b6 :: Bit,
b7 :: Bit,
b8 :: Bit }
- deriving (Eq)
+ deriving (Eq, Ord)
instance Show Octet where
apply_mask oct _ _ = oct
-instance Ord Octet where
- (Octet x1 x2 x3 x4 x5 x6 x7 x8) <= (Octet y1 y2 y3 y4 y5 y6 y7 y8)
- | x1 > y1 = False
- | x2 > y2 = False
- | x3 > y3 = False
- | x4 > y4 = False
- | x5 > y5 = False
- | x6 > y6 = False
- | x7 > y7 = False
- | x8 > y8 = False
- | otherwise = True
-
-
instance Bounded Octet where
-- | The octet with the least possible value.
minBound =
octet_tests :: TestTree
octet_tests =
testGroup "Octet Tests" [
- test_octet_from_int1,
+ test_octet_to_enum1,
test_octet_mask1,
test_octet_mask2 ]
testGroup
"Octet Properties "
[ prop_from_enum_to_enum_inverses,
- prop_read_show_inverses ]
+ prop_read_show_inverses,
+ prop_ord_instances_agree ]
-- QuickCheck properties
prop_from_enum_to_enum_inverses :: TestTree
x' :: Int
x' = read $ show oct
+-- | Ensure that the Ord instance for Octets agrees with the Ord
+-- instance for Int (i.e. that numerical comparisons work).
+prop_ord_instances_agree :: TestTree
+prop_ord_instances_agree =
+ testProperty "the Octet and Int Ord instances agree" prop
+ where
+ prop :: Int -> Int -> Property
+ prop x y = (0 <= x) && (x <= 255) && (0 <= y) && (y <= 255) ==> ord == ord'
+ where
+ ord = (x <= y)
+
+ oct1 = toEnum x :: Octet
+ oct2 = toEnum y :: Octet
+ ord' = (oct1 <= oct2)
-- HUnit Tests
-test_octet_from_int1 :: TestTree
-test_octet_from_int1 =
+test_octet_to_enum1 :: TestTree
+test_octet_to_enum1 =
testCase desc $ actual @?= expected
where
- desc = "octet_from_int 128 should parse as 10000000"
+ desc = "toEnum 128 should parse as 10000000"
expected = Octet B.One B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero
actual = toEnum 128 :: Octet