// CodeMirror version 2.23 // // All functions that need access to the editor's state live inside // the CodeMirror function. Below that, at the bottom of the file, // some utilities are defined.

// CodeMirror is the only global var we claim var CodeMirror = (function() {

// This is the function that produces an editor instance. Its
// closure is used to store the editor state.
function CodeMirror(place, givenOptions) {
  // Determine effective options based on given values and defaults.
  var options = {}, defaults = CodeMirror.defaults;
  for (var opt in defaults)
    if (defaults.hasOwnProperty(opt))
      options[opt] = (givenOptions && givenOptions.hasOwnProperty(opt) ? givenOptions : defaults)[opt];

  // The element in which the editor lives.
  var wrapper = document.createElement("div");
  wrapper.className = "CodeMirror" + (options.lineWrapping ? " CodeMirror-wrap" : "");
  // This mess creates the base DOM structure for the editor.
  wrapper.innerHTML =
    '<div style="overflow: hidden; position: relative; width: 3px; height: 0px;">' + // Wraps and hides input textarea
      '<textarea style="position: absolute; padding: 0; width: 1px; height: 1em" wrap="off" ' +
        'autocorrect="off" autocapitalize="off"></textarea></div>' +
    '<div class="CodeMirror-scroll" tabindex="-1">' +
      '<div style="position: relative">' + // Set to the height of the text, causes scrolling
        '<div style="position: relative">' + // Moved around its parent to cover visible view
          '<div class="CodeMirror-gutter"><div class="CodeMirror-gutter-text"></div></div>' +
          // Provides positioning relative to (visible) text origin
          '<div class="CodeMirror-lines"><div style="position: relative; z-index: 0">' +
            '<div style="position: absolute; width: 100%; height: 0; overflow: hidden; visibility: hidden;"></div>' +
            '<pre class="CodeMirror-cursor">&#160;</pre>' + // Absolutely positioned blinky cursor
            '<div style="position: relative; z-index: -1"></div><div></div>' + // DIVs containing the selection and the actual code
          '</div></div></div></div></div>';
  if (place.appendChild) place.appendChild(wrapper); else place(wrapper);
  // I've never seen more elegant code in my life.
  var inputDiv = wrapper.firstChild, input = inputDiv.firstChild,
      scroller = wrapper.lastChild, code = scroller.firstChild,
      mover = code.firstChild, gutter = mover.firstChild, gutterText = gutter.firstChild,
      lineSpace = gutter.nextSibling.firstChild, measure = lineSpace.firstChild,
      cursor = measure.nextSibling, selectionDiv = cursor.nextSibling,
      lineDiv = selectionDiv.nextSibling;
  themeChanged();
  // Needed to hide big blue blinking cursor on Mobile Safari
  if (ios) input.style.width = "0px";
  if (!webkit) lineSpace.draggable = true;
  lineSpace.style.outline = "none";
  if (options.tabindex != null) input.tabIndex = options.tabindex;
  if (options.autofocus) focusInput();
  if (!options.gutter && !options.lineNumbers) gutter.style.display = "none";
  // Needed to handle Tab key in KHTML
  if (khtml) inputDiv.style.height = "1px", inputDiv.style.position = "absolute";

  // Check for problem with IE innerHTML not working when we have a
  // P (or similar) parent node.
  try { stringWidth("x"); }
  catch (e) {
    if (e.message.match(/runtime/i))
      e = new Error("A CodeMirror inside a P-style element does not work in Internet Explorer. (innerHTML bug)");
    throw e;
  }

  // Delayed object wrap timeouts, making sure only one is active. blinker holds an interval.
  var poll = new Delayed(), highlight = new Delayed(), blinker;

  // mode holds a mode API object. doc is the tree of Line objects,
  // work an array of lines that should be parsed, and history the
  // undo history (instance of History constructor).
  var mode, doc = new BranchChunk([new LeafChunk([new Line("")])]), work, focused;
  loadMode();
  // The selection. These are always maintained to point at valid
  // positions. Inverted is used to remember that the user is
  // selecting bottom-to-top.
  var sel = {from: {line: 0, ch: 0}, to: {line: 0, ch: 0}, inverted: false};
  // Selection-related flags. shiftSelecting obviously tracks
  // whether the user is holding shift.
  var shiftSelecting, lastClick, lastDoubleClick, lastScrollPos = 0, draggingText,
      overwrite = false, suppressEdits = false;
  // Variables used by startOperation/endOperation to track what
  // happened during the operation.
  var updateInput, userSelChange, changes, textChanged, selectionChanged, leaveInputAlone,
      gutterDirty, callbacks;
  // Current visible range (may be bigger than the view window).
  var displayOffset = 0, showingFrom = 0, showingTo = 0, lastSizeC = 0;
  // bracketHighlighted is used to remember that a bracket has been
  // marked.
  var bracketHighlighted;
  // Tracks the maximum line length so that the horizontal scrollbar
  // can be kept static when scrolling.
  var maxLine = "", maxWidth;
  var tabCache = {};

  // Initialize the content.
  operation(function(){setValue(options.value || ""); updateInput = false;})();
  var history = new History();

  // Register our event handlers.
  connect(scroller, "mousedown", operation(onMouseDown));
  connect(scroller, "dblclick", operation(onDoubleClick));
  connect(lineSpace, "dragstart", onDragStart);
  connect(lineSpace, "selectstart", e_preventDefault);
  // 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 (!gecko) connect(scroller, "contextmenu", onContextMenu);
  connect(scroller, "scroll", function() {
    lastScrollPos = scroller.scrollTop;
    updateDisplay([]);
    if (options.fixedGutter) gutter.style.left = scroller.scrollLeft + "px";
    if (options.onScroll) options.onScroll(instance);
  });
  connect(window, "resize", function() {updateDisplay(true);});
  connect(input, "keyup", operation(onKeyUp));
  connect(input, "input", fastPoll);
  connect(input, "keydown", operation(onKeyDown));
  connect(input, "keypress", operation(onKeyPress));
  connect(input, "focus", onFocus);
  connect(input, "blur", onBlur);

  connect(scroller, "dragenter", e_stop);
  connect(scroller, "dragover", e_stop);
  connect(scroller, "drop", operation(onDrop));
  connect(scroller, "paste", function(){focusInput(); fastPoll();});
  connect(input, "paste", fastPoll);
  connect(input, "cut", operation(function(){
    if (!options.readOnly) replaceSelection("");
  }));

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

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

  function isLine(l) {return l >= 0 && l < doc.size;}
  // The instance object that we'll return. Mostly calls out to
  // local functions in the CodeMirror function. Some do some extra
  // range checking and/or clipping. operation is used to wrap the
  // call so that changes it makes are tracked, and the display is
  // updated afterwards.
  var instance = wrapper.CodeMirror = {
    getValue: getValue,
    setValue: operation(setValue),
    getSelection: getSelection,
    replaceSelection: operation(replaceSelection),
    focus: function(){window.focus(); focusInput(); onFocus(); fastPoll();},
    setOption: function(option, value) {
      var oldVal = options[option];
      options[option] = value;
      if (option == "mode" || option == "indentUnit") loadMode();
      else if (option == "readOnly" && value == "nocursor") {onBlur(); input.blur();}
      else if (option == "readOnly" && !value) {resetInput(true);}
      else if (option == "theme") themeChanged();
      else if (option == "lineWrapping" && oldVal != value) operation(wrappingChanged)();
      else if (option == "tabSize") updateDisplay(true);
      if (option == "lineNumbers" || option == "gutter" || option == "firstLineNumber" || option == "theme") {
        gutterChanged();
        updateDisplay(true);
      }
    },
    getOption: function(option) {return options[option];},
    undo: operation(undo),
    redo: operation(redo),
    indentLine: operation(function(n, dir) {
      if (typeof dir != "string") {
        if (dir == null) dir = options.smartIndent ? "smart" : "prev";
        else dir = dir ? "add" : "subtract";
      }
      if (isLine(n)) indentLine(n, dir);
    }),
    indentSelection: operation(indentSelected),
    historySize: function() {return {undo: history.done.length, redo: history.undone.length};},
    clearHistory: function() {history = new History();},
    matchBrackets: operation(function(){matchBrackets(true);}),
    getTokenAt: operation(function(pos) {
      pos = clipPos(pos);
      return getLine(pos.line).getTokenAt(mode, getStateBefore(pos.line), pos.ch);
    }),
    getStateAfter: function(line) {
      line = clipLine(line == null ? doc.size - 1: line);
      return getStateBefore(line + 1);
    },
    cursorCoords: function(start, mode) {
      if (start == null) start = sel.inverted;
      return this.charCoords(start ? sel.from : sel.to, mode);
    },
    charCoords: function(pos, mode) {
      pos = clipPos(pos);
      if (mode == "local") return localCoords(pos, false);
      if (mode == "div") return localCoords(pos, true);
      return pageCoords(pos);
    },
    coordsChar: function(coords) {
      var off = eltOffset(lineSpace);
      return coordsChar(coords.x - off.left, coords.y - off.top);
    },
    markText: operation(markText),
    setBookmark: setBookmark,
    findMarksAt: findMarksAt,
    setMarker: operation(addGutterMarker),
    clearMarker: operation(removeGutterMarker),
    setLineClass: operation(setLineClass),
    hideLine: operation(function(h) {return setLineHidden(h, true);}),
    showLine: operation(function(h) {return setLineHidden(h, false);}),
    onDeleteLine: function(line, f) {
      if (typeof line == "number") {
        if (!isLine(line)) return null;
        line = getLine(line);
      }
      (line.handlers || (line.handlers = [])).push(f);
      return line;
    },
    lineInfo: lineInfo,
    addWidget: function(pos, node, scroll, vert, horiz) {
      pos = localCoords(clipPos(pos));
      var top = pos.yBot, left = pos.x;
      node.style.position = "absolute";
      code.appendChild(node);
      if (vert == "over") top = pos.y;
      else if (vert == "near") {
        var vspace = Math.max(scroller.offsetHeight, doc.height * textHeight()),
            hspace = Math.max(code.clientWidth, lineSpace.clientWidth) - paddingLeft();
        if (pos.yBot + node.offsetHeight > vspace && pos.y > node.offsetHeight)
          top = pos.y - node.offsetHeight;
        if (left + node.offsetWidth > hspace)
          left = hspace - node.offsetWidth;
      }
      node.style.top = (top + paddingTop()) + "px";
      node.style.left = node.style.right = "";
      if (horiz == "right") {
        left = code.clientWidth - node.offsetWidth;
        node.style.right = "0px";
      } else {
        if (horiz == "left") left = 0;
        else if (horiz == "middle") left = (code.clientWidth - node.offsetWidth) / 2;
        node.style.left = (left + paddingLeft()) + "px";
      }
      if (scroll)
        scrollIntoView(left, top, left + node.offsetWidth, top + node.offsetHeight);
    },

    lineCount: function() {return doc.size;},
    clipPos: clipPos,
    getCursor: function(start) {
      if (start == null) start = sel.inverted;
      return copyPos(start ? sel.from : sel.to);
    },
    somethingSelected: function() {return !posEq(sel.from, sel.to);},
    setCursor: operation(function(line, ch, user) {
      if (ch == null && typeof line.line == "number") setCursor(line.line, line.ch, user);
      else setCursor(line, ch, user);
    }),
    setSelection: operation(function(from, to, user) {
      (user ? setSelectionUser : setSelection)(clipPos(from), clipPos(to || from));
    }),
    getLine: function(line) {if (isLine(line)) return getLine(line).text;},
    getLineHandle: function(line) {if (isLine(line)) return getLine(line);},
    setLine: operation(function(line, text) {
      if (isLine(line)) replaceRange(text, {line: line, ch: 0}, {line: line, ch: getLine(line).text.length});
    }),
    removeLine: operation(function(line) {
      if (isLine(line)) replaceRange("", {line: line, ch: 0}, clipPos({line: line+1, ch: 0}));
    }),
    replaceRange: operation(replaceRange),
    getRange: function(from, to) {return getRange(clipPos(from), clipPos(to));},

    triggerOnKeyDown: operation(onKeyDown),
    execCommand: function(cmd) {return commands[cmd](instance);},
    // Stuff used by commands, probably not much use to outside code.
    moveH: operation(moveH),
    deleteH: operation(deleteH),
    moveV: operation(moveV),
    toggleOverwrite: function() {
      if(overwrite){
        overwrite = false;
        cursor.className = cursor.className.replace(" CodeMirror-overwrite", "");
      } else {
        overwrite = true;
        cursor.className += " CodeMirror-overwrite";
      }
    },

    posFromIndex: function(off) {
      var lineNo = 0, ch;
      doc.iter(0, doc.size, function(line) {
        var sz = line.text.length + 1;
        if (sz > off) { ch = off; return true; }
        off -= sz;
        ++lineNo;
      });
      return clipPos({line: lineNo, ch: ch});
    },
    indexFromPos: function (coords) {
      if (coords.line < 0 || coords.ch < 0) return 0;
      var index = coords.ch;
      doc.iter(0, coords.line, function (line) {
        index += line.text.length + 1;
      });
      return index;
    },
    scrollTo: function(x, y) {
      if (x != null) scroller.scrollLeft = x;
      if (y != null) scroller.scrollTop = y;
      updateDisplay([]);
    },

    operation: function(f){return operation(f)();},
    refresh: function(){
      updateDisplay(true);
      if (scroller.scrollHeight > lastScrollPos)
        scroller.scrollTop = lastScrollPos;
    },
    getInputField: function(){return input;},
    getWrapperElement: function(){return wrapper;},
    getScrollerElement: function(){return scroller;},
    getGutterElement: function(){return gutter;}
  };

  function getLine(n) { return getLineAt(doc, n); }
  function updateLineHeight(line, height) {
    gutterDirty = true;
    var diff = height - line.height;
    for (var n = line; n; n = n.parent) n.height += diff;
  }

  function setValue(code) {
    var top = {line: 0, ch: 0};
    updateLines(top, {line: doc.size - 1, ch: getLine(doc.size-1).text.length},
                splitLines(code), top, top);
    updateInput = true;
  }
  function getValue(code) {
    var text = [];
    doc.iter(0, doc.size, function(line) { text.push(line.text); });
    return text.join("\n");
  }

  function onMouseDown(e) {
    setShift(e_prop(e, "shiftKey"));
    // Check whether this is a click in a widget
    for (var n = e_target(e); n != wrapper; n = n.parentNode)
      if (n.parentNode == code && n != mover) return;

