[GHC] #16299: :info pretty-prints data types with non-Type return kinds oddly

[GHC]

#16299: :info pretty-prints data types with non-Type return kinds oddly
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.10.1
       Component:  Compiler          |              Version:  8.6.3
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  ghci/scripts/T7627
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |  https://gitlab.haskell.org/ghc/ghc/merge_requests/343
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Comment (by Marge Bot <ben+marge-bot@…>):

 In [changeset:"8b476d822e97cfe4cebe6e74924d9a79148d608c/ghc"
 8b476d82/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="8b476d822e97cfe4cebe6e74924d9a79148d608c"
 Fix #16299 by deleting incorrect code from IfaceSyn

 GHCi's `:info` command was pretty-printing Haskell98-style data types
 with explicit return kinds if the return kind wasn't `Type`. This
 leads to bizarre output like this:

 ```
 λ> :i (##)
 data (##) :: TYPE ('GHC.Types.TupleRep '[]) = (##)
         -- Defined in ‘GHC.Prim’
 ```

 Or, with unlifted newtypes:

 ```
 λ> newtype T = MkT Int#
 λ> :i T
 newtype T :: TYPE 'IntRep = MkT Int#
         -- Defined at <interactive>:5:1
 ```

 The solution is simple: just delete one part from `IfaceSyn` where
 GHC mistakenly pretty-prints the return kinds for non-GADTs.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16299#comment:3>
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