// 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
window.CodeMirror = (function() {
  "use strict";
  // 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];

    var input = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em");
    input.setAttribute("wrap", "off"); input.setAttribute("autocorrect", "off"); input.setAttribute("autocapitalize", "off");
    // Wraps and hides input textarea
    var inputDiv = elt("div", [input], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
    // The empty scrollbar content, used solely for managing the scrollbar thumb.
    var scrollbarInner = elt("div", null, "CodeMirror-scrollbar-inner");
    // The vertical scrollbar. Horizontal scrolling is handled by the scroller itself.
    var scrollbar = elt("div", [scrollbarInner], "CodeMirror-scrollbar");
    // DIVs containing the selection and the actual code
    var lineDiv = elt("div"), selectionDiv = elt("div", null, null, "position: relative; z-index: -1");
    // Blinky cursor, and element used to ensure cursor fits at the end of a line
    var cursor = elt("pre", "\u00a0", "CodeMirror-cursor"), widthForcer = elt("pre", "\u00a0", "CodeMirror-cursor", "visibility: hidden");
    // Used to measure text size
    var measure = elt("div", null, null, "position: absolute; width: 100%; height: 0px; overflow: hidden; visibility: hidden;");
    var lineSpace = elt("div", [measure, cursor, widthForcer, selectionDiv, lineDiv], null, "position: relative; z-index: 0");
    var gutterText = elt("div", null, "CodeMirror-gutter-text"), gutter = elt("div", [gutterText], "CodeMirror-gutter");
    // Moved around its parent to cover visible view
    var mover = elt("div", [gutter, elt("div", [lineSpace], "CodeMirror-lines")], null, "position: relative");
    // Set to the height of the text, causes scrolling
    var sizer = elt("div", [mover], null, "position: relative");
    // Provides scrolling
    var scroller = elt("div", [sizer], "CodeMirror-scroll");
    scroller.setAttribute("tabIndex", "-1");
    // The element in which the editor lives.
    var wrapper = elt("div", [inputDiv, scrollbar, scroller], "CodeMirror" + (options.lineWrapping ? " CodeMirror-wrap" : ""));
    if (place.appendChild) place.appendChild(wrapper); else place(wrapper);

    themeChanged(); keyMapChanged();
    // Needed to hide big blue blinking cursor on Mobile Safari
    if (ios) input.style.width = "0px";
    if (!webkit) scroller.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 OS X >= 10.7. This has transparent scrollbars, so the
    // overlaying of one scrollbar with another won't work. This is a
    // temporary hack to simply turn off the overlay scrollbar. See
    // issue #727.
    if (mac_geLion) { scrollbar.style.zIndex = -2; scrollbar.style.visibility = "hidden"; }
    // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
    else if (ie_lt8) scrollbar.style.minWidth = "18px";

    // 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,
    // frontier is the point up to which the content has been parsed,
    // and history the undo history (instance of History constructor).
    var mode, doc = new BranchChunk([new LeafChunk([new Line("")])]), frontier = 0, 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, lastScrollTop = 0, draggingText,
        overwrite = false, suppressEdits = false, pasteIncoming = false;
    // Variables used by startOperation/endOperation to track what
    // happened during the operation.
    var updateInput, userSelChange, changes, textChanged, selectionChanged,
        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 = getLine(0), updateMaxLine = false, maxLineChanged = true;
    var pollingFast = false; // Ensures slowPoll doesn't cancel fastPoll
    var goalColumn = null;

    // 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, "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", onScrollMain);
    connect(scrollbar, "scroll", onScrollBar);
    connect(scrollbar, "mousedown", function() {if (focused) setTimeout(focusInput, 0);});
    var resizeHandler = connect(window, "resize", function() {
      if (wrapper.parentNode) updateDisplay(true);
      else resizeHandler();
    }, 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);

    function drag_(e) {
      if (options.onDragEvent && options.onDragEvent(instance, addStop(e))) return;
      e_stop(e);
    }
    if (options.dragDrop) {
      connect(scroller, "dragstart", onDragStart);
      connect(scroller, "dragenter", drag_);
      connect(scroller, "dragover", drag_);
      connect(scroller, "drop", operation(onDrop));
    }
    connect(scroller, "paste", function(){focusInput(); fastPoll();});
    connect(input, "paste", function(){pasteIncoming = true; fastPoll();});
    connect(input, "cut", operation(function(){
      if (!options.readOnly) replaceSelection("");
    }));

    // Needed to handle Tab key in KHTML
    if (khtml) connect(sizer, "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);
        else if (option == "keyMap") keyMapChanged();
        else if (option == "tabindex") input.tabIndex = value;
        if (option == "lineNumbers" || option == "gutter" || option == "firstLineNumber" ||
            option == "theme" || option == "lineNumberFormatter") {
          gutterChanged();
          updateDisplay(true);
        }
      },
      getOption: function(option) {return options[option];},
      getMode: function() {return mode;},
      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();},
      setHistory: function(histData) {
        history = new History();
        history.done = histData.done;
        history.undone = histData.undone;
      },
      getHistory: function() {
        function cp(arr) {
          for (var i = 0, nw = [], nwelt; i < arr.length; ++i) {
            nw.push(nwelt = []);
            for (var j = 0, elt = arr[i]; j < elt.length; ++j) {
              var old = [], cur = elt[j];
              nwelt.push({start: cur.start, added: cur.added, old: old});
              for (var k = 0; k < cur.old.length; ++k) old.push(hlText(cur.old[k]));
            }
          }
          return nw;
        }
        return {done: cp(history.done), undone: cp(history.undone)};
      },
      matchBrackets: operation(function(){matchBrackets(true);}),
      getTokenAt: operation(function(pos) {
        pos = clipPos(pos);
        return getLine(pos.line).getTokenAt(mode, getStateBefore(pos.line), options.tabSize, 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);
      },
      defaultTextHeight: function() { return textHeight(); },
      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,
      getViewport: function() { return {from: showingFrom, to: showingTo};},
      addWidget: function(pos, node, scroll, vert, horiz) {
        pos = localCoords(clipPos(pos));
        var top = pos.yBot, left = pos.x;
        node.style.position = "absolute";
        sizer.appendChild(node);
        if (vert == "over") top = pos.y;
        else if (vert == "near") {
          var vspace = Math.max(scroller.offsetHeight, doc.height * textHeight()),
              hspace = Math.max(sizer.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 = sizer.clientWidth - node.offsetWidth;
          node.style.right = "0px";
        } else {
          if (horiz == "left") left = 0;
          else if (horiz == "middle") left = (sizer.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, lineSep) {return getRange(clipPos(from), clipPos(to), lineSep);},

      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) scrollbar.scrollTop = scroller.scrollTop = y;
        updateDisplay([]);
      },
      getScrollInfo: function() {
        return {x: scroller.scrollLeft, y: scrollbar.scrollTop,
                height: scrollbar.scrollHeight, width: scroller.scrollWidth};
      },
      scrollIntoView: function(pos) {
        var coords = localCoords(pos ? clipPos(pos) : sel.inverted ? sel.from : sel.to);
        scrollIntoView(coords.x, coords.y, coords.x, coords.yBot);
      },

      setSize: function(width, height) {
        function interpret(val) {
          val = String(val);
          return /^\d+$/.test(val) ? val + "px" : val;
        }
        if (width != null) wrapper.style.width = interpret(width);
        if (height != null) scroller.style.height = interpret(height);
        instance.refresh();
      },

      operation: function(f){return operation(f)();},
      compoundChange: function(f){return compoundChange(f);},
      refresh: function(){
        updateDisplay(true, null, lastScrollTop);
        if (scrollbar.scrollHeight > lastScrollTop)
          scrollbar.scrollTop = lastScrollTop;
      },
      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 lineContent(line, wrapAt) {
      if (!line.styles)
        line.highlight(mode, line.stateAfter = getStateBefore(lineNo(line)), options.tabSize);
      return line.getContent(options.tabSize, wrapAt, options.lineWrapping);
    }

    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(lineSep) {
      var text = [];
      doc.iter(0, doc.size, function(line) { text.push(line.text); });
      return text.join(lineSep || "\n");
    }

    function onScrollBar(e) {
      if (Math.abs(scrollbar.scrollTop - lastScrollTop) > 1) {
        lastScrollTop = scroller.scrollTop = scrollbar.scrollTop;
        updateDisplay([]);
      }
    }

    function onScrollMain(e) {
      if (options.fixedGutter && gutter.style.left != scroller.scrollLeft + "px")
        gutter.style.left = scroller.scrollLeft + "px";
      if (Math.abs(scroller.scrollTop - lastScrollTop) > 1) {
        lastScrollTop = scroller.scrollTop;
        if (scrollbar.scrollTop != lastScrollTop)
          scrollbar.scrollTop = lastScrollTop;
        updateDisplay([]);
      }
      if (options.onScroll) options.onScroll(instance);
    }

    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 == sizer && 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) onContextMenu(e);
        return;
      case 2:
        if (start) setCursor(start.line, start.ch, true);
        setTimeout(focusInput, 20);
        e_preventDefault(e);
        return;
      }
      // For button 1, if it was clicked inside the editor
      // (posFromMouse returning non-null), we have to adjust the
      // selection.
      if (!start) {if (e_target(e) == scroller) e_preventDefault(e); return;}

      if (!focused) onFocus();

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

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

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

      function doSelect(cur) {
        if (type == "single") {
          setSelectionUser(start, cur);
        } else if (type == "double") {
          var word = findWordAt(cur);
          if (posLess(cur, startstart)) setSelectionUser(word.from, startend);
          else setSelectionUser(startstart, word.to);
        } else if (type == "triple") {
          if (posLess(cur, startstart)) setSelectionUser(startend, clipPos({line: cur.line, ch: 0}));
          else setSelectionUser(startstart, clipPos({line: cur.line + 1, ch: 0}));
        }
      }

      function extend(e) {
        var cur = posFromMouse(e, true);
        if (cur && !posEq(cur, last)) {
          if (!focused) onFocus();
          last = cur;
          doSelect(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) doSelect(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);
      e_preventDefault(e);
    }
    function onDrop(e) {
      if (options.onDragEvent && options.onDragEvent(instance, addStop(e))) return;
      e_preventDefault(e);
      var pos = posFromMouse(e, true), files = e.dataTransfer.files;
      if (!pos || options.readOnly) return;
      if (files && files.length && window.FileReader && window.File) {
        var n = files.length, text = Array(n), read = 0;
        var loadFile = function(file, i) {
          var reader = new FileReader;
          reader.onload = function() {
            text[i] = reader.result;
            if (++read == n) {
              pos = clipPos(pos);
              operation(function() {
                var end = replaceRange(text.join(""), pos, pos);
                setSelectionUser(pos, end);
              })();
            }
          };
          reader.readAsText(file);
        };
        for (var i = 0; i < n; ++i) loadFile(files[i], i);
      } else {
        // Don't do a replace if the drop happened inside of the selected text.
        if (draggingText && !(posLess(pos, sel.from) || posLess(sel.to, pos))) return;
        try {
          var text = e.dataTransfer.getData("Text");
          if (text) {
            compoundChange(function() {
              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 (e.dataTransfer.setDragImage)
        e.dataTransfer.setDragImage(elt('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;
    }
    var maybeTransition;
    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;
      var flipCtrlCmd = opera && mac;
      if (name == null || e.altGraphKey) return false;
      if (e_prop(e, "altKey")) name = "Alt-" + name;
      if (e_prop(e, flipCtrlCmd ? "metaKey" : "ctrlKey")) name = "Ctrl-" + name;
      if (e_prop(e, flipCtrlCmd ? "ctrlKey" : "metaKey")) name = "Cmd-" + name;

      var stopped = false;
      function stop() { stopped = true; }

      if (e_prop(e, "shiftKey")) {
        handled = lookupKey("Shift-" + name, options.extraKeys, options.keyMap,
                            function(b) {return doHandleBinding(b, true);}, stop)
               || lookupKey(name, options.extraKeys, options.keyMap, function(b) {
                 if (typeof b == "string" && /^go[A-Z]/.test(b)) return doHandleBinding(b);
               }, stop);
      } else {
        handled = lookupKey(name, options.extraKeys, options.keyMap, doHandleBinding, stop);
      }
      if (stopped) handled = false;
      if (handled) {
        e_preventDefault(e);
        restartBlink();
        if (ie_lt9) { e.oldKeyCode = e.keyCode; e.keyCode = 0; }
      }
      return handled;
    }
    function handleCharBinding(e, ch) {
      var handled = lookupKey("'" + ch + "'", options.extraKeys,
                              options.keyMap, function(b) { return doHandleBinding(b, true); });
      if (handled) {
        e_preventDefault(e);
        restartBlink();
      }
      return handled;
    }

    var lastStoppedKey = null;
    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 (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 (opera && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
      if (((opera && (!e.which || e.which < 10)) || 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 (scroller.className.search(/\bCodeMirror-focused\b/) == -1)
          scroller.className += " CodeMirror-focused";
      }
      slowPoll();
      restartBlink();
    }
    function onBlur() {
      if (focused) {
        if (options.onBlur) options.onBlur(instance);
        focused = false;
        if (bracketHighlighted)
          operation(function(){
            if (bracketHighlighted) { bracketHighlighted(); bracketHighlighted = null; }
          })();
        scroller.className = scroller.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;
      var old = [];
      doc.iter(from.line, to.line + 1, function(line) {
        old.push(newHL(line.text, line.markedSpans));
      });
      if (history) {
        history.addChange(from.line, newText.length, old);
        while (history.done.length > options.undoDepth) history.done.shift();
      }
      var lines = updateMarkedSpans(hlSpans(old[0]), hlSpans(lst(old)), from.ch, to.ch, newText);
      updateLinesNoUndo(from, to, lines, 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(newHL(line.text, line.markedSpans)); });
        out.push({start: change.start, added: change.old.length, old: replaced});
        var pos = {line: change.start + change.old.length - 1,
                   ch: editEnd(hlText(lst(replaced)), hlText(lst(change.old)))};
        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, lines, selFrom, selTo) {
      if (suppressEdits) return;
      var recomputeMaxLength = false, maxLineLength = maxLine.text.length;
      if (!options.lineWrapping)
        doc.iter(from.line, to.line + 1, function(line) {
          if (!line.hidden && line.text.length == maxLineLength) {recomputeMaxLength = true; return true;}
        });
      if (from.line != to.line || lines.length > 1) gutterDirty = true;

      var nlines = to.line - from.line, firstLine = getLine(from.line), lastLine = getLine(to.line);
      var lastHL = lst(lines);

