I'm trying to start working with Streaming package. First attempt is to simulate source of stream items (I call the function "gen") and some processor ("proc"). Both should be stateful: to be able to sabe some info about processing steps, etc. ... import Streaming import qualified Streaming.Prelude as S ... gen :: S.Stream (S.Of Int) IO [String] gen = do S.yield 1000 S.yield 2000 x <- lift getLine return ["a", "b", "c", x] -- results proc :: S.Stream (S.Of Int) IO [String] -> S.Stream (S.Of Int) IO [String] proc str = do e <- str lift $ print "Enter x:" x <- lift getLine return $ e ++ [" -- " ++ x] -- put stream items in result main :: IO main = do s <- S.mapM_ print $ S.map show gen p <- S.mapM_ print $ proc gen putStr "s: " >> print s putStr "p: " >> print p And I try to simulate "piping" between "gen" and "proc", seems that function application is enought to compose producers and consumers. But this snippet is not correct: "e <- str" extracts element not from stream, but from results (of "gen"). Even more, I don't know how to "yield" new items, based on stream items. Something like "await" of Conduit, or like in Python "for e in str: ... yield modified(e)...". Is it possible to do it with "do" notation? --- Best, Paul