Colleague has helped me with the solution for the Reader, without general solution (probably it's not possible to do so for every monad):

foo :: (a -> Reader r b) -> Reader r (a -> b)
foo f = do
r <- ask
return $ \a -> runReader (f a) r

Hope that's gonna help someone in the future.

On 6 May 2017 at 11:08, Szymon Pajzert <szymonpajzert@gmail.com> wrote:

Hello,

Lately I'm working with Reader monad. Because of that, I have to use function of signature:

Monad m => (a -> m b) -> m (a -> b).

Is this even possible to do so? Thanks in advance for your help.

Best Regards,
Szymon Pajzert