#11635: Missleading error message when using polymorpic kinds -------------------------------------+------------------------------------- Reporter: phadej | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Example program: {{{ {-# LANGUAGE TypeInType, KindSignatures, ExplicitForAll #-} import Data.Kind data X (a :: forall k. k -> * ) = X }}} errors with {{{ polykind.hs:3:1: error: Expecting one more argument to ‘a’ Expected kind ‘k0’, but ‘a’ has kind ‘forall k. k -> *’ }}} Without `TypeInType`, the error is better, yet gives false hint: {{{ polykind.hs:3:23: error: Illegal kind: forall k. k -> * Did you mean to enable TypeInType? }}} --- For the record 7.10.3 doesn't recognise polymorphic kinds at all (same program, without `Data.Kind` import): {{{ polykind.hs:3:23: parse error on input ‘forall’ }}} Which makes me think that polymorphic kinds are somehow supported, but maybe not. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11635 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler