public static Parser CreateParser(this XElement block, Context ctx)
 {
     var lexer = new MapReduce.Lexer.Lexer(block);
     var results = lexer.Lex();
     TokenBuffer buffer = new TokenBuffer(results);
     ctx.TokenBuffer = buffer;
     Parser parser = new Parser(ctx);
     return parser;
 }
        public static Parser CreateParser(this string xml, string block)
        {
            XDocument _xDoc = _xDoc = XDocument.Parse(xml);
            XElement source = _xDoc.Element(block);
            var lexer = new MapReduce.Lexer.Lexer(source);
            var results = lexer.Lex().ToList();
            TokenBuffer buffer = new TokenBuffer(results);
            MapReduce.Parser.Context ctx = new MapReduce.Parser.Context(buffer);

            Parser parser = new Parser(ctx);
            return parser;
        }