Incorrectly suggests ‘TypeOperators’
Loading the code
{-# Language RankNTypes, GADTs, MagicHash, PolyKinds, TypeInType, ConstraintKinds #-}
import Data.Kind
import GHC.Exts
import qualified Prelude
class Semi (a :: TYPE rep) where
data Free :: forall rep. (TYPE rep -> Constraint) -> TYPE rep -> Type where
Free :: (forall q. ctx q => (p -> q) -> q) -> Free ctx p
gives an incorrect suggestion
GHCi, version 8.2.0.20170507: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Main ( tXMX.hs, interpreted )
Ok, modules loaded: Main.
*Main> :kind Free Semi
Free Semi :: * -> *
*Main> :kind Free Semi Int#
<interactive>:1:1: error:
Not in scope: type constructor or class ‘#’
<interactive>:1:1: error:
Illegal operator ‘#’ in type ‘Free Semi Int #’
Use TypeOperators to allow operators in types
<interactive>:1:1: error:
Operator applied to too few arguments: Free Semi Int #
*Main>
This should recommend enabling MagicHash instead.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.0.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |