support @values for describing multidimensional containers

[gkellogg]

Allows a term definition to include an @values block to describe structured values, such as for GeoJSON

Example

{
  "@context": {
     "coordinates": {
        "@id": "geojson:coordinates",
        "@container" : "@list",
        "@values" : { 
           "@type" : "geojson:Coordinate",
           "@container" : "@set",
           "@values" : [
               {"@type" : "xsd:double", "@id":"geo:longitude"},
               {"@type" : "xsd:double", "@id":"geo:latitude"}
           ]
        }
     }
  },
  "@graph" : [{
   "@id" : "ex:LineString1",
    "coordinates" : [
          [
            3.1057405471801753,
            51.064216229943476
          ],
          [
            3.1056976318359375,
            51.063434090307574
          ]
    ]
  }]
}

Would transform to (and vice versa):

ex:LineString1 geojson:coordinates _:b0 .
_:b0 rdf:first _:b1 .
_:b1 a geojson:Coordinate ;
      geo:longitude "3.105740547180175E0"^^xsd:double ;
      geo:latitude "5.106421622994348E1"^^xsd:double .
_:b0 rdf:rest _:b2 .
_:b2 rdf:first a geojson:Coordinate ;
      geo:longitude "3.1056976318359375"^^xsd:double ;
      geo:latitude "51.063434090307574"^^xsd:double .
_:b2 rdf:rest rdf:nil .

Original issue is JSON-LD 1.1 Feature Request: support @values for describing multidimensional containers (list of lists) #397

[pietercolpaert]

Appologies -- Wrongly assumed opening this issue meant it was going to be adopted in JSON-LD 1.1 - https://twitter.com/pietercolpaert/status/1013100062879178754

Would love this proposal to be taken into account for the 1.1 spec though!

[p1d1d1]

Any thoughts how this could map to GeoSPARQL?

[Fak3]

refs json-ld/json-ld.org#52

[azaroth42]

+1 to the issue, we should discuss the proposed solution.

[azaroth42]

Actually, in re-reading, re-thinking I'm 👎 to the issue as it doesn't round trip back to the right structure. Lists of Lists is the critical one for GeoJSON-LD (and others), not being able to insert predicates into the structure. I think this one crosses the line into data transformation, which is not the point of a JSON-LD context.

[azaroth42]

Following discussion on WG call 2018-08-31, the current thinking is to close wontfix. This is the transformation of data, rather than the serialization of it, as it creates new triples. It would be a lot of work, for limited situations where it adds value, and not be able to be round-tripped back to the original format.

Please weigh in by 2018-09-07.

[mitar]

I think it would be very sad if one could not use JSON-LD together with GeoJSON. It means that GeoJSON-LD community would have to fork JSON-LD and create its own dialect, just to support that.

Please see some comments in the original issue and the original discussion.

[akuckartz]

According to json-ld/json-ld.org#397 (comment) that issue was closed in favor of this issue and now the declared intention is to also close this issue?

My experience is that the importance of geo-data is increasing significantly. JSON-LD should provide the necessary features to bridge the gap to GeoJSON - and vice versa.