[Haskell-beginners] mind your head, was: Parsing a file with data divided into sections

Magnus Therning wrote:

...

isSection line = not . isSpace . head $ line

I'ld be more careful with "head"! Imagine your binary fails with: Prelude.head: empty list

countDays [] = [] countDays ls = let day = head ls count = length $ takeWhile (isSpace . head) $ tail ls in (day, count) : countDays (drop (1 + count) ls)

here too, and better use a pattern like: ls@(hd, tl) Cheers Christian