      // First adjust the line structure
      if (from.ch == 0 && to.ch == 0 && hlText(lastHL) == "") {
        // This is a whole-line replace. Treated specially to make
        // sure line objects move the way they are supposed to.
        var added = [], prevLine = null;
        for (var i = 0, e = lines.length - 1; i < e; ++i)
          added.push(new Line(hlText(lines[i]), hlSpans(lines[i])));
        lastLine.update(lastLine.text, hlSpans(lastHL));
        if (nlines) doc.remove(from.line, nlines, callbacks);
        if (added.length) doc.insert(from.line, added);
      } else if (firstLine == lastLine) {
        if (lines.length == 1) {
          firstLine.update(firstLine.text.slice(0, from.ch) + hlText(lines[0]) + firstLine.text.slice(to.ch), hlSpans(lines[0]));
        } else {
          for (var added = [], i = 1, e = lines.length - 1; i < e; ++i)
            added.push(new Line(hlText(lines[i]), hlSpans(lines[i])));
          added.push(new Line(hlText(lastHL) + firstLine.text.slice(to.ch), hlSpans(lastHL)));
          firstLine.update(firstLine.text.slice(0, from.ch) + hlText(lines[0]), hlSpans(lines[0]));
          doc.insert(from.line + 1, added);
        }
      } else if (lines.length == 1) {
        firstLine.update(firstLine.text.slice(0, from.ch) + hlText(lines[0]) + lastLine.text.slice(to.ch), hlSpans(lines[0]));
        doc.remove(from.line + 1, nlines, callbacks);
      } else {
        var added = [];
        firstLine.update(firstLine.text.slice(0, from.ch) + hlText(lines[0]), hlSpans(lines[0]));
        lastLine.update(hlText(lastHL) + lastLine.text.slice(to.ch), hlSpans(lastHL));
        for (var i = 1, e = lines.length - 1; i < e; ++i)
          added.push(new Line(hlText(lines[i]), hlSpans(lines[i])));
        if (nlines > 1) doc.remove(from.line + 1, nlines - 1, callbacks);
        doc.insert(from.line + 1, added);
      }
      if (options.lineWrapping) {
        var perLine = Math.max(5, scroller.clientWidth / charWidth() - 3);
        doc.iter(from.line, from.line + lines.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, from.line + lines.length, function(line) {
          var l = line.text;
          if (!line.hidden && l.length > maxLineLength) {
            maxLine = line; maxLineLength = l.length; maxLineChanged = true;
            recomputeMaxLength = false;
          }
        });
        if (recomputeMaxLength) updateMaxLine = true;
      }

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

      var lendiff = lines.length - nlines - 1;
      // Remember that these lines changed, for updating the display
      changes.push({from: from.line, to: to.line + 1, diff: lendiff});
      if (options.onChange) {
        // Normalize lines to contain only strings, since that's what
        // the change event handler expects
        for (var i = 0; i < lines.length; ++i)
          if (typeof lines[i] != "string") lines[i] = lines[i].text;
        var changeObj = {from: from, to: to, text: lines};
        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(clipPos(selFrom), clipPos(selTo),
                   updateLine(sel.from.line), updateLine(sel.to.line));
    }

    function needsScrollbar() {
      var realHeight = doc.height * textHeight() + 2 * paddingTop();
      return realHeight * .99 > scroller.offsetHeight ? realHeight : false;
    }

    function updateVerticalScroll(scrollTop) {
      var scrollHeight = needsScrollbar();
      scrollbar.style.display = scrollHeight ? "block" : "none";
      if (scrollHeight) {
        scrollbarInner.style.height = sizer.style.minHeight = scrollHeight + "px";
        scrollbar.style.height = scroller.clientHeight + "px";
        if (scrollTop != null) {
          scrollbar.scrollTop = scroller.scrollTop = scrollTop;
          // 'Nudge' the scrollbar to work around a Webkit bug where,
          // in some situations, we'd end up with a scrollbar that
          // reported its scrollTop (and looked) as expected, but
          // *behaved* as if it was still in a previous state (i.e.
          // couldn't scroll up, even though it appeared to be at the
          // bottom).
          if (webkit) setTimeout(function() {
            if (scrollbar.scrollTop != scrollTop) return;
            scrollbar.scrollTop = scrollTop + (scrollTop ? -1 : 1);
            scrollbar.scrollTop = scrollTop;
          }, 0);
        }
      } else {
        sizer.style.minHeight = "";
      }
      // Position the mover div to align with the current virtual scroll position
      mover.style.top = displayOffset * textHeight() + "px";
    }

    function computeMaxLength() {
      maxLine = getLine(0); maxLineChanged = true;
      var maxLineLength = maxLine.text.length;
      doc.iter(1, doc.size, function(line) {
        var l = line.text;
        if (!line.hidden && l.length > maxLineLength) {
          maxLineLength = l.length; maxLine = line;
        }
      });
      updateMaxLine = false;
    }

    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 += lst(code).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 : lst(code).length;
      var newSel = computeSel({line: from.line + code.length - 1, ch: endch});
      updateLines(from, to, code, newSel.from, newSel.to);
    }

    function getRange(from, to, lineSep) {
      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(lineSep || "\n");
    }
    function getSelection(lineSep) {
      return getRange(sel.from, sel.to, lineSep);
    }

    function slowPoll() {
      if (pollingFast) return;
      poll.set(options.pollInterval, function() {
        readInput();
        if (focused) slowPoll();
      });
    }
    function fastPoll() {
      var missed = false;
      pollingFast = true;
      function p() {
        var changed = readInput();
        if (!changed && !missed) {missed = true; poll.set(60, p);}
        else {pollingFast = false; slowPoll();}
      }
      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 (!focused || hasSelection(input) || options.readOnly) return false;
      var text = input.value;
      if (text == prevInput) return false;
      if (!nestedOperation) startOperation();
      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) && !pasteIncoming)
        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");
      if (text.length > 1000) { input.value = prevInput = ""; }
      else prevInput = text;
      if (!nestedOperation) endOperation();
      pasteIncoming = false;
      return true;
    }
    function resetInput(user) {
      if (!posEq(sel.from, sel.to)) {
        prevInput = "";
        input.value = getSelection();
        if (focused) selectInput(input);
      } else if (user) prevInput = input.value = "";
    }

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

    function scrollCursorIntoView() {
      var coords = calculateCursorCoords();
      scrollIntoView(coords.x, coords.y, coords.x, coords.yBot);
      if (!focused) return;
      var box = sizer.getBoundingClientRect(), doScroll = null;
      if (coords.y + box.top < 0) doScroll = true;
      else if (coords.y + box.top + textHeight() > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
      if (doScroll != null) {
        var hidden = cursor.style.display == "none";
        if (hidden) {
          cursor.style.display = "";
          cursor.style.left = coords.x + "px";
          cursor.style.top = (coords.y - displayOffset) + "px";
        }
        cursor.scrollIntoView(doScroll);
        if (hidden) cursor.style.display = "none";
      }
    }
    function calculateCursorCoords() {
      var cursor = localCoords(sel.inverted ? sel.from : sel.to);
      var x = options.lineWrapping ? Math.min(cursor.x, lineSpace.offsetWidth) : cursor.x;
      return {x: x, y: cursor.y, yBot: cursor.yBot};
    }
    function scrollIntoView(x1, y1, x2, y2) {
      var scrollPos = calculateScrollPos(x1, y1, x2, y2);
      if (scrollPos.scrollLeft != null) {scroller.scrollLeft = scrollPos.scrollLeft;}
      if (scrollPos.scrollTop != null) {scrollbar.scrollTop = scroller.scrollTop = scrollPos.scrollTop;}
    }
    function calculateScrollPos(x1, y1, x2, y2) {
      var pl = paddingLeft(), pt = paddingTop();
      y1 += pt; y2 += pt; x1 += pl; x2 += pl;
      var screen = scroller.clientHeight, screentop = scrollbar.scrollTop, result = {};
      var docBottom = needsScrollbar() || Infinity;
      var atTop = y1 < pt + 10, atBottom = y2 + pt > docBottom - 10;
      if (y1 < screentop) result.scrollTop = atTop ? 0 : Math.max(0, y1);
      else if (y2 > screentop + screen) result.scrollTop = (atBottom ? docBottom : y2) - screen;

