Re: [Haskell-cafe] Question on Exercise from SOE

On Sat, 3 Jul 2004, Nathan Weston wrote:

My first thought is to use fold here, since this function accumulates a result as it traverses the list. But fold consumes one element of the list at a time, while area needs to examine the first three elements of the list, and consume two of them at a time. Is there a more general alternative to fold? Or is there some trick I'm missing here?

What's about zipping delayed versions of the list, say zipWith3 (calcArea) v (tail v) (tail (tail v)) ?