Erlang port of google s2-geometry-library https://github.com/micolous/s2-geometry-library.git
$ rebar3 compile
$ rebar3 shell s2cellid:new({51.5001525, -0.1262355}).
{s2latlngrect, LatLng}=s2latlngrect:new_from_lat_lng_degree({33.0, -122.0},{33.1, -122.1}). {covering, Cellids] = s2latlngrect:get_covering({s2latlngrect, LatLng}, 6, {8, 12}). s2cellid:to_lat_lng(864691128455135232).