Hi, I am trying to develop a parser with the Parsec library. At some point I need to do something with parser state, say, convert it to a string. I declared the type for the parser: type TParser a = GenParser Token (FiniteMap String Declaration) a The FiniteMap (which is the user state) is expected to be updated during parsing whus building some internal lookup table. and in one of the parsing functions I want to call show getState assuming it will apply show to the FiniteMap and return some string of characters. During compliation, I get: No instance for (Show (GenParser tok st st)) arising from use of `show' at (file location) In the first argument of `xxxx', namely `(show getState)' But GenParser is a newtype, not a data constructor, so attempt to write instance Show (GenParser tok st t) results in error message about missing constructor GenParser. How could I extract actual user state from the result of getState? The parser itself works as needed, but dealing with user state gets me in trouble. Dimitry Golubovsky Middletown, CT