
#14728: Is (GeneralizedNewtypeDeriving + associated type classes) completely bogus? -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.4.1 Component: Compiler (Type | Version: 8.2.2 checker) | Keywords: deriving, Resolution: fixed | TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4402 Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): So `flatten_args` has been merged into GHC, so in theory, this ticket is unblocked now. However, after looking at `flatten_args`, I have no idea how it relates to this idea. What I was expected (after reading the description in comment:3) was some sort of function of type: {{{#!hs Type -> Coercion -> Type }}} Where in the example in comment:3, the `Type` argument would be `S (Identity a) x`, the `Coercion` argument would be the newtype axiom `g :: Identity a ~R# a`, and the result `Type` would be `S a (x |> g)`. But `flatten_args` doesn't look very much like this at all, so I'm plain stumped. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14728#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler