gecko-dev/dom/xslt/xpath/txPredicateList.cpp

86 строки
2.5 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "txExpr.h"
#include "txNodeSet.h"
#include "txNodeSetContext.h"
/*
* Represents an ordered list of Predicates,
* for use with Step and Filter Expressions
*/
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();
nsRefPtr<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
PredicateList::isSensitiveTo(Expr::ContextSensitivity aContext)
{
// We're creating a new node/nodeset so we can ignore those bits.
Expr::ContextSensitivity context =
aContext & ~(Expr::NODE_CONTEXT | Expr::NODESET_CONTEXT);
if (context == Expr::NO_CONTEXT) {
return false;
}
uint32_t i, len = mPredicates.Length();
for (i = 0; i < len; ++i) {
if (mPredicates[i]->isSensitiveTo(context)) {
return true;
}
}
return false;
}
#ifdef TX_TO_STRING
void PredicateList::toString(nsAString& dest)
{
for (uint32_t i = 0; i < mPredicates.Length(); ++i) {
dest.Append(char16_t('['));
mPredicates[i]->toString(dest);
dest.Append(char16_t(']'));
}
}
#endif