[GHC] #14748: Infer context for Data instance of (data Foo f = Foo (f Bool) (f Int))
GHC
ghc-devs at haskell.org
Thu Feb 1 14:29:31 UTC 2018
#14748: Infer context for Data instance of (data Foo f = Foo (f Bool) (f Int))
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Reporter: Iceland_jack | Owner: (none)
Type: feature request | Status: new
Priority: normal | Milestone:
Component: Compiler | Version:
Resolution: | Keywords:
| QuantifiedConstraints wipT2893,
| deriving
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 RyanGlScott):
I too am skeptical that there is a robust, systematic way to do what
you're seeking. I think the intent of
https://ghc.haskell.org/trac/ghc/ticket/12245#comment:1 was to combine
quantified constraints with `StandaloneDeriving`, not have the quantified
constraints be inferred.
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14748#comment:2>
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