#10252: Abstract newtype in hs-boot -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: feature request | Status: closed Priority: normal | Milestone: Component: Compiler (Type | Version: 7.11 checker) | Keywords: backpack Resolution: worksforme | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by goldfire): This scares me. `data` and `newtype` are different! After a quick ponder, I don't see damage that can be caused by abusing this. But, if we ever had representational type families (where `type instance RepF Int = Bool` would be used to reduce `RepF Age` to `Bool`), this would be a disaster. I can't seem to find a ticket requesting representational matching for type families (or classes, or data families), but the idea has come up. (See some wonderings in this direction in #9112, for example.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10252#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler