Change example "measure" from using in to something else

[tordans]

The https://maplibre.org/maplibre-gl-js/docs/examples/measure/ example is referenced in https://maplibre.org/maplibre-style-spec/expressions/#in as a good way to learn how in works.

However, the code it shows filter: ['in', '$type', 'Point'] does not represent a good case for in. It is a simple "match" condition, not an array lookup nor a substring match.

Can we change this example to using ["all", ["match", ["geometry-type"], ["Polygon"], true, false]] or ["all", "$type", ["Polygon"], true, false]] or ["==", "$type", "Polygon"] or something like this?

See also #664

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This would mean we don't have an in example anymore (which I would argue we don't have now, either). I would consider something like https://visgl.github.io/react-map-gl/examples/filter (Code) a better fit. But even better would be a case with a ['literal', ['array']] IMO.

[1ec5]

However, the code it shows filter: ['in', '$type', 'Point'] does not represent a good case for in. It is a simple "match" condition, not an array lookup nor a substring match.

This appears to be an example of the legacy in filter, which is incompatible with expressions. So it’s ironic that it’s being given as an example of how to use the in expression operator.

[HarelM]

Feel free to submit a PR, either to this repo or maplibre gl where the example is.