Yeah that looks useful indeed. I am surprised there isn't a DIET on hackage.

On Tue, Oct 30, 2012 at 3:55 AM, Stephen Tetley <stephen.tetley@gmail.com> wrote:
Are Martin Erwig's "diets" anything close?

http://web.engr.oregonstate.edu/~erwig/diet/

On 29 October 2012 04:48, Tony Morris <tonymorris@gmail.com> wrote:
> Hi,
> I was wondering if anyone knows of a package implementing a fast lookup
> for an element in ranges.
>
> For example, this operation:
> Ord a => a -> [(a, a)] -> Bool
>