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

[Colin Paul Adams]

>>>>> "Sean" == Sean Lee <sean.ysl at gmail.com> writes:

    Sean> You get some random values? or no change at all on the
    Sean> state?

I'm not sure if the state has changed at all or not. Certainly it has
not changed correctly - the move does not get made.

As for Daniel's suggestion, I can't compile it because it says I need
an instance of NFData for Move.Move. I'm not sure what that involves.

Anyway, I don't think that evaluating move is necessarily the
solution. I need to force the entire evaluation of modifyIORef.
-- 
Colin Adams
Preston Lancashire