Scheme type families

gistfile1.txt

data HashAlgo
data SignatureAlgo

data PPKScheme' a where
  ED25519' :: PPKScheme' ED25519Scheme
  ETH' :: PPKScheme' ETHScheme
deriving instance Show a => Show (PPKScheme' a)



class Scheme a where
  type SchemePubKey a :: *
  type SchemePrivKey a :: *
  readPubKey :: a -> ByteString -> SchemePubKey a
  reify :: a

data ED25519Scheme = ED25519Scheme deriving (Eq,Show)
data ETHScheme = ETHScheme

instance Scheme a => Scheme (PPKScheme' a) where
  type SchemePubKey (PPKScheme' a) = SchemePubKey a
  type SchemePrivKey (PPKScheme' a) = SchemePrivKey a
  reify = reify
  readPubKey p bs = readPubKey reify bs


instance Scheme ED25519Scheme where
  type SchemePubKey ED25519Scheme = Ed25519.PublicKey
  type SchemePrivKey ED25519Scheme = Ed25519.PrivateKey
  readPubKey _ = maybe undefined id . importPublic
  reify = ED25519Scheme