Linkset JSON as JSON-LD https://github.com/dret/I-D/issues/119

linkset.jsonld

{
  "@context": [
    {
      "@vocab": "https://www.iana.org/assignments/link-relations/",
      "anchor": "@id",
      "href": "@id",
      "dct": "http://purl.org/dc/terms/",
      "link": "https://www.iana.org/assignments/link-relations#",
      "title": {
        "@id": "http://purl.org/dc/terms/title"
      },
      "title*": {
        "@id": "http://purl.org/dc/terms/title"
      },
      "type": {
        "@id": "dct:format",
        "@type": "@vocab"
      }
    },
    {
      "language": "@language",
      "value": "@value",
      "hreflang": {
        "@id": "https://www.w3.org/ns/activitystreams#hreflang",
        "@container": "@set"
      }
    }
  ],
    
  
  "linkset": [
    {
      "anchor": "https://example.org/article/view/7507",
      "author": [
        {
          "href": "https://orcid.org/0000-0002-4311-0897",
          "type": "rdf/xml"
        }
      ],
      "item": [
        {
          "href": "https://example.org/article/7507/item/1",
          "type": "application/pdf"
        },
        {
          "href": "https://example.org/article/7507/item/2",
          "type": "text/csv"
        }
      ],
      "cite-as": [
        {
          "href": "https://doi.org/10.841/zk2557"
        }
      ]
    },
    {
      "anchor": "https://example.com/links",
      "alternate": [
        {
          "href": "https://mirror.example.com/links"
        }
      ]
    }
  ]
} 

linkset.ttl

<https://example.com/links> <https://www.iana.org/assignments/link-relations/alternate> <https://mirror.example.com/links> .
<https://example.org/article/7507/item/1> <http://purl.org/dc/terms/format> <https://www.iana.org/assignments/link-relations/application/pdf> .
<https://example.org/article/7507/item/2> <http://purl.org/dc/terms/format> <https://www.iana.org/assignments/link-relations/text/csv> .
<https://example.org/article/view/7507> <https://www.iana.org/assignments/link-relations/author> <https://orcid.org/0000-0002-4311-0897> .
<https://example.org/article/view/7507> <https://www.iana.org/assignments/link-relations/cite-as> <https://doi.org/10.841/zk2557> .
<https://example.org/article/view/7507> <https://www.iana.org/assignments/link-relations/item> <https://example.org/article/7507/item/1> .
<https://example.org/article/view/7507> <https://www.iana.org/assignments/link-relations/item> <https://example.org/article/7507/item/2> .
<https://orcid.org/0000-0002-4311-0897> <http://purl.org/dc/terms/format> <https://www.iana.org/assignments/link-relations/rdf/xml> .
_:b0 <https://www.iana.org/assignments/link-relations/linkset> <https://example.com/links> .
_:b0 <https://www.iana.org/assignments/link-relations/linkset> <https://example.org/article/view/7507> .

About type I think we can't use @vocab trick here as it should map to some base URI for formats, like https://www.iana.org/assignments/media-types/ making https://www.iana.org/assignments/media-types/text/html etc -- but IANA never managed to decide on such a base URI. In addition that would mean format would not work with parameters like charset.

That means we should not use dct:format - which is defined with range http://purl.org/dc/terms/MediaTypeOrExtent aka an object property to a URI resource - but rather the more simple dc:format which allows plain literals. Then simply remove @type for format. That is how we mapped mediatype in https://researchobject.github.io/specifications/bundle/#json-ld

Yeah...don't introduce any new @ prefixed terms... That'll run into issues in the future for sure.

In digging a bit more, I think "linkset": {"@container": "@list"} gets a more correct result. It preserves the "linkset" relationship between multiple blank nodes: one for the linkset and one for each of the contained links (in this example).

Also, excellent points about format. We used dc:format (for likely very similar reasons) in the Web Annotation Data Model spec's context file.