wakame-0.1.0.0: src/Wakame/Lacks.hs

module Wakame.Lacks where

import Prelude

import Data.Type.Equality
import GHC.TypeLits
import Wakame.Row (FIELD)


-- | Typeclass to constrain not to have a certain key
class Lacks (k :: Symbol) (r :: [FIELD])
instance Lacks k '[]
instance (Lacks k r, KnownSymbol k', (k == k') ~ 'False) => Lacks k ('(k', a) ': r)