[GHC] #13614: Rewrite rules not applied exhaustively when simplifying from plugin

[GHC]

#13614: Rewrite rules not applied exhaustively when simplifying from plugin
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        Reporter:  nomeata           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  GHC API           |              Version:  8.1
      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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Comment (by simonpj):

 It's not just that they aren't getting applied; somehow `foo 1` is getting
 rewritten to `foo 2` which is deeply strange.  I have no hypothesis here.

 I'm not sure why you are simplifying twice.

 You don't seem to be doing occurrence analysis, although I can't see how
 that will lead to this behaviour.

 Try `-ddump-rule-rewrites`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13614#comment:1>
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