haskell - 有什么办法可以使这个 Haskell IO 函数的版本更清晰？

Question

我有大量的 IConnection conn => conn -> IO () 函数，我需要执行这些函数才能正确设置数据库。现在，它不是很漂亮，但我是 Haskell 的初学者，无法让它变得更好。

setup :: IConnection conn => conn -> IO ()
setup conn = do 
    setupUtterances conn
    commit conn
    setupSegments conn
    commit conn
    setupLevels conn
    commit conn
    setupLevelLevel conn
    commit conn
    setupTCLevelLevel conn
    commit conn
    setupPaths conn
    commit conn
    setupLabelTypes conn
    commit conn 
    setupLegalLabels conn
    commit conn
    setupTracks conn
    commit conn
    setupVariables conn
    commit conn 
    setupFeatures conn
    commit conn
    setupAssociations conn
    commit conn
    return ()

无论如何要缩短它？我在玩

sequence $ map ($ conn) [func1, func2,...]

但我无法让它工作。建议？

Answer 1

刚刚怎么样

setup conn = mapM_ ($ conn) $ intersperse commit
             [ setupUtterances,
             , setupSegments
             , setupLevels
             , setupLevelLevel
             , setupTCLevelLevel
             , setupPaths
             , setupLabelTypes
             , setupLegalLabels
             , setupTracks 
             , setupVariables 
             , setupFeatures 
             , setupAssociations
             , \_ -> return ()]

intersperse坚持 commit在所有操作和 mapM_ ($conn) 之间喂食 conn致所有 IO行动。最后 \_ -> return ()是确保 commit在这一切结束时被调用。