Euler Project: Problem 2 in Haskell

This is my solution in Haskell to the second problem:

	-- Slow
	fib 0 = 1
	fib 1 = 1
	fib n = fib (n - 2) + fib (n - 1)
	res1 =
	sum [x | x <- takeWhile (< 4000000) (map fib [1..]),
	mod x 2 == 0] -- 4613732
	-- Fast
	fast_fibs =
	1:1:zipWith (+) fast_fibs (tail fast_fibs)
	res2 =
	sum [x | x <- takeWhile (< 4000000) fast_fibs,
	mod x 2 == 0] -- 4613732

view raw euler02.hs hosted with ❤ by GitHub

I still get a bit dizzy when I think about the second solution...

You will find a great explanation of the second solution in this post:
Fibonacci numbers: the slow way or the fast and lazy way

You'll find the solutions in Haskell to Project Euler problems that I've done so far in this GitHub repository.