Datatype fields in SPARQL results are only allowed in typed-literals and not in literals.

[bnouwt]

Hi, in the JSON SPARQL results below (that were received from the SPARQL endpoint), the datatype are only allowed to occur in entries where "type": "typed-literal" (see JSON SPARQL result spec).

Apart from issue #22, this issue is about there not being any typed-literal entries. So, the solution could be to always (and only) return JSON with typed-literal instead of literal when a datatype field is present.

{
  "head": {
    "vars": [
      "s",
      "p",
      "o"
    ]
  },
  "results": {
    "bindings": [
      {
        "p": {
          "type": "uri",
          "value": "http://example.org/mainPersonsInvolved",
          "datatype": null
        },
        "o": {
          "type": "uri",
          "value": "https://tno.nl/Neil_Armstrong",
          "datatype": null
        }
      },
      {
        "p": {
          "type": "uri",
          "value": "http://example.org/hasOccurredAt",
          "datatype": null
        },
        "o": {
          "type": "literal",
          "value": "1969-07-20T20:05:00+00:00",
          "datatype": "http://www.w3.org/2001/XMLSchema#dateTime"
        }
      },
      {
        "p": {
          "type": "uri",
          "value": "http://example.org/hasNumberOfPeople",
          "datatype": null
        },
        "o": {
          "type": "literal",
          "value": "500",
          "datatype": "http://www.w3.org/2001/XMLSchema#integer"
        }
      }
    ]
  }
}