      var screenw = scroller.clientWidth, screenleft = scroller.scrollLeft;
      var gutterw = options.fixedGutter ? gutter.clientWidth : 0;
      var atLeft = x1 < gutterw + pl + 10;
      if (x1 < screenleft + gutterw || atLeft) {
        if (atLeft) x1 = 0;
        result.scrollLeft = Math.max(0, x1 - 10 - gutterw);
      } else if (x2 > screenw + screenleft - 3) {
        result.scrollLeft = x2 + 10 - screenw;
      }
      return result;
    }

    function visibleLines(scrollTop) {
      var lh = textHeight(), top = (scrollTop != null ? scrollTop : scrollbar.scrollTop) - paddingTop();
      var fromHeight = Math.max(0, Math.floor(top / lh));
      var toHeight = Math.ceil((top + scroller.clientHeight) / lh);
      return {from: lineAtHeight(doc, fromHeight),
              to: lineAtHeight(doc, toHeight)};
    }
    // 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, scrollTop) {
      if (!scroller.clientWidth) {
        showingFrom = showingTo = displayOffset = 0;
        return;
      }
      // Compute the new visible window
      // If scrollTop is specified, use that to determine which lines
      // to render instead of the current scrollbar position.
      var visible = visibleLines(scrollTop);
      // Bail out if the visible area is already rendered and nothing changed.
      if (changes !== true && changes.length == 0 && visible.from > showingFrom && visible.to < showingTo) {
        updateVerticalScroll(scrollTop);
        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 && from == showingFrom && to == showingTo) {
        updateVerticalScroll(scrollTop);
        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 = "";

      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;
      if (from != showingFrom || to != showingTo && options.onViewportChange)
        setTimeout(function(){
          if (options.onViewportChange) options.onViewportChange(instance, from, to);
        });
      showingFrom = from; showingTo = to;
      displayOffset = heightAtLine(doc, from);
      startWorker(100);

      // 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() {
        var curNode = lineDiv.firstChild, heightChanged = false;
        doc.iter(showingFrom, showingTo, function(line) {
          // Work around bizarro IE7 bug where, sometimes, our curNode
          // is magically replaced with a new node in the DOM, leaving
          // us with a reference to an orphan (nextSibling-less) node.
          if (!curNode) return;
          if (!line.hidden) {
            var height = Math.round(curNode.offsetHeight / th) || 1;
            if (line.height != height) {
              updateLineHeight(line, height);
              gutterDirty = heightChanged = true;
            }
          }
          curNode = curNode.nextSibling;
        });
        return heightChanged;
      }

      if (options.lineWrapping) checkHeights();

      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();
      }
      updateVerticalScroll(scrollTop);
      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) {
      function killNode(node) {
        var tmp = node.nextSibling;
        node.parentNode.removeChild(node);
        return tmp;
      }
      // The first pass removes the DOM nodes that aren't intact.
      if (!intact.length) removeChildren(lineDiv);
      else {
        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;
      doc.iter(from, to, function(line) {
        if (nextIntact && nextIntact.to == j) nextIntact = intact.shift();
        if (!nextIntact || nextIntact.from > j) {
          if (line.hidden) var lineElement = elt("pre");
          else {
            var lineElement = lineContent(line);
            if (line.className) lineElement.className = line.className;
            // Kludge to make sure the styled element lies behind the selection (by z-index)
            if (line.bgClassName) {
              var pre = elt("pre", "\u00a0", line.bgClassName, "position: absolute; left: 0; right: 0; top: 0; bottom: 0; z-index: -2");
              lineElement = elt("div", [pre, lineElement], null, "position: relative");
            }
          }
          lineDiv.insertBefore(lineElement, 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 fragment = document.createDocumentFragment(), i = showingFrom, normalNode;
      doc.iter(showingFrom, Math.max(showingTo, showingFrom + 1), function(line) {
        if (line.hidden) {
          fragment.appendChild(elt("pre"));
        } else {
          var marker = line.gutterMarker;
          var text = options.lineNumbers ? options.lineNumberFormatter(i + options.firstLineNumber) : null;
          if (marker && marker.text)
            text = marker.text.replace("%N%", text != null ? text : "");
          else if (text == null)
            text = "\u00a0";
          var markerElement = fragment.appendChild(elt("pre", null, marker && marker.style));
          markerElement.innerHTML = text;
          for (var j = 1; j < line.height; ++j) {
            markerElement.appendChild(elt("br"));
            markerElement.appendChild(document.createTextNode("\u00a0"));
          }
          if (!marker) normalNode = i;
        }
        ++i;
      });
      gutter.style.display = "none";
      removeChildrenAndAdd(gutterText, fragment);
      // Make sure scrolling doesn't cause number gutter size to pop
      if (normalNode != null && options.lineNumbers) {
        var node = gutterText.childNodes[normalNode - showingFrom];
        var minwidth = String(doc.size).length, val = eltText(node.firstChild), 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, fragment = document.createDocumentFragment();
        var clientWidth = lineSpace.clientWidth || lineSpace.offsetWidth;
        var clientHeight = lineSpace.clientHeight || lineSpace.offsetHeight;
        var add = function(left, top, right, height) {
          var rstyle = quirksMode ? "width: " + (!right ? clientWidth : clientWidth - right - left) + "px"
                                  : "right: " + right + "px";
          fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
                                   "px; top: " + top + "px; " + rstyle + "; height: " + height + "px"));
        };
        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);
        removeChildrenAndAdd(selectionDiv, fragment);
        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 (toEnd || ch > oldCh || ch > line.text.length) ch = line.text.length;
            return {line: lNo, ch: ch};
          }
          lNo += dir;
        }
      }
      var line = getLine(pos.line);
      var toEnd = pos.ch == line.text.length && pos.ch != oldCh;
      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;
    }
    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") {
        var screen = Math.min(scroller.clientHeight, window.innerHeight || document.documentElement.clientHeight);
        var target = coordsChar(pos.x, pos.y + screen * dir);
      } else if (unit == "line") {
        var th = textHeight();
        var target = coordsChar(pos.x, pos.y + .5 * th + dir * th);
      }
      if (unit == "page") scrollbar.scrollTop += localCoords(target, true).y - pos.y;
      setCursor(target.line, target.ch, true);
      goalColumn = pos.x;
    }

    function findWordAt(pos) {
      var line = getLine(pos.line).text;
      var start = pos.ch, end = pos.ch;
      if (line) {
        if (pos.after === false || end == line.length) --start; else ++end;
        var startChar = line.charAt(start);
        var check = isWordChar(startChar) ? isWordChar :
                    /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);} :
                    function(ch) {return !/\s/.test(ch) && isWordChar(ch);};
        while (start > 0 && check(line.charAt(start - 1))) --start;
        while (end < line.length && check(line.charAt(end))) ++end;
      }
      return {from: {line: pos.line, ch: start}, to: {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 == "smart") {
        indentation = mode.indent(state, line.text.slice(curSpaceString.length), line.text);
        if (indentation == Pass) how = "prev";
      }
      if (how == "prev") {
        if (n) indentation = getLine(n-1).indentation(options.tabSize);
        else indentation = 0;
      }
      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;

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

      if (indentString != curSpaceString)
        replaceRange(indentString, {line: n, ch: 0}, {line: n, ch: curSpaceString.length});
      line.stateAfter = null;
    }

    function loadMode() {
      mode = CodeMirror.getMode(options, options.mode);
      doc.iter(0, doc.size, function(line) { line.stateAfter = null; });
      frontier = 0;
      startWorker(100);
    }
    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.minWidth = widthForcer.style.left = "";
      } else {
        wrapper.className = wrapper.className.replace(" CodeMirror-wrap", "");
        computeMaxLength();
        doc.iter(0, doc.size, function(line) {
          if (line.height != 1 && !line.hidden) updateLineHeight(line, 1);
        });
      }
      changes.push({from: 0, to: doc.size});
    }
    function themeChanged() {
      scroller.className = scroller.className.replace(/\s*cm-s-\S+/g, "") +
        options.theme.replace(/(^|\s)\s*/g, " cm-s-");
    }
    function keyMapChanged() {
      var style = keyMap[options.keyMap].style;
      wrapper.className = wrapper.className.replace(/\s*cm-keymap-\S+/g, "") +
        (style ? " cm-keymap-" + style : "");
    }

    function TextMarker(type, style) { this.lines = []; this.type = type; if (style) this.style = style; }
    TextMarker.prototype.clear = operation(function() {
      var min, max;
      for (var i = 0; i < this.lines.length; ++i) {
        var line = this.lines[i];
        var span = getMarkedSpanFor(line.markedSpans, this);
        if (span.from != null) min = lineNo(line);
        if (span.to != null) max = lineNo(line);
        line.markedSpans = removeMarkedSpan(line.markedSpans, span);
      }
      if (min != null) changes.push({from: min, to: max + 1});
      this.lines.length = 0;
      this.explicitlyCleared = true;
    });
    TextMarker.prototype.find = function() {
      var from, to;
      for (var i = 0; i < this.lines.length; ++i) {
        var line = this.lines[i];
        var span = getMarkedSpanFor(line.markedSpans, this);
        if (span.from != null || span.to != null) {
          var found = lineNo(line);
          if (span.from != null) from = {line: found, ch: span.from};
          if (span.to != null) to = {line: found, ch: span.to};
        }
      }
      if (this.type == "bookmark") return from;
      return from && {from: from, to: to};
    };

    function markText(from, to, className, options) {
      from = clipPos(from); to = clipPos(to);
      var marker = new TextMarker("range", className);
      if (options) for (var opt in options) if (options.hasOwnProperty(opt))
        marker[opt] = options[opt];
      var curLine = from.line;
      doc.iter(curLine, to.line + 1, function(line) {
        var span = {from: curLine == from.line ? from.ch : null,
                    to: curLine == to.line ? to.ch : null,
                    marker: marker};
        line.markedSpans = (line.markedSpans || []).concat([span]);
        marker.lines.push(line);
        ++curLine;
      });
      changes.push({from: from.line, to: to.line + 1});
      return marker;
    }

    function setBookmark(pos) {
      pos = clipPos(pos);
      var marker = new TextMarker("bookmark"), line = getLine(pos.line);
      history.addChange(pos.line, 1, [newHL(line.text, line.markedSpans)], true);
      var span = {from: pos.ch, to: pos.ch, marker: marker};
      line.markedSpans = (line.markedSpans || []).concat([span]);
      marker.lines.push(line);
      return marker;
    }

    function findMarksAt(pos) {
      pos = clipPos(pos);
      var markers = [], spans = getLine(pos.line).markedSpans;
      if (spans) for (var i = 0; i < spans.length; ++i) {
        var span = spans[i];
        if ((span.from == null || span.from <= pos.ch) &&
            (span.to == null || span.to >= pos.ch))
          markers.push(span.marker);
      }
      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;
          if (!options.lineWrapping) {
            if (hidden && line.text.length == maxLine.text.length) {
              updateMaxLine = true;
            } else if (!hidden && line.text.length > maxLine.text.length) {
              maxLine = line; updateMaxLine = false;
            }
          }
          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 measureLine(line, ch) {
      if (ch == 0) return {top: 0, left: 0};
      var pre = lineContent(line, ch);
      removeChildrenAndAdd(measure, pre);
      var anchor = pre.anchor;
      var top = anchor.offsetTop, left = anchor.offsetLeft;
      // Older IEs report zero offsets for spans directly after a wrap
      if (ie && top == 0 && left == 0) {
        var backup = elt("span", "x");
        anchor.parentNode.insertBefore(backup, anchor.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) {
      var th = textHeight(), cw = charWidth(), heightPos = displayOffset + Math.floor(y / th);
      if (heightPos < 0) return {line: 0, ch: 0};
      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};
      var wrongLine = false;
      function getX(len) {
        var sp = measureLine(lineObj, len);
        if (tw) {
          var off = Math.round(sp.top / th);
          wrongLine = off != innerOff;
          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) {
          var after = x - fromX < toX - x;
          return {line: lineNo, ch: after ? from : to, after: after};
        }
        var middle = Math.ceil((from + to) / 2), middleX = getX(middle);
        if (middleX > x) {to = middle; toX = middleX; if (wrongLine) toX += 1000; }
        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, measurePre;
    function textHeight() {
      if (measurePre == null) {
        measurePre = elt("pre");
        for (var i = 0; i < 49; ++i) {
          measurePre.appendChild(document.createTextNode("x"));
          measurePre.appendChild(elt("br"));
        }
        measurePre.appendChild(document.createTextNode("x"));
      }
      var offsetHeight = lineDiv.clientHeight;
      if (offsetHeight == cachedHeightFor) return cachedHeight;
      cachedHeightFor = offsetHeight;
      removeChildrenAndAdd(measure, measurePre.cloneNode(true));
      cachedHeight = measure.firstChild.offsetHeight / 50 || 1;
      removeChildren(measure);
      return cachedHeight;
    }
    var cachedWidth, cachedWidthFor = 0;
    function charWidth() {
      if (scroller.clientWidth == cachedWidthFor) return cachedWidth;
      cachedWidthFor = scroller.clientWidth;
      var anchor = elt("span", "x");
      var pre = elt("pre", [anchor]);
      removeChildrenAndAdd(measure, pre);
      return (cachedWidth = anchor.offsetWidth || 10);
    }
    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);
    }
    var detectingSelectAll;
    function onContextMenu(e) {
      var pos = posFromMouse(e), scrollPos = scrollbar.scrollTop;
      if (!pos || 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);";
      focusInput();
      resetInput(true);
      // Adds "Select all" to context menu in FF
      if (posEq(sel.from, sel.to)) input.value = prevInput = " ";

      function rehide() {
        inputDiv.style.position = "relative";
        input.style.cssText = oldCSS;
        if (ie_lt9) scrollbar.scrollTop = scrollPos;
        slowPoll();

        // Try to detect the user choosing select-all 
        if (input.selectionStart != null) {
          clearTimeout(detectingSelectAll);
          var extval = input.value = " " + (posEq(sel.from, sel.to) ? "" : input.value), i = 0;
          prevInput = " ";
          input.selectionStart = 1; input.selectionEnd = extval.length;
          detectingSelectAll = setTimeout(function poll(){
            if (prevInput == " " && input.selectionStart == 0)
              operation(commands.selectAll)(instance);
            else if (i++ < 10) detectingSelectAll = setTimeout(poll, 500);
            else resetInput();
          }, 200);
        }
      }

