Add a Contravariant instance for Array encoder

library/Hasql/Private/Encoders.hs

@@ -339,6 +339,7 @@ Please note that the PostgreSQL @IN@ keyword does not accept an array, but rathe
 values, thus this encoder is not suited for that. Use a @value = ANY($1)@ condition instead.
 -}
 newtype Array a = Array (Array.Array a)
+  deriving (Contravariant)
 
 {-|
 Lifts a 'Value' encoder into an 'Array' encoder.

library/Hasql/Private/Encoders/Array.hs

@@ -9,6 +9,10 @@ import qualified Text.Builder as C
 data Array a =
   Array B.OID B.OID (Bool -> a -> A.Array) (a -> C.Builder)
 
+instance Contravariant Array where
+  contramap fn (Array valueOid arrayOid encoder renderer) =
+    Array valueOid arrayOid (\ intDateTimes -> encoder intDateTimes . fn) (renderer . fn)
+
 {-# INLINE value #-}
 value :: B.OID -> B.OID -> (Bool -> a -> A.Encoding) -> (a -> C.Builder) -> Array a
 value valueOID arrayOID encoder =