[GHC] #7730: :info and polykinds

[GHC]

#7730: :info and polykinds
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        Reporter:  monoidal                 |            Owner:  archblob
            Type:  bug                      |           Status:  new
        Priority:  normal                   |        Milestone:  7.8.3
       Component:  Compiler (Type checker)  |          Version:  7.6.2
      Resolution:                           |         Keywords:
Operating System:  Unknown/Multiple         |     Architecture:
 Type of failure:  None/Unknown             |  Unknown/Multiple
       Test Case:                           |       Difficulty:  Unknown
        Blocking:                           |       Blocked By:
                                            |  Related Tickets:  #8776
--------------------------------------------+------------------------------
Changes (by simonpj):

 * cc: goldfire (added)


Comment:

 Re (2) I'm not too bothered.  What you see is what you get.  That is, the
 user wrote `{-# UNPACK #-}` but it didn't happen, so it doesn't show up in
 the `IfaceSyn`.  So I'd just leave it as it is.   In your example, I guess
 you only compiled `STest` without `-O`, else you would see the UNPACK?

 Re (1) this is actually very much the same kind of issue as with
 `IfaceFunTy` vs `IfaceDictFunTy`; we don't have quite enough info in the
 `IfaceType`.  I'm adding Richard to the cc list because he is busy
 unifying types and kinds, and separating the issue of source-code
 visiblity.

 To solve (1) we'd need to add a flag saying "I a kind" to each argument of
 an `IfaceTyConApp`.  That's quite painful, `IfaceTyConApp` is very common.
 It might be better to say:
 {{{
 data IfaceType = .... | IfaceTyConApp IfaceTcArgs | ...
 data IfaceTcArgs
   = ITC_Nil
   | ITC_Type IfaceType IfaceTcArgs
   | ITC_Kind IfaceKind IfaceTcArgs
 }}}
 That would be be simple and would hardly affect in interface files.

 But I'd like to see what Richard has to say first.

 Simon

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7730#comment:28>
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