How do you write the function 'pairs' in Haskell?

Question

The pairs function needs to do something like this:

pairs [1, 2, 3, 4] -> [(1, 2), (2, 3), (3, 4)]

Answer 1

Call to the Aztec god of consecutive numbers:

import Control.Monad (ap)
import Control.Monad.Instances() -- for Monad ((->) a)

foo = zip`ap`tail $ [1,2,3,4]