Extract solution timing function

src/Main.hs

@@ -1,10 +1,6 @@
-{-# LANGUAGE OverloadedStrings #-}
-
 module Main where
 
 import qualified Data.Map as M
-import Formatting
-import Formatting.Clock
 import ProjectEuler.Problem001
 import ProjectEuler.Problem002
 import ProjectEuler.Problem004
@@ -45,7 +41,7 @@ import ProjectEuler.Problem214
 import ProjectEuler.Problem225
 import System.Environment (getArgs)
 import System.Exit (exitSuccess)
-import System.Clock
+import Util
 
 solutions :: M.Map Integer Integer
 solutions = M.fromList [
@@ -98,13 +94,9 @@ main = do
         ["--help"] -> usage >> exitSuccess
         ["-h"] -> usage >> exitSuccess
         [number] -> do
-            let n = read number :: Integer
-            start <- getTime Monotonic
-            case solution n of
-                Just result -> print result
+            case solution (read number :: Integer) of
+                Just result -> time result >>= print
                 Nothing -> putStrLn "There is no solution yet for this problem"
-            end <- getTime Monotonic
-            fprint (timeSpecs % "\n") start end
         _ -> usage >> exitSuccess
     where
         usage = putStrLn "Usage: cabal run problem [number]"

src/Util.hs

@@ -1,9 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
+
 module Util where
 
 import Data.List (delete, maximumBy, group, tails, transpose)
 import Data.Ord
 import Data.Ratio
 import qualified Data.Set as Set
+import qualified Formatting as F
+import Formatting.Clock
+import System.Clock
 
 ints :: (Enum t, Num t) => [t]
 ints = [1..]
@@ -109,3 +114,10 @@ countPartitions = (map p' [0..] !!)
            where pent x = takeWhile (<= x) $ concatMap f [1..]
                   where f k = [(m - k) `div` 2, (m + k) `div` 2]
                          where m = 3 * k * k
+
+time :: a -> IO a
+time x = do
+    start <- getTime Monotonic
+    end <- x `seq` getTime Monotonic
+    F.fprint (timeSpecs F.% "\n") start end
+    return x