[GHC] #13044: make it possible to apply GHC rewrite rules to class methods

[GHC]

#13044: make it possible to apply GHC rewrite rules to class methods
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        Reporter:  George            |                Owner:
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      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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Description changed by bgamari:

@@ -2,3 +2,4 @@
- wrote in a discussion on glasgow-haskell-users, it is too bad that we
- can't use class laws as optimizations in the form of rewrite rules. In
- that same thread Simon PJ referenced
+ wrote in a discussion on [[https://mail.haskell.org/pipermail/glasgow-
+ haskell-users/2016-November/026406.html|glasgow-haskell-users]], it is too
+ bad that we can't use class laws as optimizations in the form of rewrite
+ rules. In that same thread Simon PJ referenced

New description:

 Make it possible to apply GHC rewrite rules to class methods. As Conal
 wrote in a discussion on [[https://mail.haskell.org/pipermail/glasgow-
 haskell-users/2016-November/026406.html|glasgow-haskell-users]], it is too
 bad that we can't use class laws as optimizations in the form of rewrite
 rules. In that same thread Simon PJ referenced
 https://ghc.haskell.org/trac/ghc/ticket/11688, especially
 ticket:11688#comment:7 which gives links to similar examples.
 ticket:10528#comment:13 gives more background.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13044#comment:4>
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