Add week 2 lab

02-lab.hs

@@ -0,0 +1,39 @@
+import Data.Char
+
+orB :: Bool -> Bool -> Bool
+orB x y = x || y
+
+swap :: (x, y) -> (y, x)
+swap (x, y) = (y, x)
+
+middle :: [a] -> [a]
+middle x = tail (take ((length x) - 1) x)
+
+condrev :: [a] -> [a]
+condrev x | (length x) >= 7 = reverse x
+          | otherwise       = x
+
+dblmagic :: [Int] -> [Int]
+dblmagic x = filter (>10) (map (*2) x)
+
+wtfstring :: String -> String
+wtfstring x = reverse (map (toUpper) x)
+
+addindex :: [a] -> [(Int, a)]
+addindex x = zip [0..((length x) - 1)] x
+
+relcmp :: (Num a, Ord a) => a -> a -> Bool
+relcmp x y | x > y && x < (y*2) = True
+           | otherwise        = False
+
+third :: [a] -> a
+-- third x = head (tail (tail x))
+-- third x = x!!2
+third (_:_:x:_) = x
+
+safetail :: [a] -> [a]
+-- safetail x = if (length x) == 0 then [] else tail x
+-- safetail x | length x == 0 = []
+--            | otherwise     = tail x
+safetail [] = []
+safetail (_:xs) = xs