Signature of flatMapF in OptionT, ListT

[Joheinz]

The signature of flatMapF in OptionT is

def flatMapF[B](f: A => F[B])(implicit F: Monad[F]): OptionT[F, B]

whereas the signature of flatMapF in ListT is

def flatMapF[B](f: A => M[List[B]])(implicit M: Monad[M]) : ListT[M, B]

Me thinks, both can't be right. I would favour the version of OptionT, as OptionT and ListT have defined flatMap in the style of:

def flatMap[B](f: A => OptionT[F, B])(implicit F: Monad[F]): OptionT[F, B] (for ListT with ListT respectively).

Regards

Markus

[Joheinz]

BTW, this is what I came up with for flatMapF in ListT:

def flatMapF[B](f: A => M[B])(implicit M: Monad[M], T: Traverse[List]) : ListT[M, B] = new ListT[M,B] (
   M.bind(run) { list =>
     T.traverse(list)(f)
   }
)

Is this correct, the right approach? Markus