How to create Arbitrary instance for dependent types? - Learn - Haskell Community
Let’s say I have the following type: import Test.QuickCheck import GHC.TypeLits import Data.Kind data Vect :: Nat -> Type -> Type where VNil :: Vect 0 a VCons :: a -> Vect n a -> Vect (n + 1) a I want to be able to write some QuickChecks about my values, so I want to write an Arbitrary instance. sizedVect :: Int -> Gen a -> Gen (Vect n a) sizedVect 0 _ = pure VNil sizedVect n g = VCons <$> g <*> sizedVect (n - 1) g instance Arbitrary (Vect n a) where arbitrary :: Gen (Vect n a) arbi...| Haskell Community
