Re: [Haskell-cafe] Re: Stream processors

Okay, maybe I misunderstood, I thought by stream processors you meant functions of the type: process :: [a] -> [a] where both the input and the output are lazy lists (streams) I would assume if you want to have a stateful filter you need to maintain the state by using either: process :: [a] -> IO [a] process :: <state> -> [a] -> [a] process :: [a] -> ST s [a] Keean.