      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";
      }, options.cursorBlinkRate);
    }

    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] != 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 pos = findStartLine(n), state = pos && getLine(pos-1).stateAfter;
      if (!state) state = startState(mode);
      else state = copyState(mode, state);
      doc.iter(pos, n, function(line) {
        line.process(mode, state, options.tabSize);
        line.stateAfter = (pos == n - 1 || pos % 5 == 0) ? copyState(mode, state) : null;
      });
      return state;
    }
    function highlightWorker() {
      if (frontier >= showingTo) return;
      var end = +new Date + options.workTime, state = copyState(mode, getStateBefore(frontier));
      var startFrontier = frontier;
      doc.iter(frontier, showingTo, function(line) {
        if (frontier >= showingFrom) { // Visible
          line.highlight(mode, state, options.tabSize);
          line.stateAfter = copyState(mode, state);
        } else {
          line.process(mode, state, options.tabSize);
          line.stateAfter = frontier % 5 == 0 ? copyState(mode, state) : null;
        }
        ++frontier;
        if (+new Date > end) {
          startWorker(options.workDelay);
          return true;
        }
      });
      if (showingTo > startFrontier && frontier >= showingFrom)
        operation(function() {changes.push({from: startFrontier, to: frontier});})();
    }
    function startWorker(time) {
      if (frontier < showingTo)
        highlight.set(time, 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() {
      if (updateMaxLine) computeMaxLength();
      if (maxLineChanged && !options.lineWrapping) {
        var cursorWidth = widthForcer.offsetWidth, left = measureLine(maxLine, maxLine.text.length).left;
        if (!ie_lt8) {
          widthForcer.style.left = left + "px";
          lineSpace.style.minWidth = (left + cursorWidth) + "px";
        }
        maxLineChanged = false;
      }
      var newScrollPos, updated;
      if (selectionChanged) {
        var coords = calculateCursorCoords();
        newScrollPos = calculateScrollPos(coords.x, coords.y, coords.x, coords.yBot);
      }
      if (changes.length || newScrollPos && newScrollPos.scrollTop != null)
        updated = updateDisplay(changes, true, newScrollPos && newScrollPos.scrollTop);
      if (!updated) {
        if (selectionChanged) updateSelection();
        if (gutterDirty) updateGutter();
      }
      if (newScrollPos) scrollCursorIntoView();
      if (selectionChanged) restartBlink();

      if (focused && (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 sc = selectionChanged, cbs = callbacks; // these can be reset by callbacks
      if (textChanged && options.onChange && instance)
        options.onChange(instance, textChanged);
      if (sc && options.onCursorActivity)
        options.onCursorActivity(instance);
      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;
      };
    }

    function compoundChange(f) {
      history.startCompound();
      try { return f(); } finally { history.endCompound(); }
    }

    for (var ext in extensions)
      if (extensions.propertyIsEnumerable(ext) &&
          !instance.propertyIsEnumerable(ext))
        instance[ext] = extensions[ext];
    for (var i = 0; i < initHooks.length; ++i) initHooks[i](instance);
    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,
    onDragEvent: null,
    lineWrapping: false,
    lineNumbers: false,
    gutter: false,
    fixedGutter: false,
    firstLineNumber: 1,
    readOnly: false,
    dragDrop: true,
    onChange: null,
    onCursorActivity: null,
    onViewportChange: null,
    onGutterClick: null,
    onUpdate: null,
    onFocus: null, onBlur: null, onScroll: null,
    matchBrackets: false,
    cursorBlinkRate: 530,
    workTime: 100,
    workDelay: 200,
    pollInterval: 100,
    undoDepth: 40,
    tabindex: null,
    autofocus: null,
    lineNumberFormatter: function(integer) { return integer; }
  };

  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;
    if (arguments.length > 2) {
      mode.dependencies = [];
      for (var i = 2; i < arguments.length; ++i) mode.dependencies.push(arguments[i]);
    }
    modes[name] = mode;
  };
  CodeMirror.defineMIME = function(mime, spec) {
    mimeModes[mime] = spec;
  };
  CodeMirror.resolveMode = function(spec) {
    if (typeof spec == "string" && mimeModes.hasOwnProperty(spec))
      spec = mimeModes[spec];
    else if (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) return CodeMirror.getMode(options, "text/plain");
    var modeObj = mfactory(options, spec);
    if (modeExtensions.hasOwnProperty(spec.name)) {
      var exts = modeExtensions[spec.name];
      for (var prop in exts) if (exts.hasOwnProperty(prop)) modeObj[prop] = exts[prop];
    }
    modeObj.name = spec.name;
    return modeObj;
  };
  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 initHooks = [];
  CodeMirror.defineInitHook = function(f) {initHooks.push(f);};

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

  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");},
    defaultTab: function(cm) {
      if (cm.somethingSelected()) cm.indentSelection("add");
      else 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": "defaultTab", "Shift-Tab": "indentAuto",
    "Enter": "newlineAndIndent", "Insert": "toggleOverwrite"
  };
  // Note that the save and find-related commands aren't defined by
  // default. Unknown commands are simply ignored.
  keyMap.pcDefault = {
    "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
    "Ctrl-Home": "goDocStart", "Alt-Up": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Down": "goDocEnd",
    "Ctrl-Left": "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": "goPageDown", "Shift-Ctrl-V": "goPageUp", "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, stop) {
    function lookup(map) {
      map = getKeyMap(map);
      var found = map[name];
      if (found === false) {
        if (stop) stop();
        return true;
      }
      if (found != null && handle(found)) return true;
      if (map.nofallthrough) {
        if (stop) stop();
        return true;
      }
      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.isModifierKey = isModifierKey;

  CodeMirror.fromTextArea = function(textarea, options) {
    if (!options) options = {};
    options.value = textarea.value;
    if (!options.tabindex && textarea.tabindex)
      options.tabindex = textarea.tabindex;
    // Set autofocus to true if this textarea is focused, or if it has
    // autofocus and no other element is focused.
    if (options.autofocus == null) {
      var hasFocus = document.body;
      // doc.activeElement occasionally throws on IE
      try { hasFocus = document.activeElement; } catch(e) {}
      options.autofocus = hasFocus == textarea ||
        textarea.getAttribute("autofocus") != null && hasFocus == document.body;
    }

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

  var gecko = /gecko\/\d{7}/i.test(navigator.userAgent);
  var ie = /MSIE \d/.test(navigator.userAgent);
  var ie_lt8 = /MSIE [1-7]\b/.test(navigator.userAgent);
  var ie_lt9 = /MSIE [1-8]\b/.test(navigator.userAgent);
  var quirksMode = ie && document.documentMode == 5;
  var webkit = /WebKit\//.test(navigator.userAgent);
  var chrome = /Chrome\//.test(navigator.userAgent);
  var opera = /Opera\//.test(navigator.userAgent);
  var safari = /Apple Computer/.test(navigator.vendor);
  var khtml = /KHTML\//.test(navigator.userAgent);
  var mac_geLion = /Mac OS X 10\D([7-9]|\d\d)\D/.test(navigator.userAgent);

  // Utility functions for working with state. Exported because modes
  // sometimes need to do this.
  function copyState(mode, state) {
    if (state === true) return state;
    if (mode.copyState) return mode.copyState(state);
    var nstate = {};
    for (var n in state) {
      var val = state[n];
      if (val instanceof Array) val = val.concat([]);
      nstate[n] = val;
    }
    return nstate;
  }
  CodeMirror.copyState = copyState;
  function startState(mode, a1, a2) {
    return mode.startState ? mode.startState(a1, a2) : true;
  }
  CodeMirror.startState = startState;
  CodeMirror.innerMode = function(mode, state) {
    while (mode.innerMode) {
      var info = mode.innerMode(state);
      state = info.state;
      mode = info.mode;
    }
    return info || {mode: mode, state: state};
  };

