+
+
+-- If the two Cidrs are not adjacent, return Cidr.None. Otherwise,
+-- decrement the maskbits of cidr1 and return that; it will contain
+-- both cidr1 and cidr2.
+combine_adjacent :: Cidr -> Cidr -> Cidr
+combine_adjacent cidr1 cidr2
+ | not (adjacent cidr1 cidr2) = Cidr.None
+ | (maskbits cidr1 == Zero) = Cidr.None
+ | otherwise = cidr1 { maskbits = decrement (maskbits cidr1) }
+
+
+
+-- Determine whether or not two CIDR ranges are adjacent. If two
+-- ranges lie consecutively within the IP space, they can be
+-- combined. For example, 10.1.0.0/24 and 10.0.1.0/24 are adjacent,
+-- and can be combined in to 10.1.0.0/23.
+adjacent :: Cidr -> Cidr -> Bool
+adjacent Cidr.None _ = False
+adjacent _ Cidr.None = False
+adjacent cidr1 cidr2
+ | mbits1 /= mbits2 = False
+ | mbits1 == Maskbits.Zero = False -- They're equal.
+ | otherwise = (mbits1 == (most_sig_bit_different addr1 addr2))
+ where
+ addr1 = ipv4address cidr1
+ addr2 = ipv4address cidr2
+ mbits1 = maskbits cidr1
+ mbits2 = maskbits cidr2
+
+
+
+
+
+-- HUnit Tests
+
+test_equality1 :: Test
+test_equality1 =
+ TestCase $ assertEqual "10.1.1.0/23 equals itself" True (cidr1 == cidr1)
+ where
+ cidr1 = cidr_from_string "10.1.1.0/23"
+
+
+test_contains1 :: Test
+test_contains1 =
+ TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24" True (cidr1 `contains` cidr2)
+ where
+ cidr1 = cidr_from_string "10.1.1.0/23"
+ cidr2 = cidr_from_string "10.1.1.0/24"
+
+
+test_contains2 :: Test
+test_contains2 =
+ TestCase $ assertEqual "10.1.1.0/23 contains itself" True (cidr1 `contains` cidr1)
+ where
+ cidr1 = cidr_from_string "10.1.1.0/23"
+
+
+test_contains_proper1 :: Test
+test_contains_proper1 =
+ TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24 properly" True (cidr1 `contains_proper` cidr2)
+ where
+ cidr1 = cidr_from_string "10.1.1.0/23"
+ cidr2 = cidr_from_string "10.1.1.0/24"
+
+
+test_contains_proper2 :: Test
+test_contains_proper2 =
+ TestCase $ assertEqual "10.1.1.0/23 does not contain itself properly" False (cidr1 `contains_proper` cidr1)
+ where
+ cidr1 = cidr_from_string "10.1.1.0/23"
+
+
+cidr_tests :: [Test]
+cidr_tests = [ test_equality1,
+ test_contains1,
+ test_contains2,
+ test_contains_proper1,
+ test_contains_proper2
+ ]