Re: Stack overflow on words (repeat 'a')

i should have mentioned that Prelude.span is less strict, so: span p l = span' p l id where span' p [] = \c->c ([],[]) span' p xs@(x:xs') | p x = span' p xs' . (\c (a,b)->c (x:a,b)) | otherwise = \c->c ([],xs) -- Prelude.span fails, span succeeds test1 span = span (/=' ') $ replicate 1000000 'a' ++ [' '] test2 span = span (/=' ') $ take 1000000 (cycle "abc") ++ [' '] -- Prelude.span succeeds, span fails test3 span = take 1000000 $ fst $ span (/=' ') $ repeat 'a' claus