Quoth John Meacham : ... | just a note: I find splitBy a much nicer routine to provide. | |> splitBy :: (a -> Bool) -- ^ whether char is a separator |> -> [a] -- ^ list to split |> -> [[a]] Starting from the assumption that in most cases the list to be split will be [Char], so we can reasonably hold this up against string functions in other languages -- I think split is commonly split :: String -> String -> [String] i.e., the separator is [a], not a. Of course next they'll want regular expressions, but I use string separators of length > 1 a lot and rarely bother with regexps. But string splitBy might be an interesting alternative to regexp splits. Something like splitBy :: ([a] -> Maybe Int) -> [a] -> [[a]] breakBy :: ([a] -> Maybe Int) -> [a] -> Maybe ([a], [a]) breakBy f s = by [] f s where by _ _ [] = Nothing by c f s@(a:ax) = case f s of Just n -> Just ((reverse c), (drop n s)) Nothing -> by (a:c) f ax splitBy f s = case breakBy f s of Just (l, r) -> l:(splitBy f r) Nothing -> [s] Where in the simplest case the matching function would simply compare with a separator string, but could easily do more - eat up trailing blanks, for example. Note use of Maybe, basically to disambiguate end of data with and without match. Donn Cave, donn@drizzle.com