rapid_check_2_prop_partition.hs

prop_partition :: [Integer] -> (Integer -> Bool) -> Bool
prop_partition xs p =
  let (lhs, rhs) = partition p xs
  in and
      [ all p lhs
      , not (any p rhs)
      , sort xs == sort (lhs ++ rhs) ]
 
 rapidCheck prop_partition
 > Success