- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Sat, 5 Jan 2013 18:06:42 -0500
- To: Markus Lanthaler <markus.lanthaler@gmx.net>
- Cc: public-linked-json@w3.org, 'RDF WG' <public-rdf-wg@w3.org>
* Markus Lanthaler <markus.lanthaler@gmx.net> [2013-01-04 18:51+0100]
> As announced in the last mail, I've just fixed the last remaining issues in
> the JSON-LD Grammar section. It definitely does the job, I was just
> wondering whether we should also include a more formal, ABNF-like grammar
> (or maybe even replace the prose). Unfortunately it seems that currently
> there's no accepted way or best-practice to specify JSON "grammars" (the
> JSON Schema Internet Draft expired two years ago [1]).
>
> So I tried to come up with something ABNF-like (it's not valid ABNF) and
> would be interested in hearing your opinions. I'm not sure myself yet
> whether that helps or confuses people.
>
> graph = node-obj / node-obj[]
>
> node-obj =
> {
> "@context": context-def (0..1)
> "@id": string (0..1)
> "@type": iri / iri[] (0..1)
> "@graph": graph (0..1)
> "@annotation": string (0..1)
> property-key: property-value / property-value[] /
> language-map / annotation-map (*)
> }
>
> value-obj =
> {
> "@context": context-def (0..1)
> "@value": scalar (0..1)
> "@language": bcp47-tag / "@type": iri (0..1)
> "@annotation": string
> }
>
> list-obj =
> {
> "@context": context-def (0..1)
> "@list": list-set-value / list-set-value[] (1)
> "@annotation": string (0..1)
> }
>
> set-obj =
> {
> "@context": context-def (0..1)
> "@set": list-set-value / list-set-value[] (1)
> "@annotation": string (0..1)
> }
>
> language-map =
> {
> "@context": context-def (0..1)
> bcp47-tag: string / string[] (*)
> }
>
> annotation-map =
> {
> "@context": context-def (0..1)
> string: property-value / property-value[] (*)
> }
>
> list-set-value = scalar / node-obj / value-obj
>
> property-value = list-set-value / list-obj / set-obj
>
> context-def = null / iri / context-def-obj /
> (null / iri / context-def-obj)[]
>
> context-def-obj =
> {
> property-key: null / iri / term-def-obj (*)
> "@language": bcp47-tag (0..1)
> "@vocab": iri (0..1)
> }
>
> term-def-obj =
> {
> "@id": iri (0..1)
> "@language": bcp47-tag / "@type": iri (0..1)
> "@container": ( "@list" / "@set" /
> "@language" / "@annotation" ) (0..1)
> }
>
> bcp47-tag = string ; should this be more explicit?
>
> iri = string ; should this be more explicit?
>
> property-key = string - keyword ; any string except a keyword
>
> keyword = @context / @id / @value / @language / @type /
> @container / @list / @set / @annotation / @vocab / @graph
>
> scalar = null / string / number / true / false
I like it! It reminds me of RNC (my favorite schema language).
You could change "(0..1)" to "?".
It should be pretty easy to compile that into an actual yacc parser à la
http://www.w3.org/2005/01/yacker/uploads/results_JSON?lang=perl&markup=html
to verify and to have a speedy parser.
> [1] http://tools.ietf.org/html/draft-zyp-json-schema-03
>
>
> Cheers,
> Markus
>
>
>
> --
> Markus Lanthaler
> @markuslanthaler
>
>
--
-ericP
Received on Saturday, 5 January 2013 23:07:12 UTC