#11341: Reifying a GADT doesn't tell you the correct return type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Replying to [comment:2 jstolarek]:
In this setting I don't think it is a good idea to store indices inside `GadtC`. This would duplicate information already stored inside the constructor and make it possible to create inconsistent data constructors.
That's a good point I hadn't thought of. We definitely don't want users to be able to splice in type indices that don't match up with the actual return type. I suppose the real type indices can always be found out through something like `expand` in `th-desugar`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11341#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler