10 Haskell One Liners to Impress Your Friends

Following the meme… I would truly appreciate feedback from people whom actually know Haskell. As you may notice below, my grasp is not yet strong. Multiple Each Item in a List by 2 map (*2) [1..10] Sum a List of Numbers foldl (+) 0 [1..1000] -- or sum [1..1000] Verify if Exists in a String [...]