#14845: TypeInType, index GADT by constraint witness -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.5 Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13895 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Technically, we do promote `S`, but the promoted `S` can't ever be applied, because we can't produce evidence. Perhaps a better error message is warranted, but until we have real dependent types (and can promote dictionaries), I think we're stuck on this one. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14845#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler