iteratee-0.3.6: Iteratee-based I/O




ioIter :: (StreamChunk s el, MonadIO m) => (a -> IO (Either b (IterateeG s el m a))) -> a -> IterateeG s el m bSource

Use an IO function to choose what iteratee to run. Typically this function handles user interaction and returns with a simple iteratee such as head or seek.

The IO function takes a value of type a as input, and should return 'Right a' to continue, or 'Left b' to terminate. Upon termination, ioIter will return 'Done b'.

The second argument to ioIter is used as the initial input to the IO function, and on each successive iteration the previously returned value is used as input. Put another way, the value of type a is used like a fold accumulator. The value of type b is typically some form of control code that the application uses to signal the reason for termination.