我尝试使用 ghc 7.6.3 从 thrift-0.9.0/tutorial/hs 编译文件 HaskellServer.hs 无济于事。
在我调用的命令行上
节俭--gen hs tutorial.thrift
节俭--gen hs shared.thrift
它没有任何错误。
之后,我尝试编译
ghc HaskellServer.hs
但我得到以下错误输出:
[1 of 7] Compiling Shared_Types ( Shared_Types.hs, Shared_Types.o ) [flags changed]
[2 of 7] Compiling SharedService_Iface ( SharedService_Iface.hs, SharedService_Iface.o ) [flags
changed]
[3 of 7] Compiling SharedService ( SharedService.hs, SharedService.o ) [flags changed]
[4 of 7] Compiling Tutorial_Types ( Tutorial_Types.hs, Tutorial_Types.o ) [flags changed]
[5 of 7] Compiling Calculator_Iface ( Calculator_Iface.hs, Calculator_Iface.o ) [flags changed]
[6 of 7] Compiling Calculator ( Calculator.hs, Calculator.o ) [flags changed]
[7 of 7] Compiling Main ( HaskellServer.hs, HaskellServer.o )
HaskellServer.hs:48:33:
Couldn't match type `GHC.Int.Int32' with `Int'
Expected type: Maybe Int
Actual type: Maybe GHC.Int.Int32
In the first argument of `fromJust', namely `k'
In the second argument of `(!)', namely `(fromJust k)'
In the second argument of `($)', namely `(myLog ! (fromJust k))'
HaskellServer.hs:73:60:
Couldn't match type `Int' with `GHC.Int.Int32'
Expected type: Maybe GHC.Int.Int32
Actual type: Maybe Int
In the `f_InvalidOperation_what' field of a record
In the second argument of `($)', namely
`InvalidOperation
{f_InvalidOperation_what = Just $ fromEnum $ op work,
f_InvalidOperation_why = Just "Cannot divide by 0"}'
In the expression:
throw
$ InvalidOperation
{f_InvalidOperation_what = Just $ fromEnum $ op work,
f_InvalidOperation_why = Just "Cannot divide by 0"}
HaskellServer.hs:74:64:
Couldn't match expected type `Data.Text.Lazy.Internal.Text'
with actual type `[Char]'
In the first argument of `Just', namely `"Cannot divide by 0"'
In the `f_InvalidOperation_why' field of a record
In the second argument of `($)', namely
`InvalidOperation
{f_InvalidOperation_what = Just $ fromEnum $ op work,
f_InvalidOperation_why = Just "Cannot divide by 0"}'
HaskellServer.hs:79:53:
Couldn't match type `[Char]' with `Data.Text.Lazy.Internal.Text'
Expected type: Data.Text.Lazy.Internal.Text
Actual type: String
In the return type of a call of `show'
In the first argument of `Just', namely `(show val)'
In the second argument of `SharedStruct', namely
`(Just (show val))'
HaskellServer.hs:80:52:
Couldn't match expected type `Int' with actual type `GHC.Int.Int32'
In the first argument of `M.insert', namely `logid'
In the second argument of `(.)', namely `(M.insert logid logEntry)'
In the second argument of `($)', namely
`return . (M.insert logid logEntry)'
显然,类型有问题,但我不能说这是我的特定 GHC 版本或节俭本身的问题。
这是第一条错误消息的代码 (HaskellServer.hs:48:33):
instance SharedService_Iface CalculatorHandler where
getStruct self k = do
myLog <- readMVar (mathLog self)
return $ (myLog ! (fromJust k))
有人可以指出我正确的方向吗?
更新
生成的 thrift 文件列出了使用的编译标志:
{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
{-# OPTIONS_GHC -fno-warn-unused-imports #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}
{-# OPTIONS_GHC -fno-warn-missing-fields #-}
{-# OPTIONS_GHC -fno-warn-missing-signatures #-}