Handle GeoInterface.jl compatible tables

[rafaqz]

Probably we should allow GeoInterface.jl compatible tables in apply ? (Tables.jl compatible with a :geometry column or something else specified by GeoInterface.geometrycolumns).

But probably it should also return a Table? to keep the "returns a similar object" pattern.

Could we default to using a DataFrame and put DataFrames.jl part in an extension?

This means applyreduce could work with just Tables.jl but apply would need DataFrames.jl

[asinghvi17]

Sounds like a plan - one could also do the same for applyreduce.

Doesn't apply work correctly on FeatureCollections already?

[asinghvi17]

Apply works on GeoJSON feature collections but returns an object which is not compatible with the Tables.jl interface. Shapefile tables are not supported yet, unfortunately.

[asinghvi17]

Suppose a table has geometries of type Point, Polygon and MultiPolygon. Now, if someone calls apply on it targeting polygon types, do we skip the point, or throw an error? Does the reconstructed table contain the point (I want to say no)?