expand: certain keywords are dropped

[daenney]

Step 13.4 of the expansion algorithm handles the case where a key, after IRI expansion, matches a JSON-LD keyword. It enumerates a number of keywords that are specifically handled, and ends with 13.4.17:

Continue with the next key from element.

From my understanding of it, that should mean that any key which expanded into a keyword we did not just explicitly handle is not added to the expanded document, and therefor its value is never expanded either so can't be present in the expanded document. In effect, we're dropping that key.

One interesting tidbit, this fails in the JSON-LD playground. I think my reading of the spec is correct, so I believe this is an oversight in jsonld.js. But I'm not entirely sure. The expanded result on the playground is:

[
  {
    "@base": [
      "base"
    ],
    "@container": [
      "@language"
    ],
    "@json": [
      {}
    ],
    "@none": [
      "none"
    ],
    "@prefix": [
      "prefix"
    ],
    "@preserve": [
      "preserve"
    ],
    "@version": [
      "1.1"
    ],
    "@vocab": [
      "hello"
    ]
  }
]

[daenney]

Assuming my reading is correct, should the various frame expansion keywords be added to this test as well?

[anatoly-scherbakov]

If I understand the point correctly then the keywords in the test should be ignored specifically for the reason that they aren't keywords in the document-root context.

Here's a classification of these.

Keyword	Classification	Valid JSON-LD 1.1 use
@base	Context keyword	Context definition
@container	Term-definition keyword	Expanded term definition
@import	Context keyword	Context definition
@json	Type keyword	Value of @type
@none	Map index sentinel	Index, id, language, or type map
@prefix	Term-definition keyword	Expanded term definition
@propagate	Context keyword	Context definition
@version	Context keyword	Context definition
@vocab	Context/type keyword	Context definition or term-definition @type
@any	Algorithm sentinel	Inverse-context processing
@null	Algorithm sentinel	Inverse-context processing
@preserve	Framing-processing keyword	Framing/compaction processing

Could you please also regenerate and commit tests/expand-manifest.html:

cd tests
bundle exec rake expand-manifest.html

This is the generated-file rule in tests/Rakefile.

Non-blocking: adding @protected would complete the coverage of context/term-definition-only keywords.

[w3cbot]

anatoly-scherbakov marked as non substantive for IPR from ash-nazg.

[daenney]

@anatoly-scherbakov all done I think. I added propagate protected for good measure.

[daenney]

Sorry, I confugred propagate and protected there. Propagate was already there, I added protected as suggested.

Something I did just notice, propagate, regardless of its value, is dropped by the JSON-LD playground. Protected is kept though no matter the value.