[GHC] #9637: Type level programming needs an error function

[GHC]

#9637: Type level programming needs an error function
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        Reporter:  augustss          |                   Owner:
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.8.3
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:  #9180, #9636      |                Blocking:
                                     |  Differential Revisions:
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Changes (by goldfire):

 * related:   => #9180, #9636


Comment:

 #9180 proposes a similar mechanism at the term level. #9636 is a nice
 application of the feature proposed in this ticket.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9637#comment:7>
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