Applicative functor
Jump to navigation
Jump to search
An applicative functor has more structure than a functor but less than a monad. See the Haddock docs for Control.Applicative
It has turned out that many applications do not require monad functionality but only those of applicative functors. Monads allow you to run actions depending on the outcomes of earlier actions.
do text <- getLine
if null text
then putStrLn "You refuse to enter something?"
else putStrLn ("You entered " ++ text)
This is obviously necessary is some cases, but in other cases it is disadvantageous.