nsresult
PredicateList::evaluatePredicates(txNodeSet* nodes,
txIMatchContext* aContext)
{
NS_ASSERTION(nodes, "called evaluatePredicates with nullptr NodeSet");
nsresult rv = NS_OK;
uint32_t i, len = mPredicates.Length();
for (i = 0; i < len && !nodes->isEmpty(); ++i) {
txNodeSetContext predContext(nodes, aContext);
/*
* add nodes to newNodes that match the expression
* or, if the result is a number, add the node with the right
* position
*/
int32_t index = 0;
while (predContext.hasNext()) {
predContext.next();
RefPtr<txAExprResult> exprResult;
rv = mPredicates[i]->evaluate(&predContext,
getter_AddRefs(exprResult));
NS_ENSURE_SUCCESS(rv, rv);
// handle default, [position() == numberValue()]
if (exprResult->getResultType() == txAExprResult::NUMBER) {
if ((double)predContext.position() == exprResult->numberValue()) {
nodes->mark(index);
}
}
else if (exprResult->booleanValue()) {
nodes->mark(index);
}
++index;
}
// sweep the non-marked nodes
nodes->sweep();
}
return NS_OK;
}
bool txStepPattern::matches(const txXPathNode& aNode, txIMatchContext* aContext)
{
NS_ASSERTION(mNodeTest, "Internal error");
if (!mNodeTest->matches(aNode, aContext))
return false;
txXPathTreeWalker walker(aNode);
if ((!mIsAttr &&
txXPathNodeUtils::isAttribute(walker.getCurrentPosition())) ||
!walker.moveToParent()) {
return false;
}
if (isEmpty()) {
return true;
}
/*
* Evaluate Predicates
*
* Copy all siblings/attributes matching mNodeTest to nodes
* Up to the last Predicate do
* Foreach node in nodes
* evaluate Predicate with node as context node
* if the result is a number, check the context position,
* otherwise convert to bool
* if result is true, copy node to newNodes
* if aNode is not member of newNodes, return false
* nodes = newNodes
*
* For the last Predicate, evaluate Predicate with aNode as
* context node, if the result is a number, check the position,
* otherwise return the result converted to boolean
*/
// Create the context node set for evaluating the predicates
nsRefPtr<txNodeSet> nodes;
nsresult rv = aContext->recycler()->getNodeSet(getter_AddRefs(nodes));
NS_ENSURE_SUCCESS(rv, false);
bool hasNext = mIsAttr ? walker.moveToFirstAttribute() :
walker.moveToFirstChild();
while (hasNext) {
if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
nodes->append(walker.getCurrentPosition());
}
hasNext = mIsAttr ? walker.moveToNextAttribute() :
walker.moveToNextSibling();
}
Expr* predicate = mPredicates[0];
nsRefPtr<txNodeSet> newNodes;
rv = aContext->recycler()->getNodeSet(getter_AddRefs(newNodes));
NS_ENSURE_SUCCESS(rv, false);
PRUint32 i, predLen = mPredicates.Length();
for (i = 1; i < predLen; ++i) {
newNodes->clear();
bool contextIsInPredicate = false;
txNodeSetContext predContext(nodes, aContext);
while (predContext.hasNext()) {
predContext.next();
nsRefPtr<txAExprResult> exprResult;
rv = predicate->evaluate(&predContext, getter_AddRefs(exprResult));
NS_ENSURE_SUCCESS(rv, false);
switch(exprResult->getResultType()) {
case txAExprResult::NUMBER:
// handle default, [position() == numberValue()]
if ((double)predContext.position() ==
exprResult->numberValue()) {
const txXPathNode& tmp = predContext.getContextNode();
if (tmp == aNode)
contextIsInPredicate = true;
newNodes->append(tmp);
}
break;
default:
if (exprResult->booleanValue()) {
const txXPathNode& tmp = predContext.getContextNode();
if (tmp == aNode)
contextIsInPredicate = true;
newNodes->append(tmp);
}
break;
}
}
// Move new NodeSet to the current one
nodes->clear();
nodes->append(*newNodes);
if (!contextIsInPredicate) {
return false;
}
predicate = mPredicates[i];
}
txForwardContext evalContext(aContext, aNode, nodes);
nsRefPtr<txAExprResult> exprResult;
rv = predicate->evaluate(&evalContext, getter_AddRefs(exprResult));
NS_ENSURE_SUCCESS(rv, false);
if (exprResult->getResultType() == txAExprResult::NUMBER)
// handle default, [position() == numberValue()]
return ((double)evalContext.position() == exprResult->numberValue());
return exprResult->booleanValue();
} // matches
