[GHC] #14643: Partial type signatures in spliced TH declarations behave unexpectedly

[GHC]

#14643: Partial type signatures in spliced TH declarations behave unexpectedly
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        Reporter:  mnislaih          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      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 mnislaih):

 It looks the same under ghc 8.4 alpha:
 {{{
 GHCi, version 8.4.0.20171214: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling Minimal          ( code/debug-hoed/test/minimal.hs,
 interpreted )

 code/debug-hoed/test/minimal.hs:5:1: warning: [-Wpartial-type-signatures]
     • Found type wildcard ‘_’ standing for ‘()’
     • In the type signature:
         f :: (Monad m_a46U, _) => [m_a46U a_a46V] -> m_a46U [a_a46V]
   |
 5 | id [d|
   | ^^^^^^...

 code/debug-hoed/test/minimal.hs:5:1: warning: [-Wpartial-type-signatures]
     • Found type wildcard ‘_’ standing for ‘()’
     • In the type signature:
         f' :: (Monad m_a46U, _) => [m_a46U a_a46V] -> m_a46U [a_a46V]
   |
 5 | id [d|
   | ^^^^^^...
 Ok, one module loaded.
 *Minimal> :browse
 f ::
   (Monad GHC.Types.Any, Monad m) =>
   [GHC.Types.Any GHC.Types.Any] -> GHC.Types.Any [GHC.Types.Any]
 f' :: (Monad GHC.Types.Any, Monad m) => [m a] -> m [a]
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14643#comment:1>
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