X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FOctet.hs;h=04caae54fa6bcefab22d28415f5e2e8f6aa81064;hb=a767881c16a119a90ff80d9c14106348d8bc310d;hp=aaff3d2e0415a5029a13b5bb9fe957b449e26bd5;hpb=1b7390b71484de63c8ded01371a1dd2adf93909e;p=hath.git

diff --git a/src/Octet.hs b/src/Octet.hs
index aaff3d2..04caae5 100644
--- a/src/Octet.hs
+++ b/src/Octet.hs
@@ -1,5 +1,7 @@
 module Octet where
 
+import Test.HUnit
+
 import Bit
 
 -- An Octet consists of eight bits. For our purposes, the most
@@ -13,7 +15,13 @@ data Octet = None | Octet { b1 :: Bit,
                             b6 :: Bit,
                             b7 :: Bit,
                             b8 :: Bit }
-           deriving (Eq, Show)
+           deriving (Eq)
+
+
+instance Show Octet where
+    show Octet.None = "None"
+    show oct = show (octet_to_int oct)
+
 
 -- Convert each bit to its integer value, and multiply by the
 -- appropriate power of two. Sum them up, and we should get an integer
@@ -36,7 +44,7 @@ octet_from_int x
     | (x < 0) || (x > 255) = Octet.None
     | otherwise = (Octet a1 a2 a3 a4 a5 a6 a7 a8)
     where
-      a1 = if (x > 128) then One else Zero
+      a1 = if (x >= 128) then One else Zero
       a2 = if ((x `mod` 128) >= 64) then One else Zero
       a3 = if ((x `mod` 64)  >= 32) then One else Zero
       a4 = if ((x `mod` 32)  >= 16) then One else Zero
@@ -61,3 +69,16 @@ min_octet = Octet Zero Zero Zero Zero Zero Zero Zero Zero
 -- The octet with the greatest possible value.
 max_octet :: Octet
 max_octet = Octet One One One One One One One One
+
+
+
+-- HUnit Tests
+test_octet_from_int1 :: Test
+test_octet_from_int1 =
+    TestCase $ assertEqual "octet_from_int 128 should parse as 10000000" oct1 (octet_from_int 128)
+    where
+      oct1 = Octet One Zero Zero Zero Zero Zero Zero Zero
+
+
+octet_tests :: [Test]
+octet_tests = [ test_octet_from_int1 ]