[GHC] #8176: Language extensions not registered

[GHC]

#8176: Language extensions not registered
------------------------------------------+--------------------------------
        Reporter:  duncan                 |            Owner:
            Type:  bug                    |  thoughtpolice
        Priority:  normal                 |           Status:  new
       Component:  Compiler               |        Milestone:  7.8.1
      Resolution:                         |          Version:  7.7
Operating System:  Unknown/Multiple       |         Keywords:
 Type of failure:  None/Unknown           |     Architecture:
       Test Case:  tests/driver/T4437.hs  |  Unknown/Multiple
        Blocking:                         |       Difficulty:  Unknown
                                          |       Blocked By:
                                          |  Related Tickets:
------------------------------------------+--------------------------------

Comment (by duncan):

 So comparing with what we comitted during the recent Zurich hackathon:
 https://github.com/haskell/cabal/commit/d40207efec3133735cee89aec17974ea6c307613

  * OverloadedLists
  * EmptyCase
  * AutoDeriveTypeable
  * NegativeLiterals
  * NumDecimals
  * NullaryTypeClasses

 We added all these because they were documented in the user guide already.

 We didn't add TypeHoles on the theory that it would not be used in
 released packages. However on reflection it would be better to add it as a
 registered extension but to have an explicit check for it not being used
 in distributed packages (e.g. like we complain about -Werror).

 So what are we still missing then?

  * ExplicitNamespaces
  * AllowAmbiguousTypes

 We should check these are documented in the user guide and then register
 them in Language.Haskell.Extensions.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8176#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler