Haskell如何在Windows上调用ffi

抱歉，如果这是一个新手问题。我试图从Haskell调用一个C函数。我目前正在Windows上使用堆栈。我从以下简单的例子开始，这个例子效果很好：

import Prelude hiding (sin)
 
import Foreign.C -- get the C types
 
-- pure function
foreign import ccall "sin" c_sin :: CDouble -> CDouble

sin :: Double -> Double
sin d = realToFrac (c_sin (realToFrac d))

main = do
    print . sin =<< readLn

我得到以下错误：

src\Main.hs:1:12: warning:
    -#include and INCLUDE pragmas are deprecated: They no longer have any effect
Linking src\Main.exe ...
src\Main.o:fake:(.text+0x56): undefined reference to `myfunc'
collect2.exe: error: ld returned 1 exit status
`gcc.exe' failed in phase `Linker'. (Exit code: 1)

我已经在

myfunction.c

中将

myfunc

定义为一个常规的c函数，并带有相应的inc头

myfunction.h

对于编译应用程序，我使用的是

stack ghc src/Main.hs src/myfunction.c

---

我的所有源代码都位于我的项目的

src

目录下。

好的，终于找到了，下面是更新的代码：

{-# INCLUDE "myfunction.h" #-}

{-# LANGUAGE ForeignFunctionInterface #-}


import Prelude hiding (sin)
 
import Foreign.C -- get the C types
 
-- pure function
foreign import ccall "sin" c_sin :: CDouble -> CDouble
foreign import ccall "myfunction" c_myfunction :: Double -> Double

sin :: Double -> Double
sin d = realToFrac (c_sin (realToFrac d))

myfunction :: Double -> Double
myfunction d = realToFrac(c_myfunction d)

main = do
  print . sin =<< readLn
  print . myfunction =<< readLn

{-#包括“myfunction.h”#-}
{-#语言外来功能接口#-}
导入前奏隐藏（sin）
 
import Foreign.C——获取C类型
 
--纯函数
国外进口ccall“sin”c_sin:：CDouble->CDouble
国外进口ccall“myfunction”c_myfunction:：Double->Double
sin：：Double->Double
sin d=realToFrac（c_sin（realToFrac d））
myfunction:：Double->Double
myfunction d=realToFrac（c_myfunction d）
main=do
印刷品。罪=
{-# INCLUDE "myfunction.h" #-}

{-# LANGUAGE ForeignFunctionInterface #-}


import Prelude hiding (sin)
 
import Foreign.C -- get the C types
 
-- pure function
foreign import ccall "sin" c_sin :: CDouble -> CDouble
foreign import ccall "myfunction" c_myfunction :: Double -> Double

sin :: Double -> Double
sin d = realToFrac (c_sin (realToFrac d))

myfunction :: Double -> Double
myfunction d = realToFrac(c_myfunction d)

main = do
  print . sin =<< readLn
  print . myfunction =<< readLn