[GHC] #12976: GHCi displays the kinds of unboxed tuples incorrectly

[GHC]

#12976: GHCi displays the kinds of unboxed tuples incorrectly
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        Reporter:  RyanGlScott       |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  GHCi              |              Version:  8.0.2
      Resolution:  invalid           |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #12985            |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * status:  new => closed
 * resolution:   => invalid
 * related:   => #12985


Comment:

 Replying to [comment:4 goldfire]:
 > The `(#,#)` type constructor takes 4 arguments, `(r1 :: RuntimeRep)`,
 `(r2 :: RuntimeRep)`, `(a :: TYPE r1)`, and `(b :: TYPE r2)`. Because
 there is no type-level lambda, it ''must'' take these arguments in order.
 So we cannot supply the third argument (the `Int#` in the `(#,#) Int#`
 case) without supplying the second. Initially, this second argument is a
 unification variable, but this gets defaulted to `PtrRepLifted` before
 printing.
 >
 > Does that explain it?

 Now it makes sense! Thanks. I'm a bit saddened that we apparently don't
 have a way to make `(#,#) Int# :: forall (r2 :: RuntimeRep). TYPE r2 ->
 TYPE 'UnboxedTupleRep`, but maybe that problem will be fixed once we have
 visible kind applications (#12045).

 > And I have no idea what's going on with TH. That looks like a separate
 ticket to me.

 OK. I've opened #12985 specifically to address that issue.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12976#comment:5>
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