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

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

  function getMarkedSpanFor(spans, marker) {
    if (spans) for (var i = 0; i < spans.length; ++i) {
      var span = spans[i];
      if (span.marker == marker) return span;
    }
  }

  function removeMarkedSpan(spans, span) {
    var r;
    for (var i = 0; i < spans.length; ++i)
      if (spans[i] != span) (r || (r = [])).push(spans[i]);
    return r;
  }

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

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

  function updateMarkedSpans(oldFirst, oldLast, startCh, endCh, newText) {
    if (!oldFirst && !oldLast) return newText;
    // Get the spans that 'stick out' on both sides
    var first = markedSpansBefore(oldFirst, startCh);
    var last = markedSpansAfter(oldLast, endCh);

    // Next, merge those two ends
    var sameLine = newText.length == 1, offset = lst(newText).length + (sameLine ? startCh : 0);
    if (first) {
      // Fix up .to properties of first
      for (var i = 0; i < first.length; ++i) {
        var span = first[i];
        if (span.to == null) {
          var found = getMarkedSpanFor(last, span.marker);
          if (!found) span.to = startCh;
          else if (sameLine) span.to = found.to == null ? null : found.to + offset;
        }
      }
    }
    if (last) {
      // Fix up .from in last (or move them into first in case of sameLine)
      for (var i = 0; i < last.length; ++i) {
        var span = last[i];
        if (span.to != null) span.to += offset;
        if (span.from == null) {
          var found = getMarkedSpanFor(first, span.marker);
          if (!found) {
            span.from = offset;
            if (sameLine) (first || (first = [])).push(span);
          }
        } else {
          span.from += offset;
          if (sameLine) (first || (first = [])).push(span);
        }
      }
    }

    var newMarkers = [newHL(newText[0], first)];
    if (!sameLine) {
      // Fill gap with whole-line-spans
      var gap = newText.length - 2, gapMarkers;
      if (gap > 0 && first)
        for (var i = 0; i < first.length; ++i)
          if (first[i].to == null)
            (gapMarkers || (gapMarkers = [])).push({from: null, to: null, marker: first[i].marker});
      for (var i = 0; i < gap; ++i)
        newMarkers.push(newHL(newText[i+1], gapMarkers));
      newMarkers.push(newHL(lst(newText), last));
    }
    return newMarkers;
  }

  // hl stands for history-line, a data structure that can be either a
  // string (line without markers) or a {text, markedSpans} object.
  function hlText(val) { return typeof val == "string" ? val : val.text; }
  function hlSpans(val) {
    if (typeof val == "string") return null;
    var spans = val.markedSpans, out = null;
    for (var i = 0; i < spans.length; ++i) {
      if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }
      else if (out) out.push(spans[i]);
    }
    return !out ? spans : out.length ? out : null;
  }
  function newHL(text, spans) { return spans ? {text: text, markedSpans: spans} : text; }

  function detachMarkedSpans(line) {
    var spans = line.markedSpans;
    if (!spans) return;
    for (var i = 0; i < spans.length; ++i) {
      var lines = spans[i].marker.lines;
      var ix = indexOf(lines, line);
      lines.splice(ix, 1);
    }
    line.markedSpans = null;
  }

  function attachMarkedSpans(line, spans) {
    if (!spans) return;
    for (var i = 0; i < spans.length; ++i)
      var marker = spans[i].marker.lines.push(line);
    line.markedSpans = spans;
  }

  // When measuring the position of the end of a line, different
  // browsers require different approaches. If an empty span is added,
  // many browsers report bogus offsets. Of those, some (Webkit,
  // recent IE) will accept a space without moving the whole span to
  // the next line when wrapping it, others work with a zero-width
  // space.
  var eolSpanContent = " ";
  if (gecko || (ie && !ie_lt8)) eolSpanContent = "\u200b";
  else if (opera) eolSpanContent = "";

  // Line objects. These hold state related to a line, including
  // highlighting info (the styles array).
  function Line(text, markedSpans) {
    this.text = text;
    this.height = 1;
    attachMarkedSpans(this, markedSpans);
  }
  Line.prototype = {
    update: function(text, markedSpans) {
      this.text = text;
      this.stateAfter = this.styles = null;
      detachMarkedSpans(this);
      attachMarkedSpans(this, markedSpans);
    },
    // 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 || (this.styles = []);
      var pos = st.length = 0;
      if (this.text == "" && mode.blankLine) mode.blankLine(state);
      while (!stream.eol()) {
        var style = mode.token(stream, state), substr = stream.current();
        stream.start = stream.pos;
        if (pos && st[pos-1] == style) {
          st[pos-2] += substr;
        } else if (substr) {
          st[pos++] = substr; st[pos++] = style;
        }
        // Give up when line is ridiculously long
        if (stream.pos > 5000) {
          st[pos++] = this.text.slice(stream.pos); st[pos++] = null;
          break;
        }
      }
    },
    process: function(mode, state, tabSize) {
      var stream = new StringStream(this.text, tabSize);
      if (this.text == "" && mode.blankLine) mode.blankLine(state);
      while (!stream.eol() && stream.pos <= 5000) {
        mode.token(stream, state);
        stream.start = stream.pos;
      }
    },
    // 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, tabSize, ch) {
      var txt = this.text, stream = new StringStream(txt, tabSize);
      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.
    getContent: function(tabSize, wrapAt, compensateForWrapping) {
      var first = true, col = 0, specials = /[\t\u0000-\u0019\u200b\u2028\u2029\uFEFF]/g;
      var pre = elt("pre");
      function span_(html, 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 (!specials.test(text)) {
          col += text.length;
          var content = document.createTextNode(text);
        } else {
          var content = document.createDocumentFragment(), pos = 0;
          while (true) {
            specials.lastIndex = pos;
            var m = specials.exec(text);
            var skipped = m ? m.index - pos : text.length - pos;
            if (skipped) {
              content.appendChild(document.createTextNode(text.slice(pos, pos + skipped)));
              col += skipped;
            }
            if (!m) break;
            pos += skipped + 1;
            if (m[0] == "\t") {
              var tabWidth = tabSize - col % tabSize;
              content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
              col += tabWidth;
            } else {
              var token = elt("span", "\u2022", "cm-invalidchar");
              token.title = "\\u" + m[0].charCodeAt(0).toString(16);
              content.appendChild(token);
              col += 1;
            }
          }
        }
        if (style) html.appendChild(elt("span", [content], style));
        else html.appendChild(content);
      }
      var span = span_;
      if (wrapAt != null) {
        var outPos = 0, anchor = pre.anchor = elt("span");
        span = function(html, text, style) {
          var l = text.length;
          if (wrapAt >= outPos && wrapAt < outPos + l) {
            var cut = wrapAt - outPos;
            if (cut) {
              span_(html, text.slice(0, cut), style);
              // See comment at the definition of spanAffectsWrapping
              if (compensateForWrapping) {
                var view = text.slice(cut - 1, cut + 1);
                if (spanAffectsWrapping.test(view)) html.appendChild(elt("wbr"));
                else if (!ie_lt8 && /\w\w/.test(view)) html.appendChild(document.createTextNode("\u200d"));
              }
            }
            html.appendChild(anchor);
            span_(anchor, opera ? text.slice(cut, cut + 1) : text.slice(cut), style);
            if (opera) span_(html, text.slice(cut + 1), style);
            wrapAt--;
            outPos += l;
          } else {
            outPos += l;
            span_(html, text, style);
            if (outPos == wrapAt && outPos == len) {
              setTextContent(anchor, eolSpanContent);
              html.appendChild(anchor);
            }
            // Stop outputting HTML when gone sufficiently far beyond measure
            else if (outPos > wrapAt + 10 && /\s/.test(text)) span = function(){};
          }
        };
      }

