#11673: Doesn't accept type -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: invalid | 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: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => invalid Comment: Well, if you write {{{ instance ... where id :: Transformer f f id = ... }}} then GHC tries to understand the signature you wrote. Since `Transformer` poly-kinded, what you get is the signature {{{ id :: forall i k. forall (f :: i -> k). Transformer f foo }}} But `Cat.id` doesn't have that type. So I think this is just what's expected. Can you suggest any improvement to the user manual that would make this clearer? Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11673#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler