Haskellで文字列のSplitその２

Data.Listのwords関数がそれっぽい挙動をしている
https://downloads.haskell.org/~ghc/7.4.1/docs/html/libraries/base/src/Data-List.html

import Data.Char        ( isSpace )

words  :: String -> [String]
words s =  case dropWhile {-partain:Char.-}isSpace s of
                "" -> []
                s' -> w : words s''
                      where (w, s'') =
                             break {-partain:Char.-}isSpace s'

こんなかんじか
結局isSpaceっていうのを使ってる

import Data.Char        ( isSpace )

hogewords  :: String -> [String]
hogewords s =  case dropWhile {-partain:Char.-}isSpace s of
                "" -> []
                s' -> w : hogewords s''
                      where (w, s'') =
                             break {-partain:Char.-}isSpace s'

main = do
    print $ hogewords "hoge moge"

Data.Char(isSpace)の定義
git.haskell.org/packages/base/GHC/Unicode.hs

isSpace                 :: Char -> Bool
-- isSpace includes non-breaking space
-- Done with explicit equalities both for efficiency, and to avoid a tiresome
-- recursion with GHC.List elem
isSpace c               =  c == ' '     ||
                           c == '\t'    ||
                           c == '\n'    ||
                           c == '\r'    ||
                           c == '\f'    ||
                           c == '\v'    ||
                           c == '\xa0'  ||
                           iswspace (fromIntegral (ord c)) /= 0