#13598: role annotation for newtype (partially?) ignored? -------------------------------------+------------------------------------- Reporter: edsko | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.2.1-rc2 Resolution: invalid | 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 facundo.dominguez): From what the paper says, I gather that the reason to enable coercions between `C a` and `C b` when the constructors are in scope is to offer zero-cost coercions which wouldn't be possible to achieve if only the `foo1` route is allowed. I guess the user guide could discuss the newtype nuances for Coercible. Otherwise it looks like GHC is allowing coercions when it shouldn't. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13598#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler