clarify overriding resources about levelgraph-jsonld

[mcollina]

If we have the full resource loaded, we can apply one of the json diff
algorithms out there and apply only the changes. I'm on the go with no
references but I've seen many on npm (then there is the issue of picking
one :P).

[elf-pavlik]

interesting note by David I. Lehn in email on Web Payments list: http://lists.w3.org/Archives/Public/public-webpayments/2014Jan/0048.html

There are issues to consider when comparing SPARQL, Changeset vocab,
JSON Patch, or other systems for triple editing. SPARQL and the
Changeset vocab will be able to edit linked data at a lower triples
level. JSON Patch may require that data be framed into a strict
JSON-LD format so that the patch paths make sense. That could require
finishing the framing spec. If you can read and write the full
resource data then just HTTP verbs and a read-modify-write process
could work for edits. I imagine editing data with blank nodes is full
of issues too. And the ease of any approach probably depends on
implementation details of the client and server. It could be a
challenge to come up with a good general solution.

Here we go again with #8

[...] I imagine editing data with blank nodes is full
of issues too. [...]

[mcollina]

Agreed that is a big issue.

I prefer working code against long specs, so let's try to sketch something more efficient than the current implementation. JSON patch can work, as we are already forcing our representation to a strict JSON-LD format (either compact or expanded). If it works, we can share it with the world and ask for feedbacks!

[elf-pavlik]

👍
I would also prefer to get something working first without getting distracted with peculiarities of blank nodes 😉

[mcollina]

As for inner nodes, let's consider they always have an @id.
If they are blank, they automatically got a UUID-generated one (or any other strategy we might want to use!)