Reimplemented words function from haskell Data.Char

newwords.hs

import Data.Char (isSpace)

words' :: String -> [String]
words' [] = []
words' ls = tail (foldr step [] (' ':ls))
    where
        step x (y:ys)
            | isSpace x = if null y then []:ys else []:y:ys
            | otherwise = (x:y):ys
        step x _ 
            | isSpace x = []
            | otherwise = [[x]]