[Haskell-cafe] `typeof' is not a (visible) method of class `Typeable' ?

Hi All, While I was trying to declare Language.Haskell.TH.Exp as an instance of "Typeable", ghci 6.4 yields this error. It does not allow me to define an instance of "typeof". Does anybody know what should be the right way of doing this? Thanks. -W-M- @ @ | \_/