Part 1 Chapter 7 Exercise 6 - part 2.

Author: PiotrJustyna

part1_chapter7_exercise6/Main.hs

@@ -6,13 +6,29 @@
 -- ghci
 --
 -- :load Main
+type Bit = Int
+
 main = do
     putStrLn "int2bin 9"
     putStrLn . show $ int2bin 9
 
+    putStrLn "chop8 [1, 2, 3, 4, 5, 6, 7, 8, 9]"
+    putStrLn . show $ chop8 [1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+    putStrLn "chop8' [1, 2, 3, 4, 5, 6, 7, 8, 9]"
+    putStrLn . show $ chop8' [1, 2, 3, 4, 5, 6, 7, 8, 9]
+
 unfold :: (a -> Bool) -> (a -> a) -> (a -> a) -> a -> [a]
 unfold predicate headFunction tailFunction x
     | predicate x = []
     | otherwise = headFunction x : unfold predicate headFunction tailFunction (tailFunction x)
 
-int2bin = unfold (== 0) (`mod` 2) (`div` 2)
+int2bin :: Int -> [Int]
+int2bin = unfold (== 0) (`mod` 2) (`div` 2)
+
+chop8 :: [Bit] -> [[Bit]]
+chop8 [] = []
+chop8 bits = (take 8 bits) : (chop8 (drop 8 bits))
+
+chop8' :: [Bit] -> [[Bit]]
+chop8' = unfold null (take 8) (drop 8)