Re: Compacting rdf:Seq

Hi Gregg,

thanks for your suggestion. I was able to reproduce it with
http://rdf.greggkellogg.net/distiller. However, why do you need to change
the input JSON-LD? I tried to follow the same procedure with my JSON-LD
provided with the @context, but I ended up with rdf:first and rdf:rest
instead of @list. Is there a problem in my @context?

- Jindřich

On Sun, Dec 20, 2015 at 2:05 AM, Gregg Kellogg <gregg@greggkellogg.net>
wrote:

> On Dec 19, 2015, at 9:56 AM, Jindřich Mynarz <mynarzjindrich@gmail.com>
> wrote:
>
> Hi,
>
> is it possible to compact rdf:Seq?
>
> For example, let's have this JSON-LD:
>
> {
>   "@graph": [{
>     "ex:list": "_:b1"
>   }, {
>     "@id": "_:b1",
>     "rdf:first": "_:b2",
>     "rdf:rest": "_:b3"
>   }, {
>     "@id": "_:b2",
>     "foaf:name": "Alice"
>   }, {
>     "@id": "_:b3",
>     "rdf:first": "_:b4",
>     "rdf:rest": "rdf:nil"
>   }, {
>     "@id": "_:b4",
>     "foaf:name": "Bob"
>   }]
> }
>
> We try to compact it with this context:
>
> {
>  "@context": {
>     "ex": "http://example.com/",
>     "foaf": "http://xmlns.com/foaf/0.1/",
>     "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
>     "ex:list": {"@container": "@list",
>                 "@type": "@id"},
>     "rdf:first": {"@type": "@id"},
>     "rdf:rest": {"@type": "@id"}
>   }
> }
>
> JSON-LD playground (jsonld.js) returns the following:
>
> {
>   "@context": {
>     "ex": "http://example.com/",
>     "foaf": "http://xmlns.com/foaf/0.1/",
>     "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
>     "ex:list": {
>       "@container": "@list",
>       "@type": "@id"
>     },
>     "rdf:first": {
>       "@type": "@id"
>     },
>     "rdf:rest": {
>       "@type": "@id"
>     }
>   },
>   "@graph": [
>     {
>       "ex:list": [
>         "_:b1"
>       ]
>     },
>     {
>       "@id": "_:b1",
>       "rdf:first": "_:b2",
>       "rdf:rest": "_:b3"
>     },
>     {
>       "@id": "_:b2",
>       "foaf:name": "Alice"
>     },
>     {
>       "@id": "_:b3",
>       "rdf:first": "_:b4",
>       "rdf:rest": "rdf:nil"
>     },
>     {
>       "@id": "_:b4",
>       "foaf:name": "Bob"
>     }
>   ]
> }
>
> Is it possible to get to a compact representation of rdf:Seq (
> http://www.w3.org/TR/json-ld/#sets-and-lists), like the following?
>
> {
>   "@context": {
>     "ex": "http://example.com/",
>     "foaf": "http://xmlns.com/foaf/0.1/",
>     "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
>     "ex:list": {
>       "@container": "@list",
>       "@type": "@id"
>     },
>     "rdf:first": {
>       "@type": "@id"
>     },
>     "rdf:rest": {
>       "@type": "@id"
>     }
>   },
>   "@graph": [
>     {
>       "ex:list": [
>         "_:b2", "_:b4"
>       ]
>     },
>     {
>       "@id": "_:b2",
>       "foaf:name": "Alice"
>     },
>     {
>       "@id": "_:b4",
>       "foaf:name": "Bob"
>     }
>   ]
> }
>
>
> You can do much of what you want by going through RDF. If you turn the
> original input into N-Quads, and then serialize that back to JSON-LD you’ll
> get an @list. They playground doesn’t show N-Quads to JSON-LD, but you can
> do this through my Distiller (http://rdf.greggkellogg.net/distiller). I
> modified your input a bit:
>
> {
>  "@context": {
>     "ex": "http://example.com/",
>     "foaf": "http://xmlns.com/foaf/0.1/",
>     "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>   },
>   "@graph": [{
>     "ex:list": {"@id": "_:b1"}
>   }, {
>     "@id": "_:b1",
>     "rdf:first": {"@id": "_:b2"},
>     "rdf:rest": {"@id": "_:b3"}
>   }, {
>     "@id": "_:b2",
>     "foaf:name": "Alice"
>   }, {
>     "@id": "_:b3",
>     "rdf:first": {"@id": "_:b4"},
>     "rdf:rest": {"@id": "rdf:nil"}
>   }, {
>     "@id": "_:b4",
>     "foaf:name": "Bob"
>   }]
> }
>
> If you transform from JSON-LD to RDF and then serialize back to JSON-LD
> you get the following:
>
> {
>   "@context": {
>     "foaf": "http://xmlns.com/foaf/0.1/"
>   },
>   "@graph": [
>     {
>       "@id": "_:b0",
>       "http://example.com/list": {
>         "@list": [
>           {
>             "@id": "_:b2"
>           },
>           {
>             "@id": "_:b4"
>           }
>         ]
>       }
>     },
>     {
>       "@id": "_:b2",
>       "foaf:name": "Alice"
>     },
>     {
>       "@id": "_:b4",
>       "foaf:name": "Bob"
>     }
>   ]
> }
>
> To improve further requires framing, but not that it is using the @list
> shorthand. You can use the playground with your context to get the
> following:
>
> {
>   "@context": {
>     "ex": "http://example.com/",
>     "foaf": "http://xmlns.com/foaf/0.1/",
>     "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
>     "ex:list": {
>       "@container": "@list",
>       "@type": "@id"
>     },
>     "rdf:first": {
>       "@type": "@id"
>     },
>     "rdf:rest": {
>       "@type": "@id"
>     }
>   },
>   "@graph": [
>     {
>       "@id": "_:b0",
>       "ex:list": [
>         "_:b2",
>         "_:b4"
>       ]
>     },
>     {
>       "@id": "_:b2",
>       "foaf:name": "Alice"
>     },
>     {
>       "@id": "_:b4",
>       "foaf:name": "Bob"
>     }
>   ]
> }
>
> Gregg
>
> - Jindřich
>
> --
> Jindřich Mynarz
> http://mynarz.net/#jindrich
>
>
>