CodeMirror 2 overlay parser for beard

gistfile1.js

CodeMirror.defineMode("beard", function(config, parserConfig) {
    var beardOverlay = {
        token: function(stream, state) {
        if (stream.match("{{")) {
            while ((ch = stream.next()) != null) {
                if (ch == "}" && stream.next() == "}") {
                    break;
                }
            }
            return "beard";
        }
        if (stream.match("{#")) {
            while ((ch = stream.next()) != null) {
                if (ch == "#" && stream.next() == "}") {
                    break;
                }
            }
            return "comment";
        }
        while (stream.next() != null && !(
            stream.match("{{", false) || stream.match("{#", false))) {
        }
        return null;
    }
    };
    return CodeMirror.overlayParser(
        CodeMirror.getMode(config, parserConfig.backdrop || "text/html"),
        beardOverlay);
});