[GHC] #7967: With dependent types, error reported in seemingly unrelated function

[GHC]

#7967: With dependent types, error reported in seemingly unrelated function
-----------------------------+----------------------------------------------
Reporter:  goldfire          |          Owner:                  
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.7               |       Keywords:  DataKinds, GADTs
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:                  
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Comment(by simonpj@…):

 commit 262cab0f1c928fb3fea9afa4d2c442edb3103c08
 {{{
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Wed Jun 12 09:38:54 2013 +0100

     Fix the constraint simplifier (Trac #7967)

     Richard's bug report showed up a couple of subtleties in the
 constraint solver

     * We can strengthen the kind invariants on CTyEqCan and CFunEqCan
         See Note [Kind orientation for CTyEqCan]
         and Note [Kind orientation for CFunEqCan] in TcRnTypes
       There are some changes to reOrient and checkKind in TcCanonical
       to support these stronger invarants.

     * In TcSimplify we must make sure that we re-simplify if defaultTyVar
       does anything.  See Note [Must simplify after defaulting] in
 TcSimplify.

     The usual round of refactoring follows!

  compiler/typecheck/TcCanonical.lhs |  174
 ++++++++++++++++++++----------------
  compiler/typecheck/TcInteract.lhs  |   77 +++-------------
  compiler/typecheck/TcRnTypes.lhs   |   53 ++++++++++-
  compiler/typecheck/TcSMonad.lhs    |    6 +-
  compiler/typecheck/TcSimplify.lhs  |   53 ++++++++----
  5 files changed, 194 insertions(+), 169 deletions(-)
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7967#comment:1>
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