我正在尝试用Haskell写一个输出音频的程序，我决定使用OpenAL作为音频后端，考虑到我使用OpenAL的经验很少，我想我要做的第一件事就是在Haskell中复制OpenAL programmer's guide中的示例代码，这是用C编写的。
下面是该指南中的C代码：

// Initialization
Device = alcOpenDevice(NULL); // select the "preferred device"

if (Device) {
    Context=alcCreateContext(Device,NULL);
    alcMakeContextCurrent(Context);
}

// Check for EAX 2.0 support
g_bEAX = alIsExtensionPresent("EAX2.0");

// Generate Buffers
alGetError(); // clear error code

alGenBuffers(NUM_BUFFERS, g_Buffers);
if ((error = alGetError()) != AL_NO_ERROR)
{
    DisplayALError("alGenBuffers :", error);
    return;
}

// Load test.wav
loadWAVFile("test.wav",&format,&data,&size,&freq,&loop);
if ((error = alGetError()) != AL_NO_ERROR)
{
    DisplayALError("alutLoadWAVFile test.wav : ", error);
    alDeleteBuffers(NUM_BUFFERS, g_Buffers);
    return;
}

// Copy test.wav data into AL Buffer 0
alBufferData(g_Buffers[0],format,data,size,freq);
if ((error = alGetError()) != AL_NO_ERROR)
{
    DisplayALError("alBufferData buffer 0 : ", error);
    alDeleteBuffers(NUM_BUFFERS, g_Buffers);
    return;
}

// Unload test.wav
unloadWAV(format,data,size,freq);
if ((error = alGetError()) != AL_NO_ERROR)
{
    DisplayALError("alutUnloadWAV : ", error);
    alDeleteBuffers(NUM_BUFFERS, g_Buffers);
    return;
}

// Generate Sources
alGenSources(1,source);
if ((error = alGetError()) != AL_NO_ERROR)
{
    DisplayALError("alGenSources 1 : ", error);
    return;
}

// Attach buffer 0 to source
alSourcei(source[0], AL_BUFFER, g_Buffers[0]);
if ((error = alGetError()) != AL_NO_ERROR)
{
    DisplayALError("alSourcei AL_BUFFER 0 : ", error);
}

// Exit
Context=alcGetCurrentContext();
Device=alcGetContextsDevice(Context);
alcMakeContextCurrent(NULL);
alcDestroyContext(Context);
alcCloseDevice(Device);

字符串
这是我目前为止得到的：

module Main where

import Data.Maybe ( fromJust )
import Data.StateVar ( ($=) )
import Sound.OpenAL ( genObjectNames )
import qualified Sound.OpenAL.AL as AL
import qualified Sound.OpenAL.ALC as ALC

main :: IO ()
main = do
    -- Initialization
    maybeDevice <- ALC.openDevice Nothing  -- select the "preferred device"
    let device = fromJust maybeDevice

    maybeContext <- ALC.createContext device streamAttributes
    ALC.currentContext $= maybeContext

    -- Generate buffers
    errors <- AL.alErrors  -- clear error code
    [g_buffers] <- genObjectNames n_buffers

    -- Exit
    deviceClosed <- ALC.closeDevice device
    return ()

    where streamAttributes = [ ALC.Frequency 44100,
                               ALC.MonoSources 1,
                               ALC.StereoSources 0 ]
          n_buffers = 3

型
不幸的是，我在尝试生成缓冲区时遇到了一点障碍。目前，当我编译上述Haskell代码时，我得到以下错误：

app/Main.hs:19:20: error:
    • No instance for (Data.ObjectName.GeneratableObjectName a0)
        arising from a use of ‘genObjectNames’
    • In a stmt of a 'do' block:
        [g_buffers] <- genObjectNames n_buffers
      In the expression:
        do maybeDevice <- ALC.openDevice Nothing
           let device = fromJust maybeDevice
           maybeContext <- ALC.createContext device streamAttributes
           ALC.currentContext $= maybeContext
           ....
      In an equation for ‘main’:
          main
            = do maybeDevice <- ALC.openDevice Nothing
                 let device = ...
                 maybeContext <- ALC.createContext device streamAttributes
                 ....
            where
                streamAttributes = [ALC.Frequency 44100, ....]
                n_buffers = 3
   |
19 |     [g_buffers] <- genObjectNames n_buffers
   |                    ^^^^^^^^^^^^^^

型
我对Haskell不是很有经验，所以我发现很难准确地指出我在这里做错了什么。我使用https://hackage.haskell.org/package/OpenAL来提供绑定。任何帮助都将不胜感激。