[Haskell-beginners] Throughly confused by this error message

[Michael Litchard]

I'd like someone to help me learn what questions to ask about this
error. I'm not sure how to contextualize. I will include code segments
that I think are important, and trust your questions will reveal what
I am leaving out.



HtmlParsing.lhs:81:25:
    The first argument of ($) takes one argument,
    but its type `URLString' has none
    In the second argument of `($)', namely `initial $ method_GET'
    In a stmt of a 'do' expression:
          curlResp curl $ initial $ method_GET
    In the expression:
      do { let initial = urlInitial urlSequence
               login = urlLogin urlSequence
               ....;
             curlResp curl $ initial $ method_GET;
             curlResp curl $ urlLogin urlSequence $ loginOpts user pass;
             curlResp curl $ urlFlash1 urlSequence resourceOpts;
           .... }


> generateResourceHtml :: Curl -> String -> String -> FilePath -> IO (Either String String)
> generateResourceHtml curl user pass ipFile = do
>   urlSequence <- popURLrec ipFile
>   let makeIDPage = do
>       let initial = urlInitial urlSequence
>           login = urlLogin urlSequence
>           flash1 = urlFlash1 urlSequence
>           flash2 = urlFlash2 urlSequence
>           showWebForwards = urlShowWebForwards urlSequence
>           quickCreate = urlQuickCreate urlSequence
>           getResource =  urlGetResource urlSequence
>       curlResp curl $ initial $ method_GET
>       curlResp curl $ urlLogin urlSequence $ loginOpts user pass
>       curlResp curl $ urlFlash1 urlSequence resourceOpts
>       curlResp curl $ urlFlash2 urlSequence resourceOpts
>       curlResp curl $ urlShowWebForwards urlSequence resourceOpts
>       curlResp curl $ urlQuickCreate urlSequence resourceOpts
>       curlResp curl $ urlGetResource urlSequence resourceOpts
>   runErrorT makeIDPage

> data URLSequence = URLSequence { urlInitial :: URLString
>                                , urlLogin :: URLString
>                                , urlFlash1 :: URLString
>                                , urlFlash2 :: URLString
>                                , urlShowWebForwards :: URLString
>                                , urlQuickCreate :: URLString
>                                , urlGetResource :: URLString
>                                } deriving Show

> curlResp :: (Error e, MonadError e m, MonadIO m) =>
>       Curl -> URLString -> [CurlOption] -> m String --CurlResponse
> curlResp curl url opts = do
>   resp <- liftIO $ (do_curl_ curl url opts :: IO CurlResponse)
>   let code   = respCurlCode resp
>       status = respStatus resp
>   if code /= CurlOK || status /= 200
>      then throwError $ strMsg $ "Error: " ++ show code ++ " -- " ++ show status
>      else return $ respBody resp