[GHC] #13324: Allow PartialTypeSignatures in the instance context of a standalone deriving declaration

[GHC]

#13324: Allow PartialTypeSignatures in the instance context of a standalone
deriving declaration
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #10607            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 > Instead of their fully spelled-out, more laborious counterparts. This
 would be crucial for Template Haskell, as its ability to infer these
 contexts is quite limited (see #10607 for an example where this cropped
 up).

 It seems like for this to be useful we will want the ability to more
 precisely apply `PartialTypeSignatures` (in particular from splices) to
 ensure that users are forced to enable it for their entire module to avoid
 spurious errors. Is there a ticket for this yet?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13324#comment:3>
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