#9788: `coerce` has an impossible type -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 | Type of failure: hour) | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- {{{ GHCi, version 7.8.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> :set -fprint-explicit-foralls Prelude> :set -fprint-explicit-kinds Prelude> import Data.Coerce Prelude Data.Coerce> :t coerce coerce :: forall (k :: BOX) (a :: k) (b :: k). Coercible k a b => a -> b }}} Are those types `a` and `b` really of kind `k`? They certainly shouldn't be. This is worse in HEAD: GHC panics. (Actually, I think panicking is an improvement.) Easy to fix, happily. Will do so in the course of other work. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9788 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler