private static ResultSetRewindable unique(ResultSetRewindable results) {
// VERY crude. Utilises the fact that bindings have value equality.
List<Binding> x = new ArrayList<Binding>();
Set<Binding> seen = new HashSet<Binding>();
for (; results.hasNext(); ) {
Binding b = results.nextBinding();
if (seen.contains(b)) continue;
seen.add(b);
x.add(b);
}
QueryIterator qIter = new QueryIterPlainWrapper(x.iterator());
ResultSet rs =
new ResultSetStream(results.getResultVars(), ModelFactory.createDefaultModel(), qIter);
return ResultSetFactory.makeRewindable(rs);
}
private ResultSetRewindable convertToStrings(ResultSetRewindable resultsActual) {
List<Binding> bindings = new ArrayList<Binding>();
while (resultsActual.hasNext()) {
Binding b = resultsActual.nextBinding();
BindingMap b2 = BindingFactory.create();
for (String vn : resultsActual.getResultVars()) {
Var v = Var.alloc(vn);
Node n = b.get(v);
String s;
if (n == null) s = "";
else if (n.isBlank()) s = "_:" + n.getBlankNodeLabel();
else s = NodeFunctions.str(n);
b2.add(v, NodeFactory.createLiteral(s));
}
bindings.add(b2);
}
ResultSet rs =
new ResultSetStream(
resultsActual.getResultVars(), null, new QueryIterPlainWrapper(bindings.iterator()));
return ResultSetFactory.makeRewindable(rs);
}