#8028: Panic on degenerate closed type family -------------------------------------------------+------------------------- Reporter: monoidal | Owner: goldfire Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.7 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect warning at | Unknown/Multiple compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------------------+------------------------- Comment (by Adam Gundry <adam@…>): In [changeset:"4efa421327cf127ebefde59b2eece693e37dc3c6/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="4efa421327cf127ebefde59b2eece693e37dc3c6" Permit empty closed type families Fixes #9840 and #10306, and includes an alternative resolution to #8028. This permits empty closed type families, and documents them in the user guide. It updates the Haddock submodule to support the API change. Test Plan: Added `indexed-types/should_compile/T9840` and updated `indexed-types/should_fail/ClosedFam4` and `th/T8028`. Reviewers: austin, simonpj, goldfire Reviewed By: goldfire Subscribers: bgamari, jstolarek, thomie, goldfire Differential Revision: https://phabricator.haskell.org/D841 GHC Trac Issues: #9840, #10306 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8028#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler