#8485: Type roles in GHCi ------------------------------------+------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- This works: {{{ λ> data A a; type role A nominal λ> :i A type role A nominal data A a }}} This doesn't: {{{ λ> data A a λ> type role A nominal λ> :i A type role A phantom data A a }}} Accepting role annotations after the definition probably leads to problems when intermediate definitions relied on the earlier role; so I think the second situation should give an error. In fact, in the second snippet GHC does not even require -XRoleAnnotations. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8485 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler