The input and output are infinite streams. I have a few questions:

1) Is it possible to change it to use arrows? How would it look like? 2) How would one implement an continuous time version?

Yampa can do *exactly* what you're asking for. Unfortunately the code seems to be a little rough and there are many space leaks (some of which are alluded to in the source code comments). Definitely make sure to profile memory usage as you code.