Expressing `@container: @set`?

[BigBlueHat]

https://www.w3.org/TR/json-ld/#sets

The dataset: true feature creates "@container": "@graph". Is there a way to express an @set (or @list) container?

[iherman]

The feature is already present, just not where you thought it would be. If the range of a property is set to rdf:List, then the relevant property entry in the context file will include the "@container" : "@list" entry.

There is no "@container" : "@set" because that is the default in JSON-LD. I could generate it for all properties that are not lists, but it would just pollute the context unnecessarily.

The fact that "@container" is also used for a "@graph" in JSON-LD is, in my view, a bad design decision. It conflates two extremely different notions (the usage of a particular construct within an RDF graph, and the usage of datasets); this bad design means that constructions might become either under-specified or simply wrong. There was a glaring error in VCDM1.0 due to this conflation, for example, which nobody realized back then.

[iherman]

One minor issue, however; in RDF, there is no way to define that "This is a list whose elements are of a specific type". Something akin to the someInterface<T> in typescript. This means that this type of restriction cannot really be expressed in the yml file. I will think about allowing it, to generate such an explanation text into the HTML (even if the restriction cannot be expressed in the Turtle or JSON-LD versions of the vocabulary).

[iherman]

I realize I was wrong: it does make sense to use @set in the context file: it also says that the values are always in an array, even if there is only one.

I will look into this.

[BigBlueHat]

Thanks @iherman! Happy to help test. 😁