionHandlers = CodeMirror.optionHandlers = {};

// The default configuration options.
var defaults = CodeMirror.defaults = {};

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;
}

var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.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) {
  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) {
  loadMode(cm);
  clearCaches(cm);
  regChange(cm);
}, true);
option("electricChars", true);
option("rtlMoveVisually", !windows);

option("theme", "default", function(cm) {
  themeChanged(cm);
  guttersChanged(cm);
}, true);
option("keyMap", "default", keyMapChanged);
option("extraKeys", null);

option("onKeyEvent", null);
option("onDragEvent", null);

option("lineWrapping", false, wrappingChanged, true);
option("gutters", [], function(cm) {
  setGuttersForLineNumbers(cm.options);
  guttersChanged(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, updateScrollbars, true);
option("lineNumbers", false, function(cm) {
  setGuttersForLineNumbers(cm.options);
  guttersChanged(cm);
}, true);
option("firstLineNumber", 1, guttersChanged, true);
option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);
option("showCursorWhenSelecting", false, updateSelection, true);

option("readOnly", false, function(cm, val) {
  if (val == "nocursor") {onBlur(cm); cm.display.input.blur();}
  else if (!val) resetInput(cm, true);
});
option("dragDrop", true);

option("cursorBlinkRate", 530);
option("cursorScrollMargin", 0);
option("cursorHeight", 1);
option("workTime", 100);
option("workDelay", 100);
option("flattenSpans", true);
option("pollInterval", 100);
option("undoDepth", 40, function(cm, val){cm.doc.history.undoDepth = val;});
option("historyEventDelay", 500);
option("viewportMargin", 10, function(cm){cm.refresh();}, true);
option("maxHighlightLength", 10000, function(cm){loadMode(cm); cm.refresh();}, true);
option("moveInputWithCursor", true, function(cm, val) {
  if (!val) cm.display.inputDiv.style.top = cm.display.inputDiv.style.left = 0;
});

option("tabindex", null, function(cm, val) {
  cm.display.input.tabIndex = val || "";
});
option("autofocus", null);

// MODE DEFINITION AND QUERYING

// Known modes, by name and by MIME
var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};

CodeMirror.defineMode = function(name, mode) {
  if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;
  if (arguments.length > 2) {
    mode.dependencies = [];
    for (var i = 2; i < arguments.length; ++i) mode.dependencies.push(arguments[i]);
  }
  modes[name] = mode;
};

CodeMirror.defineMIME = function(mime, spec) {
  mimeModes[mime] = spec;
};

CodeMirror.resolveMode = function(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];
    spec = createObj(found, spec);
    spec.name = found.name;
  } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
    return CodeMirror.resolveMode("application/xml");
  }
  if (typeof spec == "string") return {name: spec};
  else return spec || {name: "null"};
};

CodeMirror.getMode = function(options, spec) {
  spec = CodeMirror.resolveMode(spec);
  var mfactory = modes[spec.name];
  if (!mfactory) return CodeMirror.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;
  return modeObj;
};

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

var modeExtensions = CodeMirror.modeExtensions = {};
CodeMirror.extendMode = function(mode, properties) {
  var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
  copyObj(properties, exts);
};

// EXTENSIONS

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

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

// MODE STATE HANDLING

// Utility functions for working with state. Exported because modes
// sometimes need to do this.
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;
}
CodeMirror.copyState = copyState;

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

CodeMirror.innerMode = function(mode, state) {
  while (mode.innerMode) {
    var info = mode.innerMode(state);
    state = info.state;
    mode = info.mode;
  }
  return info || {mode: mode, state: state};
};

// STANDARD COMMANDS

var commands = CodeMirror.commands = {
  selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()));},
  killLine: function(cm) {
    var from = cm.getCursor(true), to = cm.getCursor(false), sel = !posEq(from, to);
    if (!sel && cm.getLine(from.line).length == from.ch)
      cm.replaceRange("", from, Pos(from.line + 1, 0), "+delete");
    else cm.replaceRange("", from, sel ? to : Pos(from.line), "+delete");
  },
  deleteLine: function(cm) {
    var l = cm.getCursor().line;
    cm.replaceRange("", Pos(l, 0), Pos(l), "+delete");
  },
  undo: function(cm) {cm.undo();},
  redo: function(cm) {cm.redo();},
  goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},
  goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},
  goLineStart: function(cm) {
    cm.extendSelection(lineStart(cm, cm.getCursor().line));
  },
  goLineStartSmart: function(cm) {
    var cur = cm.getCursor(), start = lineStart(cm, cur.line);
    var line = cm.getLineHandle(start.line);
    var order = getOrder(line);
    if (!order || order[0].level == 0) {
      var firstNonWS = Math.max(0, line.text.search(/\S/));
      var inWS = cur.line == start.line && cur.ch <= firstNonWS && cur.ch;
      cm.extendSelection(Pos(start.line, inWS ? 0 : firstNonWS));
    } else cm.extendSelection(start);
  },
  goLineEnd: function(cm) {
    cm.extendSelection(lineEnd(cm, cm.getCursor().line));
  },
  goLineRight: function(cm) {
    var top = cm.charCoords(cm.getCursor(), "div").top + 5;
    cm.extendSelection(cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div"));
  },
  goLineLeft: function(cm) {
    var top = cm.charCoords(cm.getCursor(), "div").top + 5;
    cm.extendSelection(cm.coordsChar({left: 0, top: top}, "div"));
  },
  goLineUp: function(cm) {cm.moveV(-1, "line");},
  goLineDown: function(cm) {cm.moveV(1, "line");},
  goPageUp: function(cm) {cm.moveV(-1, "page");},
  goPageDown: function(cm) {cm.moveV(1, "page");},
  goCharLeft: function(cm) {cm.moveH(-1, "char");},
  goCharRight: function(cm) {cm.moveH(1, "char");},
  goColumnLeft: function(cm) {cm.moveH(-1, "column");},
  goColumnRight: function(cm) {cm.moveH(1, "column");},
  goWordLeft: function(cm) {cm.moveH(-1, "word");},
  goGroupRight: function(cm) {cm.moveH(1, "group");},
  goGroupLeft: function(cm) {cm.moveH(-1, "group");},
  goWordRight: function(cm) {cm.moveH(1, "word");},
  delCharBefore: function(cm) {cm.deleteH(-1, "char");},
  delCharAfter: function(cm) {cm.deleteH(1, "char");},
  delWordBefore: function(cm) {cm.deleteH(-1, "word");},
  delWordAfter: function(cm) {cm.deleteH(1, "word");},
  delGroupBefore: function(cm) {cm.deleteH(-1, "group");},
  delGroupAfter: function(cm) {cm.deleteH(1, "group");},
  indentAuto: function(cm) {cm.indentSelection("smart");},
  indentMore: function(cm) {cm.indentSelection("add");},
  indentLess: function(cm) {cm.indentSelection("subtract");},
  insertTab: function(cm) {cm.replaceSelection("\t", "end", "+input");},
  defaultTab: function(cm) {
    if (cm.somethingSelected()) cm.indentSelection("add");
    else cm.replaceSelection("\t", "end", "+input");
  },
  transposeChars: function(cm) {
    var cur = cm.getCursor(), line = cm.getLine(cur.line);
    if (cur.ch > 0 && cur.ch < line.length - 1)
      cm.replaceRange(line.charAt(cur.ch) + line.charAt(cur.ch - 1),
                      Pos(cur.line, cur.ch - 1), Pos(cur.line, cur.ch + 1));
  },
  newlineAndIndent: function(cm) {
    operation(cm, function() {
      cm.replaceSelection("\n", "end", "+input");
      cm.indentLine(cm.getCursor().line, null, true);
    })();
  },
  toggleOverwrite: function(cm) {cm.toggleOverwrite();}
};

// STANDARD KEYMAPS

var keyMap = CodeMirror.keyMap = {};
keyMap.basic = {
  "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
  "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
  "Delete": "delCharAfter", "Backspace": "delCharBefore", "Tab": "defaultTab", "Shift-Tab": "indentAuto",
  "Enter": "newlineAndIndent", "Insert": "toggleOverwrite"
};
// Note that the save and find-related commands aren't defined by
// default. 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", "Alt-Up": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Down": "goDocEnd",
  "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",
  fallthrough: "basic"
};
keyMap.macDefault = {
  "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
  "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
  "Alt-Right": "goGroupRight", "Cmd-Left": "goLineStart", "Cmd-Right": "goLineEnd", "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",
  fallthrough: ["basic", "emacsy"]
};
keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;
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"
};

// KEYMAP DISPATCH

function getKeyMap(val) {
  if (typeof val == "string") return keyMap[val];
  else return val;
}

function lookupKey(name, maps, handle) {
  function lookup(map) {
    map = getKeyMap(map);
    var found = map[name];
    if (found === false) return "stop";
    if (found != null && handle(found)) return true;
    if (map.nofallthrough) return "stop";

    var fallthrough = map.fallthrough;
    if (fallthrough == null) return false;
    if (Object.prototype.toString.call(fallthrough) != "[object Array]")
      return lookup(fallthrough);
    for (var i = 0, e = fallthrough.length; i < e; ++i) {
      var done = lookup(fallthrough[i]);
      if (done) return done;
    }
    return false;
  }

  for (var i = 0; i < maps.length; ++i) {
    var done = lookup(maps[i]);
    if (done) return done;
  }
}
function isModifierKey(event) {
  var name = keyNames[event.keyCode];
  return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
}
function keyName(event, noShift) {
  if (opera && event.keyCode == 34 && event["char"]) return false;
  var name = keyNames[event.keyCode];
  if (name == null || event.altGraphKey) return false;
  if (event.altKey) name = "Alt-" + name;
  if (flipCtrlCmd ? event.metaKey : event.ctrlKey) name = "Ctrl-" + name;
  if (flipCtrlCmd ? event.ctrlKey : event.metaKey) name = "Cmd-" + name;
  if (!noShift && event.shiftKey) name = "Shift-" + name;
  return name;
}
CodeMirror.lookupKey = lookupKey;
CodeMirror.isModifierKey = isModifierKey;
CodeMirror.keyName = keyName;

// FROMTEXTAREA

CodeMirror.fromTextArea = function(textarea, options) {
  if (!options) 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 = document.body;
    // doc.activeElement occasionally throws on IE
    try { hasFocus = document.activeElement; } catch(e) {}
    options.autofocus = hasFocus == textarea ||
      textarea.getAttribute("autofocus") != null && hasFocus == document.body;
  }

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

  textarea.style.display = "none";
  var cm = CodeMirror(function(node) {
    textarea.parentNode.insertBefore(node, textarea.nextSibling);
  }, options);
  cm.save = save;
  cm.getTextArea = function() { return textarea; };
  cm.toTextArea = function() {
    save();
    textarea.parentNode.removeChild(cm.getWrapperElement());
    textarea.style.display = "";
    if (textarea.form) {
      off(textarea.form, "submit", save);
      if (typeof textarea.form.submit == "function")
        textarea.form.submit = realSubmit;
    }
  };
  return cm;
};

// STRING STREAM

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

// The character stream used by a mode's parser.
function StringStream(string, tabSize) {
  this.pos = this.start = 0;
  this.string = string;
  this.tabSize = tabSize || 8;
  this.lastColumnPos = this.lastColumnValue = 0;
}

StringStream.prototype = {
  eol: function() {return this.pos >= this.string.length;},
  sol: function() {return this.pos == 0;},
  peek: function() {return this.string.charAt(this.pos) || undefined;},
  next: function() {
    if (this.pos < this.string.length)
      return this.string.charAt(this.pos++);
  },
  eat: function(match) {
    var ch = this.string.charAt(this.pos);
    if (typeof match == "string") var ok = ch == match;
    else var ok = ch && (match.test ? match.test(ch) : match(ch));
    if (ok) {++this.pos; return ch;}
  },
  eatWhile: function(match) {
    var start = this.pos;
    while (this.eat(match)){}
    return this.pos > start;
  },
  eatSpace: function() {
    var start = this.pos;
    while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;
    return this.pos > start;
  },
  skipToEnd: function() {this.pos = this.string.length;},
  skipTo: function(ch) {
    var found = this.string.indexOf(ch, this.pos);
    if (found > -1) {this.pos = found; return true;}
  },
  backUp: function(n) {this.pos -= n;},
  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;
  },
  indentation: function() {return countColumn(this.string, null, this.tabSize);},
  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;
    }
  },
  current: function(){return this.string.slice(this.start, this.pos);}
};
CodeMirror.StringStream = StringStream;

// TEXTMARKERS

function TextMarker(doc, type) {
  this.lines = [];
  this.type = type;
  this.doc = doc;
}
CodeMirror.TextMarker = TextMarker;

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

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

TextMarker.prototype.find = function() {
  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 || span.to != null) {
      var found = lineNo(line);
      if (span.from != null) from = Pos(found, span.from);
      if (span.to != null) to = Pos(found, span.to);
    }
  }
  if (this.type == "bookmark") return from;
  return from && {from: from, to: to};
};

TextMarker.prototype.changed = function() {
  var pos = this.find(), cm = this.doc.cm;
  if (!pos || !cm) return;
  var line = getLine(this.doc, pos.from.line);
  clearCachedMeasurement(cm, line);
  if (pos.from.line >= cm.display.showingFrom && pos.from.line < cm.display.showingTo) {
    for (var node = cm.display.lineDiv.firstChild; node; node = node.nextSibling) if (node.lineObj == line) {
      if (node.offsetHeight != line.height) updateLineHeight(line, node.offsetHeight);
      break;
    }
    runInOp(cm, function() { cm.curOp.selectionChanged = true; });
  }
};

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);
  }
};

function markText(doc, from, to, options, type) {
  if (options && options.shared) return markTextShared(doc, from, to, options, type);
  if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);

  var marker = new TextMarker(doc, type);
  if (type == "range" && !posLess(from, to)) return marker;
  if (options) copyObj(options, marker);
  if (marker.replacedWith) {
    marker.collapsed = true;
    marker.replacedWith = elt("span", [marker.replacedWith], "CodeMirror-widget");
  }
  if (marker.collapsed) sawCollapsedSpans = true;

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

  var curLine = from.line, size = 0, collapsedAtStart, collapsedAtEnd, cm = doc.cm, updateMaxLine;
  doc.iter(curLine, to.line + 1, function(line) {
    if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(doc, line) == cm.display.maxLine)
      updateMaxLine = true;
    var span = {from: null, to: null, marker: marker};
    size += line.text.length;
    if (curLine == from.line) {span.from = from.ch; size -= from.ch;}
    if (curLine == to.line) {span.to = to.ch; size -= line.text.length - to.ch;}
    if (marker.collapsed) {
      if (curLine == to.line) collapsedAtEnd = collapsedSpanAt(line, to.ch);
      if (curLine == from.line) collapsedAtStart = collapsedSpanAt(line, from.ch);
      else updateLineHeight(line, 0);
    }
    addMarkedSpan(line, span);
    ++curLine;
  });
  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() { marker.clear(); });

  if (marker.readOnly) {
    sawReadOnlySpans = true;
    if (doc.history.done.length || doc.history.undone.length)
      doc.clearHistory();
  }
  if (marker.collapsed) {
    if (collapsedAtStart != collapsedAtEnd)
      throw new Error("Inserting collapsed marker overlapping an existing one");
    marker.size = size;
    marker.atomic = true;
  }
  if (cm) {
    if (updateMaxLine) cm.curOp.updateMaxLine = true;
    if (marker.className || marker.startStyle || marker.endStyle || marker.collapsed)
      regChange(cm, from.line, to.line + 1);
    if (marker.atomic) reCheckSelection(cm);
  }
  return marker;
}

// SHARED TEXTMARKERS

function SharedTextMarker(markers, primary) {
  this.markers = markers;
  this.primary = primary;
  for (var i = 0, me = this; i < markers.length; ++i) {
    markers[i].parent = this;
    on(markers[i], "clear", function(){me.clear();});
  }
}
CodeMirror.SharedTextMarker = SharedTextMarker;

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() {
  return this.primary.find();
};

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.replacedWith;
  linkedDocs(doc, function(doc) {
    if (widget) options.replacedWith = 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);
}

// TEXTMARKER SPANS

function getMarkedSpanFor(spans, marker) {
  if (spans) for (var i = 0; i < spans.length; ++i) {
    var span = spans[i];
    if (span.marker == marker) return span;
  }
}
function removeMarkedSpan(spans, span) {
  for (var r, i = 0; i < spans.length; ++i)
    if (spans[i] != span) (r || (r = [])).push(spans[i]);
  return r;
}
function addMarkedSpan(line, span) {
  line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
  span.marker.attachLine(line);
}

function markedSpansBefore(old, startCh, isInsert) {
  if (old) for (var i = 0, nw; 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 || marker.type == "bookmark" && span.from == startCh && (!isInsert || !span.marker.insertLeft)) {
      var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);
      (nw || (nw = [])).push({from: span.from,
                              to: endsAfter ? null : span.to,
                              marker: marker});
    }
  }
  return nw;
}

function markedSpansAfter(old, endCh, isInsert) {
  if (old) for (var i = 0, nw; 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 || marker.type == "bookmark" && span.from == endCh && (!isInsert || span.marker.insertLeft)) {
      var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);
      (nw || (nw = [])).push({from: startsBefore ? null : span.from - endCh,
                              to: span.to == null ? null : span.to - endCh,
                              marker: marker});
    }
  }
  return nw;
}

function stretchSpansOverChange(doc, change) {
  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 = posEq(change.from, change.to);
  // 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 = 0; i < last.length; ++i) {
      var span = last[i];
      if (span.to != null) span.to += offset;
      if (span.from == null) {
        var found = getMarkedSpanFor(first, span.marker);
        if (!found) {
          span.from = offset;
          if (sameLine) (first || (first = [])).push(span);
        }
      } else {
        span.from += offset;
        if (sameLine) (first || (first = [])).push(span);
      }
    }
  }

  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 = 0; i < first.length; ++i)
        if (first[i].to == null)
          (gapMarkers || (gapMarkers = [])).push({from: null, to: null, marker: first[i].marker});
    for (var i = 0; i < gap; ++i)
      newMarkers.push(gapMarkers);
    newMarkers.push(last);
  }
  return newMarkers;
}

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;
}

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();
    for (var j = 0; j < parts.length; ++j) {
      var p = parts[j];
      if (posLess(p.to, m.from) || posLess(m.to, p.from)) continue;
      var newParts = [j, 1];
      if (posLess(p.from, m.from) || !mk.inclusiveLeft && posEq(p.from, m.from))
        newParts.push({from: p.from, to: m.from});
      if (posLess(m.to, p.to) || !mk.inclusiveRight && posEq(p.to, m.to))
        newParts.push({from: m.to, to: p.to});
      parts.splice.apply(parts, newParts);
      j += newParts.length - 1;
    }
  }
  return parts;
}

function collapsedSpanAt(line, ch) {
  var sps = sawCollapsedSpans && line.markedSpans, found;
  if (sps) for (var sp, i = 0; i < sps.length; ++i) {
    sp = sps[i];
    if (!sp.marker.collapsed) continue;
    if ((sp.from == null || sp.from < ch) &&
        (sp.to == null || sp.to > ch) &&
        (!found || found.width < sp.marker.width))
      found = sp.marker;
  }
  return found;
}
function collapsedSpanAtStart(line) { return collapsedSpanAt(line, -1); }
function collapsedSpanAtEnd(line) { return collapsedSpanAt(line, line.text.length + 1); }

function visualLine(doc, line) {
  var merged;
  while (merged = collapsedSpanAtStart(line))
    line = getLine(doc, merged.find().from.line);
  return line;
}

function lineIsHidden(doc, line) {
  var sps = sawCollapsedSpans && line.markedSpans;
  if (sps) for (var sp, i = 0; i < sps.length; ++i) {
    sp = sps[i];
    if (!sp.marker.collapsed) continue;
    if (sp.from == null) return true;
    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().to, endLine = getLine(doc, end.line);
    return lineIsHiddenInner(doc, endLine, getMarkedSpanFor(endLine.markedSpans, span.marker));
  }
  if (span.marker.inclusiveRight && span.to == line.text.length)
    return true;
  for (var sp, i = 0; i < line.markedSpans.length; ++i) {
    sp = line.markedSpans[i];
    if (sp.marker.collapsed && sp.from == span.to &&
        (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
        lineIsHiddenInner(doc, line, sp)) return true;
  }
}

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;
}

// LINE WIDGETS

var LineWidget = CodeMirror.LineWidget = function(cm, node, options) {
  for (var opt in options) if (options.hasOwnProperty(opt))
    this[opt] = options[opt];
  this.cm = cm;
  this.node = node;
};
function widgetOperation(f) {
  return function() {
    var withOp = !this.cm.curOp;
    if (withOp) startOperation(this.cm);
    try {var result = f.apply(this, arguments);}
    finally {if (withOp) endOperation(this.cm);}
    return result;
  };
}
LineWidget.prototype.clear = widgetOperation(function() {
  var ws = this.line.widgets, no = lineNo(this.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) this.line.widgets = null;
  updateLineHeight(this.line, Math.max(0, this.line.height - widgetHeight(this)));
  regChange(this.cm, no, no + 1);
});
LineWidget.prototype.changed = widgetOperation(function() {
  var oldH = this.height;
  this.height = null;
  var diff = widgetHeight(this) - oldH;
  if (!diff) return;
  updateLineHeight(this.line, this.line.height + diff);
  var no = lineNo(this.line);
  regChange(this.cm, no, no + 1);
});

function widgetHeight(widget) {
  if (widget.height != null) return widget.height;
  if (!widget.node.parentNode || widget.node.parentNode.nodeType != 1)
    removeChildrenAndAdd(widget.cm.display.measure, elt("div", [widget.node], null, "position: relative"));
  return widget.height = widget.node.offsetHeight;
}

function addLineWidget(cm, handle, node, options) {
  var widget = new LineWidget(cm, node, options);
  if (widget.noHScroll) cm.display.alignWidgets = true;
  changeLine(cm, handle, function(line) {
    (line.widgets || (line.widgets = [])).push(widget);
    widget.line = line;
    if (!lineIsHidden(cm.doc, line) || widget.showIfHidden) {
      var aboveVisible = heightAtLine(cm, line) < cm.display.scroller.scrollTop;
      updateLineHeight(line, line.height + widgetHeight(widget));
      if (aboveVisible) addToScrollPos(cm, 0, widget.height);
    }
    return true;
  });
  return widget;
}

