#6005: Template Haskell disallows use of promoted data constructor in same
splice
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Reporter: goldfire | Owner:
Type: bug | Status: closed
Priority: normal | Milestone:
Component: Template Haskell | Version: 7.5
Resolution: fixed | Keywords: DataKinds PolyKinds
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: GHC rejects valid program | Difficulty: Unknown
Testcase: th/T6005, T6005a | Blockedby:
Blocking: | Related:
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Changes (by simonpj):
* status: new => closed
* testcase: th/T6005 => th/T6005, T6005a
* resolution: => fixed
Comment:
This turns out to be unrelated to data kinds etc. Instead it is simply to
do with the difficulty of type-checking Template Haskell brackets,
something that led me to propose a
[http://hackage.haskell.org/trac/ghc/blog/Template%20Haskell%20Proposal
complete overhaul] (not yet done).
In this case we are generating the derived code for the bracket when we
typecheck the bracket. This is silly because it's sure to type check; and
it goes wrong too for reasons that are not intersting.
I have brutally simply suppressed all 'deriving' processing inside TH
brackets. It'll all become irrelevant with the overhaul.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6005#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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