與Haskell和節儉的乒乓球卡住

Question

我想用Haskell和節儉做一個簡單的乒乓球。但是，它只會重複一次，然後卡住了。我認爲問題出在Thrift的正確使用中，而不是在Haskell中。可能有些東西沒有正確刷新。有沒有人有過Thrift的經驗，可以幫助我對如何解決這個問題進行有根據的猜測？

服務器：

echorequest :: TXT 
echorequest = TXT { 
    f_TXT_anytxt = Just "Ping" 
    } 

echoreply :: TXT 
echoreply = TXT { 
    f_TXT_anytxt = Just "Pong" 
    } 

serverFunc :: a -> (BinaryProtocol Handle, BinaryProtocol Handle) 
       -> IO Bool 
serverFunc a (h1,h2) = do 
    let t1 = getTransport h1 
    dat <- read_TXT h1 
-- the following two lines are only for debugging 
    putStrLn "Recieved data:" 
    print dat 
    write_TXT h1 echoreply 
    tFlush t1 
-- the following line is for debugging 
    putStrLn "Data written" 

    return False 


main :: IO() 
main = do 
    runBasicServer() serverFunc 4390 
    putStrLn "Server stopped" 

客戶：

main :: IO() 
main = do 
    h <- connectTo "127.0.0.1" $ PortNumber 4390 
    let proto = BinaryProtocol h 
    putStrLn "Client started" 
    let tryOnePing c i = do 
     write_TXT proto echorequest 
     putStrLn "ping sent" 
     tFlush h 
     w <- read_TXT proto 
     putStrLn "pong received" 
     return $ if w == echoreply then c+1 else c 
    c <- foldM tryOnePing 0 [0 .. 1000] 
    tClose h 
    print (c, 10000 - c) 

Answer 1

您的問題是你從serverFunc返回false。哈斯克爾將循環，直到你返回false（由你的代碼中，只有一次）

http://hackage.haskell.org/packages/archive/thrift/0.6.0/doc/html/src/Thrift-Server.html#line-65