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Call IO network from inside haskeline

I have an existing program that takes command line arguments (username, password, date), and then uses the library Network.HTTP.Conduitto send an XML message to the server. Then I parse the results, do some work, and use blaze-html to write to the file.

Everything works like a charm; however, I decided to use haskelineso that the password was not visible. I can create a command-line program that receives user-supplied values ​​and displays them, but if I call a function that uses a conduit, it never returns.

Here is the violation code:

main = runInputT defaultSettings loop
where 
    loop :: InputT IO ()
    loop = do
        Just username <- getInputLine "WM username: "
        Just password <- getPassword (Just '*') "WM password: "
        Just date     <- getInputLine "Date (YYYYMMDD): "

        outputStrLn "querying WM..."
        clients <- lift $ getWMClients username password
        outputStrLn "successfully retrieved client list from WM..."

        let outHeader = renderHeader date username

        reportString <- mapM  (\x -> createString x clients)  cList

        lift $ writeFile (date ++ "_report.html") (outHeader ++ concat reportString)
        outputStrLn "Done"

GetWMClients function:

getWMClients :: Username -> String -> IO [Client]
getWMClients username password = do
    let f = [Size "-1", Skip "0"]
    let fs = [Select "id",
              Select "status",
              Select "last-name",
              Select "first-name",
             ]
    let query = WMQuery {transaction=SHARE,service=Query,businessObject=CONT,field=f,fields=fs}

    results <- doQuery username (Just password) Nothing (Just query)
    rows <- xmlResultsToMaps results

    let clients = map makeClient rows
    return clients

, " WM...". , http-conduit . , ?

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+5
1

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-- Isolate the haskeline monad to just the input part:
main = loop
where 
    loop :: IO ()
    loop = do
      (username,password,date) <- runInputT defaultSettings $ do
        Just username <- getInputLine "WM username: "
        Just password <- getPassword (Just '*') "WM password: "
        Just date     <- getInputLine "Date (YYYYMMDD): "
        return (username,password,date)

      putStrLn "querying WM..."
      clients <- getWMClients username password
      putStrLn "successfully retrieved client list from WM..."

      let outHeader = renderHeader date username

      putString <- mapM  (\x -> createString x clients)  cList

      writeFile (date ++ "_report.html") (outHeader ++ concat reportString)
      putStrLn "Done"
+1

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