    // See if this is a click in the gutter
    for (var n = e_target(e); n != wrapper; n = n.parentNode)
      if (n.parentNode == gutterText) {
        if (options.onGutterClick)
          options.onGutterClick(instance, indexOf(gutterText.childNodes, n) + showingFrom, e);
        return e_preventDefault(e);
      }

    var start = posFromMouse(e);

    switch (e_button(e)) {
    case 3:
      if (gecko && !mac) onContextMenu(e);
      return;
    case 2:
      if (start) setCursor(start.line, start.ch, true);
      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) == scroller) e_preventDefault(e); return;}

    if (!focused) onFocus();

    var now = +new Date;
    if (lastDoubleClick && lastDoubleClick.time > now - 400 && posEq(lastDoubleClick.pos, start)) {
      e_preventDefault(e);
      setTimeout(focusInput, 20);
      return selectLine(start.line);
    } else if (lastClick && lastClick.time > now - 400 && posEq(lastClick.pos, start)) {
      lastDoubleClick = {time: now, pos: start};
      e_preventDefault(e);
      return selectWordAt(start);
    } else { lastClick = {time: now, pos: start}; }

    var last = start, going;
    if (dragAndDrop && !options.readOnly && !posEq(sel.from, sel.to) &&
        !posLess(start, sel.from) && !posLess(sel.to, start)) {
      // Let the drag handler handle this.
      if (webkit) lineSpace.draggable = true;
      var up = connect(document, "mouseup", operation(function(e2) {
        if (webkit) lineSpace.draggable = false;
        draggingText = false;
        up();
        if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
          e_preventDefault(e2);
          setCursor(start.line, start.ch, true);
          focusInput();
        }
      }), true);
      draggingText = true;
      // IE's approach to draggable
      if (lineSpace.dragDrop) lineSpace.dragDrop();
      return;
    }
    e_preventDefault(e);
    setCursor(start.line, start.ch, true);

    function extend(e) {
      var cur = posFromMouse(e, true);
      if (cur && !posEq(cur, last)) {
        if (!focused) onFocus();
        last = cur;
        setSelectionUser(start, cur);
        updateInput = false;
        var visible = visibleLines();
        if (cur.line >= visible.to || cur.line < visible.from)
          going = setTimeout(operation(function(){extend(e);}), 150);
      }
    }

    function done(e) {
      clearTimeout(going);
      var cur = posFromMouse(e);
      if (cur) setSelectionUser(start, cur);
      e_preventDefault(e);
      focusInput();
      updateInput = true;
      move(); up();
    }
    var move = connect(document, "mousemove", operation(function(e) {
      clearTimeout(going);
      e_preventDefault(e);
      if (!ie && !e_button(e)) done(e);
      else extend(e);
    }), true);
    var up = connect(document, "mouseup", operation(done), true);
  }
  function onDoubleClick(e) {
    for (var n = e_target(e); n != wrapper; n = n.parentNode)
      if (n.parentNode == gutterText) return e_preventDefault(e);
    var start = posFromMouse(e);
    if (!start) return;
    lastDoubleClick = {time: +new Date, pos: start};
    e_preventDefault(e);
    selectWordAt(start);
  }
  function onDrop(e) {
    e.preventDefault();
    var pos = posFromMouse(e, true), files = e.dataTransfer.files;
    if (!pos || options.readOnly) return;
    if (files && files.length && window.FileReader && window.File) {
      function loadFile(file, i) {
        var reader = new FileReader;
        reader.onload = function() {
          text[i] = reader.result;
          if (++read == n) {
            pos = clipPos(pos);
            operation(function() {
              var end = replaceRange(text.join(""), pos, pos);
              setSelectionUser(pos, end);
            })();
          }
        };
        reader.readAsText(file);
      }
      var n = files.length, text = Array(n), read = 0;
      for (var i = 0; i < n; ++i) loadFile(files[i], i);
    }
    else {
      try {
        var text = e.dataTransfer.getData("Text");
        if (text) {
          var curFrom = sel.from, curTo = sel.to;
          setSelectionUser(pos, pos);
          if (draggingText) replaceRange("", curFrom, curTo);
          replaceSelection(text);
          focusInput();
        }
      }
      catch(e){}
    }
  }
  function onDragStart(e) {
    var txt = getSelection();
    e.dataTransfer.setData("Text", txt);

    // Use dummy image instead of default browsers image.
    if (gecko || chrome) {
      var img = document.createElement('img');
      img.scr = 'data:image/gif;base64,R0lGODdhAgACAIAAAAAAAP///ywAAAAAAgACAAACAoRRADs='; //1x1 image
      e.dataTransfer.setDragImage(img, 0, 0);
    }
  }

  function doHandleBinding(bound, dropShift) {
    if (typeof bound == "string") {
      bound = commands[bound];
      if (!bound) return false;
    }
    var prevShift = shiftSelecting;
    try {
      if (options.readOnly) suppressEdits = true;
      if (dropShift) shiftSelecting = null;
      bound(instance);
    } catch(e) {
      if (e != Pass) throw e;
      return false;
    } finally {
      shiftSelecting = prevShift;
      suppressEdits = false;
    }
    return true;
  }
  function handleKeyBinding(e) {
    // Handle auto keymap transitions
    var startMap = getKeyMap(options.keyMap), next = startMap.auto;
    clearTimeout(maybeTransition);
    if (next && !isModifierKey(e)) maybeTransition = setTimeout(function() {
      if (getKeyMap(options.keyMap) == startMap) {
        options.keyMap = (next.call ? next.call(null, instance) : next);
      }
    }, 50);

    var name = keyNames[e_prop(e, "keyCode")], handled = false;
    if (name == null || e.altGraphKey) return false;
    if (e_prop(e, "altKey")) name = "Alt-" + name;
    if (e_prop(e, "ctrlKey")) name = "Ctrl-" + name;
    if (e_prop(e, "metaKey")) name = "Cmd-" + name;

    if (e_prop(e, "shiftKey")) {
      handled = lookupKey("Shift-" + name, options.extraKeys, options.keyMap,
                          function(b) {return doHandleBinding(b, true);})
             || lookupKey(name, options.extraKeys, options.keyMap, function(b) {
               if (typeof b == "string" && /^go[A-Z]/.test(b)) return doHandleBinding(b);
             });
    } else {
      handled = lookupKey(name, options.extraKeys, options.keyMap, doHandleBinding);
    }
    if (handled) {
      e_preventDefault(e);
      if (ie) { e.oldKeyCode = e.keyCode; e.keyCode = 0; }
    }
    return handled;
  }
  function handleCharBinding(e, ch) {
    var handled = lookupKey("'" + ch + "'", options.extraKeys,
                            options.keyMap, doHandleBinding);
    if (handled) e_preventDefault(e);
    return handled;
  }

  var lastStoppedKey = null, maybeTransition;
  function onKeyDown(e) {
    if (!focused) onFocus();
    if (ie && e.keyCode == 27) { e.returnValue = false; }
    if (pollingFast) { if (readInput()) pollingFast = false; }
    if (options.onKeyEvent && options.onKeyEvent(instance, addStop(e))) return;
    var code = e_prop(e, "keyCode");
    // IE does strange things with escape.
    setShift(code == 16 || e_prop(e, "shiftKey"));
    // First give onKeyEvent option a chance to handle this.
    var handled = handleKeyBinding(e);
    if (window.opera) {
      lastStoppedKey = handled ? code : null;
      // Opera has no cut event... we try to at least catch the key combo
      if (!handled && code == 88 && e_prop(e, mac ? "metaKey" : "ctrlKey"))
        replaceSelection("");
    }
  }
  function onKeyPress(e) {
    if (pollingFast) readInput();
    if (options.onKeyEvent && options.onKeyEvent(instance, addStop(e))) return;
    var keyCode = e_prop(e, "keyCode"), charCode = e_prop(e, "charCode");
    if (window.opera && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
    if (((window.opera && !e.which) || khtml) && handleKeyBinding(e)) return;
    var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
    if (options.electricChars && mode.electricChars && options.smartIndent && !options.readOnly) {
      if (mode.electricChars.indexOf(ch) > -1)
        setTimeout(operation(function() {indentLine(sel.to.line, "smart");}), 75);
    }
    if (handleCharBinding(e, ch)) return;
    fastPoll();
  }
  function onKeyUp(e) {
    if (options.onKeyEvent && options.onKeyEvent(instance, addStop(e))) return;
    if (e_prop(e, "keyCode") == 16) shiftSelecting = null;
  }

  function onFocus() {
    if (options.readOnly == "nocursor") return;
    if (!focused) {
      if (options.onFocus) options.onFocus(instance);
      focused = true;
      if (wrapper.className.search(/\bCodeMirror-focused\b/) == -1)
        wrapper.className += " CodeMirror-focused";
      if (!leaveInputAlone) resetInput(true);
    }
    slowPoll();
    restartBlink();
  }
  function onBlur() {
    if (focused) {
      if (options.onBlur) options.onBlur(instance);
      focused = false;
      if (bracketHighlighted)
        operation(function(){
          if (bracketHighlighted) { bracketHighlighted(); bracketHighlighted = null; }
        })();
      wrapper.className = wrapper.className.replace(" CodeMirror-focused", "");
    }
    clearInterval(blinker);
    setTimeout(function() {if (!focused) shiftSelecting = null;}, 150);
  }

