title: What is wrong with this Haskell let-in indentation?
body: <p>In the below Haskell code, I get an error "parse error on input 'in'". From what I've read, the indentation I've used should be fine. I in fact use 'let' and 'in' with similar indentation ('let' aligned with 'in') successfully elsewhere in my code. What rule have I broken that causes this 'in' to be a problem? If I add a space in front of 'in' (making it 1-space furthur in than 'let') it compiles fine.</p>
  
  <pre><code>runTests :: IO ()
  runTests = do
               let results = fmap testLispExpr testLispText
                   resultStrings = fmap show results
                   putSeq (x:xs) = do putStrLn x
                                      putSeq xs
                   putSeq [] = return ()
               in putSeq resultStrings
  </code></pre>
  
  <p>All help is appreciated. Thanks in advance.</p>