#13595: Should ‘coerce’ be levity polymorphic? -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: | LevityPolymorphism Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13592 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * keywords: => LevityPolymorphism Comment: Yes, you are right: I think `coerce` (and similarly `Coercible`) should have type {{{ coerce :: forall l (a::TYPE l) (b::Type l). a -> b }}} More realistically than your example, I think we might reasonably want {{{ newtype Age = MkAge Int f :: Array# Age -> Array# Int f a = coerce a }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13595#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler