#9840: Permit empty closed type families -------------------------------------+------------------------------------- Reporter: adamgundry | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.8.3 checker) | Operating System: Keywords: | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Difficulty: Unknown | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- At the moment, closed type families without any equations fail with a parse error. In addition, they cannot be created by TH (see #8028). Would it be possible to permit these instead? My use case is in my typechecker plugin for units of measure, where I want to add new type-level operators without any equational theory (because it will be supplied by the plugin) and without users having the ability to introduce their own type family instances. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9840 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler