#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 simonpj): I think it's this. `S` is a data constructor with an evidence argument. At the term level we pass evidence to `S`. But if we promote `S` we don't have a type-level version of evidence. So I was going to say "we don't promote `S`". But then I remembered that `TypeInType` is supposed to allow GADTs at the type level. So now I'm confused. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14845#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler