Re: [Haskell-cafe] trace function

Alexander Vodomerov wrote:

main = do putStrLn "xxx" return (trace "yyy" ()) putStrLn "zzz"

only xxx and zzz is displayed. yyy is missing.

This is because you never demanded the value of (trace "yyy" ()), so it was never computed. The joys of laziness! To force its evaluation try main = do putStrLn "xxx" () <- return (trace "yyy" ()) putStrLn "zzz" Regards, Malcolm