#11450: Associated types at wrong type in instance -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 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 think it's best to require the variables to be the same. They are the same under the hood, so they should be the same on top of the hood, too. The fact that we didn't require this previously is a bug, in my opinion. I don't see how the example in comment:5 argues otherwise. Yes, instances should allow non-linear uses of variables, but I don't see that as related to this overall issue. I could see someone arguing about spurious code breakage here, but I'm not too worried. And the change they would have to make is fully backward compatible. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11450#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler