On Fri, 2 Oct 2015, Mario Blažević wrote:
The benefits of applicative do, if I understand the motivation correctly, are not so much to help in writing new code intended to be applicative. Instead it lets the programmer write in monadic style and at the same time enables the compiler to convert the code to applicative style if possible. This has the potential to automatically improve performance of legacy Haskell codebase, as well as any new beginner-friendly code that relies on syntactic sugar.
I see the benefit of ApplicativeDo in the short distance of the value producer and the value naming. E.g. compare liftA3 (\x y z -> complicatedFunc x y z) produceX produceY produceZ and do x <- produceX y <- produceY z <- produceZ pure $ complicatedFunc x y z Using the first style you may easily introduce inconsistencies if you change the order of produceX, produceY, produceZ, whereas with the second style you will certainly change whole lines and stay consistent this way.