[Haskell-cafe] The "type & data" constructor confused me !

data Layout a = forall l. (LayoutClass l a, Read (l a)) => Layout (l a) readsLayout :: Layout a -> String -> [(Layout a, String)] readsLayout (Layout l) s = [(Layout (asTypeOf x l), rs) | (x, rs) <- reads s] Why is the first parameter of readsLayout "(Layout l)" not "Layout (l a)" ? Sincerely! ----- e^(π.i) + 1 = 0 -- View this message in context: http://haskell.1045720.n5.nabble.com/The-type-data-constructor-confused-me-t... Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.