#10116: Closed type families: Warn if it doesn't handle all cases -------------------------------------+------------------------------------- Reporter: andrewthad | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Resolution: | 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 gkaracha): Replying to [comment:11 goldfire]:
`G` is inhabited at the type level, by `Any` for example.
Oh, I see, right, Yet, both `Any` and `Loopy` need `UndecidableInstances`. Is there a way to inhabit `G` without enabling `UndecidableInstances`? I expect a good check to be able to handle everything anyway, I am just asking in an attempt to identify a subset of the language for which the check can have nice properties. :-) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10116#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler