[Haskell-cafe] list comprehension with multiple generator|targets

I'm guessing this isn't supported, but might be worth asking - can I extend a list comprehension like ['A' | A <- s] to multiple values? Like, data V = A | B | C pv :: [V] -> [Char] pv [] = [] pv (A:x) = 'A':(pv x) pv (B:x) = 'B':(pv x) pv (_:x) = pv x -- can that be a list comprehension, like pv s = [ 'A' | A <- s -- ?? ] thanks, Donn