#12045: Visible kind application -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: mnguyen Type: feature request | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: | TypeApplications TypeInType | GHCProposal Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: 14579 Related Tickets: #15782 | Differential Rev(s): Phab:D5229 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Richard Eisenberg <rae@…>): In [changeset:"255d2e323a8879a7296a5ab94e6cc49023e2c86e/ghc" 255d2e3/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="255d2e323a8879a7296a5ab94e6cc49023e2c86e" Fix embarrassing, egregious bug in roles of (->) Previously, I had inexplicably decided that (->)'s roles were all Representational. But, of course, its first two parameters are *dependent* RuntimeReps. All dependent parameters have a Nominal role, because all roles in kinds are Nominal. Fix is easy, but I have no idea how the world hasn't come crashing down before now. This was found while investigating #15801, which requires visible type application in types to observe. Hence, the test case will come with the main patch for #12045. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12045#comment:20> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler