[GHC] #13887: Template Haskell pretty-printer doesn't parenthesize infix datatype names in data declarations

[GHC]

#13887: Template Haskell pretty-printer doesn't parenthesize infix datatype names
in data declarations
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  ak3n
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Template Haskell  |              Version:  8.0.1
      Resolution:  fixed             |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3717,
       Wiki Page:                    |  Phab:D3802
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * differential:  Phab:D3717 => Phab:D3717, Phab:D3802


Comment:

 I found yet another example of this sort of thing:

 {{{#!hs
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE TemplateHaskell #-}
 module Main where

 import Data.Proxy
 import GHC.Generics
 import Language.Haskell.TH

 main :: IO ()
 main = do
   putStrLn $([t| Proxy  (:*:) |] >>= stringE . pprint)
   putStrLn $([t| Proxy '(:*:) |] >>= stringE . pprint)
   putStrLn $([t| Proxy '(:)   |] >>= stringE . pprint)
 }}}

 {{{
 Data.Proxy.Proxy (GHC.Generics.:*:)
 Data.Proxy.Proxy 'GHC.Generics.:*:
 Data.Proxy.Proxy 'GHC.Types.:
 }}}

 Unfortunately, we must have overlooked applying this fix to //promoted//
 infix constructors.

 I've got a patch at Phab:D3802 which addresses this.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13887#comment:9>
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