[GHC] #4178: Lazy evaluation of type families causes quantified type variables to escape

[GHC]

#4178: Lazy evaluation of type families causes quantified type variables to escape
---------------------------------+------------------------------------------
    Reporter:  intoverflow       |        Owner:                           
        Type:  bug               |       Status:  new                      
    Priority:  normal            |    Milestone:                           
   Component:  Compiler          |      Version:  6.12.1                   
    Keywords:                    |   Difficulty:                           
          Os:  Unknown/Multiple  |     Testcase:                           
Architecture:  Unknown/Multiple  |      Failure:  GHC rejects valid program
---------------------------------+------------------------------------------

Comment(by simonpj):

 Agreed.  I'll add this to my list of tickets for when the new type
 inference machinery is done.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4178#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler