Keep mode explici [Re: Annotation syntax]

On 05/09/2020 20:34, Olaf Hartig wrote:
> On lördag 5 september 2020 kl. 11:37:09 CEST Ghislain Atemezing wrote:
>>> Le 4 sept. 2020 à 00:30, Holger Knublauch <holger@topquadrant.com> a écrit
>>> [...]
>>> If RDF* in the most general sense is SA mode then the PG mode could be,
>>> for example, called RDF+ aka RDF plus. It would be a bit like OWL Full vs
>>> OWL DL, or SHACL-SPARQL vs SHACL Core. Some tools will elect to support
>>> PG mode/RDF+ only.
>> +1. I like this analogy. Probably RDF+ can confused some of us using RDFS+
>> (as a profile to do reasoning). What about saying RDF* when you support
>> both SA and PG (like OWL Full), then RDF*-XX (XX = SA or PG) if someone
>> supports just one of them?
> +1

I think that an even better way to /not/ confuse people would be to get
rid of modes altogether! To quote Pat Hayes on this list in a previous
message [1]:

> these are not two ‘modes’ but two languages, indistinguishable in
syntax but with different semantics. That is a truly terrible idea.

One benefit that I saw in the discussion about "annotation syntax" was
to propose a different syntax for the "PG-mode use cases", which would
have allowed us to keep the original syntax (<< >>) exclusively for the
"SA-mode use cases" -- but maybe I was misinterpreting.

So if really there is a consensus that << >> should be interpretable in
two different ways depending on the "mode", then let me suggest the
following:

add to RDF* and SPARQL* a directive @mode (or maybe MODE for
SPARQL*...), akin to @prefix or @base, to make the mode explicit. So one
would either write:

  @mode PG.

  <<:bob :worksFor :ACME>> :since 2018.

or

  @mode SA.

  :alice :believes <<:bob :worksFor :ACME>>.

If @mode was absent, I would prefer the default value to be SA, but I
understand that some implementations already assume PG mode, so maybe
the default value could be left unspecified for backward compatibility.

  pa


[1] https://lists.w3.org/Archives/Public/public-rdf-star/2019Sep/0052.html