Puf.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/Utils.hs b/src/Utils.hs
index 03d6db3..82b31ca 100644
--- a/src/Utils.hs
+++ b/src/Utils.hs
@@ -2,6 +2,7 @@
 module Utils where
 
 import Data.Bits
+import Data.Word (Word8, Word16, Word32)
 
 
 -------------------------------------------------------------------------------
@@ -19,3 +20,20 @@ fromBits = foldl (\a b -> 2 * a + b) 0 . reverse
 
 extractBits :: Bits a => a -> [Int] -> Int
 extractBits x r = fromBits $ toBits x r
+
+
+-------------------------------------------------------------------------------
+-- Size Convertion
+
+convertLong :: Word32 -> Int -> Word32
+convertLong x 1 = x .&. 0x000000FF
+convertLong x 2 = x .&. 0x0000FFFF
+convertLong x 3 = x
+convertLong _ s = error $ "Wrong size (" ++ show s ++ ") of convertLong"
+
+combineLong :: Word32 -> Word32 -> Int -> Word32
+combineLong update base 1 = base .&. 0xFFFFFF00 .|. (convertLong update 1)
+combineLong update base 2 = base .&. 0xFFFF0000 .|. (convertLong update 2)
+combineLong update _    3 = update
+combineLong _      _    s = error $
+    "Wrong size (" ++ show s ++ ") of combineLong"