title: Haskell - Syntax error because of using tabs instead of spaces
body: <p>i am learning Haskell from learnyouhaskell.com and got this error message when compiling my program.</p>
  
  <p>Error:</p>
  
  <pre><code>baby.hs:25:26: error:
      parse error on input `='
      Perhaps you need a 'let' in a 'do' block?
      e.g. 'let x = 5' instead of 'x = 5'
  </code></pre>
  
  <p>Code:</p>
  
  <pre><code>bump :: [String] -&gt; IO ()
  bump [fileName, numberString] = do
      handle &lt;- openFile fileName ReadMode
      (tempName, tempHandle) &lt;- openTempFile "." "temp"
      contents &lt;- hGetContents handle
      let number = read numberString
          text = lines contents
          bumpLine = text !! number
          newText = delete (text !! number) text
      hPutStr tempHandle $ unlines (bumpLine:newText)
      hClose handle
      hClose tempHandle
      removeFile fileName
      renameFile tempName fileName
  </code></pre>
  
  <p>Can anyone help me with this?</p>