#15532: Relaxing Levity-Polymorphic Binder Check for Lifted vs Unlifted pointers -------------------------------------+------------------------------------- Reporter: andrewthad | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Resolution: | Keywords: | LevityPolymorphism Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: 14917 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by andrewthad): So, you couldn't write `map` or `foldr` or anything like that, but you could get a levity polymorphic index lookup: {{{ (!) :: forall (v :: Levity) (a :: TYPE ('PtrRep v)). Int -> List a -> a }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15532#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler