#10607: Auto derive from top to bottom -------------------------------------+------------------------------------- Reporter: songzh | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: deriving, | typeclass, auto Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13324 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by songzh): Replying to [comment:23 RyanGlScott]:
songzh, I finally delivered on my promise to implement the ability to use `PartialTypeSignatures` in standalone `deriving` declarations //à la// `deriving _ => Eq (Foo a)`. Does this make things easier for you on your end?
Yes! Your `Any` wrinkle has worked very well already, but this will make a lot improvement for `derive-topdown` package. With new `PartialTypeSignatures` a lot of code can be removed in the package, but for compatibility reason, I will keep them for older GHC. Even though class instance contexts can be generated and inferred now and type role is carefully handled for now, three other packages,`primitive`, `th-expand-syns`, `transformers` ,still are needed. This stops current `derive-topdown` being used inside ghc's code, so I will write a minimal package in order to reduce the dependencies of `derive-topdown`. Thanks. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10607#comment:24 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler