[Haskell-cafe] different behaviours with or without putStrLn
corentin.dupont at gmail.com
Sun Jan 12 22:07:17 UTC 2014
I'm experimenting different behaviours with or without a "putStrLn"! :(
Basically, with the following code, I want the evaluation to really happen
on the "evaluate".
I found out that it doesn't: it is evaluated elsewhere (I don't know where).
If I put a putStrLn (commented below), the evaluation really happens there.
*execCommand :: (TVar MyState) -> StateT MyState IO () -> IO ()execCommand
ts sm = do s <- atomically $ readTVar ts s' <- execStateT sm s s'' <-
evaluate s' --evaluation should happen here, but it doesn't
--putStrLn $ displayMulti $ _multi s'' atomically $ writeTVar ts s''*
To give you more context, I have a state that, when evaluated, might not
So I added a watchdog (like in mueval), that will kill the thread in case
the evaluation doesn't terminate.
That's why I need to be sure of where the evaluation takes place.
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