diff options
| -rw-r--r-- | lec06/Fibonacci.hs | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lec06/Fibonacci.hs b/lec06/Fibonacci.hs index 70d8934..2b6e343 100644 --- a/lec06/Fibonacci.hs +++ b/lec06/Fibonacci.hs @@ -23,3 +23,14 @@ streamToList (Cons a s) = a : streamToList s instance Show a => Show (Stream a) where show s = show $ take 20 $ streamToList s +-- Exercise 4 + +streamRepeat :: a -> Stream a +streamRepeat e = Cons e (streamRepeat e) + +streamMap :: (a -> b) -> Stream a -> Stream b +streamMap f (Cons a as) = Cons (f a) (streamMap f as) + +streamFromSeed :: (a -> a) -> a -> Stream a +streamFromSeed f s = Cons s (streamFromSeed f (f s)) + |