#9118: Can't eta-reduce representational coercions -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: #9117 -------------------------------------+------------------------------------ Comment (by rwbarton): (Type families are like type synonyms in this regard; you can't define `type Pair a = (a, a)` and then talk about `Functor Pair`.) It looks like #8555 is for `Coercion (f a) (f b) -> Coercion a b`, while this ticket is for `Coercion (f a) (g a) -> Coercion f g`. I don't know whether those are literally the same construction in Core but I expect they are equally easy if not. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9118#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler