[GHC] #15009: Float equalities past local equalities

[GHC]

#15009: Float equalities past local equalities
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  feature request   |               Status:  closed
        Priority:  normal            |            Milestone:  8.4.3
       Component:  Compiler          |              Version:  8.2.2
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:  gadt/T15009
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by nfrisby):

 I've worked through some interesting examples and distilled them into a
 first draft rule. CTRL+F for "Rule 20181104" on wiki:FloatMoreEqs2018. The
 page has dated entries, but today's should supersede all the older ones.

 I'm traveling on vacation for a couple weeks, so that will certainly
 derail me for a while. Today's entry was an effort to have something
 useful to come back to, but it has a couple TODOs. I think the first
 (Example 5) is a matter of finding the right presentation, while the
 second (Does RHS of {{{w}}} matter?) is something I just haven't thought
 much about yet.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15009#comment:20>
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