Re: [Haskell-beginners] How to display a time difference?

...

...

...

...

"Yitzchak" == Yitzchak Gale writes:

Yitzchak> Colin Paul Adams wrote: >> The code of the following routine is intended to indicate how >> long it takes for the computer to make a move. However the time >> is printed (as very close to zero) long before the move is >> made. Yitzchak> You are writing a thunk to the IORef. It only gets Yitzchak> computed later on when you read the value. Yitzchak> Try using: >> readIORef game_state_ior >>= evaluate >> . update_interactive_from_move move >>= writeIORef >> game_state_ior Yitzchak> evaluate is in Control.Exception. Still no joy with: play_move :: IORef Game_state -> IO () play_move game_state_ior = do (_, state, _) <- readIORef game_state_ior putStr "Playing AI: " start_time <- getCurrentTime let move = recommended_move state readIORef game_state_ior >>= evaluate . update_interactive_from_move move >>= writeIORef game_state_ior end_time <- getCurrentTime putStrLn $ show $ (diffUTCTime end_time start_time) -- Colin Adams Preston Lancashire