Another correction... Brian Hulley wrote:
data Col1 a = One a data Col2 a = One a | Two auseOne :: ( //One col a) => col -> a useOne (One x) = x
should be useOne :: (//One a col) => col -> a _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe