Hi All What is the state-of-the-practice in type-level programming? I know Günther started this thread about monads, but I seem to remember him having a long running problem with "typeful" database programming, and I wonder if some of his problems are really in the later area. Compared to monads, type-level programming seems much more a wild frontier - scattered docs, fewer definitive examples, no de-facto standard library. The HList paper provides an implementation of extensible records - have people found it palatable in practice? Roel van Dijk's Hackage rev-dependency page indicates only 1 package depends on it, and HaskellDB appears, at least from a cursory look, to support its own re-implementation of of HList. Best wishes Stephen