Btw, which three-liner do you mean?

fib 0 = 0

fib 1 = 1

fib n = fib (n-1) + fib (n-2)

Oh, that version takes exponential time to compute. The one-liner I gave computes up to the n-th Fibonacci number in linear time.

Your version is definitely more performant, but the three liner is just a bit nicer to read (especially for beginners) :)

Yes. It depends on what you want to show. Your version shows how to define functions and some simple pattern matching.

Having worked with Haskell for a year now I still can't read much more than functions and pattern matching! :D

Not in Haskell, it doesn't. Haskell stores everything for you, right?

No, it doesn't.