[GHC] #9813: Error when reifying type constructor

[GHC]

#9813: Error when reifying type constructor
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              Reporter:  owst        |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:              |       Blocked By:
  None/Unknown                       |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by goldfire):

 Only top-level declaration splices break up declaration groups. Your code
 has an expression splice, which is in the first declaration group and thus
 can't "see" it.

 I agree that your code ''is'' reasonable, but I also think that 7.8's
 behavior of breaking things into declaration groups is more predictable
 (once you know the rule). In general, otherwise, it would be quite hard
 for a human to figure out exactly which things are reifiable from a given
 splice -- it would all depend on GHC's internal topological sorting
 process.

 If you can propose an alternative, straightforward rule defining what
 should be available to `reify`, I'd be interested.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9813#comment:4>
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