Get the _real_ time of stuff in ghci

time-ghci

:{
let ghciTime cmd = do
     let mkVar n u = "ghciTime_" ++ n ++ "_" ++ show (Data.Unique.hashUnique u)
     startVar <- mkVar "start" <$> Data.Unique.newUnique
     resVar <- mkVar "res" <$> Data.Unique.newUnique
     endVar <- mkVar "end" <$> Data.Unique.newUnique
     pure $ unlines
       [ startVar ++ " <- Data.Time.getCurrentTime"
       , resVar ++ "<- " ++ cmd
       , endVar ++ " <- Data.Time.getCurrentTime"
       , unwords ["pure", resVar, "<* (System.IO.putStrLn $ show $ Data.Time.diffUTCTime", endVar, startVar, ")"]
       ]
:}

:def time ghciTime