#12592: Explicit type signature for type classes fails -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): This is expected behavior. I think the problem is that you're confusing a type with its kind. In the definition for `IxCopointed` above, your kind for w -- `IxFunct i` or `i -> i -> Type -> Type` -- implies that the type of `i` is `i`, which is not what you mean. That is, when you say `w :: IxFunct i`, then the first two arguments to `w` should have ''kind'' `i`, not necessarily ''be'' `i`. Does this clarify? And I don't see a way to improve the error message (beyond the general improvement our error messages would enjoy). If so, please close the ticket. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12592#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler