# Featured functions

*Featured function* pages are quick overviews of interesting functions we just want to draw more attention to.

`($)`

`(a -> b) -> a -> b`

`intercalate`

`[a] -> [[a]] -> [a]`

`mapMaybe`

`(a -> Maybe b) -> [a] -> [b]`

`null`

`Foldable t => t a -> Bool`

- Rounding
`round :: (RealFrac a, Integral b) => a -> b`

`truncate :: (RealFrac a, Integral b) => a -> b`

`ceiling :: (RealFrac a, Integral b) => a -> b`

`floor :: (RealFrac a, Integral b) => a -> b`

- Singleton
`singleton :: a -> [a]`