      var st = this.styles, allText = this.text, marked = this.markedSpans;
      var len = allText.length;
      function styleToClass(style) {
        if (!style) return null;
        return "cm-" + style.replace(/ +/g, " cm-");
      }
      if (!allText && wrapAt == null) {
        span(pre, " ");
      } 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(pre, str, styleToClass(style));
        }
      } else {
        marked.sort(function(a, b) { return a.from - b.from; });
        var pos = 0, i = 0, text = "", style, sg = 0;
        var nextChange = marked[0].from || 0, marks = [], markpos = 0;
        var advanceMarks = function() {
          var m;
          while (markpos < marked.length &&
                 ((m = marked[markpos]).from == pos || m.from == null)) {
            if (m.marker.type == "range") 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;
            if (to == null) 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) {
                var mark = marks[j];
                appliedStyle = (appliedStyle ? appliedStyle + " " : "") + mark.marker.style;
                if (mark.marker.endStyle && mark.to === Math.min(end, upto)) appliedStyle += " " + mark.marker.endStyle;
                if (mark.marker.startStyle && mark.from === pos) appliedStyle += " " + mark.marker.startStyle;
              }
              span(pre, 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 pre;
    },
    cleanUp: function() {
      this.parent = null;
      detachMarkedSpans(this);
    }
  };

  // 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 = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
      for (var i = 0, e = lines.length; i < e; ++i) lines[i].parent = this;
    },
    iterN: function(at, n, op) {
      for (var e = at + n; at < e; ++at)
        if (op(this.lines[at])) return true;
    }
  };
  function BranchChunk(children) {
    this.children = children;
    var size = 0, height = 0;
    for (var i = 0, e = children.length; i < e; ++i) {
      var ch = children[i];
      size += ch.chunkSize(); height += ch.height;
      ch.parent = this;
    }
    this.size = size;
    this.height = height;
    this.parent = null;
  }
  BranchChunk.prototype = {
    chunkSize: function() { return this.size; },
    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 = [];
    this.compound = 0;
    this.closed = false;
  }
  History.prototype = {
    addChange: function(start, added, old) {
      this.undone.length = 0;
      var time = +new Date, cur = lst(this.done), last = cur && lst(cur);
      var dtime = time - this.time;

      if (cur && !this.closed && this.compound) {
        cur.push({start: start, added: added, old: old});
      } else if (dtime > 400 || !last || this.closed ||
                 last.start > start + old.length || last.start + last.added < start) {
        this.done.push([{start: start, added: added, old: old}]);
        this.closed = false;
      } else {
        var startBefore = Math.max(0, last.start - start),
            endAfter = Math.max(0, (start + old.length) - (last.start + last.added));
        for (var i = startBefore; i > 0; --i) last.old.unshift(old[i - 1]);
        for (var i = endAfter; i > 0; --i) last.old.push(old[old.length - i]);
        if (startBefore) last.start = start;
        last.added += added - (old.length - startBefore - endAfter);
      }
      this.time = time;
    },
    startCompound: function() {
      if (!this.compound++) this.closed = true;
    },
    endCompound: function() {
      if (!--this.compound) this.closed = true;
    }
  };

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

  function e_preventDefault(e) {
    if (e.preventDefault) e.preventDefault();
    else e.returnValue = false;
  }
  function e_stopPropagation(e) {
    if (e.stopPropagation) e.stopPropagation();
    else e.cancelBubble = true;
  }
  function e_stop(e) {e_preventDefault(e); e_stopPropagation(e);}
  CodeMirror.e_stop = e_stop;
  CodeMirror.e_preventDefault = e_preventDefault;
  CodeMirror.e_stopPropagation = e_stopPropagation;

  function e_target(e) {return e.target || e.srcElement;}
  function e_button(e) {
    var b = e.which;
    if (b == null) {
      if (e.button & 1) b = 1;
      else if (e.button & 2) b = 3;
      else if (e.button & 4) b = 2;
    }
    if (mac && e.ctrlKey && b == 1) b = 3;
    return b;
  }

  // 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";}};

  // Detect drag-and-drop
  var dragAndDrop = function() {
    // There is *some* kind of drag-and-drop support in IE6-8, but I
    // couldn't get it to work yet.
    if (ie_lt9) return false;
    var div = elt('div');
    return "draggable" in div || "dragDrop" in div;
  }();

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

  // For a reason I have yet to figure out, some browsers disallow
  // word wrapping between certain characters *only* if a new inline
  // element is started between them. This makes it hard to reliably
  // measure the position of things, since that requires inserting an
  // extra span. This terribly fragile set of regexps matches the
  // character combinations that suffer from this phenomenon on the
  // various browsers.
  var spanAffectsWrapping = /^$/; // Won't match any two-character string
  if (gecko) spanAffectsWrapping = /$'/;
  else if (safari) spanAffectsWrapping = /\-[^ \-?]|\?[^ !'\"\),.\-\/:;\?\]\}]/;
  else if (chrome) spanAffectsWrapping = /\-[^ \-\.?]|\?[^ \-\.?\]\}:;!'\"\),\/]|[\.!\"#&%\)*+,:;=>\]|\}~][\(\{\[<]|\$'/;

  // 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 eltOffset(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;
  }

  function eltText(node) {
    return node.textContent || node.innerText || node.nodeValue || "";
  }

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

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

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

  // 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};}

  function elt(tag, content, className, style) {
    var e = document.createElement(tag);
    if (className) e.className = className;
    if (style) e.style.cssText = style;
    if (typeof content == "string") setTextContent(e, content);
    else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
    return e;
  }
  function removeChildren(e) {
    e.innerHTML = "";
    return e;
  }
  function removeChildrenAndAdd(parent, e) {
    removeChildren(parent).appendChild(e);
  }
  function setTextContent(e, str) {
    if (ie_lt9) {
      e.innerHTML = "";
      e.appendChild(document.createTextNode(str));
    } else e.textContent = str;
  }

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

  // See if "".split is the broken IE version, if so, provide an
  // alternative way to split lines.
  var splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {
    var pos = 0, result = [], l = string.length;
    while (pos <= l) {
      var nl = string.indexOf("\n", pos);
      if (nl == -1) nl = string.length;
      var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
      var rt = line.indexOf("\r");
      if (rt != -1) {
        result.push(line.slice(0, rt));
        pos += rt + 1;
      } else {
        result.push(line);
        pos = nl + 1;
      }
    }
    return result;
  } : function(string){return string.split(/\r\n?|\n/);};
  CodeMirror.splitLines = splitLines;

  var hasSelection = window.getSelection ? function(te) {
    try { return te.selectionStart != te.selectionEnd; }
    catch(e) { return false; }
  } : function(te) {
    try {var range = te.ownerDocument.selection.createRange();}
    catch(e) {}
    if (!range || range.parentElement() != te) return false;
    return range.compareEndPoints("StartToEnd", range) != 0;
  };

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

  CodeMirror.version = "2.36";

  return CodeMirror;
})();
