Idiomatic bidirectional Pipes with downstream state without loss

Question

Say I have simple producer/consumer model where the consumer wants to pass back some state to the producer. For instance, let the downstream-flowing objects be objects we wa

Answer 1

The 'const's are where you are dropping the data. In order to get all the data, you probably want to do a push-based workflow as follows:

writeObjects :: Object -> Proxy ObjectId Object () X IO r
writeObjects obj = go 0 obj
  where
    go objid obj = do
        lift $ putStrLn $ "Wrote "++show obj
        obj' <- request objid
        go (objid + 1) obj'

-- produceObjects as before

main = void $ run $ produceObjects objects >>~ writeObjects