[GHC] #9022: TH pretty printer and GHC parser semicolon placement mismatch

[GHC]

#9022: TH pretty printer and GHC parser semicolon placement mismatch
-------------------------------------+-------------------------------------
              Reporter:  roldugin    |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:  7.10.1
             Component:  Template    |          Version:  7.8.1
  Haskell                            |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:
       Type of failure:  GHC         |  Related Tickets:
  rejects valid program              |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------

Comment (by roldugin):

 You're right!

 `let` expressions should be fine:
 {{{
 > pprint <$> runQ [| let { x = 3; y = 4 } in x + y |]
 "let {x_0 = 3; y_1 = 4}\n in x_0 GHC.Num.+ y_1"
 }}}

 But there is indeed a problem with `let` statements:
 {{{
 > pprint <$> runQ [| do let { x = 3; y = 4 } ; return (x + y) |]
 "do {let {x_0 = 3}; {y_1 = 4}; GHC.Base.return (x_0 GHC.Num.+ y_1)}"
 }}}

 I think pretty printing `LetS` will need to use custom `pprDecs` like
 `LetE` does around line 149.

 Unfortunately, I can't do it right now but I will when I get a minute.

 George

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9022#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler