[Haskell] Haskell implementation of infixr and infixl/priorities

Hi, I´m progarmming a parser for functional programs. Now I want to implement the infixL and infixR feature to increase the readability of the code. I would be very glad if anyone can send me some information about the implementation of this feature of the Haskell parser or where I can find something about it. Futher qurestion: Is it possible to define priorities for functions in Haskell? Any hints about that? kind regards & nice weekend, Peter Theissen Technische Universität Darmstadt