  // Replace the range from from to to by the strings in newText.
  // Afterwards, set the selection to selFrom, selTo.
  function updateLines(from, to, newText, selFrom, selTo) {
    if (suppressEdits) return;
    if (history) {
      var old = [];
      doc.iter(from.line, to.line + 1, function(line) { old.push(line.text); });
      history.addChange(from.line, newText.length, old);
      while (history.done.length > options.undoDepth) history.done.shift();
    }
    updateLinesNoUndo(from, to, newText, selFrom, selTo);
  }
  function unredoHelper(from, to) {
    if (!from.length) return;
    var set = from.pop(), out = [];
    for (var i = set.length - 1; i >= 0; i -= 1) {
      var change = set[i];
      var replaced = [], end = change.start + change.added;
      doc.iter(change.start, end, function(line) { replaced.push(line.text); });
      out.push({start: change.start, added: change.old.length, old: replaced});
      var pos = clipPos({line: change.start + change.old.length - 1,
                         ch: editEnd(replaced[replaced.length-1], change.old[change.old.length-1])});
      updateLinesNoUndo({line: change.start, ch: 0}, {line: end - 1, ch: getLine(end-1).text.length}, change.old, pos, pos);
    }
    updateInput = true;
    to.push(out);
  }
  function undo() {unredoHelper(history.done, history.undone);}
  function redo() {unredoHelper(history.undone, history.done);}

  function updateLinesNoUndo(from, to, newText, selFrom, selTo) {
    if (suppressEdits) return;
    var recomputeMaxLength = false, maxLineLength = maxLine.length;
    if (!options.lineWrapping)
      doc.iter(from.line, to.line, function(line) {
        if (line.text.length == maxLineLength) {recomputeMaxLength = true; return true;}
      });
    if (from.line != to.line || newText.length > 1) gutterDirty = true;

    var nlines = to.line - from.line, firstLine = getLine(from.line), lastLine = getLine(to.line);
    // First adjust the line structure, taking some care to leave highlighting intact.
    if (from.ch == 0 && to.ch == 0 && newText[newText.length - 1] == "") {
      // This is a whole-line replace. Treated specially to make
      // sure line objects move the way they are supposed to.
      var added = [], prevLine = null;
      if (from.line) {
        prevLine = getLine(from.line - 1);
        prevLine.fixMarkEnds(lastLine);
      } else lastLine.fixMarkStarts();
      for (var i = 0, e = newText.length - 1; i < e; ++i)
        added.push(Line.inheritMarks(newText[i], prevLine));
      if (nlines) doc.remove(from.line, nlines, callbacks);
      if (added.length) doc.insert(from.line, added);
    } else if (firstLine == lastLine) {
      if (newText.length == 1)
        firstLine.replace(from.ch, to.ch, newText[0]);
      else {
        lastLine = firstLine.split(to.ch, newText[newText.length-1]);
        firstLine.replace(from.ch, null, newText[0]);
        firstLine.fixMarkEnds(lastLine);
        var added = [];
        for (var i = 1, e = newText.length - 1; i < e; ++i)
          added.push(Line.inheritMarks(newText[i], firstLine));
        added.push(lastLine);
        doc.insert(from.line + 1, added);
      }
    } else if (newText.length == 1) {
      firstLine.replace(from.ch, null, newText[0]);
      lastLine.replace(null, to.ch, "");
      firstLine.append(lastLine);
      doc.remove(from.line + 1, nlines, callbacks);
    } else {
      var added = [];
      firstLine.replace(from.ch, null, newText[0]);
      lastLine.replace(null, to.ch, newText[newText.length-1]);
      firstLine.fixMarkEnds(lastLine);
      for (var i = 1, e = newText.length - 1; i < e; ++i)
        added.push(Line.inheritMarks(newText[i], firstLine));
      if (nlines > 1) doc.remove(from.line + 1, nlines - 1, callbacks);
      doc.insert(from.line + 1, added);
    }
    if (options.lineWrapping) {
      var perLine = scroller.clientWidth / charWidth() - 3;
      doc.iter(from.line, from.line + newText.length, function(line) {
        if (line.hidden) return;
        var guess = Math.ceil(line.text.length / perLine) || 1;
        if (guess != line.height) updateLineHeight(line, guess);
      });
    } else {
      doc.iter(from.line, i + newText.length, function(line) {
        var l = line.text;
        if (l.length > maxLineLength) {
          maxLine = l; maxLineLength = l.length; maxWidth = null;
          recomputeMaxLength = false;
        }
      });
      if (recomputeMaxLength) {
        maxLineLength = 0; maxLine = ""; maxWidth = null;
        doc.iter(0, doc.size, function(line) {
          var l = line.text;
          if (l.length > maxLineLength) {
            maxLineLength = l.length; maxLine = l;
          }
        });
      }
    }

    // Add these lines to the work array, so that they will be
    // highlighted. Adjust work lines if lines were added/removed.
    var newWork = [], lendiff = newText.length - nlines - 1;
    for (var i = 0, l = work.length; i < l; ++i) {
      var task = work[i];
      if (task < from.line) newWork.push(task);
      else if (task > to.line) newWork.push(task + lendiff);
    }
    var hlEnd = from.line + Math.min(newText.length, 500);
    highlightLines(from.line, hlEnd);
    newWork.push(hlEnd);
    work = newWork;
    startWorker(100);
    // Remember that these lines changed, for updating the display
    changes.push({from: from.line, to: to.line + 1, diff: lendiff});
    var changeObj = {from: from, to: to, text: newText};
    if (textChanged) {
      for (var cur = textChanged; cur.next; cur = cur.next) {}
      cur.next = changeObj;
    } else textChanged = changeObj;

    // Update the selection
    function updateLine(n) {return n <= Math.min(to.line, to.line + lendiff) ? n : n + lendiff;}
    setSelection(selFrom, selTo, updateLine(sel.from.line), updateLine(sel.to.line));

    // Make sure the scroll-size div has the correct height.
    if (scroller.clientHeight)
      code.style.height = (doc.height * textHeight() + 2 * paddingTop()) + "px";
  }

  function replaceRange(code, from, to) {
    from = clipPos(from);
    if (!to) to = from; else to = clipPos(to);
    code = splitLines(code);
    function adjustPos(pos) {
      if (posLess(pos, from)) return pos;
      if (!posLess(to, pos)) return end;
      var line = pos.line + code.length - (to.line - from.line) - 1;
      var ch = pos.ch;
      if (pos.line == to.line)
        ch += code[code.length-1].length - (to.ch - (to.line == from.line ? from.ch : 0));
      return {line: line, ch: ch};
    }
    var end;
    replaceRange1(code, from, to, function(end1) {
      end = end1;
      return {from: adjustPos(sel.from), to: adjustPos(sel.to)};
    });
    return end;
  }
  function replaceSelection(code, collapse) {
    replaceRange1(splitLines(code), sel.from, sel.to, function(end) {
      if (collapse == "end") return {from: end, to: end};
      else if (collapse == "start") return {from: sel.from, to: sel.from};
      else return {from: sel.from, to: end};
    });
  }
  function replaceRange1(code, from, to, computeSel) {
    var endch = code.length == 1 ? code[0].length + from.ch : code[code.length-1].length;
    var newSel = computeSel({line: from.line + code.length - 1, ch: endch});
    updateLines(from, to, code, newSel.from, newSel.to);
  }

  function getRange(from, to) {
    var l1 = from.line, l2 = to.line;
    if (l1 == l2) return getLine(l1).text.slice(from.ch, to.ch);
    var code = [getLine(l1).text.slice(from.ch)];
    doc.iter(l1 + 1, l2, function(line) { code.push(line.text); });
    code.push(getLine(l2).text.slice(0, to.ch));
    return code.join("\n");
  }
  function getSelection() {
    return getRange(sel.from, sel.to);
  }

  var pollingFast = false; // Ensures slowPoll doesn't cancel fastPoll
  function slowPoll() {
    if (pollingFast) return;
    poll.set(options.pollInterval, function() {
      startOperation();
      readInput();
      if (focused) slowPoll();
      endOperation();
    });
  }
  function fastPoll() {
    var missed = false;
    pollingFast = true;
    function p() {
      startOperation();
      var changed = readInput();
      if (!changed && !missed) {missed = true; poll.set(60, p);}
      else {pollingFast = false; slowPoll();}
      endOperation();
    }
    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.)
  var prevInput = "";
  function readInput() {
    if (leaveInputAlone || !focused || hasSelection(input) || options.readOnly) return false;
    var text = input.value;
    if (text == prevInput) return false;
    shiftSelecting = null;
    var same = 0, l = Math.min(prevInput.length, text.length);
    while (same < l && prevInput[same] == text[same]) ++same;
    if (same < prevInput.length)
      sel.from = {line: sel.from.line, ch: sel.from.ch - (prevInput.length - same)};
    else if (overwrite && posEq(sel.from, sel.to))
      sel.to = {line: sel.to.line, ch: Math.min(getLine(sel.to.line).text.length, sel.to.ch + (text.length - same))};
    replaceSelection(text.slice(same), "end");
    prevInput = text;
    return true;
  }
  function resetInput(user) {
    if (!posEq(sel.from, sel.to)) {
      prevInput = "";
      input.value = getSelection();
      selectInput(input);
    } else if (user) prevInput = input.value = "";
  }

  function focusInput() {
    if (options.readOnly != "nocursor") input.focus();
  }

  function scrollEditorIntoView() {
    if (!cursor.getBoundingClientRect) return;
    var rect = cursor.getBoundingClientRect();
    // IE returns bogus coordinates when the instance sits inside of an iframe and the cursor is hidden
    if (ie && rect.top == rect.bottom) return;
    var winH = window.innerHeight || Math.max(document.body.offsetHeight, document.documentElement.offsetHeight);
    if (rect.top < 0 || rect.bottom > winH) cursor.scrollIntoView();
  }
  function scrollCursorIntoView() {
    var cursor = localCoords(sel.inverted ? sel.from : sel.to);
    var x = options.lineWrapping ? Math.min(cursor.x, lineSpace.offsetWidth) : cursor.x;
    return scrollIntoView(x, cursor.y, x, cursor.yBot);
  }
  function scrollIntoView(x1, y1, x2, y2) {
    var pl = paddingLeft(), pt = paddingTop();
    y1 += pt; y2 += pt; x1 += pl; x2 += pl;
    var screen = scroller.clientHeight, screentop = scroller.scrollTop, scrolled = false, result = true;
    if (y1 < screentop) {scroller.scrollTop = Math.max(0, y1); scrolled = true;}
    else if (y2 > screentop + screen) {scroller.scrollTop = y2 - screen; scrolled = true;}

    var screenw = scroller.clientWidth, screenleft = scroller.scrollLeft;
    var gutterw = options.fixedGutter ? gutter.clientWidth : 0;
    if (x1 < screenleft + gutterw) {
      if (x1 < 50) x1 = 0;
      scroller.scrollLeft = Math.max(0, x1 - 10 - gutterw);
      scrolled = true;
    }
    else if (x2 > screenw + screenleft - 3) {
      scroller.scrollLeft = x2 + 10 - screenw;
      scrolled = true;
      if (x2 > code.clientWidth) result = false;
    }
    if (scrolled && options.onScroll) options.onScroll(instance);
    return result;
  }

  function visibleLines() {
    var lh = textHeight(), top = scroller.scrollTop - paddingTop();
    var from_height = Math.max(0, Math.floor(top / lh));
    var to_height = Math.ceil((top + scroller.clientHeight) / lh);
    return {from: lineAtHeight(doc, from_height),
            to: lineAtHeight(doc, to_height)};
  }
  // Uses a set of changes plus the current scroll position to
  // determine which DOM updates have to be made, and makes the
  // updates.
  function updateDisplay(changes, suppressCallback) {
    if (!scroller.clientWidth) {
      showingFrom = showingTo = displayOffset = 0;
      return;
    }
    // Compute the new visible window
    var visible = visibleLines();
    // Bail out if the visible area is already rendered and nothing changed.
    if (changes !== true && changes.length == 0 && visible.from > showingFrom && visible.to < showingTo) return;
    var from = Math.max(visible.from - 100, 0), to = Math.min(doc.size, visible.to + 100);
    if (showingFrom < from && from - showingFrom < 20) from = showingFrom;
    if (showingTo > to && showingTo - to < 20) to = Math.min(doc.size, showingTo);

    // Create a range of theoretically intact lines, and punch holes
    // in that using the change info.
    var intact = changes === true ? [] :
      computeIntact([{from: showingFrom, to: showingTo, domStart: 0}], changes);
    // 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.domStart += (from - range.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) return;
    intact.sort(function(a, b) {return a.domStart - b.domStart;});

    var th = textHeight(), gutterDisplay = gutter.style.display;
    lineDiv.style.display = "none";
    patchDisplay(from, to, intact);
    lineDiv.style.display = gutter.style.display = "";

    // Position the mover div to align with the lines it's supposed
    // to be showing (which will cover the visible display)
    var different = from != showingFrom || to != showingTo || lastSizeC != scroller.clientHeight + th;
    // This is just a bogus formula that detects when the editor is
    // resized or the font size changes.
    if (different) lastSizeC = scroller.clientHeight + th;
    showingFrom = from; showingTo = to;
    displayOffset = heightAtLine(doc, from);
    mover.style.top = (displayOffset * th) + "px";
    if (scroller.clientHeight)
      code.style.height = (doc.height * th + 2 * paddingTop()) + "px";

    // Since this is all rather error prone, it is honoured with the
    // only assertion in the whole file.
    if (lineDiv.childNodes.length != showingTo - showingFrom)
      throw new Error("BAD PATCH! " + JSON.stringify(intact) + " size=" + (showingTo - showingFrom) +
                      " nodes=" + lineDiv.childNodes.length);

    function checkHeights() {
      maxWidth = scroller.clientWidth;
      var curNode = lineDiv.firstChild, heightChanged = false;
      doc.iter(showingFrom, showingTo, function(line) {
        if (!line.hidden) {
          var height = Math.round(curNode.offsetHeight / th) || 1;
          if (line.height != height) {
            updateLineHeight(line, height);
            gutterDirty = heightChanged = true;
          }
        }
        curNode = curNode.nextSibling;
      });
      if (heightChanged)
        code.style.height = (doc.height * th + 2 * paddingTop()) + "px";
      return heightChanged;
    }

    if (options.lineWrapping) {
      checkHeights();
    } else {
      if (maxWidth == null) maxWidth = stringWidth(maxLine);
      if (maxWidth > scroller.clientWidth) {
        lineSpace.style.width = maxWidth + "px";
        // Needed to prevent odd wrapping/hiding of widgets placed in here.
        code.style.width = "";
        code.style.width = scroller.scrollWidth + "px";
      } else {
        lineSpace.style.width = code.style.width = "";
      }
    }

    gutter.style.display = gutterDisplay;
    if (different || gutterDirty) {
      // If the gutter grew in size, re-check heights. If those changed, re-draw gutter.
      updateGutter() && options.lineWrapping && checkHeights() && updateGutter();
    }
    updateSelection();
    if (!suppressCallback && options.onUpdate) options.onUpdate(instance);
    return true;
  }

  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,
                        domStart: range.domStart});
        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, domStart: range.domStart});
          if (change.to < range.to)
            intact2.push({from: change.to + diff, to: range.to + diff,
                          domStart: range.domStart + (change.to - range.from)});
        }
      }
      intact = intact2;
    }
    return intact;
  }

  function patchDisplay(from, to, intact) {
    // The first pass removes the DOM nodes that aren't intact.
    if (!intact.length) lineDiv.innerHTML = "";
    else {
      function killNode(node) {
        var tmp = node.nextSibling;
        node.parentNode.removeChild(node);
        return tmp;
      }
      var domPos = 0, curNode = lineDiv.firstChild, n;
      for (var i = 0; i < intact.length; ++i) {
        var cur = intact[i];
        while (cur.domStart > domPos) {curNode = killNode(curNode); domPos++;}
        for (var j = 0, e = cur.to - cur.from; j < e; ++j) {curNode = curNode.nextSibling; domPos++;}
      }
      while (curNode) curNode = killNode(curNode);
    }
    // This pass fills in the lines that actually changed.
    var nextIntact = intact.shift(), curNode = lineDiv.firstChild, j = from;
    var scratch = document.createElement("div");
    doc.iter(from, to, function(line) {
      if (nextIntact && nextIntact.to == j) nextIntact = intact.shift();
      if (!nextIntact || nextIntact.from > j) {
        if (line.hidden) var html = scratch.innerHTML = "<pre></pre>";
        else {
          var html = '<pre' + (line.className ? ' class="' + line.className + '"' : '') + '>'
            + line.getHTML(makeTab) + '</pre>';
          // Kludge to make sure the styled element lies behind the selection (by z-index)
          if (line.bgClassName)
            html = '<div style="position: relative"><pre class="' + line.bgClassName +
            '" style="position: absolute; left: 0; right: 0; top: 0; bottom: 0; z-index: -2">&#160;</pre>' + html + "</div>";
        }
        scratch.innerHTML = html;
        lineDiv.insertBefore(scratch.firstChild, curNode);
      } else {
        curNode = curNode.nextSibling;
      }
      ++j;
    });
  }

  function updateGutter() {
    if (!options.gutter && !options.lineNumbers) return;
    var hText = mover.offsetHeight, hEditor = scroller.clientHeight;
    gutter.style.height = (hText - hEditor < 2 ? hEditor : hText) + "px";
    var html = [], i = showingFrom, normalNode;
    doc.iter(showingFrom, Math.max(showingTo, showingFrom + 1), function(line) {
      if (line.hidden) {
        html.push("<pre></pre>");
      } else {
        var marker = line.gutterMarker;
        var text = options.lineNumbers ? i + options.firstLineNumber : null;
        if (marker && marker.text)
          text = marker.text.replace("%N%", text != null ? text : "");
        else if (text == null)
          text = "\u00a0";
        html.push((marker && marker.style ? '<pre class="' + marker.style + '">' : "<pre>"), text);
        for (var j = 1; j < line.height; ++j) html.push("<br/>&#160;");
        html.push("</pre>");
        if (!marker) normalNode = i;
      }
      ++i;
    });
    gutter.style.display = "none";
    gutterText.innerHTML = html.join("");
    // Make sure scrolling doesn't cause number gutter size to pop
    if (normalNode != null) {
      var node = gutterText.childNodes[normalNode - showingFrom];
      var minwidth = String(doc.size).length, val = eltText(node), pad = "";
      while (val.length + pad.length < minwidth) pad += "\u00a0";
      if (pad) node.insertBefore(document.createTextNode(pad), node.firstChild);
    }
    gutter.style.display = "";
    var resized = Math.abs((parseInt(lineSpace.style.marginLeft) || 0) - gutter.offsetWidth) > 2;
    lineSpace.style.marginLeft = gutter.offsetWidth + "px";
    gutterDirty = false;
    return resized;
  }
  function updateSelection() {
    var collapsed = posEq(sel.from, sel.to);
    var fromPos = localCoords(sel.from, true);
    var toPos = collapsed ? fromPos : localCoords(sel.to, true);
    var headPos = sel.inverted ? fromPos : toPos, th = textHeight();
    var wrapOff = eltOffset(wrapper), lineOff = eltOffset(lineDiv);
    inputDiv.style.top = Math.max(0, Math.min(scroller.offsetHeight, headPos.y + lineOff.top - wrapOff.top)) + "px";
    inputDiv.style.left = Math.max(0, Math.min(scroller.offsetWidth, headPos.x + lineOff.left - wrapOff.left)) + "px";
    if (collapsed) {
      cursor.style.top = headPos.y + "px";
      cursor.style.left = (options.lineWrapping ? Math.min(headPos.x, lineSpace.offsetWidth) : headPos.x) + "px";
      cursor.style.display = "";
      selectionDiv.style.display = "none";
    } else {
      var sameLine = fromPos.y == toPos.y, html = "";
      function add(left, top, right, height) {
        html += '<div class="CodeMirror-selected" style="position: absolute; left: ' + left +
          'px; top: ' + top + 'px; right: ' + right + 'px; height: ' + height + 'px"></div>';
      }
      var clientWidth = lineSpace.clientWidth || lineSpace.offsetWidth;
      var clientHeight = lineSpace.clientHeight || lineSpace.offsetHeight;
      if (sel.from.ch && fromPos.y >= 0) {
        var right = sameLine ? clientWidth - toPos.x : 0;
        add(fromPos.x, fromPos.y, right, th);
      }
      var middleStart = Math.max(0, fromPos.y + (sel.from.ch ? th : 0));
      var middleHeight = Math.min(toPos.y, clientHeight) - middleStart;
      if (middleHeight > 0.2 * th)
        add(0, middleStart, 0, middleHeight);
      if ((!sameLine || !sel.from.ch) && toPos.y < clientHeight - .5 * th)
        add(0, toPos.y, clientWidth - toPos.x, th);
      selectionDiv.innerHTML = html;
      cursor.style.display = "none";
      selectionDiv.style.display = "";
    }
  }

  function setShift(val) {
    if (val) shiftSelecting = shiftSelecting || (sel.inverted ? sel.to : sel.from);
    else shiftSelecting = null;
  }
  function setSelectionUser(from, to) {
    var sh = shiftSelecting && clipPos(shiftSelecting);
    if (sh) {
      if (posLess(sh, from)) from = sh;
      else if (posLess(to, sh)) to = sh;
    }
    setSelection(from, to);
    userSelChange = true;
  }
  // Update the selection. Last two args are only used by
  // updateLines, since they have to be expressed in the line
  // numbers before the update.
  function setSelection(from, to, oldFrom, oldTo) {
    goalColumn = null;
    if (oldFrom == null) {oldFrom = sel.from.line; oldTo = sel.to.line;}
    if (posEq(sel.from, from) && posEq(sel.to, to)) return;
    if (posLess(to, from)) {var tmp = to; to = from; from = tmp;}

    // Skip over hidden lines.
    if (from.line != oldFrom) {
      var from1 = skipHidden(from, oldFrom, sel.from.ch);
      // If there is no non-hidden line left, force visibility on current line
      if (!from1) setLineHidden(from.line, false);
      else from = from1;
    }
    if (to.line != oldTo) to = skipHidden(to, oldTo, sel.to.ch);

    if (posEq(from, to)) sel.inverted = false;
    else if (posEq(from, sel.to)) sel.inverted = false;
    else if (posEq(to, sel.from)) sel.inverted = true;

    if (options.autoClearEmptyLines && posEq(sel.from, sel.to)) {
      var head = sel.inverted ? from : to;
      if (head.line != sel.from.line && sel.from.line < doc.size) {
        var oldLine = getLine(sel.from.line);
        if (/^\s+$/.test(oldLine.text))
          setTimeout(operation(function() {
            if (oldLine.parent && /^\s+$/.test(oldLine.text)) {
              var no = lineNo(oldLine);
              replaceRange("", {line: no, ch: 0}, {line: no, ch: oldLine.text.length});
            }
          }, 10));
      }
    }

    sel.from = from; sel.to = to;
    selectionChanged = true;
  }
  function skipHidden(pos, oldLine, oldCh) {
    function getNonHidden(dir) {
      var lNo = pos.line + dir, end = dir == 1 ? doc.size : -1;
      while (lNo != end) {
        var line = getLine(lNo);
        if (!line.hidden) {
          var ch = pos.ch;
          if (ch > oldCh || ch > line.text.length) ch = line.text.length;
          return {line: lNo, ch: ch};
        }
        lNo += dir;
      }
    }
    var line = getLine(pos.line);
    if (!line.hidden) return pos;
    if (pos.line >= oldLine) return getNonHidden(1) || getNonHidden(-1);
    else return getNonHidden(-1) || getNonHidden(1);
  }
  function setCursor(line, ch, user) {
    var pos = clipPos({line: line, ch: ch || 0});
    (user ? setSelectionUser : setSelection)(pos, pos);
  }

  function clipLine(n) {return Math.max(0, Math.min(n, doc.size-1));}
  function clipPos(pos) {
    if (pos.line < 0) return {line: 0, ch: 0};
    if (pos.line >= doc.size) return {line: doc.size-1, ch: getLine(doc.size-1).text.length};
    var ch = pos.ch, linelen = getLine(pos.line).text.length;
    if (ch == null || ch > linelen) return {line: pos.line, ch: linelen};
    else if (ch < 0) return {line: pos.line, ch: 0};
    else return pos;
  }

  function findPosH(dir, unit) {
    var end = sel.inverted ? sel.from : sel.to, line = end.line, ch = end.ch;
    var lineObj = getLine(line);
    function findNextLine() {
      for (var l = line + dir, e = dir < 0 ? -1 : doc.size; l != e; l += dir) {
        var lo = getLine(l);
        if (!lo.hidden) { line = l; lineObj = lo; return true; }
      }
    }
    function moveOnce(boundToLine) {
      if (ch == (dir < 0 ? 0 : lineObj.text.length)) {
        if (!boundToLine && findNextLine()) ch = dir < 0 ? lineObj.text.length : 0;
        else return false;
      } else ch += dir;
      return true;
    }
    if (unit == "char") moveOnce();
    else if (unit == "column") moveOnce(true);
    else if (unit == "word") {
      var sawWord = false;
      for (;;) {
        if (dir < 0) if (!moveOnce()) break;
        if (isWordChar(lineObj.text.charAt(ch))) sawWord = true;
        else if (sawWord) {if (dir < 0) {dir = 1; moveOnce();} break;}
        if (dir > 0) if (!moveOnce()) break;
      }
    }
    return {line: line, ch: ch};
  }
  function moveH(dir, unit) {
    var pos = dir < 0 ? sel.from : sel.to;
    if (shiftSelecting || posEq(sel.from, sel.to)) pos = findPosH(dir, unit);
    setCursor(pos.line, pos.ch, true);
  }
  function deleteH(dir, unit) {
    if (!posEq(sel.from, sel.to)) replaceRange("", sel.from, sel.to);
    else if (dir < 0) replaceRange("", findPosH(dir, unit), sel.to);
    else replaceRange("", sel.from, findPosH(dir, unit));
    userSelChange = true;
  }
  var goalColumn = null;
  function moveV(dir, unit) {
    var dist = 0, pos = localCoords(sel.inverted ? sel.from : sel.to, true);
    if (goalColumn != null) pos.x = goalColumn;
    if (unit == "page") dist = Math.min(scroller.clientHeight, window.innerHeight || document.documentElement.clientHeight);
    else if (unit == "line") dist = textHeight();
    var target = coordsChar(pos.x, pos.y + dist * dir + 2);
    if (unit == "page") scroller.scrollTop += localCoords(target, true).y - pos.y;
    setCursor(target.line, target.ch, true);
    goalColumn = pos.x;
  }

  function selectWordAt(pos) {
    var line = getLine(pos.line).text;
    var start = pos.ch, end = pos.ch;
    while (start > 0 && isWordChar(line.charAt(start - 1))) --start;
    while (end < line.length && isWordChar(line.charAt(end))) ++end;
    setSelectionUser({line: pos.line, ch: start}, {line: pos.line, ch: end});
  }
  function selectLine(line) {
    setSelectionUser({line: line, ch: 0}, clipPos({line: line + 1, ch: 0}));
  }
  function indentSelected(mode) {
    if (posEq(sel.from, sel.to)) return indentLine(sel.from.line, mode);
    var e = sel.to.line - (sel.to.ch ? 0 : 1);
    for (var i = sel.from.line; i <= e; ++i) indentLine(i, mode);
  }

