{-# LANGUAGE Rank2Types #-} -- !!! Rank 2 polymorphism -- Both f and g are rejected by Hugs [April 2001] module Foo where data T = T { t1 :: forall a. a -> a , t2 :: forall a b. a->b->b } -- Test pattern bindings for polymorphic fields f :: T -> (Int,Char) f t = let T { t1 = my_t1 } = t in (my_t1 3, my_t1 'c') -- Test record update with polymorphic fields g :: T -> T g t = t { t2 = \x y -> y }