According to arq --help, there's a --strict option:
--strict Operate in strict SPARQL mode (no
extensions of any kind)
However, ARQ doesn't complain about <p>{2}
$ arq --strict --data empty.n3 "select * where { ?s <p>{2} ?o }"
---------
| s | o |
=========
---------
As I read it, the working draft path language [1] allowed elt{n} (and
similar), but the SPARQL 1.1 recommendation property path syntax [2]
doesn't include them. Shouldn't arq with --strict choke on them? I
only noticed this when it came up in a StackOverflow question [3]
where a user with an old version of Jena was using such a query, and I
was trying to put together an example showing that the current
version, in strict mode, would reject it.
Unless this is intended behavior, I can open a JIRA (and maybe look
into making a patch).
//JT
[1] http://www.w3.org/TR/2010/WD-sparql11-property-paths-20100126/#path-language
[2] http://www.w3.org/TR/sparql11-query/#pp-language
[3] http://stackoverflow.com/q/18919742/1281433
--
Joshua Taylor, http://www.cs.rpi.edu/~tayloj/
