Wed, 27 Feb 2002 11:41:57 -0500 (EST)
On Wed, 27 Feb 2002, Juan M. Duran wrote:
> I got a function with type :: IO [[Double]], and what I want is write this
> output in a file, how can I do it... I mean, I cannot doit by just using
Does something like this help at all?
myfn :: IO [[Double]]
myfn = return [[1.346, 4.144], [5.143, 2.453]]
format_doubles :: [[Double]] -> String
format_doubles x = foldr (++) "" (map format_line x)
format_line :: [Double] -> String
format_line  = "\n"
format_line x = foldr1 (\x y -> x ++ ", " ++ y) (map show x) ++ "\n"
main = myfn >>= (\x -> return $ format_doubles x) >>= putStr
Okay, it's not the most readable bit of code, but I'm guessing it covers
the bit that's confusing you.
All the best,