[GHC] #9146: GHC.TypeLits import don't quite work

[GHC]

#9146: GHC.TypeLits import don't quite work
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       Reporter:  yuriyt            |             Owner:
           Type:  bug               |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.8.2
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
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 If you explicitly import any of the things that are Compiler Magic from
 `GHC.TypeLits` you get an error:

 {{{
 import GHC.TypeLits ((+), (-))
 ...
 }}}

 {{{
 [1 of 1] Compiling Main             ( typelit_export_bug.hs, interpreted )

 typelit_export_bug.hs:1:22:
     Module `GHC.TypeLits' does not export `(+)'

 typelit_export_bug.hs:1:27:
     Module `GHC.TypeLits' does not export `(-)'
 Failed, modules loaded: none.
 }}}

 If you do the opposite, it also doesn't work
 {{{
 import GHC.TypeLits hiding ((+), (-))
 ...
 }}}

 {{{
 [1 of 1] Compiling Main             ( typelit_export_bug.hs, interpreted )

 typelit_export_bug.hs:3:1: Warning:
     Module `GHC.TypeLits' does not export `(+)'

 typelit_export_bug.hs:3:1: Warning:
     Module `GHC.TypeLits' does not export `(-)'
 }}}

 The use case is that I would like to define my own `+` and have one
 instance for `Nat` and others for other types of my choosing. It isn't
 more than a minor annoyance, however, there aren't many thing defined in
 `GHC.TypeLits` so I can write `import qualified GHC.TypeLits; import
 GHC.TypeLits (Nat, natVal, Symbol, symbolVal ...`

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9146>
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