#13337: GHC doesn't think a type is of kind *, despite having evidence for it -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.2 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Ah, I completely overlooked bottoming equalities. Thanks for the reference. In light of this, my "equivalent" program in comment:3 is not equivalent at all, since the `k ~ Type` evidence in `go_on` isn't known //a priori// to terminate, whereas in the original program, the equality is known not to bottom out by pattern matching on `Refl`. So I suppose a better title for this bug would be "GHC doesn't think a type is of kind *, despite having Typeable-induced evidence for it", and the first program would be related to Dependent Haskell, which is, erm, in progress :) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13337#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler