[GHC] #8171: Extending ExtendedDefaultRules

[GHC]

#8171: Extending ExtendedDefaultRules
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        Reporter:  ekmett            |            Owner:
            Type:  feature request   |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by ekmett):

 FWIW- We've been using a simpler system just like the one you proposed in
 our compiler for a Haskell-like language at work since its inception a
 couple of years ago with no user issues. We did so mostly because we
 couldn't be bothered to come up with a more complex system of rules.

 https://github.com/ermine-language/ermine-
 legacy/blob/948a053b6f9ea274d11bf34cb2e3a9c7f3937923/src/main/scala/com/clarifi/reporting/ermine/Subst.scala#L382

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8171#comment:8>
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