fixed little memory leak concerning float values

src/Affection.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE BangPatterns #-}
 module Affection
     ( withAffection
     , getAffection
@@ -108,10 +109,11 @@ withAffection AffectionConfig{..} = do
         -- clean the renderer form last time
         SDL.clear renderer
         -- compute dt and update elapsedTime
-        let dt = (fromIntegral $ toNanoSecs $ diffTimeSpec lastTime now) / (fromIntegral 10 ^ 9)
+        let !dt = (fromIntegral $ toNanoSecs $ diffTimeSpec lastTime now) / (fromIntegral 10 ^ 9)
+            !ne = elapsedTime ad + dt
         put $ ad
           { drawStack = []
-          , elapsedTime = elapsedTime ad + dt
+          , elapsedTime = ne
           }
         -- poll events
         evs <- preHandleEvents =<< liftIO SDL.pollEvents