most_sig_bit_different )
where
+import Data.Word (Word32)
import Test.Tasty ( TestTree, testGroup )
import Test.Tasty.HUnit ( (@?=), testCase )
octet2 :: Octet,
octet3 :: Octet,
octet4 :: Octet }
- deriving (Eq)
+ deriving (Eq, Ord)
instance Show IPv4Address where
-- | Convert an 'Int' @x@ to an 'IPv4Address'. Each octet of @x@ is
-- right-shifted by the appropriate number of bits, and the fractional
-- part is dropped.
- toEnum x =
+ toEnum y =
IPv4Address oct1 oct2 oct3 oct4
where
+ -- Convert the input Int to a Word32 before we proceed. On x86,
+ -- the Int that we get could be negative (half of all IP
+ -- addresses correspond to negative numbers), and then the magic
+ -- below doesn't work. The Word32 type is unsigned, so we do the
+ -- math on that and then convert everything back to Int later on
+ -- once we have four much-smaller non-negative numbers.
+ x = fromIntegral y :: Word32
+
-- Chop off the higher octets. x1 = x `mod` 2^32, would be
-- redundant.
x2 = x `mod` 2^(24 :: Integer)
x3 = x `mod` 2^(16 :: Integer)
- x4 = x `mod` 2^(8 :: Integer)
+ x4 = (fromIntegral $ x `mod` 2^(8 :: Integer)) :: Int
-- Perform right-shifts. x4 doesn't need a shift.
- shifted_x1 = x `quot` 2^(24 :: Integer)
- shifted_x2 = x2 `quot` 2^(16 :: Integer)
- shifted_x3 = x3 `quot` 2^(8 :: Integer)
+ shifted_x1 = (fromIntegral $ x `quot` 2^(24 :: Integer)) :: Int
+ shifted_x2 = (fromIntegral $ x2 `quot` 2^(16 :: Integer)) :: Int
+ shifted_x3 = fromIntegral $ x3 `quot` 2^(8 :: Integer) :: Int
oct1 = toEnum shifted_x1 :: Octet
oct2 = toEnum shifted_x2 :: Octet
oct3 = toEnum shifted_x3 :: Octet
test_minBound,
test_most_sig_bit_different1,
test_most_sig_bit_different2,
+ test_ord_instance1,
+ test_ord_instance2,
+ test_ord_instance3,
+ test_ord_instance4,
test_to_enum ]
ipv4address_properties :: TestTree
where
desc = "192.168.0.0 in base-10 is 3232235520"
expected = mk_testaddr 192 168 0 0
- actual = toEnum 3232235520 :: IPv4Address
+ -- We declare the big number as Word32 because otherwise, on x86,
+ -- we get a warning that it's too big to fit in a 32-bit integer.
+ -- Ultimately we convert it to a (negative) Int on those systems
+ -- anyway, but the gymnastics declare our intent to the compiler.
+ actual = toEnum (fromIntegral (3232235520 :: Word32)) :: IPv4Address
+
+
+test_ord_instance1 :: TestTree
+test_ord_instance1 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 127.0.0.1"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 127 0 0 1
+ expected = True
+ actual = addr1 <= addr2
+
+
+test_ord_instance2 :: TestTree
+test_ord_instance2 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 127.0.1.0"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 127 0 1 0
+ expected = True
+ actual = addr1 <= addr2
+
+test_ord_instance3 :: TestTree
+test_ord_instance3 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 127.1.0.0"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 127 1 0 0
+ expected = True
+ actual = addr1 <= addr2
+
+test_ord_instance4 :: TestTree
+test_ord_instance4 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 128.0.0.0"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 128 0 0 0
+ expected = True
+ actual = addr1 <= addr2