[GHC] #5910: Holes with other constraints

[GHC]

#5910: Holes with other constraints
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    Reporter:  xnyhps                   |       Owner:                                   
        Type:  feature request          |      Status:  new                              
    Priority:  normal                   |   Milestone:                                   
   Component:  Compiler (Type checker)  |     Version:  7.5                              
    Keywords:  holes                    |          Os:  Unknown/Multiple                 
Architecture:  Unknown/Multiple         |     Failure:  Incorrect warning at compile-time
  Difficulty:  Unknown                  |    Testcase:                                   
   Blockedby:                           |    Blocking:                                   
     Related:                           |  
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Comment(by simonpj):

 Replying to [comment:5 xnyhps]:
 >
 > However, there's a one problem with this approach. The code that handles
 prioritization of errors and the code that handles deferring type erros to
 runtime, as far as I can tell, do different things to handle multiple
 errors: when `-fdefer-type-errors` is on, '''every''' error is reported
 and no prioritization is done. This also means that when just holes are
 deferred, the class ambiguity errors I initially had still happen. Do you
 have a suggestion on how to avoid this, other than always deferring all
 type errors?

 Can you give me a concrete example, showing the behaviour you get, and the
 behaviour you want?

 Do you have a separate flag to enable holes? I assume so.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5910#comment:6>
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