Issue with @container arrays

[kasei]

Test t0080 uses a @container array value:

"@container": ["@graph", "@set"]

The changelog seems to suggest that this is OK:

The value for @container in an expanded term definition can also be an array containing any appropriate container keyword along with @set (other than @list). This allows a way to ensure that such entry values will always be expressed in array form.

However, Create Term Definition step 21.1 is not written in a way that supports this combination of container values:

Initialize container to the value associated with the @container entry, which MUST be either @graph, @id, @index, @language, @list, @set, @type, or an array containing exactly any one of those keywords, an array containing @graph and either @id or @index optionally including @set, or an array containing a combination of @set and any of @index, @id, @type, @language in any order . Otherwise, an invalid container mapping has been detected and processing is aborted.

I read this as indicating that ["@graph", "@set"] is an invalid container mapping, and processing will be aborted. Is that correct? Can this text and/or the test suite be updated to clarify this?

[gkellogg]

No, it is permissible to use ["@graph", "@set"], and there are steps in both Compaction and IRI Compaction that take advantage of this. @graph should be added to the list of keywords for which @set can be used.

[pchampin]

Actually the part that says

containing @graph and either @id or @index optionally including @set

does cover that case...

[kasei]

@pchampin how does that cover this case when the container does not contain either @id or @index?

[pchampin]

oh, you are right :-/ sorry

[iherman]

This issue was discussed in a meeting.

• RESOLVED: Update api Create Term Definition step to allow the set of combinations from syntax 9.15.1

View the transcript

4.4. @graph, @set
Rob Sanderson: #242
Rob Sanderson: "@container": ["@graph", "@set"] is used in a test, but the text of the algorithm implies that it is illegal
Gregg Kellogg: this is an ommision in the algorithm in the list of things allowed with @graph
… the normative section of the syntax does allow this combination
Gregg Kellogg: http://localhost:8000/?specStatus=CR&publishDate=2019-12-12#expanded-term-definition
Pierre-Antoine Champin: https://www.w3.org/TR/json-ld11/#expanded-term-definition
Rob Sanderson: > If the expanded term definition contains the @container keyword, its value MUST be either @list, @set, @language, @index, @id, @graph, @type, or be null or an array containing exactly any one of those keywords, or a combination of @set and any of @index, @id, @graph, @type, @language in any order
Rob Sanderson: so the API and Syntax documents are out of sync
Gregg Kellogg: there was examples specifically added about it
Proposed resolution: Update api Create Term Definition step to allow the set of combinations from syntax 9.15.1 (Rob Sanderson)
Gregg Kellogg: +1
Rob Sanderson: +1
David I. Lehn: +1
Ivan Herman: 0
Tim Cole: +1
Harold Solbrig: +1
Benjamin Young: +1
Pierre-Antoine Champin: +1
Resolution #5: Update api Create Term Definition step to allow the set of combinations from syntax 9.15.1

[gkellogg]

@kasei, please let us know if changes in #248 satisfactorily address your concern.

[kasei]

Looks good, thanks.