kh: implement null check correctly
@@ -113,7 +113,7 @@ drawState :: St -> [Ev]
drawState St{..} = hist <> out <> cur <> spin
where
hist = drawHistory <$> toList sHistory
- out | null <- sLine = []
+ out | null sLine = []
| otherwise = [EvEdit sLine]
cur | (0, _) <- sCurPos = []
| otherwise = [EvMove sCurPos]
