[GHC] #11362: T6137 doesn't pass with reversed uniques

[GHC]

#11362: T6137 doesn't pass with reversed uniques
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        Reporter:  niteria           |                Owner:  niteria
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:  4012
 Related Tickets:  #11371            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 I have not been following this ticket, but I'm very lost at the last
 comment.

 * `cab_lhs` is a list of types that are the type patterns on the LHS of an
 axiom.

 * `cab_rhs` is the type on the RHS of an axiom.

 What do you mean by an order of the RHS? There's just one thing.

 The line of code you include is for data family axioms, where the RHS has
 a certain prescribed form. I can see how "order" might apply here. But the
 Core Lint code should work over all axioms, including type family axioms,
 for which the RHS has no notion of ordering at all. What makes you say
 that Core Lint is assuming this?

 It is possible something somewhere is assuming an ordering property about
 data family axioms, in particular, but it's not Core Lint.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11362#comment:5>
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