I tried a fresh install of Haskell platform on my Vista box and I find that starting the thread does not return to the prompt. Is there some setting I need to do? Sent from my Windows Phone ------------------------------ From: Steffen Schuldenzucker Sent: Monday, 7 February 2011 6:46 PM To: C K Kashyap Cc: Haskell Cafe Subject: Re: [Haskell-cafe] Extending GHCi On 02/07/2011 12:45 PM, C K Kashyap wrote:

$ ghci GHCi, version 6.12.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package ffi-1.0 ... linking ... done. Prelude> :m +Data.IORef Control.Concurrent Control.Monad Prelude Data.IORef Control.Concurrent Control.Monad> msg <- newIORef "Hello" Prelude Data.IORef Control.Concurrent Control.Monad> let echo = forever $ readIORef msg >>= putStrLn >> threadDelay 3000000 Prelude Data.IORef Control.Concurrent Control.Monad> t <- forkIO echo Hello Prelude Data.IORef Control.Concurrent Control.Monad> Hello Hello writeIORefHello msg "World" Prelude Data.IORef Control.Concurrent Control.Monad> World World

On my mac, this works..but on Linux, the moment I do t <- forkIO ... , it starts off a thread in the foreground and does not return to the prompt. Strange. Works for me (ghc 6.12.1 on Debian squeeze).