#9636: Function with type error accepted -------------------------------------+------------------------------------- Reporter: augustss | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by dreixel): I don't see why `T Bool` is "not a type". If you really want something like that, you should index `T` over a closed kind: {{{ {-# LANGUAGE DataKinds, TypeFamilies #-} data Un = TInt type family T (a :: Un) :: * where T TInt = () }}} Now it's clear that `T Bool` is indeed not a type, and gives rise to a kind error. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9636#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler