Haskell version of Idris !-notation (bang notation)

Question

I\'ve had the luxury of learning a bit of Idris lately and one thing I\'ve found extremely convenient is the !-notation, which let\'s me shorten monadic code inside a do block s

Answer 1

An alternative to @chi's answer is liftA3 someFunction a b c (with join if needed).

Answer 2

Since every monad is an Applicative (with GHC >= 7.10) we can write

someFunction <$> a <*> b <*> c

Note that if someFunction returns a monadic value of type m T, the above will return m (m T), which is likely not what we want (as @pigworker points out below). We can however join the two layers together:

join $ someFunction <$> a <*> b <*> c

Answer 3

Speaking of arrows...

import Control.Arrow

a' = Kleisli $ const a
b' = Kleisli $ const b
c' = Kleisli $ const c

foo = (`runKleisli`()) $
  (a' &&& b') &&& c' >>> uncurry (uncurry someFunction)

Not that I recommend this.