Donald Bruce Stewart wrote:

Can I ask if just using a `seq` works as well? That was enough (now I recall) for the watchdog code I posted earlier.

-- Don

In my case this doesn't work

timeout :: DeepSeq a => Int -> IO a -> IO (Maybe a) timeout n t = do res <- par_io timer thr --timer return res where thr = do res <- t return $! Just res timer = do threadDelay $ n * 1000 return Nothing

It's probably because "resolve" function has type

resolve :: CNF -> (Bool, [(Int,Int)]) So it should be sequenced deeper.