Re: [Haskell-cafe] Animas/Yampa - Using Zip as a Routing Function in a Parallel Switch with Feedback

I'm not totally sure, but I sense that you may need a one-instant delay in your looping code here:

...

        rec             let senses = map (\state -> (inputEvents, state)) states             states <- par route activities -< senses

Try adding a one-instant delay by passing the output of your parallel switch through the iPre signal function:

   states <- iPre [] <<< par route activities -< senses

Hope that helps.

Indeed, that did solve the issue! Apparently the recursion was not well-founded for reasons beyond my comprehension, so injecting an initial value was all that was needed. Thanks! --   M. George Hansen   technopolitica@gmail.com