// LINE DATA STRUCTURE

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

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);
}

function cleanUpLine(line) {
  line.parent = null;
  detachMarkedSpans(line);
}

// Run the given mode's parser over a line, update the styles
// array, which contains alternating fragments of text and CSS
// classes.
function runMode(cm, text, mode, state, f) {
  var flattenSpans = mode.flattenSpans;
  if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;
  var curText = "", curStyle = null;
  var stream = new StringStream(text, cm.options.tabSize), style;
  if (text == "" && mode.blankLine) mode.blankLine(state);
  while (!stream.eol()) {
    if (stream.pos > cm.options.maxHighlightLength) {
      flattenSpans = false;
      // Webkit seems to refuse to render text nodes longer than 57444 characters
      stream.pos = Math.min(text.length, stream.start + 50000);
      style = null;
    } else {
      style = mode.token(stream, state);
    }
    var substr = stream.current();
    stream.start = stream.pos;
    if (!flattenSpans || curStyle != style) {
      if (curText) f(curText, curStyle);
      curText = substr; curStyle = style;
    } else curText = curText + substr;
  }
  if (curText) f(curText, curStyle);
}

function highlightLine(cm, line, state) {
  // 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];
  // Compute the base array of styles
  runMode(cm, line.text, cm.doc.mode, state, function(txt, style) {st.push(txt, style);});

  // Run overlays, adjust style array.
  for (var o = 0; o < cm.state.overlays.length; ++o) {
    var overlay = cm.state.overlays[o], i = 1;
    runMode(cm, line.text, overlay.mode, true, function(txt, style) {
      var start = i, len = txt.length;
      // Ensure there's a token end at the current position, and that i points at it
      while (len) {
        var cur = st[i], len_ = cur.length;
        if (len_ <= len) {
          len -= len_;
        } else {
          st.splice(i, 1, cur.slice(0, len), st[i+1], cur.slice(len));
          len = 0;
        }
        i += 2;
      }
      if (!style) return;
      if (overlay.opaque) {
        st.splice(start, i - start, txt, style);
        i = start + 2;
      } else {
        for (; start < i; start += 2) {
          var cur = st[start+1];
          st[start+1] = cur ? cur + " " + style : style;
        }
      }
    });
  }

  return st;
}

function getLineStyles(cm, line) {
  if (!line.styles || line.styles[0] != cm.state.modeGen)
    line.styles = highlightLine(cm, line, line.stateAfter = getStateBefore(cm, lineNo(line)));
  return line.styles;
}

// Lightweight form of highlight -- proceed over this line and
// update state, but don't save a style array.
function processLine(cm, line, state) {
  var mode = cm.doc.mode;
  var stream = new StringStream(line.text, cm.options.tabSize);
  if (line.text == "" && mode.blankLine) mode.blankLine(state);
  while (!stream.eol() && stream.pos <= cm.options.maxHighlightLength) {
    mode.token(stream, state);
    stream.start = stream.pos;
  }
}

var styleToClassCache = {};
function styleToClass(style) {
  if (!style) return null;
  return styleToClassCache[style] ||
    (styleToClassCache[style] = "cm-" + style.replace(/ +/g, " cm-"));
}

function lineContent(cm, realLine, measure) {
  var merged, line = realLine, lineBefore, sawBefore, simple = true;
  while (merged = collapsedSpanAtStart(line)) {
    simple = false;
    line = getLine(cm.doc, merged.find().from.line);
    if (!lineBefore) lineBefore = line;
  }

  var builder = {pre: elt("pre"), col: 0, pos: 0, display: !measure,
                 measure: null, addedOne: false, cm: cm};
  if (line.textClass) builder.pre.className = line.textClass;

  do {
    builder.measure = line == realLine && measure;
    builder.pos = 0;
    builder.addToken = builder.measure ? buildTokenMeasure : buildToken;
    if ((ie || webkit) && cm.getOption("lineWrapping"))
      builder.addToken = buildTokenSplitSpaces(builder.addToken);
    if (measure && sawBefore && line != realLine && !builder.addedOne) {
      measure[0] = builder.pre.appendChild(zeroWidthElement(cm.display.measure));
      builder.addedOne = true;
    }
    var next = insertLineContent(line, builder, getLineStyles(cm, line));
    sawBefore = line == lineBefore;
    if (next) {
      line = getLine(cm.doc, next.to.line);
      simple = false;
    }
  } while (next);

  if (measure && !builder.addedOne)
    measure[0] = builder.pre.appendChild(simple ? elt("span", "\u00a0") : zeroWidthElement(cm.display.measure));
  if (!builder.pre.firstChild && !lineIsHidden(cm.doc, realLine))
    builder.pre.appendChild(document.createTextNode("\u00a0"));

  var order;
  // Work around problem with the reported dimensions of single-char
  // direction spans on IE (issue #1129). See also the comment in
  // cursorCoords.
  if (measure && ie && (order = getOrder(line))) {
    var l = order.length - 1;
    if (order[l].from == order[l].to) --l;
    var last = order[l], prev = order[l - 1];
    if (last.from + 1 == last.to && prev && last.level < prev.level) {
      var span = measure[builder.pos - 1];
      if (span) span.parentNode.insertBefore(span.measureRight = zeroWidthElement(cm.display.measure),
                                             span.nextSibling);
    }
  }

  signal(cm, "renderLine", cm, realLine, builder.pre);
  return builder.pre;
}

var tokenSpecialChars = /[\t\u0000-\u0019\u00ad\u200b\u2028\u2029\uFEFF]/g;
function buildToken(builder, text, style, startStyle, endStyle) {
  if (!text) return;
  if (!tokenSpecialChars.test(text)) {
    builder.col += text.length;
    var content = document.createTextNode(text);
  } else {
    var content = document.createDocumentFragment(), pos = 0;
    while (true) {
      tokenSpecialChars.lastIndex = pos;
      var m = tokenSpecialChars.exec(text);
      var skipped = m ? m.index - pos : text.length - pos;
      if (skipped) {
        content.appendChild(document.createTextNode(text.slice(pos, pos + skipped)));
        builder.col += skipped;
      }
      if (!m) break;
      pos += skipped + 1;
      if (m[0] == "\t") {
        var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
        content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
        builder.col += tabWidth;
      } else {
        var token = elt("span", "\u2022", "cm-invalidchar");
        token.title = "\\u" + m[0].charCodeAt(0).toString(16);
        content.appendChild(token);
        builder.col += 1;
      }
    }
  }
  if (style || startStyle || endStyle || builder.measure) {
    var fullStyle = style || "";
    if (startStyle) fullStyle += startStyle;
    if (endStyle) fullStyle += endStyle;
    return builder.pre.appendChild(elt("span", [content], fullStyle));
  }
  builder.pre.appendChild(content);
}

