[GHC] #14969: panic on incorrect syntax

[GHC]

#14969: panic on incorrect syntax
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        Reporter:  johnleo           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.5
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by simonpj):

 * cc: pallm@… (added)


Comment:

 I think this is a variant of #14884.

 The machinery that Mathias Gissurarson (cc'd) has implemented for
 reporting typed holes, does not set type-variable level numbers properly.
 In that context it doesn't matter much; but it's very unsatisfactory.

 I recently had a long conversation with Mathias about various improvements
 to the type-hole-reporting  mechanism.  So we can expect improvements
 here.

 Here is the [wiki:Holes main wiki page about typed holes] which summarises
 the state of play

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14969#comment:4>
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