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

    var line = getLine(n), curSpace = line.indentation(options.tabSize),
        curSpaceString = line.text.match(/^\s*/)[0], indentation;
    if (how == "prev") {
      if (n) indentation = getLine(n-1).indentation(options.tabSize);
      else indentation = 0;
    }
    else if (how == "smart") indentation = mode.indent(state, line.text.slice(curSpaceString.length), line.text);
    else if (how == "add") indentation = curSpace + options.indentUnit;
    else if (how == "subtract") indentation = curSpace - options.indentUnit;
    indentation = Math.max(0, indentation);
    var diff = indentation - curSpace;

    if (!diff) {
      if (sel.from.line != n && sel.to.line != n) return;
      var indentString = curSpaceString;
    }
    else {
      var indentString = "", pos = 0;
      if (options.indentWithTabs)
        for (var i = Math.floor(indentation / options.tabSize); i; --i) {pos += options.tabSize; indentString += "\t";}
      while (pos < indentation) {++pos; indentString += " ";}
    }

    replaceRange(indentString, {line: n, ch: 0}, {line: n, ch: curSpaceString.length});
  }

  function loadMode() {
    mode = CodeMirror.getMode(options, options.mode);
    doc.iter(0, doc.size, function(line) { line.stateAfter = null; });
    work = [0];
    startWorker();
  }
  function gutterChanged() {
    var visible = options.gutter || options.lineNumbers;
    gutter.style.display = visible ? "" : "none";
    if (visible) gutterDirty = true;
    else lineDiv.parentNode.style.marginLeft = 0;
  }
  function wrappingChanged(from, to) {
    if (options.lineWrapping) {
      wrapper.className += " CodeMirror-wrap";
      var perLine = scroller.clientWidth / charWidth() - 3;
      doc.iter(0, doc.size, function(line) {
        if (line.hidden) return;
        var guess = Math.ceil(line.text.length / perLine) || 1;
        if (guess != 1) updateLineHeight(line, guess);
      });
      lineSpace.style.width = code.style.width = "";
    } else {
      wrapper.className = wrapper.className.replace(" CodeMirror-wrap", "");
      maxWidth = null; maxLine = "";
      doc.iter(0, doc.size, function(line) {
        if (line.height != 1 && !line.hidden) updateLineHeight(line, 1);
        if (line.text.length > maxLine.length) maxLine = line.text;
      });
    }
    changes.push({from: 0, to: doc.size});
  }
  function makeTab(col) {
    var w = options.tabSize - col % options.tabSize, cached = tabCache[w];
    if (cached) return cached;
    for (var str = '<span class="cm-tab">', i = 0; i < w; ++i) str += " ";
    return (tabCache[w] = {html: str + "</span>", width: w});
  }
  function themeChanged() {
    scroller.className = scroller.className.replace(/\s*cm-s-\w+/g, "") +
      options.theme.replace(/(^|\s)\s*/g, " cm-s-");
  }

  function TextMarker() { this.set = []; }
  TextMarker.prototype.clear = operation(function() {
    var min = Infinity, max = -Infinity;
    for (var i = 0, e = this.set.length; i < e; ++i) {
      var line = this.set[i], mk = line.marked;
      if (!mk || !line.parent) continue;
      var lineN = lineNo(line);
      min = Math.min(min, lineN); max = Math.max(max, lineN);
      for (var j = 0; j < mk.length; ++j)
        if (mk[j].marker == this) mk.splice(j--, 1);
    }
    if (min != Infinity)
      changes.push({from: min, to: max + 1});
  });
  TextMarker.prototype.find = function() {
    var from, to;
    for (var i = 0, e = this.set.length; i < e; ++i) {
      var line = this.set[i], mk = line.marked;
      for (var j = 0; j < mk.length; ++j) {
        var mark = mk[j];
        if (mark.marker == this) {
          if (mark.from != null || mark.to != null) {
            var found = lineNo(line);
            if (found != null) {
              if (mark.from != null) from = {line: found, ch: mark.from};
              if (mark.to != null) to = {line: found, ch: mark.to};
            }
          }
        }
      }
    }
    return {from: from, to: to};
  };

  function markText(from, to, className) {
    from = clipPos(from); to = clipPos(to);
    var tm = new TextMarker();
    if (!posLess(from, to)) return tm;
    function add(line, from, to, className) {
      getLine(line).addMark(new MarkedText(from, to, className, tm));
    }
    if (from.line == to.line) add(from.line, from.ch, to.ch, className);
    else {
      add(from.line, from.ch, null, className);
      for (var i = from.line + 1, e = to.line; i < e; ++i)
        add(i, null, null, className);
      add(to.line, null, to.ch, className);
    }
    changes.push({from: from.line, to: to.line + 1});
    return tm;
  }

  function setBookmark(pos) {
    pos = clipPos(pos);
    var bm = new Bookmark(pos.ch);
    getLine(pos.line).addMark(bm);
    return bm;
  }

  function findMarksAt(pos) {
    pos = clipPos(pos);
    var markers = [], marked = getLine(pos.line).marked;
    if (!marked) return markers;
    for (var i = 0, e = marked.length; i < e; ++i) {
      var m = marked[i];
      if ((m.from == null || m.from <= pos.ch) &&
          (m.to == null || m.to >= pos.ch))
        markers.push(m.marker || m);
    }
    return markers;
  }

  function addGutterMarker(line, text, className) {
    if (typeof line == "number") line = getLine(clipLine(line));
    line.gutterMarker = {text: text, style: className};
    gutterDirty = true;
    return line;
  }
  function removeGutterMarker(line) {
    if (typeof line == "number") line = getLine(clipLine(line));
    line.gutterMarker = null;
    gutterDirty = true;
  }

  function changeLine(handle, op) {
    var no = handle, line = handle;
    if (typeof handle == "number") line = getLine(clipLine(handle));
    else no = lineNo(handle);
    if (no == null) return null;
    if (op(line, no)) changes.push({from: no, to: no + 1});
    else return null;
    return line;
  }
  function setLineClass(handle, className, bgClassName) {
    return changeLine(handle, function(line) {
      if (line.className != className || line.bgClassName != bgClassName) {
        line.className = className;
        line.bgClassName = bgClassName;
        return true;
      }
    });
  }
  function setLineHidden(handle, hidden) {
    return changeLine(handle, function(line, no) {
      if (line.hidden != hidden) {
        line.hidden = hidden;
        updateLineHeight(line, hidden ? 0 : 1);
        var fline = sel.from.line, tline = sel.to.line;
        if (hidden && (fline == no || tline == no)) {
          var from = fline == no ? skipHidden({line: fline, ch: 0}, fline, 0) : sel.from;
          var to = tline == no ? skipHidden({line: tline, ch: 0}, tline, 0) : sel.to;
          // Can't hide the last visible line, we'd have no place to put the cursor
          if (!to) return;
          setSelection(from, to);
        }
        return (gutterDirty = true);
      }
    });
  }

  function lineInfo(line) {
    if (typeof line == "number") {
      if (!isLine(line)) return null;
      var n = line;
      line = getLine(line);
      if (!line) return null;
    }
    else {
      var n = lineNo(line);
      if (n == null) return null;
    }
    var marker = line.gutterMarker;
    return {line: n, handle: line, text: line.text, markerText: marker && marker.text,
            markerClass: marker && marker.style, lineClass: line.className, bgClass: line.bgClassName};
  }

  function stringWidth(str) {
    measure.innerHTML = "<pre><span>x</span></pre>";
    measure.firstChild.firstChild.firstChild.nodeValue = str;
    return measure.firstChild.firstChild.offsetWidth || 10;
  }
  // These are used to go from pixel positions to character
  // positions, taking varying character widths into account.
  function charFromX(line, x) {
    if (x <= 0) return 0;
    var lineObj = getLine(line), text = lineObj.text;
    function getX(len) {
      measure.innerHTML = "<pre><span>" + lineObj.getHTML(makeTab, len) + "</span></pre>";
      return measure.firstChild.firstChild.offsetWidth;
    }
    var from = 0, fromX = 0, to = text.length, toX;
    // Guess a suitable upper bound for our search.
    var estimated = Math.min(to, Math.ceil(x / charWidth()));
    for (;;) {
      var estX = getX(estimated);
      if (estX <= x && estimated < to) estimated = Math.min(to, Math.ceil(estimated * 1.2));
      else {toX = estX; to = estimated; break;}
    }
    if (x > toX) return to;
    // Try to guess a suitable lower bound as well.
    estimated = Math.floor(to * 0.8); estX = getX(estimated);
    if (estX < x) {from = estimated; fromX = estX;}
    // Do a binary search between these bounds.
    for (;;) {
      if (to - from <= 1) return (toX - x > x - fromX) ? from : to;
      var middle = Math.ceil((from + to) / 2), middleX = getX(middle);
      if (middleX > x) {to = middle; toX = middleX;}
      else {from = middle; fromX = middleX;}
    }
  }

  var tempId = Math.floor(Math.random() * 0xffffff).toString(16);
  function measureLine(line, ch) {
    if (ch == 0) return {top: 0, left: 0};
    var extra = "";
    // Include extra text at the end to make sure the measured line is wrapped in the right way.
    if (options.lineWrapping) {
      var end = line.text.indexOf(" ", ch + 6);
      extra = htmlEscape(line.text.slice(ch + 1, end < 0 ? line.text.length : end + (ie ? 5 : 0)));
    }
    measure.innerHTML = "<pre>" + line.getHTML(makeTab, ch) +
      '<span id="CodeMirror-temp-' + tempId + '">' + htmlEscape(line.text.charAt(ch) || " ") + "</span>" +
      extra + "</pre>";
    var elt = document.getElementById("CodeMirror-temp-" + tempId);
    var top = elt.offsetTop, left = elt.offsetLeft;
    // Older IEs report zero offsets for spans directly after a wrap
    if (ie && top == 0 && left == 0) {
      var backup = document.createElement("span");
      backup.innerHTML = "x";
      elt.parentNode.insertBefore(backup, elt.nextSibling);
      top = backup.offsetTop;
    }
    return {top: top, left: left};
  }
  function localCoords(pos, inLineWrap) {
    var x, lh = textHeight(), y = lh * (heightAtLine(doc, pos.line) - (inLineWrap ? displayOffset : 0));
    if (pos.ch == 0) x = 0;
    else {
      var sp = measureLine(getLine(pos.line), pos.ch);
      x = sp.left;
      if (options.lineWrapping) y += Math.max(0, sp.top);
    }
    return {x: x, y: y, yBot: y + lh};
  }
  // Coords must be lineSpace-local
  function coordsChar(x, y) {
    if (y < 0) y = 0;
    var th = textHeight(), cw = charWidth(), heightPos = displayOffset + Math.floor(y / th);
    var lineNo = lineAtHeight(doc, heightPos);
    if (lineNo >= doc.size) return {line: doc.size - 1, ch: getLine(doc.size - 1).text.length};
    var lineObj = getLine(lineNo), text = lineObj.text;
    var tw = options.lineWrapping, innerOff = tw ? heightPos - heightAtLine(doc, lineNo) : 0;
    if (x <= 0 && innerOff == 0) return {line: lineNo, ch: 0};
    function getX(len) {
      var sp = measureLine(lineObj, len);
      if (tw) {
        var off = Math.round(sp.top / th);
        return Math.max(0, sp.left + (off - innerOff) * scroller.clientWidth);
      }
      return sp.left;
    }
    var from = 0, fromX = 0, to = text.length, toX;
    // Guess a suitable upper bound for our search.
    var estimated = Math.min(to, Math.ceil((x + innerOff * scroller.clientWidth * .9) / cw));
    for (;;) {
      var estX = getX(estimated);
      if (estX <= x && estimated < to) estimated = Math.min(to, Math.ceil(estimated * 1.2));
      else {toX = estX; to = estimated; break;}
    }
    if (x > toX) return {line: lineNo, ch: to};
    // Try to guess a suitable lower bound as well.
    estimated = Math.floor(to * 0.8); estX = getX(estimated);
    if (estX < x) {from = estimated; fromX = estX;}
    // Do a binary search between these bounds.
    for (;;) {
      if (to - from <= 1) return {line: lineNo, ch: (toX - x > x - fromX) ? from : to};
      var middle = Math.ceil((from + to) / 2), middleX = getX(middle);
      if (middleX > x) {to = middle; toX = middleX;}
      else {from = middle; fromX = middleX;}
    }
  }
  function pageCoords(pos) {
    var local = localCoords(pos, true), off = eltOffset(lineSpace);
    return {x: off.left + local.x, y: off.top + local.y, yBot: off.top + local.yBot};
  }

