+
+-- | Consumes and returns the next message, if it satisfies the specified predicate.
+--
+-- @since 0.5.2.0
+satisfy :: (FromServerMessage -> Bool) -> Session FromServerMessage
+satisfy pred = do
+
+ skipTimeout <- overridingTimeout <$> get
+ timeoutId <- curTimeoutId <$> get
+ unless skipTimeout $ do
+ chan <- asks messageChan
+ timeout <- asks (messageTimeout . config)
+ void $ liftIO $ forkIO $ do
+ threadDelay (timeout * 1000000)
+ writeChan chan (TimeoutMessage timeoutId)
+
+ x <- await
+
+ unless skipTimeout $
+ modify $ \s -> s { curTimeoutId = timeoutId + 1 }
+
+ modify $ \s -> s { lastReceivedMessage = Just x }
+
+ if pred x
+ then do
+ logMsg LogServer x
+ return x
+ else empty
+
+-- | Matches a message of type @a@.
+message :: forall a. (Typeable a, FromJSON a) => Session a
+message =
+ let parser = decode . encodeMsg :: FromServerMessage -> Maybe a
+ in named (T.pack $ show $ head $ snd $ splitTyConApp $ last $ typeRepArgs $ typeOf parser) $
+ castMsg <$> satisfy (isJust . parser)