Handle plurals when specifying values for queries

[ledsoft]

Currently, when a query of the following kind is used and multiple values are specified for it, it leads to an invalid SPARQL query. JOPA should be able to either translate the query to a valid form or refuse the query with a more informative exception.

While it will be relatively simple to handle cases where only one variable is used, problematic may be cases with multiple variables with inequal number of values.

Query:

SELECT ?x WHERE { ?x ex:hasValue ?value }

Resulting invalid SPARQL:

SELECT ?x WHERE { ?x ex:hasValue ?value } VALUES {(<http://example.org/valueOne>, <http://example.org/valueTwo>)}