  var cachedHeight, cachedHeightFor, measureText;
  function textHeight() {
    if (measureText == null) {
      measureText = "<pre>";
      for (var i = 0; i < 49; ++i) measureText += "x<br/>";
      measureText += "x</pre>";
    }
    var offsetHeight = lineDiv.clientHeight;
    if (offsetHeight == cachedHeightFor) return cachedHeight;
    cachedHeightFor = offsetHeight;
    measure.innerHTML = measureText;
    cachedHeight = measure.firstChild.offsetHeight / 50 || 1;
    measure.innerHTML = "";
    return cachedHeight;
  }
  var cachedWidth, cachedWidthFor = 0;
  function charWidth() {
    if (scroller.clientWidth == cachedWidthFor) return cachedWidth;
    cachedWidthFor = scroller.clientWidth;
    return (cachedWidth = stringWidth("x"));
  }
  function paddingTop() {return lineSpace.offsetTop;}
  function paddingLeft() {return lineSpace.offsetLeft;}

  function posFromMouse(e, liberal) {
    var offW = eltOffset(scroller, true), x, y;
    // Fails unpredictably on IE[67] when mouse is dragged around quickly.
    try { x = e.clientX; y = e.clientY; } catch (e) { return null; }
    // This is a mess of a heuristic to try and determine whether a
    // scroll-bar was clicked or not, and to return null if one was
    // (and !liberal).
    if (!liberal && (x - offW.left > scroller.clientWidth || y - offW.top > scroller.clientHeight))
      return null;
    var offL = eltOffset(lineSpace, true);
    return coordsChar(x - offL.left, y - offL.top);
  }
  function onContextMenu(e) {
    var pos = posFromMouse(e), scrollPos = scroller.scrollTop;
    if (!pos || window.opera) return; // Opera is difficult.
    if (posEq(sel.from, sel.to) || posLess(pos, sel.from) || !posLess(pos, sel.to))
      operation(setCursor)(pos.line, pos.ch);

    var oldCSS = input.style.cssText;
    inputDiv.style.position = "absolute";
    input.style.cssText = "position: fixed; width: 30px; height: 30px; top: " + (e.clientY - 5) +
      "px; left: " + (e.clientX - 5) + "px; z-index: 1000; background: white; " +
      "border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";
    leaveInputAlone = true;
    var val = input.value = getSelection();
    focusInput();
    selectInput(input);
    function rehide() {
      var newVal = splitLines(input.value).join("\n");
      if (newVal != val) operation(replaceSelection)(newVal, "end");
      inputDiv.style.position = "relative";
      input.style.cssText = oldCSS;
      if (ie_lt9) scroller.scrollTop = scrollPos;
      leaveInputAlone = false;
      resetInput(true);
      slowPoll();
    }

    if (gecko) {
      e_stop(e);
      var mouseup = connect(window, "mouseup", function() {
        mouseup();
        setTimeout(rehide, 20);
      }, true);
    } else {
      setTimeout(rehide, 50);
    }
  }

  // Cursor-blinking
  function restartBlink() {
    clearInterval(blinker);
    var on = true;
    cursor.style.visibility = "";
    blinker = setInterval(function() {
      cursor.style.visibility = (on = !on) ? "" : "hidden";
    }, 650);
  }

  var matching = {"(": ")>", ")": "(<", "[": "]>", "]": "[<", "{": "}>", "}": "{<"};
  function matchBrackets(autoclear) {
    var head = sel.inverted ? sel.from : sel.to, line = getLine(head.line), pos = head.ch - 1;
    var match = (pos >= 0 && matching[line.text.charAt(pos)]) || matching[line.text.charAt(++pos)];
    if (!match) return;
    var ch = match.charAt(0), forward = match.charAt(1) == ">", d = forward ? 1 : -1, st = line.styles;
    for (var off = pos + 1, i = 0, e = st.length; i < e; i+=2)
      if ((off -= st[i].length) <= 0) {var style = st[i+1]; break;}

    var stack = [line.text.charAt(pos)], re = /[(){}[\]]/;
    function scan(line, from, to) {
      if (!line.text) return;
      var st = line.styles, pos = forward ? 0 : line.text.length - 1, cur;
      for (var i = forward ? 0 : st.length - 2, e = forward ? st.length : -2; i != e; i += 2*d) {
        var text = st[i];
        if (st[i+1] != null && st[i+1] != style) {pos += d * text.length; continue;}
        for (var j = forward ? 0 : text.length - 1, te = forward ? text.length : -1; j != te; j += d, pos+=d) {
          if (pos >= from && pos < to && re.test(cur = text.charAt(j))) {
            var match = matching[cur];
            if (match.charAt(1) == ">" == forward) stack.push(cur);
            else if (stack.pop() != match.charAt(0)) return {pos: pos, match: false};
            else if (!stack.length) return {pos: pos, match: true};
          }
        }
      }
    }
    for (var i = head.line, e = forward ? Math.min(i + 100, doc.size) : Math.max(-1, i - 100); i != e; i+=d) {
      var line = getLine(i), first = i == head.line;
      var found = scan(line, first && forward ? pos + 1 : 0, first && !forward ? pos : line.text.length);
      if (found) break;
    }
    if (!found) found = {pos: null, match: false};
    var style = found.match ? "CodeMirror-matchingbracket" : "CodeMirror-nonmatchingbracket";
    var one = markText({line: head.line, ch: pos}, {line: head.line, ch: pos+1}, style),
        two = found.pos != null && markText({line: i, ch: found.pos}, {line: i, ch: found.pos + 1}, style);
    var clear = operation(function(){one.clear(); two && two.clear();});
    if (autoclear) setTimeout(clear, 800);
    else bracketHighlighted = clear;
  }

  // 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(n) {
    var minindent, minline;
    for (var search = n, lim = n - 40; search > lim; --search) {
      if (search == 0) return 0;
      var line = getLine(search-1);
      if (line.stateAfter) return search;
      var indented = line.indentation(options.tabSize);
      if (minline == null || minindent > indented) {
        minline = search - 1;
        minindent = indented;
      }
    }
    return minline;
  }
  function getStateBefore(n) {
    var start = findStartLine(n), state = start && getLine(start-1).stateAfter;
    if (!state) state = startState(mode);
    else state = copyState(mode, state);
    doc.iter(start, n, function(line) {
      line.highlight(mode, state, options.tabSize);
      line.stateAfter = copyState(mode, state);
    });
    if (start < n) changes.push({from: start, to: n});
    if (n < doc.size && !getLine(n).stateAfter) work.push(n);
    return state;
  }
  function highlightLines(start, end) {
    var state = getStateBefore(start);
    doc.iter(start, end, function(line) {
      line.highlight(mode, state, options.tabSize);
      line.stateAfter = copyState(mode, state);
    });
  }
  function highlightWorker() {
    var end = +new Date + options.workTime;
    var foundWork = work.length;
    while (work.length) {
      if (!getLine(showingFrom).stateAfter) var task = showingFrom;
      else var task = work.pop();
      if (task >= doc.size) continue;
      var start = findStartLine(task), state = start && getLine(start-1).stateAfter;
      if (state) state = copyState(mode, state);
      else state = startState(mode);

      var unchanged = 0, compare = mode.compareStates, realChange = false,
          i = start, bail = false;
      doc.iter(i, doc.size, function(line) {
        var hadState = line.stateAfter;
        if (+new Date > end) {
          work.push(i);
          startWorker(options.workDelay);
          if (realChange) changes.push({from: task, to: i + 1});
          return (bail = true);
        }
        var changed = line.highlight(mode, state, options.tabSize);
        if (changed) realChange = true;
        line.stateAfter = copyState(mode, state);
        if (compare) {
          if (hadState && compare(hadState, state)) return true;
        } else {
          if (changed !== false || !hadState) unchanged = 0;
          else if (++unchanged > 3 && (!mode.indent || mode.indent(hadState, "") == mode.indent(state, "")))
            return true;
        }
        ++i;
      });
      if (bail) return;
      if (realChange) changes.push({from: task, to: i + 1});
    }
    if (foundWork && options.onHighlightComplete)
      options.onHighlightComplete(instance);
  }
  function startWorker(time) {
    if (!work.length) return;
    highlight.set(time, operation(highlightWorker));
  }

  // 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.
  function startOperation() {
    updateInput = userSelChange = textChanged = null;
    changes = []; selectionChanged = false; callbacks = [];
  }
  function endOperation() {
    var reScroll = false, updated;
    if (selectionChanged) reScroll = !scrollCursorIntoView();
    if (changes.length) updated = updateDisplay(changes, true);
    else {
      if (selectionChanged) updateSelection();
      if (gutterDirty) updateGutter();
    }
    if (reScroll) scrollCursorIntoView();
    if (selectionChanged) {scrollEditorIntoView(); restartBlink();}

    if (focused && !leaveInputAlone &&
        (updateInput === true || (updateInput !== false && selectionChanged)))
      resetInput(userSelChange);

    if (selectionChanged && options.matchBrackets)
      setTimeout(operation(function() {
        if (bracketHighlighted) {bracketHighlighted(); bracketHighlighted = null;}
        if (posEq(sel.from, sel.to)) matchBrackets(false);
      }), 20);
    var tc = textChanged, cbs = callbacks; // these can be reset by callbacks
    if (selectionChanged && options.onCursorActivity)
      options.onCursorActivity(instance);
    if (tc && options.onChange && instance)
      options.onChange(instance, tc);
    for (var i = 0; i < cbs.length; ++i) cbs[i](instance);
    if (updated && options.onUpdate) options.onUpdate(instance);
  }
  var nestedOperation = 0;
  function operation(f) {
    return function() {
      if (!nestedOperation++) startOperation();
      try {var result = f.apply(this, arguments);}
      finally {if (!--nestedOperation) endOperation();}
      return result;
    };
  }

  for (var ext in extensions)
    if (extensions.propertyIsEnumerable(ext) &&
        !instance.propertyIsEnumerable(ext))
      instance[ext] = extensions[ext];
  return instance;
} // (end of function CodeMirror)

// The default configuration options.
CodeMirror.defaults = {
  value: "",
  mode: null,
  theme: "default",
  indentUnit: 2,
  indentWithTabs: false,
  smartIndent: true,
  tabSize: 4,
  keyMap: "default",
  extraKeys: null,
  electricChars: true,
  autoClearEmptyLines: false,
  onKeyEvent: null,
  lineWrapping: false,
  lineNumbers: false,
  gutter: false,
  fixedGutter: false,
  firstLineNumber: 1,
  readOnly: false,
  onChange: null,
  onCursorActivity: null,
  onGutterClick: null,
  onHighlightComplete: null,
  onUpdate: null,
  onFocus: null, onBlur: null, onScroll: null,
  matchBrackets: false,
  workTime: 100,
  workDelay: 200,
  pollInterval: 100,
  undoDepth: 40,
  tabindex: null,
  autofocus: null
};

var ios = /AppleWebKit/.test(navigator.userAgent) && /Mobile\/\w+/.test(navigator.userAgent);
var mac = ios || /Mac/.test(navigator.platform);
var win = /Win/.test(navigator.platform);

// 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;
  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 (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) {
  var spec = CodeMirror.resolveMode(spec);
  var mfactory = modes[spec.name];
  if (!mfactory) {
    if (window.console) console.warn("No mode " + spec.name + " found, falling back to plain text.");
    return CodeMirror.getMode(options, "text/plain");
  }
  return mfactory(options, spec);
};
CodeMirror.listModes = function() {
  var list = [];
  for (var m in modes)
    if (modes.propertyIsEnumerable(m)) list.push(m);
  return list;
};
CodeMirror.listMIMEs = function() {
  var list = [];
  for (var m in mimeModes)
    if (mimeModes.propertyIsEnumerable(m)) list.push({mime: m, mode: mimeModes[m]});
  return list;
};

var extensions = CodeMirror.extensions = {};
CodeMirror.defineExtension = function(name, func) {
  extensions[name] = func;
};

var commands = CodeMirror.commands = {
  selectAll: function(cm) {cm.setSelection({line: 0, ch: 0}, {line: cm.lineCount() - 1});},
  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, {line: from.line + 1, ch: 0});
    else cm.replaceRange("", from, sel ? to : {line: from.line});
  },
  deleteLine: function(cm) {var l = cm.getCursor().line; cm.replaceRange("", {line: l, ch: 0}, {line: l});},
  undo: function(cm) {cm.undo();},
  redo: function(cm) {cm.redo();},
  goDocStart: function(cm) {cm.setCursor(0, 0, true);},
  goDocEnd: function(cm) {cm.setSelection({line: cm.lineCount() - 1}, null, true);},
  goLineStart: function(cm) {cm.setCursor(cm.getCursor().line, 0, true);},
  goLineStartSmart: function(cm) {
    var cur = cm.getCursor();
    var text = cm.getLine(cur.line), firstNonWS = Math.max(0, text.search(/\S/));
    cm.setCursor(cur.line, cur.ch <= firstNonWS && cur.ch ? 0 : firstNonWS, true);
  },
  goLineEnd: function(cm) {cm.setSelection({line: cm.getCursor().line}, null, true);},
  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");},
  goWordRight: function(cm) {cm.moveH(1, "word");},
  delCharLeft: function(cm) {cm.deleteH(-1, "char");},
  delCharRight: function(cm) {cm.deleteH(1, "char");},
  delWordLeft: function(cm) {cm.deleteH(-1, "word");},
  delWordRight: function(cm) {cm.deleteH(1, "word");},
  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");},
  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),
                      {line: cur.line, ch: cur.ch - 1}, {line: cur.line, ch: cur.ch + 1});
  },
  newlineAndIndent: function(cm) {
    cm.replaceSelection("\n", "end");
    cm.indentLine(cm.getCursor().line);
  },
  toggleOverwrite: function(cm) {cm.toggleOverwrite();}
};

var keyMap = CodeMirror.keyMap = {};
keyMap.basic = {
  "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
  "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
  "Delete": "delCharRight", "Backspace": "delCharLeft", "Tab": "insertTab", "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": "goWordLeft", "Ctrl-Right": "goWordRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
  "Ctrl-Backspace": "delWordLeft", "Ctrl-Delete": "delWordRight", "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": "goWordLeft",
  "Alt-Right": "goWordRight", "Cmd-Left": "goLineStart", "Cmd-Right": "goLineEnd", "Alt-Backspace": "delWordLeft",
  "Ctrl-Alt-Backspace": "delWordRight", "Alt-Delete": "delWordRight", "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": "goPageUp", "Shift-Ctrl-V": "goPageDown", "Ctrl-D": "delCharRight", "Ctrl-H": "delCharLeft",
  "Alt-D": "delWordRight", "Alt-Backspace": "delWordLeft", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars"
};

function getKeyMap(val) {
  if (typeof val == "string") return keyMap[val];
  else return val;
}
function lookupKey(name, extraMap, map, handle) {
  function lookup(map) {
    map = getKeyMap(map);
    var found = map[name];
    if (found != null && handle(found)) return true;
    if (map.catchall) return handle(map.catchall);
    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) {
      if (lookup(fallthrough[i])) return true;
    }
    return false;
  }
  if (extraMap && lookup(extraMap)) return true;
  return lookup(map);
}
function isModifierKey(event) {
  var name = keyNames[e_prop(event, "keyCode")];
  return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
}

CodeMirror.fromTextArea = function(textarea, options) {
  if (!options) options = {};
  options.value = textarea.value;
  if (!options.tabindex && textarea.tabindex)
    options.tabindex = textarea.tabindex;
  if (options.autofocus == null && textarea.getAttribute("autofocus") != null)
    options.autofocus = true;

  function save() {textarea.value = instance.getValue();}
  if (textarea.form) {
    // Deplorable hack to make the submit method do the right thing.
    var rmSubmit = connect(textarea.form, "submit", save, true);
    if (typeof textarea.form.submit == "function") {
      var realSubmit = textarea.form.submit;
      function wrappedSubmit() {
        save();
        textarea.form.submit = realSubmit;
        textarea.form.submit();
        textarea.form.submit = wrappedSubmit;
      }
      textarea.form.submit = wrappedSubmit;
    }
  }

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

// 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;

// 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;
}
StringStream.prototype = {
  eol: function() {return this.pos >= this.string.length;},
  sol: function() {return this.pos == 0;},
  peek: function() {return this.string.charAt(this.pos);},
  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() {return countColumn(this.string, this.start, this.tabSize);},
  indentation: function() {return countColumn(this.string, null, this.tabSize);},
  match: function(pattern, consume, caseInsensitive) {
    if (typeof pattern == "string") {
      function cased(str) {return caseInsensitive ? str.toLowerCase() : str;}
      if (cased(this.string).indexOf(cased(pattern), this.pos) == this.pos) {
        if (consume !== false) this.pos += pattern.length;
        return true;
      }
    }
    else {
      var match = this.string.slice(this.pos).match(pattern);
      if (match && consume !== false) this.pos += match[0].length;
      return match;
    }
  },
  current: function(){return this.string.slice(this.start, this.pos);}
};
CodeMirror.StringStream = StringStream;

function MarkedText(from, to, className, marker) {
  this.from = from; this.to = to; this.style = className; this.marker = marker;
}
MarkedText.prototype = {
  attach: function(line) { this.marker.set.push(line); },
  detach: function(line) {
    var ix = indexOf(this.marker.set, line);
    if (ix > -1) this.marker.set.splice(ix, 1);
  },
  split: function(pos, lenBefore) {
    if (this.to <= pos && this.to != null) return null;
    var from = this.from < pos || this.from == null ? null : this.from - pos + lenBefore;
    var to = this.to == null ? null : this.to - pos + lenBefore;
    return new MarkedText(from, to, this.style, this.marker);
  },
  dup: function() { return new MarkedText(null, null, this.style, this.marker); },
  clipTo: function(fromOpen, from, toOpen, to, diff) {
    if (fromOpen && to > this.from && (to < this.to || this.to == null))
      this.from = null;
    else if (this.from != null && this.from >= from)
      this.from = Math.max(to, this.from) + diff;
    if (toOpen && (from < this.to || this.to == null) && (from > this.from || this.from == null))
      this.to = null;
    else if (this.to != null && this.to > from)
      this.to = to < this.to ? this.to + diff : from;
  },
  isDead: function() { return this.from != null && this.to != null && this.from >= this.to; },
  sameSet: function(x) { return this.marker == x.marker; }
};

function Bookmark(pos) {
  this.from = pos; this.to = pos; this.line = null;
}
Bookmark.prototype = {
  attach: function(line) { this.line = line; },
  detach: function(line) { if (this.line == line) this.line = null; },
  split: function(pos, lenBefore) {
    if (pos < this.from) {
      this.from = this.to = (this.from - pos) + lenBefore;
      return this;
    }
  },
  isDead: function() { return this.from > this.to; },
  clipTo: function(fromOpen, from, toOpen, to, diff) {
    if ((fromOpen || from < this.from) && (toOpen || to > this.to)) {
      this.from = 0; this.to = -1;
    } else if (this.from > from) {
      this.from = this.to = Math.max(to, this.from) + diff;
    }
  },
  sameSet: function(x) { return false; },
  find: function() {
    if (!this.line || !this.line.parent) return null;
    return {line: lineNo(this.line), ch: this.from};
  },
  clear: function() {
    if (this.line) {
      var found = indexOf(this.line.marked, this);
      if (found != -1) this.line.marked.splice(found, 1);
      this.line = null;
    }
  }
};

// Line objects. These hold state related to a line, including
// highlighting info (the styles array).
function Line(text, styles) {
  this.styles = styles || [text, null];
  this.text = text;
  this.height = 1;
  this.marked = this.gutterMarker = this.className = this.bgClassName = this.handlers = null;
  this.stateAfter = this.parent = this.hidden = null;
}
Line.inheritMarks = function(text, orig) {
  var ln = new Line(text), mk = orig && orig.marked;
  if (mk) {
    for (var i = 0; i < mk.length; ++i) {
      if (mk[i].to == null && mk[i].style) {
        var newmk = ln.marked || (ln.marked = []), mark = mk[i];
        var nmark = mark.dup(); newmk.push(nmark); nmark.attach(ln);
      }
    }
  }
  return ln;
}
Line.prototype = {
  // Replace a piece of a line, keeping the styles around it intact.
  replace: function(from, to_, text) {
    var st = [], mk = this.marked, to = to_ == null ? this.text.length : to_;
    copyStyles(0, from, this.styles, st);
    if (text) st.push(text, null);
    copyStyles(to, this.text.length, this.styles, st);
    this.styles = st;
    this.text = this.text.slice(0, from) + text + this.text.slice(to);
    this.stateAfter = null;
    if (mk) {
      var diff = text.length - (to - from);
      for (var i = 0; i < mk.length; ++i) {
        var mark = mk[i];
        mark.clipTo(from == null, from || 0, to_ == null, to, diff);
        if (mark.isDead()) {mark.detach(this); mk.splice(i--, 1);}
      }
    }
  },
  // Split a part off a line, keeping styles and markers intact.
  split: function(pos, textBefore) {
    var st = [textBefore, null], mk = this.marked;
    copyStyles(pos, this.text.length, this.styles, st);
    var taken = new Line(textBefore + this.text.slice(pos), st);
    if (mk) {
      for (var i = 0; i < mk.length; ++i) {
        var mark = mk[i];
        var newmark = mark.split(pos, textBefore.length);
        if (newmark) {
          if (!taken.marked) taken.marked = [];
          taken.marked.push(newmark); newmark.attach(taken);
          if (newmark == mark) mk.splice(i--, 1);
        }
      }
    }
    return taken;
  },
  append: function(line) {
    var mylen = this.text.length, mk = line.marked, mymk = this.marked;
    this.text += line.text;
    copyStyles(0, line.text.length, line.styles, this.styles);
    if (mymk) {
      for (var i = 0; i < mymk.length; ++i)
        if (mymk[i].to == null) mymk[i].to = mylen;
    }
    if (mk && mk.length) {
      if (!mymk) this.marked = mymk = [];
      outer: for (var i = 0; i < mk.length; ++i) {
        var mark = mk[i];
        if (!mark.from) {
          for (var j = 0; j < mymk.length; ++j) {
            var mymark = mymk[j];
            if (mymark.to == mylen && mymark.sameSet(mark)) {
              mymark.to = mark.to == null ? null : mark.to + mylen;
              if (mymark.isDead()) {
                mymark.detach(this);
                mk.splice(i--, 1);
              }
              continue outer;
            }
          }
        }
        mymk.push(mark);
        mark.attach(this);
        mark.from += mylen;
        if (mark.to != null) mark.to += mylen;
      }
    }
  },
  fixMarkEnds: function(other) {
    var mk = this.marked, omk = other.marked;
    if (!mk) return;
    for (var i = 0; i < mk.length; ++i) {
      var mark = mk[i], close = mark.to == null;
      if (close && omk) {
        for (var j = 0; j < omk.length; ++j)
          if (omk[j].sameSet(mark)) {close = false; break;}
      }
      if (close) mark.to = this.text.length;
    }
  },
  fixMarkStarts: function() {
    var mk = this.marked;
    if (!mk) return;
    for (var i = 0; i < mk.length; ++i)
      if (mk[i].from == null) mk[i].from = 0;
  },
  addMark: function(mark) {
    mark.attach(this);
    if (this.marked == null) this.marked = [];
    this.marked.push(mark);
    this.marked.sort(function(a, b){return (a.from || 0) - (b.from || 0);});
  },
  // Run the given mode's parser over a line, update the styles
  // array, which contains alternating fragments of text and CSS
  // classes.
  highlight: function(mode, state, tabSize) {
    var stream = new StringStream(this.text, tabSize), st = this.styles, pos = 0;
    var changed = false, curWord = st[0], prevWord;
    if (this.text == "" && mode.blankLine) mode.blankLine(state);
    while (!stream.eol()) {
      var style = mode.token(stream, state);
      var substr = this.text.slice(stream.start, stream.pos);
      stream.start = stream.pos;
      if (pos && st[pos-1] == style)
        st[pos-2] += substr;
      else if (substr) {
        if (!changed && (st[pos+1] != style || (pos && st[pos-2] != prevWord))) changed = true;
        st[pos++] = substr; st[pos++] = style;
        prevWord = curWord; curWord = st[pos];
      }
      // Give up when line is ridiculously long
      if (stream.pos > 5000) {
        st[pos++] = this.text.slice(stream.pos); st[pos++] = null;
        break;
      }
    }
    if (st.length != pos) {st.length = pos; changed = true;}
    if (pos && st[pos-2] != prevWord) changed = true;
    // Short lines with simple highlights return null, and are
    // counted as changed by the driver because they are likely to
    // highlight the same way in various contexts.
    return changed || (st.length < 5 && this.text.length < 10 ? null : false);
  },
  // Fetch the parser token for a given character. Useful for hacks
  // that want to inspect the mode state (say, for completion).
  getTokenAt: function(mode, state, ch) {
    var txt = this.text, stream = new StringStream(txt);
    while (stream.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,
            state: state};
  },
  indentation: function(tabSize) {return countColumn(this.text, null, tabSize);},
  // Produces an HTML fragment for the line, taking selection,
  // marking, and highlighting into account.
  getHTML: function(makeTab, endAt) {
    var html = [], first = true, col = 0;
    function span(text, style) {
      if (!text) return;
      // Work around a bug where, in some compat modes, IE ignores leading spaces
      if (first && ie && text.charAt(0) == " ") text = "\u00a0" + text.slice(1);
      first = false;
      if (text.indexOf("\t") == -1) {
        col += text.length;
        var escaped = htmlEscape(text);
      } else {
        var escaped = "";
        for (var pos = 0;;) {
          var idx = text.indexOf("\t", pos);
          if (idx == -1) {
            escaped += htmlEscape(text.slice(pos));
            col += text.length - pos;
            break;
          } else {
            col += idx - pos;
            var tab = makeTab(col);
            escaped += htmlEscape(text.slice(pos, idx)) + tab.html;
            col += tab.width;
            pos = idx + 1;
          }
        }
      }
      if (style) html.push('<span class="', style, '">', escaped, "</span>");
      else html.push(escaped);
    }
    var st = this.styles, allText = this.text, marked = this.marked;
    var len = allText.length;
    if (endAt != null) len = Math.min(endAt, len);
    function styleToClass(style) {
      if (!style) return null;
      return "cm-" + style.replace(/ +/g, " cm-");
    }