function buildTokenMeasure(builder, text, style, startStyle, endStyle) {
  var wrapping = builder.cm.options.lineWrapping;
  for (var i = 0; i < text.length; ++i) {
    var ch = text.charAt(i), start = i == 0;
    if (ch >= "\ud800" && ch < "\udbff" && i < text.length - 1) {
      ch = text.slice(i, i + 2);
      ++i;
    } else if (i && wrapping && spanAffectsWrapping(text, i)) {
      builder.pre.appendChild(elt("wbr"));
    }
    var span = builder.measure[builder.pos] =
      buildToken(builder, ch, style,
                 start && startStyle, i == text.length - 1 && endStyle);
    // In IE single-space nodes wrap differently than spaces
    // embedded in larger text nodes, except when set to
    // white-space: normal (issue #1268).
    if (ie && wrapping && ch == " " && i && !/\s/.test(text.charAt(i - 1)) &&
        i < text.length - 1 && !/\s/.test(text.charAt(i + 1)))
      span.style.whiteSpace = "normal";
    builder.pos += ch.length;
  }
  if (text.length) builder.addedOne = true;
}

function buildTokenSplitSpaces(inner) {
  function split(old) {
    var out = " ";
    for (var i = 0; i < old.length - 2; ++i) out += i % 2 ? " " : "\u00a0";
    out += " ";
    return out;
  }
  return function(builder, text, style, startStyle, endStyle) {
    return inner(builder, text.replace(/ {3,}/, split), style, startStyle, endStyle);
  };
}

function buildCollapsedSpan(builder, size, widget) {
  if (widget) {
    if (!builder.display) widget = widget.cloneNode(true);
    builder.pre.appendChild(widget);
    if (builder.measure && size) {
      builder.measure[builder.pos] = widget;
      builder.addedOne = true;
    }
  }
  builder.pos += size;
}

// 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;
  if (!spans) {
    for (var i = 1; i < styles.length; i+=2)
      builder.addToken(builder, styles[i], styleToClass(styles[i+1]));
    return;
  }

  var allText = line.text, len = allText.length;
  var pos = 0, i = 1, text = "", style;
  var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, collapsed;
  for (;;) {
    if (nextChange == pos) { // Update current marker set
      spanStyle = spanEndStyle = spanStartStyle = "";
      collapsed = null; nextChange = Infinity;
      var foundBookmark = null;
      for (var j = 0; j < spans.length; ++j) {
        var sp = spans[j], m = sp.marker;
        if (sp.from <= pos && (sp.to == null || sp.to > pos)) {
          if (sp.to != null && nextChange > sp.to) { nextChange = sp.to; spanEndStyle = ""; }
          if (m.className) spanStyle += " " + m.className;
          if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;
          if (m.endStyle && sp.to == nextChange) spanEndStyle += " " + m.endStyle;
          if (m.collapsed && (!collapsed || collapsed.marker.width < m.width))
            collapsed = sp;
        } else if (sp.from > pos && nextChange > sp.from) {
          nextChange = sp.from;
        }
        if (m.type == "bookmark" && sp.from == pos && m.replacedWith)
          foundBookmark = m.replacedWith;
      }
      if (collapsed && (collapsed.from || 0) == pos) {
        buildCollapsedSpan(builder, (collapsed.to == null ? len : collapsed.to) - pos,
                           collapsed.from != null && collapsed.marker.replacedWith);
        if (collapsed.to == null) return collapsed.marker.find();
      }
      if (foundBookmark && !collapsed) buildCollapsedSpan(builder, 0, foundBookmark);
    }
    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 : "");
        }
        if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
        pos = end;
        spanStartStyle = "";
      }
      text = styles[i++]; style = styleToClass(styles[i++]);
    }
  }
}

// DOCUMENT DATA STRUCTURE

function updateDoc(doc, change, markedSpans, selAfter, estimateHeight) {
  function spansFor(n) {return markedSpans ? markedSpans[n] : null;}
  function update(line, text, spans) {
    updateLine(line, text, spans, estimateHeight);
    signalLater(line, "change", line, change);
  }

  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;

  // First adjust the line structure
  if (from.ch == 0 && to.ch == 0 && lastText == "") {
    // This is a whole-line replace. Treated specially to make
    // sure line objects move the way they are supposed to.
    for (var i = 0, e = text.length - 1, added = []; i < e; ++i)
      added.push(makeLine(text[i], spansFor(i), estimateHeight));
    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 {
      for (var added = [], i = 1, e = text.length - 1; i < e; ++i)
        added.push(makeLine(text[i], spansFor(i), estimateHeight));
      added.push(makeLine(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);
    }
  } 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);
    for (var i = 1, e = text.length - 1, added = []; i < e; ++i)
      added.push(makeLine(text[i], spansFor(i), estimateHeight));
    if (nlines > 1) doc.remove(from.line + 1, nlines - 1);
    doc.insert(from.line + 1, added);
  }

  signalLater(doc, "change", doc, change);
  setSelection(doc, selAfter.anchor, selAfter.head, null, true);
}

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

LeafChunk.prototype = {
  chunkSize: function() { return this.lines.length; },
  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);
  },
  collapse: function(lines) {
    lines.splice.apply(lines, [lines.length, 0].concat(this.lines));
  },
  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, e = lines.length; i < e; ++i) lines[i].parent = this;
  },
  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, e = children.length; i < e; ++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 (this.size - n < 25) {
      var lines = [];
      this.collapse(lines);
      this.children = [new LeafChunk(lines)];
      this.children[0].parent = this;
    }
  },
  collapse: function(lines) {
    for (var i = 0, e = this.children.length; i < e; ++i) this.children[i].collapse(lines);
  },
  insertInner: function(at, lines, height) {
    this.size += lines.length;
    this.height += height;
    for (var i = 0, e = this.children.length; i < e; ++i) {
      var child = this.children[i], sz = child.chunkSize();
      if (at <= sz) {
        child.insertInner(at, lines, height);
        if (child.lines && child.lines.length > 50) {
          while (child.lines.length > 50) {
            var spilled = child.lines.splice(child.lines.length - 25, 25);
            var newleaf = new LeafChunk(spilled);
            child.height -= newleaf.height;
            this.children.splice(i + 1, 0, newleaf);
            newleaf.parent = this;
          }
          this.maybeSpill();
        }
        break;
      }
      at -= sz;
    }
  },
  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, e = this.children.length; i < e; ++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;
    }
  }
};

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

  BranchChunk.call(this, [new LeafChunk([makeLine("", null)])]);
  this.first = firstLine;
  this.scrollTop = this.scrollLeft = 0;
  this.cantEdit = false;
  this.history = makeHistory();
  this.frontier = firstLine;
  var start = Pos(firstLine, 0);
  this.sel = {from: start, to: start, head: start, anchor: start, shift: false, extend: false, goalColumn: null};
  this.id = ++nextDocId;
  this.modeOption = mode;

  if (typeof text == "string") text = splitLines(text);
  updateDoc(this, {from: start, to: start, text: text}, null, {head: start, anchor: start});
};

