[GHC] #5719: Empty tuple doesn't have kind Constraint

[GHC]

#5719: Empty tuple doesn't have kind Constraint
---------------------------------+------------------------------------------
    Reporter:  simonpj           |       Owner:                  
        Type:  bug               |      Status:  new             
    Priority:  normal            |   Milestone:                  
   Component:  Compiler          |     Version:  7.3             
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown    
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
---------------------------------+------------------------------------------

Comment(by simonpj):

 Aha. Confusion
  * I didn't know that `TcHsType` was doing that, and thought the error was
 becuase of the unit tuple thing, so I fixed the parser to do the right
 thing.  I think that's cleaner anyway.
  * After doing that I realised that the original program was wrong anyway,
 as you point out.  So I fixed it as above.
  * In fact it still didn't work becuase there was a real bug in the way
 default family instances were generated, so I fixed that too.

 Bottom line; you are right, but I prefer to stick with `HsTupleTy`
 throughout.  I'll take the `TcHsType` fix out.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5719#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler