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);
}
public static Op substitute(Op op, Var var, Node node) {
Binding b = BindingFactory.binding(var, node);
return substitute(op, b);
}