Maps · World: choropleths and the world's countries

ChoroplethLayer washes each area by its value, keyed by its id or a
property's text or number, on one hue's scale from its faintest at the
least value to its strongest at the most; an area without a value reads
as no data. ChoroplethMap lays it on the owner's map, with or without
tiles, and puts a legend of the scale and of no data in the corner; a
value that matches no area is logged once. WorldMap washes Natural
Earth's 110m countries, bundled trimmed by scripts/countries.py, by ISO
3166 alpha-2 code, and fails on a key that is no code. A shape now
paints as one fill and one edge path per world in view.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/maps/mod.rs

@@ -1,3 +1,4 @@
+mod choropleth;
 mod cluster;
 mod coords;
 mod geo;
@@ -10,7 +11,9 @@ mod picker;
 mod tests;
 mod tile;
 mod view;
+mod world;
 
+pub use choropleth::{ChoroplethKey, ChoroplethLayer, ChoroplethMap};
 pub use coords::{CoordFormat, CoordinateDisplay};
 pub use geo::{LatLon, MAX_LAT, MapViewport, Tile};
 pub use geojson::{Feature, Geometry, read_geojson};
@@ -18,3 +21,4 @@ pub use layer::{GeoHeatmap, GeoJsonLayer, MapLayer, RouteLine};
 pub use marker::{MapMarker, MapPopup};
 pub use picker::LocationPicker;
 pub use view::MapView;
+pub use world::WorldMap;