uageExtensions :: Maybe Language -> [ExtensionFlag]

languageExtensions Nothing
    -- Nothing => the default case
    = Opt_NondecreasingIndentation -- This has been on by default for some time
    : delete Opt_DatatypeContexts  -- The Haskell' committee decided to
                                   -- remove datatype contexts from the
                                   -- language:
   -- http://www.haskell.org/pipermail/haskell-prime/2011-January/003335.html
      (languageExtensions (Just Haskell2010))

  
languageExtensions :: Maybe Language -> [ExtensionFlag]
languageExtensions Nothing
    -- Nothing => the default case
    = Opt_NondecreasingIndentation -- This has been on by default for some time
    : delete Opt_DatatypeContexts  -- The Haskell' committee decided to
                                   -- remove datatype contexts from the
                                   -- language:
   -- http://www.haskell.org/pipermail/haskell-prime/2011-January/003335.html
      (languageExtensions (Just Haskell2010))
languageExtensions Nothing
    -- Nothing => the default case
    = Opt_NondecreasingIndentation -- This has been on by default for some time
    : delete Opt_DatatypeContexts  -- The Haskell' committee decided to
                                   -- remove datatype contexts from the
                                   -- language:
   -- http://www.haskell.org/pipermail/haskell-prime/2011-January/003335.html
      (languageExtensions (Just Haskell2010))