Sliding window data structure

[Per Gustafsson]

Richard A. O'Keefe wrote:

>For what it's worth, the Erlang code seems to be about twice as slow as
>SICStus Prolog, and that's with c(window, [verbose,hipe]) in a hipe-
>enabled Erlang.
>  
>
That should be c(window, [native]) in order to native-compile the module.

Per