[GHC] #11610: Remove IEThingAll constructor from IE datatype

[GHC]

#11610: Remove IEThingAll constructor from IE datatype
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        Reporter:  mpickering        |                Owner:
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 Ah I see.  So you propose to kill off `IEThingAll n` in favour of
 `IEThingWith n IEWildCard [] []`.

 Yes that seems fine.  Better make certain that the behaviour is identical
 but it jolly well ought to be.

 Meanwhile, could you also add a comment with
 {{{
 data IEWildcard = NoIEWildcard | IEWildcard Int deriving (Eq, Data,
 Typeable)
 }}}
 What is this `Int`?  Comment plus example.  (I think it may indicate where
 the single `...` occurs in the list perhaps?

 Ditto in
 {{{
 data ImpExpSubSpec = ImpExpAbs
                    | ImpExpAll
                    | ImpExpList [Located RdrName]
                    | ImpExpAllWith [Located (Maybe RdrName)]
 }}}
 what is this `Maybe` doing?  Perhaps `Nothing` indicates `..`? Might you
 add commentary and an example to explain?

 Data types are such a golden golden opportunity for comments :-).

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11610#comment:3>
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