#13324: Allow PartialTypeSignatures in the instance context of a standalone deriving declaration -------------------------------------+------------------------------------- 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: | -------------------------------------+------------------------------------- Comment (by simonpj):
Since it's morally equivalent to just using a deriving Eq clause.
And it'll be implementationally the same as using `deriving Eq` too! So the same things will happen automatically. In the code, the `mtheta` variable will tbe `Nothing` rather than `Just`. Just allowing a wildcard on its own would be a good start. But we have code for doing the "subtraction" in cases like `(Eq a, _) => blah`, so it would not be too hard to support that too. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13324#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler