CodeMirror.runMode = function(string, modespec, callback, options) {

  function esc(str) {

    return str.replace(/[<&]/g, function(ch) { return ch == "<" ? "&lt;" : "&amp;"; });

  }



  var mode = CodeMirror.getMode(CodeMirror.defaults, modespec);

  var isNode = callback.nodeType == 1;

  var tabSize = (options && options.tabSize) || CodeMirror.defaults.tabSize;

  if (isNode) {

    var node = callback, accum = [], col = 0;

    callback = function(text, style) {

      if (text == "\n") {

        accum.push("<br>");

        col = 0;

        return;

      }

      var escaped = "";

      // HTML-escape and replace tabs

      for (var pos = 0;;) {

        var idx = text.indexOf("\t", pos);

        if (idx == -1) {

          escaped += esc(text.slice(pos));

          col += text.length - pos;

          break;

        } else {

          col += idx - pos;

          escaped += esc(text.slice(pos, idx));

          var size = tabSize - col % tabSize;

          col += size;

          for (var i = 0; i < size; ++i) escaped += " ";

          pos = idx + 1;

        }

      }



      if (style) 

        accum.push("<span class=\"cm-" + esc(style) + "\">" + escaped + "</span>");

      else

        accum.push(escaped);

    };

  }

  var lines = CodeMirror.splitLines(string), state = CodeMirror.startState(mode);

  for (var i = 0, e = lines.length; i < e; ++i) {

    if (i) callback("\n");

    var stream = new CodeMirror.StringStream(lines[i]);

    while (!stream.eol()) {

      var style = mode.token(stream, state);

      callback(stream.current(), style, i, stream.start);

      stream.start = stream.pos;

    }

  }

  if (isNode)

    node.innerHTML = accum.join("");

};

