Put two monadic values into a pair and return it

Question

I am playing with Parsec and I want to combine two parsers into one with the result put in a pair, and then feed it another function to operate on the parse result to write something like this:

try (pFactor <&> (char '*' *> pTerm) `using` (*))

So I wrote this:

(<&>) :: (Monad m) => m a -> m b -> m (a, b)
pa <&> pb = do
  a <- pa
  b <- pb
  return (a, b)

And

using :: (Functor f) => f (a, b) -> (a -> b -> c) -> f c
p `using` f = (uncurry f) <$> p

Is there anything similar to (<&>) which has been implemented somewhere? Or could this be written pointfree? I tried fmap (,) but it seems hard to match the type.

Answer 1

Is there anything similar to (<&>) which has been implemented somewhere? Or could this be written pointfreely? I tried fmap (,) but it seems hard to match the type.

I don't now if it's implemented anywhere, but <&> should be the same as liftM2 (,). The difference to fmap is, that liftM2 lifts a binary function into the monad.