The file src/Control/Processor.hs has documentation inside.

See the "cv-combinators" package for example usage.

TODO:
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- Currently we get segfault if usb cable disconnects

- Make built-in stuff for processors that output "Maybe" types: if the result is Nothing, the next processor
  in the chain will not be called. 
  - Implement using the Maybe IO monad instead of regular IO monad?
  - Make something that lifts IO processors into this monad for those who don't need the Maybe type?
  - The type we want is Processor IO a (Maybe b)
  - Also possible to use Either, etc...