Doc.prototype = createObj(BranchChunk.prototype, {
  constructor: Doc,
  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);
  },

  insert: function(at, lines) {
    var height = 0;
    for (var i = 0, e = lines.length; i < e; ++i) height += lines[i].height;
    this.insertInner(at - this.first, lines, height);
  },
  remove: function(at, n) { this.removeInner(at - this.first, n); },

  getValue: function(lineSep) {
    var lines = getLines(this, this.first, this.first + this.size);
    if (lineSep === false) return lines;
    return lines.join(lineSep || "\n");
  },
  setValue: 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: splitLines(code), origin: "setValue"},
               {head: top, anchor: top}, true);
  },
  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 || "\n");
  },

  getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},
  setLine: function(line, text) {
    if (isLine(this, line))
      replaceRange(this, text, Pos(line, 0), clipPos(this, Pos(line)));
  },
  removeLine: function(line) {
    if (line) replaceRange(this, "", clipPos(this, Pos(line - 1)), clipPos(this, Pos(line)));
    else replaceRange(this, "", Pos(0, 0), clipPos(this, Pos(1, 0)));
  },

  getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},
  getLineNumber: function(line) {return lineNo(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 sel = this.sel, pos;
    if (start == null || start == "head") pos = sel.head;
    else if (start == "anchor") pos = sel.anchor;
    else if (start == "end" || start === false) pos = sel.to;
    else pos = sel.from;
    return copyPos(pos);
  },
  somethingSelected: function() {return !posEq(this.sel.head, this.sel.anchor);},

  setCursor: docOperation(function(line, ch, extend) {
    var pos = clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line);
    if (extend) extendSelection(this, pos);
    else setSelection(this, pos, pos);
  }),
  setSelection: docOperation(function(anchor, head) {
    setSelection(this, clipPos(this, anchor), clipPos(this, head || anchor));
  }),
  extendSelection: docOperation(function(from, to) {
    extendSelection(this, clipPos(this, from), to && clipPos(this, to));
  }),

  getSelection: function(lineSep) {return this.getRange(this.sel.from, this.sel.to, lineSep);},
  replaceSelection: function(code, collapse, origin) {
    makeChange(this, {from: this.sel.from, to: this.sel.to, text: splitLines(code), origin: origin}, collapse || "around");
  },
  undo: docOperation(function() {makeChangeFromHistory(this, "undo");}),
  redo: docOperation(function() {makeChangeFromHistory(this, "redo");}),

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

  historySize: function() {
    var hist = this.history;
    return {undo: hist.done.length, redo: hist.undone.length};
  },
  clearHistory: function() {this.history = makeHistory();},

  markClean: function() {
    this.history.dirtyCounter = 0;
    this.history.lastOp = this.history.lastOrigin = null;
  },
  isClean: function () {return this.history.dirtyCounter == 0;},

  getHistory: function() {
    return {done: copyHistoryArray(this.history.done),
            undone: copyHistoryArray(this.history.undone)};
  },
  setHistory: function(histData) {
    var hist = this.history = makeHistory();
    hist.done = histData.done.slice(0);
    hist.undone = histData.undone.slice(0);
  },

  markText: function(from, to, options) {
    return markText(this, clipPos(this, from), clipPos(this, to), options, "range");
  },
  setBookmark: function(pos, options) {
    var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
                    insertLeft: options && options.insertLeft};
    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;
  },
  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;
    this.iter(function(line) {
      var sz = line.text.length + 1;
      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;
    this.iter(this.first, coords.line, function (line) {
      index += line.text.length + 1;
    });
    return index;
  },

  copy: function(copyHistory) {
    var doc = new Doc(getLines(this, this.first, this.first + this.size), this.modeOption, this.first);
    doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
    doc.sel = {from: this.sel.from, to: this.sel.to, head: this.sel.head, anchor: this.sel.anchor,
               shift: this.sel.shift, extend: false, goalColumn: this.sel.goalColumn};
    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);
    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}];
    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);
      break;
    }
    // If the histories were shared, split them again
    if (other.history == this.history) {
      var splitIds = [other.id];
      linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);
      other.history = makeHistory();
      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;}
});

Doc.prototype.eachLine = Doc.prototype.iter;

// The Doc methods that should be available on CodeMirror instances
var dontDelegate = "iter insert remove copy getEditor".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]);

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);
}

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);
  if (!cm.options.lineWrapping) computeMaxLength(cm);
  cm.options.mode = doc.modeOption;
  regChange(cm);
}

// LINE UTILITIES

function getLine(chunk, n) {
  n -= chunk.first;
  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];
}

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;
}
function getLines(doc, from, to) {
  var out = [];
  doc.iter(from, to, function(line) { out.push(line.text); });
  return out;
}

function updateLineHeight(line, height) {
  var diff = height - line.height;
  for (var n = line; n; n = n.parent) n.height += diff;
}

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;
}

function lineAtHeight(chunk, h) {
  var n = chunk.first;
  outer: do {
    for (var i = 0, e = chunk.children.length; i < e; ++i) {
      var child = chunk.children[i], ch = child.height;
      if (h < ch) { chunk = child; continue outer; }
      h -= ch;
      n += child.chunkSize();
    }
    return n;
  } while (!chunk.lines);
  for (var i = 0, e = chunk.lines.length; i < e; ++i) {
    var line = chunk.lines[i], lh = line.height;
    if (h < lh) break;
    h -= lh;
  }
  return n + i;
}

function heightAtLine(cm, lineObj) {
  lineObj = visualLine(cm.doc, 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 = 0; i < p.children.length; ++i) {
      var cur = p.children[i];
      if (cur == chunk) break;
      else h += cur.height;
    }
  }
  return h;
}

function getOrder(line) {
  var order = line.order;
  if (order == null) order = line.order = bidiOrdering(line.text);
  return order;
}

// HISTORY

function makeHistory() {
  return {
    // Arrays of history events. Doing something adds an event to
    // done and clears undo. Undoing moves events from done to
    // undone, redoing moves them in the other direction.
    done: [], undone: [], undoDepth: Infinity,
    // Used to track when changes can be merged into a single undo
    // event
    lastTime: 0, lastOp: null, lastOrigin: null,
    // Used by the isClean() method
    dirtyCounter: 0
  };
}

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;
  });
}

function historyChangeFromChange(doc, change) {
  var histChange = {from: 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) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);
  return histChange;
}

function addToHistory(doc, change, selAfter, opId) {
  var hist = doc.history;
  hist.undone.length = 0;
  var time = +new Date, cur = lst(hist.done);

  if (cur &&
      (hist.lastOp == opId ||
       hist.lastOrigin == change.origin && change.origin &&
       ((change.origin.charAt(0) == "+" && doc.cm && hist.lastTime > time - doc.cm.options.historyEventDelay) ||
        change.origin.charAt(0) == "*"))) {
    // Merge this change into the last event
    var last = lst(cur.changes);
    if (posEq(change.from, change.to) && posEq(change.from, last.to)) {
      // 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));
    }
    cur.anchorAfter = selAfter.anchor; cur.headAfter = selAfter.head;
  } else {
    // Can not be merged, start a new event.
    cur = {changes: [historyChangeFromChange(doc, change)],
           anchorBefore: doc.sel.anchor, headBefore: doc.sel.head,
           anchorAfter: selAfter.anchor, headAfter: selAfter.head};
    hist.done.push(cur);
    while (hist.done.length > hist.undoDepth)
      hist.done.shift();
    if (hist.dirtyCounter < 0)
      // The user has made a change after undoing past the last clean state.
      // We can never get back to a clean state now until markClean() is called.
      hist.dirtyCounter = NaN;
    else
      hist.dirtyCounter++;
  }
  hist.lastTime = time;
  hist.lastOp = opId;
  hist.lastOrigin = change.origin;
}

function removeClearedSpans(spans) {
  if (!spans) return null;
  for (var i = 0, out; 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;
}

function getOldSpans(doc, change) {
  var found = change["spans_" + doc.id];
  if (!found) return null;
  for (var i = 0, nw = []; i < change.text.length; ++i)
    nw.push(removeClearedSpans(found[i]));
  return nw;
}

// 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) {
  for (var i = 0, copy = []; i < events.length; ++i) {
    var event = events[i], changes = event.changes, newChanges = [];
    copy.push({changes: newChanges, anchorBefore: event.anchorBefore, headBefore: event.headBefore,
               anchorAfter: event.anchorAfter, headAfter: event.headAfter});
    for (var j = 0; j < changes.length; ++j) {
      var change = changes[j], m;
      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;
}

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

function rebaseHistSel(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;
    for (var j = 0; j < sub.changes.length; ++j) {
      var cur = sub.changes[j];
      if (!sub.copied) { cur.from = copyPos(cur.from); cur.to = copyPos(cur.to); }
      if (to < cur.from.line) {
        cur.from.line += diff;
        cur.to.line += diff;
      } else if (from <= cur.to.line) {
        ok = false;
        break;
      }
    }
    if (!sub.copied) {
      sub.anchorBefore = copyPos(sub.anchorBefore); sub.headBefore = copyPos(sub.headBefore);
      sub.anchorAfter = copyPos(sub.anchorAfter); sub.readAfter = copyPos(sub.headAfter);
      sub.copied = true;
    }
    if (!ok) {
      array.splice(0, i + 1);
      i = 0;
    } else {
      rebaseHistSel(sub.anchorBefore); rebaseHistSel(sub.headBefore);
      rebaseHistSel(sub.anchorAfter); rebaseHistSel(sub.headAfter);
    }
  }
}

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);
}

// EVENT OPERATORS

function stopMethod() {e_stop(this);}
// Ensure an event has a stop method.
function addStop(event) {
  if (!event.stop) event.stop = stopMethod;
  return event;
}

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_stop(e) {e_preventDefault(e); e_stopPropagation(e);}
CodeMirror.e_stop = e_stop;
CodeMirror.e_preventDefault = e_preventDefault;
CodeMirror.e_stopPropagation = e_stopPropagation;

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;
}

// EVENT HANDLING

function on(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 = {});
    var arr = map[type] || (map[type] = []);
    arr.push(f);
  }
}

function off(emitter, type, f) {
  if (emitter.removeEventListener)
    emitter.removeEventListener(type, f, false);
  else if (emitter.detachEvent)
    emitter.detachEvent("on" + type, f);
  else {
    var arr = emitter._handlers && emitter._handlers[type];
    if (!arr) return;
    for (var i = 0; i < arr.length; ++i)
      if (arr[i] == f) { arr.splice(i, 1); break; }
  }
}

function signal(emitter, type /*, values...*/) {
  var arr = emitter._handlers && emitter._handlers[type];
  if (!arr) return;
  var args = Array.prototype.slice.call(arguments, 2);
  for (var i = 0; i < arr.length; ++i) arr[i].apply(null, args);
}

var delayedCallbacks, delayedCallbackDepth = 0;
function signalLater(emitter, type /*, values...*/) {
  var arr = emitter._handlers && emitter._handlers[type];
  if (!arr) return;
  var args = Array.prototype.slice.call(arguments, 2);
  if (!delayedCallbacks) {
    ++delayedCallbackDepth;
    delayedCallbacks = [];
    setTimeout(fireDelayed, 0);
  }
  function bnd(f) {return function(){f.apply(null, args);};};
  for (var i = 0; i < arr.length; ++i)
    delayedCallbacks.push(bnd(arr[i]));
}

function fireDelayed() {
  --delayedCallbackDepth;
  var delayed = delayedCallbacks;
  delayedCallbacks = null;
  for (var i = 0; i < delayed.length; ++i) delayed[i]();
}

function hasHandler(emitter, type) {
  var arr = emitter._handlers && emitter._handlers[type];
  return arr && arr.length > 0;
}

CodeMirror.on = on; CodeMirror.off = off; CodeMirror.signal = signal;

// MISC UTILITIES

// Number of pixels added to scroller and sizer to hide scrollbar
var scrollerCutOff = 30;

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

function Delayed() {this.id = null;}
Delayed.prototype = {set: function(ms, f) {clearTimeout(this.id); this.id = setTimeout(f, ms);}};

// 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; i < end; ++i) {
    if (string.charAt(i) == "\t") n += tabSize - (n % tabSize);
    else ++n;
  }
  return n;
}
CodeMirror.countColumn = countColumn;

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 selectInput(node) {
  if (ios) { // Mobile Safari apparently has a bug where select() is broken.
    node.selectionStart = 0;
    node.selectionEnd = node.value.length;
  } else node.select();
}

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

function createObj(base, props) {
  function Obj() {}
  Obj.prototype = base;
  var inst = new Obj();
  if (props) copyObj(props, inst);
  return inst;
}

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

function emptyArray(size) {
  for (var a = [], i = 0; i < size; ++i) a.push(undefined);
  return a;
}

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

var nonASCIISingleCaseWordChar = /[\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
function isWordChar(ch) {
  return /\w/.test(ch) || ch > "\x80" &&
    (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));
}

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

var isExtendingChar = /[\u0300-\u036F\u0483-\u0487\u0488-\u0489\u0591-\u05BD\u05BF\u05C1-\u05C2\u05C4-\u05C5\u05C7\u0610-\u061A\u064B-\u065F\u0670\u06D6-\u06DC\u06DF-\u06E4\u06E7-\u06E8\u06EA-\u06ED\uA66F\uA670-\uA672\uA674-\uA67D\uA69F\udc00-\udfff]/;

// DOM UTILITIES

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") setTextContent(e, content);
  else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
  return e;
}

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 setTextContent(e, str) {
  if (ie_lt9) {
    e.innerHTML = "";
    e.appendChild(document.createTextNode(str));
  } else e.textContent = str;
}

function getRect(node) {
  return node.getBoundingClientRect();
}
CodeMirror.replaceGetRect = function(f) { getRect = f; };

// FEATURE DETECTION

// 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_lt9) return false;
  var div = elt('div');
  return "draggable" in div || "dragDrop" in div;
}();

// For a reason I have yet to figure out, some browsers disallow
// word wrapping between certain characters *only* if a new inline
// element is started between them. This makes it hard to reliably
// measure the position of things, since that requires inserting an
// extra span. This terribly fragile set of tests matches the
// character combinations that suffer from this phenomenon on the
// various browsers.
function spanAffectsWrapping() { return false; }
if (gecko) // Only for "$'"
  spanAffectsWrapping = function(str, i) {
    return str.charCodeAt(i - 1) == 36 && str.charCodeAt(i) == 39;
  };
else if (safari && !/Version\/([6-9]|\d\d)\b/.test(navigator.userAgent))
  spanAffectsWrapping = function(str, i) {
    return /\-[^ \-?]|\?[^ !\'\"\),.\-\/:;\?\]\}]/.test(str.slice(i - 1, i + 1));
  };
else if (webkit)
  spanAffectsWrapping = function(str, i) {
    if (i > 1 && str.charCodeAt(i - 1) == 45 && /\w/.test(str.charAt(i - 2)) && /[^\-?\.]/.test(str.charAt(i)))
      return true;
    return /[~!#%&*)=+}\]|\"\.>,:;][({[<]|\?[\w~`@#$%\^&*(_=+{[|><]/.test(str.slice(i - 1, i + 1));
  };

var knownScrollbarWidth;
function scrollbarWidth(measure) {
  if (knownScrollbarWidth != null) return knownScrollbarWidth;
  var test = elt("div", null, null, "width: 50px; height: 50px; overflow-x: scroll");
  removeChildrenAndAdd(measure, test);
  if (test.offsetWidth)
    knownScrollbarWidth = test.offsetHeight - test.clientHeight;
  return knownScrollbarWidth || 0;
}

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_lt8;
  }
  if (zwspSupported) return elt("span", "\u200b");
  else return elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
}

// See if "".split is the broken IE version, if so, provide an
// alternative way to split lines.
var splitLines = "\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/);};
CodeMirror.splitLines = splitLines;

var hasSelection = window.getSelection ? function(te) {
  try { return te.selectionStart != te.selectionEnd; }
  catch(e) { return false; }
} : function(te) {
  try {var 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';
})();

// KEY NAMING

var keyNames = {3: "Enter", 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: ";", 91: "Mod", 92: "Mod", 93: "Mod", 109: "-", 107: "=", 127: "Delete",
                186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
                221: "]", 222: "'", 63276: "PageUp", 63277: "PageDown", 63275: "End", 63273: "Home",
                63234: "Left", 63232: "Up", 63235: "Right", 63233: "Down", 63302: "Insert", 63272: "Delete"};
CodeMirror.keyNames = keyNames;
(function() {
  // Number keys
  for (var i = 0; i < 10; i++) keyNames[i + 48] = String(i);
  // Alphabetic keys
  for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);
  // Function keys
  for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;
})();

// BIDI HELPERS

function iterateBidiSections(order, from, to, f) {
  if (!order) return f(from, to, "ltr");
  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");
  }
}

function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }
function bidiRight(part) { return part.level % 2 ? part.from : part.to; }

function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }
function lineRight(line) {
  var order = getOrder(line);
  if (!order) return line.text.length;
  return bidiRight(lst(order));
}

function lineStart(cm, lineN) {
  var line = getLine(cm.doc, lineN);
  var visual = visualLine(cm.doc, line);
  if (visual != line) lineN = lineNo(visual);
  var order = getOrder(visual);
  var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);
  return Pos(lineN, ch);
}
function lineEnd(cm, lineN) {
  var merged, line;
  while (merged = collapsedSpanAtEnd(line = getLine(cm.doc, lineN)))
    lineN = merged.find().to.line;
  var order = getOrder(line);
  var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);
  return Pos(lineN, ch);
}

function compareBidiLevel(order, a, b) {
  var linedir = order[0].level;
  if (a == linedir) return true;
  if (b == linedir) return false;
  return a < b;
}
var bidiOther;
function getBidiPartAt(order, pos) {
  for (var i = 0, found; i < order.length; ++i) {
    var cur = order[i];
    if (cur.from < pos && cur.to > pos) { bidiOther = null; return i; }
    if (cur.from == pos || cur.to == pos) {
      if (found == null) {
        found = i;
      } else if (compareBidiLevel(order, cur.level, order[found].level)) {
        bidiOther = found;
        return i;
      } else {
        bidiOther = i;
        return found;
      }
    }
  }
  bidiOther = null;
  return found;
}

function moveInLine(line, pos, dir, byUnit) {
  if (!byUnit) return pos + dir;
  do pos += dir;
  while (pos > 0 && isExtendingChar.test(line.text.charAt(pos)));
  return pos;
}

// This is somewhat involved. It is needed in order to move
// 'visually' through bi-directional text -- i.e., pressing left
// should make the cursor go left, even when in RTL text. The
// tricky part is the 'jumps', where RTL and LTR text touch each
// other. This often requires the cursor offset to move more than
// one unit, in order to visually move one unit.
function moveVisually(line, start, dir, byUnit) {
  var bidi = getOrder(line);
  if (!bidi) return moveLogically(line, start, dir, byUnit);
  var pos = getBidiPartAt(bidi, start), part = bidi[pos];
  var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);

  for (;;) {
    if (target > part.from && target < part.to) return target;
    if (target == part.from || target == part.to) {
      if (getBidiPartAt(bidi, target) == pos) return target;
      part = bidi[pos += dir];
      return (dir > 0) == part.level % 2 ? part.to : part.from;
    } else {
      part = bidi[pos += dir];
      if (!part) return null;
      if ((dir > 0) == part.level % 2)
        target = moveInLine(line, part.to, -1, byUnit);
      else
        target = moveInLine(line, part.from, 1, byUnit);
    }
  }
}

function moveLogically(line, start, dir, byUnit) {
  var target = start + dir;
  if (byUnit) while (target > 0 && isExtendingChar.test(line.text.charAt(target))) target += dir;
  return target < 0 || target > line.text.length ? null : target;
}

// 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%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLL";
  // Character types for codepoints 0x600 to 0x6ff
  var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmmrrrrrrrrrrrrrrrrrr";
  function charType(code) {
    if (code <= 0xff) return lowTypes.charAt(code);
    else if (0x590 <= code && code <= 0x5f4) return "R";
    else if (0x600 <= code && code <= 0x6ff) return arabicTypes.charAt(code - 0x600);
    else if (0x700 <= code && code <= 0x8ac) return "r";
    else return "L";
  }

  var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
  var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
  // Browsers seem to always treat the boundaries of block elements as being L.
  var outerType = "L";

  return function(str) {
    if (!bidiRE.test(str)) return false;
    var len = str.length, types = [];
    for (var i = 0, type; i < len; ++i)
      types.push(type = 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 = 0, prev = outerType; i < len; ++i) {
      var type = types[i];
      if (type == "m") types[i] = 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 = 0, cur = outerType; i < len; ++i) {
      var type = types[i];
      if (type == "1" && cur == "r") types[i] = "n";
      else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "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 = 1, prev = types[0]; i < len - 1; ++i) {
      var type = types[i];
      if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
      else if (type == "," && prev == types[i+1] &&
               (prev == "1" || prev == "n")) types[i] = prev;
      prev = type;
    }

    // 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 = 0; i < len; ++i) {
      var type = types[i];
      if (type == ",") types[i] = "N";
      else if (type == "%") {
        for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
        var replace = (i && types[i-1] == "!") || (end < len - 1 && types[end] == "1") ? "1" : "N";
        for (var j = i; j < end; ++j) types[j] = replace;
        i = 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 = 0, cur = outerType; i < len; ++i) {
      var type = types[i];
      if (cur == "L" && type == "1") types[i] = "L";
      else if (isStrong.test(type)) cur = type;
    }

    // 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 = 0; i < len; ++i) {
      if (isNeutral.test(types[i])) {
        for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}
        var before = (i ? types[i-1] : outerType) == "L";
        var after = (end < len - 1 ? types[end] : outerType) == "L";
        var replace = before || after ? "L" : "R";
        for (var j = i; j < end; ++j) types[j] = replace;
        i = end - 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 = 0; i < len;) {
      if (countsAsLeft.test(types[i])) {
        var start = i;
        for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}
        order.push({from: start, to: i, level: 0});
      } else {
        var pos = i, at = order.length;
        for (++i; i < len && types[i] != "L"; ++i) {}
        for (var j = pos; j < i;) {
          if (countsAsNum.test(types[j])) {
            if (pos < j) order.splice(at, 0, {from: pos, to: j, level: 1});
            var nstart = j;
            for (++j; j < i && countsAsNum.test(types[j]); ++j) {}
            order.splice(at, 0, {from: nstart, to: j, level: 2});
            pos = j;
          } else ++j;
        }
        if (pos < i) order.splice(at, 0, {from: pos, to: i, level: 1});
      }
    }
    if (order[0].level == 1 && (m = str.match(/^\s+/))) {
      order[0].from = m[0].length;
      order.unshift({from: 0, to: m[0].length, level: 0});
    }
    if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
      lst(order).to -= m[0].length;
      order.push({from: len - m[0].length, to: len, level: 0});
    }
    if (order[0].level != lst(order).level)
      order.push({from: len, to: len, level: order[0].level});

    return order;
  };
})();

// THE END

CodeMirror.version = "3.13";

return CodeMirror;

})();