[GHC] #12382: Rename clasing type variables more consistently

[GHC]

#12382: Rename clasing type variables more consistently
-------------------------------------+-------------------------------------
           Reporter:  nomeata        |             Owner:
               Type:  feature        |            Status:  new
  request                            |
           Priority:  low            |         Milestone:
          Component:  Compiler       |           Version:  8.1
  (Type checker)                     |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 This is minor polishing, but polish is nice:

 Consider
 {{{
 :t (id,id,id)
 (id,id,id) :: (a -> a, a1 -> a1, a2 -> a2)
 }}}
 this looks as if the first `a` is in some way better or more important.
 What I’d like to see is
 {{{
 :t (id,id,id)
 (id,id,id) :: (a1 -> a2, a2 -> a2, a3 -> a3)
 }}}

 In other words: If two type variables clash and need to be renamed, then
 rename both (all) of them.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12382>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler