[GHC] #5813: Offer a compiler warning for failable pattern matches

[GHC]

#5813: Offer a compiler warning for failable pattern matches
---------------------------------+------------------------------------------
    Reporter:  snoyberg          |       Owner:                  
        Type:  feature request   |      Status:  new             
    Priority:  normal            |   Milestone:  7.6.1           
   Component:  Compiler          |     Version:  7.2.2           
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown    
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
---------------------------------+------------------------------------------

Comment(by maeder):

 Replying to [comment:5 simonmar]:
 > In reply to maeder: the manual desugaring you describe is not semantics-
 preserving, so it's not surprising that you suddently get a new warning.

 I know, the missing cases are turned into nice _fail_ message (including
 the file position) that I would like to create explicitly by a suitable
 (non-pure?) function.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5813#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler