[postgis-devel] Is errorIfGeometryCollection necessary for relate ops?

[Martin Davis]

re what is happening in Shapely with relate on GeometryCollections:

In fact, homogeneous GeometryCollections of Points and LineStrings can be
trivially converted to MultiPoints and MultiLineStrings.  Is is possible
that Shapely is doing this automatically?

Handling homogeneous GCs would be a nice enhancement for JTS & GEOS....

On Fri, Apr 10, 2015 at 12:50 AM, Sandro Santilli <strk at keybit.net> wrote:

> On Fri, Apr 10, 2015 at 11:55:08AM +1200, Mike Toews wrote:
>
> > so I'm wondering what is stopping PostGIS from supporting relate
> > operations with geometry collections?
>
> JTS explicitly refuses to compute the intersection matrix between
> geometries if one of them is a collection:
>
>
> http://sourceforge.net/p/jts-topo-suite/code/HEAD/tree/tags/Version_1.13/jts/java/src/com/vividsolutions/jts/geom/Geometry.java#l1032
>
> I'm not sure why, nor why GEOS doesn't follow it:
>
> https://github.com/libgeos/libgeos/blob/3.4.2/src/geom/Geometry.cpp#L443-L448
>
> Maybe Martin can shed a light here ?
>
> --strk;
>
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