record timestamps of silence

1 files changed, 12 insertions, 7 deletions

diff --git a/midi-dump.hs b/midi-dump.hs
index b3698ae..308e008 100644
--- a/midi-dump.hs
+++ b/midi-dump.hs
@@ -9,16 +9,21 @@ import Data.Maybe
 import Data.List
 import System.Clock
 
+verbose = False
+
 main = main' `AlsaExc.catch` handler
   where
-  handler e = putStrLn $ "alsa_exception: " ++ AlsaExc.show e
+  handler e = when (verbose) $ putStrLn $ "alsa_exception: " ++ AlsaExc.show e
 
-data EVENT = EVENT TimeSpec Event.T
+data EVENT = MidiEvent TimeSpec Event.T | Silence TimeSpec
   deriving Show
 
+isSilence (Silence _) = True
+isSilence _ = False
+
 data LoopState = LoopState {
   keysDown :: MidiPitchSet,
-  inputHistory :: [Maybe EVENT],
+  inputHistory :: [EVENT],
   lastTick :: TimeSpec
 }
 
@@ -45,15 +50,15 @@ loop = do
   else do
     now <- liftIO $ getTime Monotonic
     let delta = now - startTime
-    let newEvents = map (Just . (EVENT now)) events
+    let newEvents = map (MidiEvent now) events
 
     liftIO $ printChordLn newKeys
     modify $ \s -> s { keysDown = newKeys, inputHistory = newEvents ++ inputHistory s }
 
     when (Set.null newKeys) $ do
-      hist <- gets (takeWhile isJust . inputHistory)
-      liftIO $ print hist
-      modify $ \s -> s { inputHistory = Nothing:inputHistory s }
+      hist <- gets $ takeWhile (not . isSilence) . inputHistory
+      liftIO $ print $ reverse hist
+      modify $ \s -> s { inputHistory = Silence now:inputHistory s }
 
     modify $ \s -> s { lastTick = now }
   loop