#8165: Use GeneralizedNewtypeDeriving to automatically create associated type families -------------------------------------+------------------------------------ Reporter: MikeIzbicki | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by goldfire): This auto-generation seems to be rather different from the way `GeneralizedNewtypeDeriving` works in other contexts. In particular, the instances that you're generating are not directly related to any existing instances. Are you proposing that type families used on derived instances should just "look through" the newtype and be applied to the base type? Or only in cases with type variables? And, where does the `HasRing a =>` constraint come from? Without those constraints, I can see more of a coherent and general picture here... but it doesn't seem like `GeneralizedNewtypeDeriving` to me. Perhaps you're really proposing a new extension for generation of type family instances for newtypes? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8165#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler