#11449: Treat '_' consistently in type declarations -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 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): I would love to see (A) accepted (perhaps with some language extension). I think (C) should be rejected. After all, the type variable ''is'' used there. It's used in the type family declaration, where `a` is not ''bound'' -- it is ''used''. Accordingly, {{{ class C a where type F a type F a = Int }}} should not emit any warnings. The only bound variable, `a`, is indeed used. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11449#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler