What advantage does Monad give us over an Applicative?

Question

I\'ve read this article, but didn\'t understand last section.

The author says that Monad gives us context sensitivity, but it\'s possible to achieve the same result

Answer 1

With monads, subsequent effects can depend on previous values. For example, you can have:

main = do
    b <- readLn :: IO Bool
    if b
      then fireMissiles
      else return ()

You can't do that with Applicatives - the result value of one effectfull computation can't determine what effect will follow.

Somewhat related:

• Why can applicative functors have side effects, but functors can't?
• Good examples of Not a Functor/Functor/Applicative/Monad?