Douglas Crockford 2007-02-21 This is chapter 9 of Beautiful Code. Introduction Vaughan Pratt presented "Top Down Operator Precedence" at the first annual Principles of Programming Languages Symposium in Boston in 1973. In the paper Pratt described a parsing technique that combines the best properties of Recursive Descent and Floyd's Operator Precedence. It is easy to use. It feels a lot like Recur