>>> concat (Just [1, 2, 3]) [1,2,3]
>>> concat (Left 42) []
>>> concat [[1, 2, 3], [4, 5], [6], []] [1,2,3,4,5,6]
>>> concatMap (take 3) [[1..], [10..], [100..], [1000..]] [1,2,3,10,11,12,100,101,102,1000,1001,1002]
>>> concatMap (take 3) (Just [1..]) [1,2,3]
>>> import Data.List.NonEmpty (NonEmpty (..)) >>> sconcat $ "Hello" :| [" ", "Haskell", "!"] "Hello Haskell!"