#10797: Kind-level functional dependencies are not resolved properly -------------------------------------+------------------------------------- Reporter: danilo2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by danilo2): And one more additional fact. We can implement what I want creating some boilerplate. I'm sure there should be way to avoid it (without using TemplateHaskell): {{{ class BaseType a b | a -> b where baseType :: a -> b instance {-# OVERLAPPABLE #-} out ~ (Proxy a) => BaseType (Proxy a) out instance {-# OVERLAPPABLE #-} out ~ (Proxy a) => BaseType (Proxy (a t1)) out instance {-# OVERLAPPABLE #-} out ~ (Proxy a) => BaseType (Proxy (a t1 t2)) out instance {-# OVERLAPPABLE #-} out ~ (Proxy a) => BaseType (Proxy (a t1 t2 t3)) out instance {-# OVERLAPPABLE #-} out ~ (Proxy a) => BaseType (Proxy (a t1 t2 t3 t4)) out instance {-# OVERLAPPABLE #-} out ~ (Proxy a) => BaseType (Proxy (a t1 t2 t3 t4 t5)) out ... }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10797#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler