Re: [core] [T2TRG] Review of CoRAL

Christian M. Amsüss <christian@amsuess.com> Sat, 10 November 2018 09:54 UTC

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Date: Sat, 10 Nov 2018 10:54:35 +0100
From: Christian =?iso-8859-1?B?TS4gQW1z/HNz?= <christian@amsuess.com>
To: Klaus Hartke <hartke@projectcool.de>
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Subject: Re: [core] [T2TRG] Review of CoRAL
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On Sat, Nov 10, 2018 at 10:08:55AM +0100, Klaus Hartke wrote:
> Christian Amsüss wrote:
> > > The draft currently specifies that a base IRI is resolved against the
> > > current context IRI, not the previous base IRI.
> >
> > Thanks; likewise, I missed updating the current relation number. Both
> > being fixed.

Oh: I did not fix all of it. What my original code did was change the
context IRI as well (which I had fixed), but I kept working off the same
base IRI.

> I just checked how Turtle does it, and it seems that in Turtle a base
> IRI is resolved against the previous base IRI.

I checked HTML, but they only allow a single base href. XML's (and thus
Atom's) xml:base URIs can't be relative references anyway. In JSON-LD,
the @base must be in the @context if I understand the text right, so
there can only be one like in HTML.

>     #base <foo/>
>     #base <bar/>
>
> Advantage: Since link targets are more likely to be relative to the
> context than to the previous link targets, this should generate
> slightly more compact CBOR representations.

I'd think that situations of deep links will be rather unlikely anyway
(if / says something about /foo/bar/, it probably says something about
/foo/ too, and /foo/bar/ will be linked to from /foo/ and not / in the
likely cases.)

> Document with base IRIs relative to previous base IRI:
> 
>     #base <foo/>
>     #base <../bar/>
> 
> Advantages: Since the context IRI is not used after the first base IRI
> directive, a processor can reuse the memory for the context IRI to
> store the base IRI instead of having to allocate memory for both. It
> would match the intuition of people who are familiar with Turtle.

I'd rather think of it as "updated in-place" than "freed and reused",
but yes, it might be more RAM efficient (esp. interesting with non-zero
nesting limits). Transfering intuition from related formats is a bonus
too, so...

> Would it make sense to switch?

yes.

Christian

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