feat(rust/sedona-geos): Implement ST_LineMerge()

[yutannihilation]

This pull request implements ST_LineMerge.

https://postgis.net/docs/en/ST_LineMerge.html

This is mostly straightforward using GEOS's LineMerge via the geos crate. One thing to note is that, the direction-aware version (.line_merge_directed()) requires GEOS >= v3.11, which was released 3.5 years ago. I don't think this is a difficult requirement, but I'm not really sure.

https://github.com/georust/geos/blob/47afbad2483e489911ddb456417808340e9342c3/src/geometry.rs#L2796-L2802

> SELECT ST_LineMerge(ST_GeomFromWKT('MULTILINESTRING ((0 0, 1 0), (1 0, 1 1))'));
┌────────────────────────────────────────────────────────────────────────────────┐
│ st_linemerge(st_geomfromwkt(Utf8("MULTILINESTRING ((0 0, 1 0), (1 0, 1 1))"))) │
│                                    geometry                                    │
╞════════════════════════════════════════════════════════════════════════════════╡
│ LINESTRING(0 0,1 0,1 1)                                                        │
└────────────────────────────────────────────────────────────────────────────────┘

[paleolimbot]

Thank you!

Did you want to add a Python integration test for this here? (I can also file a follow-up issue so we don't forget)

[petern48]

interesting. The docs say "Other geometry types return an empty GeometryCollection" in the note. Though that doesn't seem to be the case for POLYGON or LINESTRING input 🤷.

Could we test some empty geometries, for both of these tests? Those can often catch weird edge cases.

[yutannihilation]

Thanks for catching. I simply didn't notice the note...

I'll add empty cases.

[yutannihilation]

Did you want to add a Python integration test for this here?

Do you mean benchmark tests? I just forgot to do so, but now I don't immediately see how to add tests as it probably requires specific inputs of touching line segments.

[petern48]

(I will leave this for @paleolimbot to clarify what he meant and answer this: #503 (comment), given there were python integration tests already).

[paleolimbot]

One thing to note is that, the direction-aware version (.line_merge_directed()) requires GEOS >= v3.11

I think our current minimum is 3.12 (for M coordinates), so this is no problem. We could try harder to support older GEOS with some feature flags or defines if this comes up.

Did you want to add a Python integration test for this here?

That was just me reviewing too fast 🤦 . Sorry!

[yutannihilation]

I see. Thanks for clarifying!