@Override
protected void details(IndentedWriter out, SerializationContext sCxt) {
out.println(Utils.className(this));
out.incIndent();
op.output(out, sCxt);
out.decIndent();
}
QueryIterator exec(Op op, QueryIterator input) {
push(input);
int x = stack.size();
op.visit(this);
int y = stack.size();
if (x != y) Log.warn(this, "Possible stack misalignment");
QueryIterator qIter = pop();
return qIter;
}
/**
* This method controls whether any binding in given binding list is service
*
* @param op
* @param bindingList
* @return
*/
private static boolean controlWhetherBindingIsService(Op op, List<Binding> bindingList) {
// try to cast Op value to OpService
OpService opService = null;
if (op.getClass().asSubclass(OpService.class).equals(OpService.class)) {
opService = (OpService) op;
}
// if casting is successful control service is variable and service
// variable is binding variable
if (opService != null && isServiceVariable(opService) && bindingList.size() > 0) {
BindingMap binding = (BindingMap) bindingList.get(0);
List<Var> varList = generateVarList(binding.vars());
Var var = varList.get(0);
Node serviceNode = binding.get(var);
if (serviceNode != null) {
return true;
}
}
return false;
}
public static ExprList collectExprs(Op op, ExprList result) {
if (op instanceof OpLeftJoin) {
OpLeftJoin x = (OpLeftJoin) op;
if (x.getExprs() != null) {
result.addAll(x.getExprs());
}
collectExprs(x.getLeft(), result);
collectExprs(x.getRight(), result);
} else if (op instanceof OpFilter) {
OpFilter x = (OpFilter) op;
result.addAll(x.getExprs());
collectExprs(x.getSubOp(), result);
} else if (op instanceof OpJoin) {
OpJoin x = (OpJoin) op;
collectExprs(x.getLeft(), result);
collectExprs(x.getRight(), result);
} else if (op instanceof OpUnion) {
System.out.println(
"Warning: Collecting expressions from unions. Since the same vars may appear within different (parts of) unions, it may be ambiguous to which part the expression refers.");
OpUnion x = (OpUnion) op;
collectExprs(x.getLeft(), result);
collectExprs(x.getRight(), result);
} else if (op instanceof OpQuadPattern) {
} else if (op instanceof OpSequence) {
OpSequence x = (OpSequence) op;
for (Op element : x.getElements()) {
collectExprs(element, result);
}
} else {
throw new RuntimeException("Not implemented. Type: " + op.getClass());
}
return result;
}
protected Table eval(Op op) {
op.visit(this);
return pop();
}