midi-dump.hs


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import AlsaSeq
import Control.Concurrent (threadDelay)
import qualified Sound.ALSA.Exception as AlsaExc
import qualified Data.Set as Set

main = (do

  withAlsaInit $ \h public private q publicAddr privateAddr -> do
  cmdlineAlsaConnect h public

  let
    forwardNOW = forwardNoteEvent h q publicAddr
    go keysDown = do
      keysDown' <- parseAlsaEvents h keysDown forwardNOW
      if (keysDown == keysDown') then
        threadDelay 15000 -- 15ms.  Seems like a lot, but it sounds OK.  Cuts CPU down to 2%.
      else do
        printChordLn keysDown'
      go keysDown'

  putStrLn "Rock on!"
  go Set.empty)
     `AlsaExc.catch` \e ->
       putStrLn $ "alsa_exception: " ++ AlsaExc.show e