Understanding strictness and bottom

Haskell Excercises & Code/Chapter27 - Nonstrictness/chapterEx.hs

@@ -1,2 +1,19 @@
+{-# LANGUAGE Strict #-}
+-- this is an extension to enable strictness
+
 module ChaptEx where
 
+data List a = Nil | Cons a (List a) deriving (Show)
+
+take' n _ | n <= 0 = Nil
+take' _ Nil = Nil
+take' n (Cons x xs) = (Cons x (take' (n-1) xs))
+
+map' _ Nil = Nil
+map' f (Cons x xs) = (Cons (f x) (map' f xs))
+
+repeat' x = xs 
+  where xs = (Cons x xs)
+
+main = do
+    print $ take' 10 $ map' (+1) (repeat' 1)

Haskell Excercises & Code/Chapter27 - Nonstrictness/evaluEx.hs

@@ -14,5 +14,5 @@ module EvEx where
 -- ((((foldr const 'z' ['a','b']) const 'c' ) const 'd') const 'e')
 -- (((((foldr const 'z' ['a']) const 'b') const 'c') const 'd') const 'e'
 -- ((((((foldr const 'z' [] ) const 'a' ) const 'b') const 'c') const 'd') const 'e')
--- Wrong reasoning 
+-- Wrong reasoning but answer = 'a'
 7. foldr (flip const) 'z' ['a'..'e']