What is the Applicative type class in Haskell?

What is the Applicative type class in Haskell?

The Applicative type class in Haskell is a way to apply functions wrapped in a context (like Maybe or List) to values also wrapped in a context.

Can you give me an example of how to use Applicative in Haskell?

Sure! Here's a simple example:

import Control.Applicative

-- Using Maybe
f :: Int -> Maybe Int
f x = Just (x + 1)

g :: Int -> Maybe Int
g x = Just (x * 2)

result = f <$> Just 3 <*> g <$> Just 4
-- result will be Just 9

What are some common instances of the Applicative type class?

Common instances include Maybe, List, and IO. Each of these types allows you to apply functions in a context.

How does Applicative differ from Functor and Monad?

Applicative is a generalization of Functor, allowing for functions that take multiple arguments. Monad is more powerful, enabling chaining of operations.