QueryResponse: Use three-way sum to distinguish Canceled and Timedout.

1 files changed, 11 insertions, 10 deletions

diff --git a/dht/src/Network/BitTorrent/MainlineDHT.hs b/dht/src/Network/BitTorrent/MainlineDHT.hs
index bb556bc6..e604f5e5 100644
--- a/dht/src/Network/BitTorrent/MainlineDHT.hs
+++ b/dht/src/Network/BitTorrent/MainlineDHT.hs
@@ -1033,21 +1033,22 @@ announceH (SwarmsDatabase peers toks _) naddr announcement = do
 isReadonlyClient :: MainlineClient -> Bool
 isReadonlyClient client = False -- TODO
 
-mainlineSend :: ( BEncode a
-                , BEncode a2
+mainlineSend :: ( BEncode xqry
+                , BEncode xrsp
                 ) => Method
-                  -> (a2 -> b)
-                  -> (t -> a)
+                  -> (xrsp -> rsp)
+                  -> (qry -> xqry)
                   -> MainlineClient
-                  -> t
+                  -> qry
                   -> NodeInfo
-                  -> IO (Maybe b)
+                  -> IO (Maybe rsp)
 mainlineSend meth unwrap msg client nid addr = do
     reply <- sendQuery client serializer (msg nid) addr
-    -- sendQuery will return (Just (Left _)) on a parse error.  We're going to
-    -- blow it away with the join-either sequence.
-    -- TODO: Do something with parse errors.
-    return $ join $ either (const Nothing) Just <$> reply
+    return $ case reply of
+        Success (Right x) -> Just x
+        Success (Left e)  -> Nothing -- TODO: Do something with parse errors.
+        Canceled          -> Nothing
+        TimedOut          -> Nothing
  where
     serializer = MethodSerializer
         { methodTimeout  = \ni -> return (ni, 5000000)