Shorthand for `relType` via keys within `sdfRelation` map?

[JKRhb]

In the current draft revision, thee are a couple of examples where the keys within the sdfRelation objects are very similar to the relType value, see the example below for example:

"sdfRelation": {
  "sameAs": {
    "relType": "exont:same-as",
    "target": "saref:TemperatureSensor"
  }
}

Since this creates a certain redundancy and potentially also bloat (when many sdfRelations are being used, I was wondering whether we could define a short definition where the key (or "given name") can also encode the relationship (see the (updated) example below):

"sdfRelation": {
  "exont:same-as": {
    "target": "saref:TemperatureSensor"
  }
}

With this approach, the structure may become more compact, while it should also have a somewhat positive performance impact.

[cabo]

This looks like a CURIE, but is used in places where it would be parsed like a QNP (quality name prefix).
Also, it is losing the qualification as a (spec-time) link relation.
A shorter form would be good, but maybe we can avoid these two drawbacks.

[JKRhb]

Thank you, @cabo, for the feedback and for pointing out these drawbacks!

Thinking about other possible approaches, one alternative would be of course to rather use an array of relation definitions:

sdfRelation:
  - relType: exont:same-as
    target: saref:TemperatureSensor
  - relType: exont:next-to
    target: "#/sdfObject/second-object"
    description: This object is adjacent to the second object

JSON Version of Example 1

{
  "sdfRelation": [
    {
      "relType": "exont:same-as",
      "target": "saref:TemperatureSensor"
    },
    {
      "relType": "exont:next-to",
      "target": "#/sdfObject/second-object",
      "description": "This object is adjacent to the second object"
    }
  ]
}

This approach might have the drawback of a worse human-readability when being referred to via a JSON pointer, for instance. But then again, that might actually not be an issue here.

A second alternative could be pre-registering certain relation types, that could be used directly within an SDF definition:

sdfRelation:same-as:
  target: saref:TemperatureSensor
sdfRelation:next-to:
  target: "#/sdfObject/second-object"
  description: This object is adjacent to the second object

JSON Version of Example 2

{
  "sdfRelation:same-as": {
    "target": "saref:TemperatureSensor"
  },
  "sdfRelation:next-to": {
    "target": "#/sdfObject/second-object",
    "description": "This object is adjacent to the second object"
  }
}

But I am not sure whether that creates too much overhead. Also, the downside of this approach is that only one relation type of a kind can be used within a single definition, so that might not be desirable.