Re: [GHC] #10734: pprint of ‘let’ inside ‘do’ prints invalid Haskell

[GHC]

#10734: pprint of ‘let’ inside ‘do’ prints invalid Haskell
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        Reporter:  Fuuzetsu          |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Template Haskell  |                 Version:  7.10.2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by Fuuzetsu):

 Also a problem on 7.10.2

 The `Ppr` instance for `LetS` constructor is just not good enough.

 {{{#!hs
 Prelude Language.Haskell.TH.Ppr Language.Haskell.TH> pprint <$> runQ [| do
 { let { x = 5; y = 3 }; return x; } |]
 "do {let x_0 = 5\n        y_1 = 3;\n    GHC.Base.return x_0}"
 }}}

 Worst thing is that there is no easy way to override this…

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10734#comment:1>
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