Mapbox GL JS has excellent examples. This is a result of I cribbed freely from https://docs.mapbox.com/mapbox-gl-js/examples/ and everything worked. Not all projects have good examples. John Firebaugh (who has since moved on from Mapbox), Colleen McGinnis, and the GL JS and Documentation teams put a ton of work into these and it shows.
Mapbox GL JS Expressions give a developer ample control over styling and
filtering while keeping the styling API abstract and simple. In several parts
of its API, Mapbox GL JS can evaluate Lisp-like expressions composed of
["+", 4, ["*", 3, 2]] evaluates to
4 + (3 * 2), or
JS expressions operators contains feature property and map attribute getters.
snuggs and rio-calc) is that developers
to build expressions.
Another first for me is that I'm using Turf, the well-known simple features geometry library created by Morgan Herlocker. In my app I'm creating features on the fly derived from the intersections of features in a Mapbox tileset. Turf is fast and its functions take and return GeoJSON objects, which makes it easy for me to use and easy to integrate with Mapbox GL JS and other libraries or plugins. Turf is indispensable for a web app like the one I'm writing.