@type as an array allowed for literals

[Tpt]

[Sorry, this might be duplicated, I have not read the list of open issues carefully]

When given the following JSON-Ld, jsonld.js returns an invalid RDF triple, contenating the two literal datatypes with a ,:

{
  "@id": "http://example.com/s",
  "http://example.com/s": {
    "@value": "foo",
    "@type": ["http://example.com/bar", "http://example.com/baz"]
  }
}

<http://example.com/s> <http://example.com/s> "foo"^^<http://example.com/bar,http://example.com/baz> .

Json-ld.org playground

I guess it should be a syntax error instead.