Haskellだと小数点のmodをとるのが大変

BDepression.hs

module Main where
import Control.Applicative
import Data.List
import Data.Maybe
import Data.Function (on)
import Text.Printf

splitBy :: (a -> Bool) -> [a] -> [[a]]
splitBy p [] = []
splitBy p xs = a : (splitBy p $ dropWhile p $ b)
   where
     (a, b) = break p xs
 
split :: String -> [String]
split = splitBy (==':')


primes3 = 2:f [3] [3,5..]
    where f (x:xs) ys = let (ps, qs) = span (< x^2) ys
                        in  ps ++ f (xs ++ ps) [z | z <- qs, mod z x /= 0]


input = lines <$> readFile "input.txt"


rr :: (Read a, Num a) => String -> a
rr = read


timeAngle hh mm = a 
    where
      a = (fromIntegral ha) + ma 
      ha = (30 *  (read hh)::Integer) `mod` 360
      ma = (30 / 60) * ((read mm) :: Float)

minutesAngle mm = (360 / 60) * (read mm)

format text = d1 ++ if d2 == ".0" then "" else d2
    where
      (d1,d2) = break (=='.') text


f hh mm = ta ++ " " ++ ma
    where
      ta = format . show . timeAngle hh $ mm
      ma = format . show . minutesAngle $ mm

main :: IO ()
main = 
    do {ns <- lines<$>getContents
       ; mapM_ (\hour -> printf "%s" . (\ [hh,mm] -> f hh mm) . split $ hour) ns
       }