getFileSize不考虑作为文件句柄

Question

我正在尝试以下代码：

readALine :: FilePath -> IO ()
readALine fname = do 
  putStr . show $ "Filename: " ++ fname ++ "; "
  hand <- openFile fname ReadMode
  if getFileSize hand > 0 then do 
      fline  <- hGetLine hand
      hClose hand
      print $ "First line: " <> fline
  else return ()

但是它给出了以下错误：

$ runghc firstline2.hs

firstline2.hs:20:18: error:
    • Couldn't match type ‘GHC.IO.Handle.Types.Handle’ with ‘[Char]’
      Expected type: FilePath
        Actual type: GHC.IO.Handle.Types.Handle
    • In the first argument of ‘getFileSize’, namely ‘hand’
      In the first argument of ‘(>)’, namely ‘getFileSize hand’
      In the expression: getFileSize hand > 0

问题出在哪里，如何解决？感谢您的帮助。