newtype AtLeastTwoAndUnique a = AtLeastTwoAndUnique (Array a)

toArray :: forall a. AtLeastTwoAndUnique a -> Array a
toArray (AtLeastTwoAndUnique xs) = xs

first :: forall a. AtLeastTwoAndUnique a -> a
first = Unsafe.head

instance arbAtLeastTwoAndUnique :: (Arbitrary a) => Arbitrary (AtLeastTwoAndUnique a) where
  arbitrary = AtLeastTwoAndUnique <$> arbitrary `suchThat` (\xs -> unique xs && atLeastTwo xs)
    where
    unique xs = nub xs == xs
    atLeastTwo = (>= 2) <<< length