    if (!allText && endAt == null)
      span(" ");
    else if (!marked || !marked.length)
      for (var i = 0, ch = 0; ch < len; i+=2) {
        var str = st[i], style = st[i+1], l = str.length;
        if (ch + l > len) str = str.slice(0, len - ch);
        ch += l;
        span(str, styleToClass(style));
      }
    else {
      var pos = 0, i = 0, text = "", style, sg = 0;
      var nextChange = marked[0].from || 0, marks = [], markpos = 0;
      function advanceMarks() {
        var m;
        while (markpos < marked.length &&
               ((m = marked[markpos]).from == pos || m.from == null)) {
          if (m.style != null) marks.push(m);
          ++markpos;
        }
        nextChange = markpos < marked.length ? marked[markpos].from : Infinity;
        for (var i = 0; i < marks.length; ++i) {
          var to = marks[i].to || Infinity;
          if (to == pos) marks.splice(i--, 1);
          else nextChange = Math.min(to, nextChange);
        }
      }
      var m = 0;
      while (pos < len) {
        if (nextChange == pos) advanceMarks();
        var upto = Math.min(len, nextChange);
        while (true) {
          if (text) {
            var end = pos + text.length;
            var appliedStyle = style;
            for (var j = 0; j < marks.length; ++j)
              appliedStyle = (appliedStyle ? appliedStyle + " " : "") + marks[j].style;
            span(end > upto ? text.slice(0, upto - pos) : text, appliedStyle);
            if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
            pos = end;
          }
          text = st[i++]; style = styleToClass(st[i++]);
        }
      }
    }
    return html.join("");
  },
  cleanUp: function() {
    this.parent = null;
    if (this.marked)
      for (var i = 0, e = this.marked.length; i < e; ++i) this.marked[i].detach(this);
  }
};
// Utility used by replace and split above
function copyStyles(from, to, source, dest) {
  for (var i = 0, pos = 0, state = 0; pos < to; i+=2) {
    var part = source[i], end = pos + part.length;
    if (state == 0) {
      if (end > from) dest.push(part.slice(from - pos, Math.min(part.length, to - pos)), source[i+1]);
      if (end >= from) state = 1;
    }
    else if (state == 1) {
      if (end > to) dest.push(part.slice(0, to - pos), source[i+1]);
      else dest.push(part, source[i+1]);
    }
    pos = end;
  }
}

// Data structure that holds the sequence of lines.
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; },
  remove: function(at, n, callbacks) {
    for (var i = at, e = at + n; i < e; ++i) {
      var line = this.lines[i];
      this.height -= line.height;
      line.cleanUp();
      if (line.handlers)
        for (var j = 0; j < line.handlers.length; ++j) callbacks.push(line.handlers[j]);
    }
    this.lines.splice(at, n);
  },
  collapse: function(lines) {
    lines.splice.apply(lines, [lines.length, 0].concat(this.lines));
  },
  insertHeight: function(at, lines, height) {
    this.height += height;
    this.lines.splice.apply(this.lines, [at, 0].concat(lines));
    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; },
  remove: function(at, n, callbacks) {
    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.remove(at, rm, callbacks);
        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);
  },
  insert: function(at, lines) {
    var height = 0;
    for (var i = 0, e = lines.length; i < e; ++i) height += lines[i].height;
    this.insertHeight(at, lines, height);
  },
  insertHeight: 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.insertHeight(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();
  },
  iter: function(from, to, op) { this.iterN(from, to - from, op); },
  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;
    }
  }
};

function getLineAt(chunk, n) {
  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 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, e = chunk.children.length; ; ++i) {
      if (chunk.children[i] == cur) break;
      no += chunk.children[i].chunkSize();
    }
  }
  return no;
}
function lineAtHeight(chunk, h) {
  var n = 0;
  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(chunk, n) {
  var h = 0;
  outer: do {
    for (var i = 0, e = chunk.children.length; i < e; ++i) {
      var child = chunk.children[i], sz = child.chunkSize();
      if (n < sz) { chunk = child; continue outer; }
      n -= sz;
      h += child.height;
    }
    return h;
  } while (!chunk.lines);
  for (var i = 0; i < n; ++i) h += chunk.lines[i].height;
  return h;
}

// The history object 'chunks' changes that are made close together
// and at almost the same time into bigger undoable units.
function History() {
  this.time = 0;
  this.done = []; this.undone = [];
}
History.prototype = {
  addChange: function(start, added, old) {
    this.undone.length = 0;
    var time = +new Date, cur = this.done[this.done.length - 1], last = cur && cur[cur.length - 1];
    var dtime = time - this.time;
    if (dtime > 400 || !last) {
      this.done.push([{start: start, added: added, old: old}]);
    } else if (last.start > start + old.length || last.start + last.added < start - last.added + last.old.length) {
      cur.push({start: start, added: added, old: old});
    } else {
      var oldoff = 0;
      if (start < last.start) {
        for (var i = last.start - start - 1; i >= 0; --i)
          last.old.unshift(old[i]);
        oldoff = Math.min(0, added - old.length);
        last.added += last.start - start + oldoff;
        last.start = start;
      } else if (last.start < start) {
        oldoff = start - last.start;
        added += oldoff;
      }
      for (var i = last.added - oldoff, e = old.length; i < e; ++i)
        last.old.push(old[i]);
      if (last.added < added) last.added = added;
    }
    this.time = time;
  }
};

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) {
  if (e.which) return e.which;
  else if (e.button & 1) return 1;
  else if (e.button & 2) return 3;
  else if (e.button & 4) return 2;
}

// Allow 3rd-party code to override event properties by adding an override
// object to an event object.
function e_prop(e, prop) {
  var overridden = e.override && e.override.hasOwnProperty(prop);
  return overridden ? e.override[prop] : e[prop];
}

// Event handler registration. If disconnect is true, it'll return a
// function that unregisters the handler.
function connect(node, type, handler, disconnect) {
  if (typeof node.addEventListener == "function") {
    node.addEventListener(type, handler, false);
    if (disconnect) return function() {node.removeEventListener(type, handler, false);};
  }
  else {
    var wrapHandler = function(event) {handler(event || window.event);};
    node.attachEvent("on" + type, wrapHandler);
    if (disconnect) return function() {node.detachEvent("on" + type, wrapHandler);};
  }
}
CodeMirror.connect = connect;

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

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

var gecko = /gecko\/\d{7}/i.test(navigator.userAgent);
var ie = /MSIE \d/.test(navigator.userAgent);
var ie_lt9 = /MSIE [1-8]\b/.test(navigator.userAgent);
var webkit = /WebKit\//.test(navigator.userAgent);
var chrome = /Chrome\//.test(navigator.userAgent);
var khtml = /KHTML\//.test(navigator.userAgent);

// 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 = document.createElement('div');
  return "draggable" in div || "dragDrop" in div;
}();

var lineSep = "\n";
// Feature-detect whether newlines in textareas are converted to \r\n
(function () {
  var te = document.createElement("textarea");
  te.value = "foo\nbar";
  if (te.value.indexOf("\r") > -1) lineSep = "\r\n";
}());

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

function computedStyle(elt) {
  if (elt.currentStyle) return elt.currentStyle;
  return window.getComputedStyle(elt, null);
}

// Find the position of an element by following the offsetParent chain.
// If screen==true, it returns screen (rather than page) coordinates.
function eltOffset(node, screen) {
  var bod = node.ownerDocument.body;
  var x = 0, y = 0, skipBody = false;
  for (var n = node; n; n = n.offsetParent) {
    var ol = n.offsetLeft, ot = n.offsetTop;
    // Firefox reports weird inverted offsets when the body has a border.
    if (n == bod) { x += Math.abs(ol); y += Math.abs(ot); }
    else { x += ol, y += ot; }
    if (screen && computedStyle(n).position == "fixed")
      skipBody = true;
  }
  var e = screen && !skipBody ? null : bod;
  for (var n = node.parentNode; n != e; n = n.parentNode)
    if (n.scrollLeft != null) { x -= n.scrollLeft; y -= n.scrollTop;}
  return {left: x, top: y};
}
// Use the faster and saner getBoundingClientRect method when possible.
if (document.documentElement.getBoundingClientRect != null) eltOffset = function(node, screen) {
  // Take the parts of bounding client rect that we are interested in so we are able to edit if need be,
  // since the returned value cannot be changed externally (they are kept in sync as the element moves within the page)
  try { var box = node.getBoundingClientRect(); box = { top: box.top, left: box.left }; }
  catch(e) { box = {top: 0, left: 0}; }
  if (!screen) {
    // Get the toplevel scroll, working around browser differences.
    if (window.pageYOffset == null) {
      var t = document.documentElement || document.body.parentNode;
      if (t.scrollTop == null) t = document.body;
      box.top += t.scrollTop; box.left += t.scrollLeft;
    } else {
      box.top += window.pageYOffset; box.left += window.pageXOffset;
    }
  }
  return box;
};

// Get a node's text content.
function eltText(node) {
  return node.textContent || node.innerText || node.nodeValue || "";
}
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();
}

// Operations on {line, ch} objects.
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 {line: x.line, ch: x.ch};}

var escapeElement = document.createElement("pre");
function htmlEscape(str) {
  escapeElement.textContent = str;
  return escapeElement.innerHTML;
}
// Recent (late 2011) Opera betas insert bogus newlines at the start
// of the textContent, so we strip those.
if (htmlEscape("a") == "\na")
  htmlEscape = function(str) {
    escapeElement.textContent = str;
    return escapeElement.innerHTML.slice(1);
  };
// Some IEs don't preserve tabs through innerHTML
else if (htmlEscape("\t") != "\t")
  htmlEscape = function(str) {
    escapeElement.innerHTML = "";
    escapeElement.appendChild(document.createTextNode(str));
    return escapeElement.innerHTML;
  };
CodeMirror.htmlEscape = htmlEscape;

// Used to position the cursor after an undo/redo by finding the
// last edited character.
function editEnd(from, to) {
  if (!to) return 0;
  if (!from) return to.length;
  for (var i = from.length, j = to.length; i >= 0 && j >= 0; --i, --j)
    if (from.charAt(i) != to.charAt(j)) break;
  return j + 1;
}

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 isWordChar(ch) {
  return /\w/.test(ch) || ch.toUpperCase() != ch.toLowerCase();
}

// 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, nl, result = [];
  while ((nl = string.indexOf("\n", pos)) > -1) {
    result.push(string.slice(pos, string.charAt(nl-1) == "\r" ? nl - 1 : nl));
    pos = nl + 1;
  }
  result.push(string.slice(pos));
  return result;
} : function(string){return string.split(/\r?\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;
};

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

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", 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;
})();

return CodeMirror;

})();