[Haskell-cafe] wordsBy in the base libraries?

[Yitzchak Gale]

Neil Mitchell wrote:
> You are still over by one test. Try instead:
>
> wordsBy :: (a -> Bool) -> [a] -> [[a]]
> wordsBy p s = case dropWhile p s of
>    []      -> []
>    s':rest -> (s':w) : wordsBy p (drop 1 s'')
>           where (w, s'') = break p rest

This still has the redundant empty list tests,
and in fact introduces another one in drop 1,
as well as some gratuitous arithmetic.

-Yitz