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

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/* -*- 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/. */
/**
* ExprParser
* This class is used to parse XSL Expressions
* @see ExprLexer
**/
#include "txExprParser.h"
#include "txExprLexer.h"
#include "txExpr.h"
#include "txStack.h"
#include "nsGkAtoms.h"
#include "nsError.h"
#include "txIXPathContext.h"
#include "txStringUtils.h"
#include "txXPathNode.h"
#include "txXPathOptimizer.h"
/**
* Creates an Attribute Value Template using the given value
* This should move to XSLProcessor class
*/
nsresult
txExprParser::createAVT(const nsSubstring& aAttrValue,
txIParseContext* aContext,
Expr** aResult)
{
*aResult = nullptr;
nsresult rv = NS_OK;
nsAutoPtr<Expr> expr;
FunctionCall* concat = nullptr;
nsAutoString literalString;
bool inExpr = false;
nsSubstring::const_char_iterator iter, start, end, avtStart;
aAttrValue.BeginReading(iter);
aAttrValue.EndReading(end);
avtStart = iter;
while (iter != end) {
// Every iteration through this loop parses either a literal section
// or an expression
start = iter;
nsAutoPtr<Expr> newExpr;
if (!inExpr) {
// Parse literal section
literalString.Truncate();
while (iter != end) {
char16_t q = *iter;
if (q == '{' || q == '}') {
// Store what we've found so far and set a new |start| to
// skip the (first) brace
literalString.Append(Substring(start, iter));
start = ++iter;
// Unless another brace follows we've found the start of
// an expression (in case of '{') or an unbalanced brace
// (in case of '}')
if (iter == end || *iter != q) {
if (q == '}') {
aContext->SetErrorOffset(iter - avtStart);
return NS_ERROR_XPATH_UNBALANCED_CURLY_BRACE;
}
inExpr = true;
break;
}
// We found a second brace, let that be part of the next
// literal section being parsed and continue looping
}
++iter;
}
if (start == iter && literalString.IsEmpty()) {
// Restart the loop since we didn't create an expression
continue;
}
newExpr = new txLiteralExpr(literalString +
Substring(start, iter));
}
else {
// Parse expressions, iter is already past the initial '{' when
// we get here.
while (iter != end) {
if (*iter == '}') {
rv = createExprInternal(Substring(start, iter),
start - avtStart, aContext,
getter_Transfers(newExpr));
NS_ENSURE_SUCCESS(rv, rv);
inExpr = false;
++iter; // skip closing '}'
break;
}
else if (*iter == '\'' || *iter == '"') {
char16_t q = *iter;
while (++iter != end && *iter != q) {} /* do nothing */
if (iter == end) {
break;
}
}
++iter;
}
if (inExpr) {
aContext->SetErrorOffset(start - avtStart);
return NS_ERROR_XPATH_UNBALANCED_CURLY_BRACE;
}
}
// Add expression, create a concat() call if necessary
if (!expr) {
expr = newExpr;
}
else {
if (!concat) {
concat = new txCoreFunctionCall(txCoreFunctionCall::CONCAT);
NS_ENSURE_TRUE(concat, NS_ERROR_OUT_OF_MEMORY);
rv = concat->addParam(expr.forget());
expr = concat;
NS_ENSURE_SUCCESS(rv, rv);
}
rv = concat->addParam(newExpr.forget());
NS_ENSURE_SUCCESS(rv, rv);
}
}
if (inExpr) {
aContext->SetErrorOffset(iter - avtStart);
return NS_ERROR_XPATH_UNBALANCED_CURLY_BRACE;
}
if (!expr) {
expr = new txLiteralExpr(EmptyString());
}
*aResult = expr.forget();
return NS_OK;
}
nsresult
txExprParser::createExprInternal(const nsSubstring& aExpression,
uint32_t aSubStringPos,
txIParseContext* aContext, Expr** aExpr)
{
NS_ENSURE_ARG_POINTER(aExpr);
*aExpr = nullptr;
txExprLexer lexer;
nsresult rv = lexer.parse(aExpression);
if (NS_FAILED(rv)) {
nsASingleFragmentString::const_char_iterator start;
aExpression.BeginReading(start);
aContext->SetErrorOffset(lexer.mPosition - start + aSubStringPos);
return rv;
}
nsAutoPtr<Expr> expr;
rv = createExpr(lexer, aContext, getter_Transfers(expr));
if (NS_SUCCEEDED(rv) && lexer.peek()->mType != Token::END) {
rv = NS_ERROR_XPATH_BINARY_EXPECTED;
}
if (NS_FAILED(rv)) {
nsASingleFragmentString::const_char_iterator start;
aExpression.BeginReading(start);
aContext->SetErrorOffset(lexer.peek()->mStart - start + aSubStringPos);
return rv;
}
txXPathOptimizer optimizer;
Expr* newExpr = nullptr;
rv = optimizer.optimize(expr, &newExpr);
NS_ENSURE_SUCCESS(rv, rv);
*aExpr = newExpr ? newExpr : expr.forget();
return NS_OK;
}
/**
* Private Methods
*/
/**
* Creates a binary Expr for the given operator
*/
nsresult
txExprParser::createBinaryExpr(nsAutoPtr<Expr>& left, nsAutoPtr<Expr>& right,
Token* op, Expr** aResult)
{
NS_ASSERTION(op, "internal error");
*aResult = nullptr;
Expr* expr = nullptr;
switch (op->mType) {
//-- math ops
case Token::ADDITION_OP :
expr = new txNumberExpr(left, right, txNumberExpr::ADD);
break;
case Token::SUBTRACTION_OP:
expr = new txNumberExpr(left, right, txNumberExpr::SUBTRACT);
break;
case Token::DIVIDE_OP :
expr = new txNumberExpr(left, right, txNumberExpr::DIVIDE);
break;
case Token::MODULUS_OP :
expr = new txNumberExpr(left, right, txNumberExpr::MODULUS);
break;
case Token::MULTIPLY_OP :
expr = new txNumberExpr(left, right, txNumberExpr::MULTIPLY);
break;
//-- case boolean ops
case Token::AND_OP:
expr = new BooleanExpr(left, right, BooleanExpr::AND);
break;
case Token::OR_OP:
expr = new BooleanExpr(left, right, BooleanExpr::OR);
break;
//-- equality ops
case Token::EQUAL_OP :
expr = new RelationalExpr(left, right, RelationalExpr::EQUAL);
break;
case Token::NOT_EQUAL_OP :
expr = new RelationalExpr(left, right, RelationalExpr::NOT_EQUAL);
break;
//-- relational ops
case Token::LESS_THAN_OP:
expr = new RelationalExpr(left, right, RelationalExpr::LESS_THAN);
break;
case Token::GREATER_THAN_OP:
expr = new RelationalExpr(left, right,
RelationalExpr::GREATER_THAN);
break;
case Token::LESS_OR_EQUAL_OP:
expr = new RelationalExpr(left, right,
RelationalExpr::LESS_OR_EQUAL);
break;
case Token::GREATER_OR_EQUAL_OP:
expr = new RelationalExpr(left, right,
RelationalExpr::GREATER_OR_EQUAL);
break;
default:
NS_NOTREACHED("operator tokens should be already checked");
return NS_ERROR_UNEXPECTED;
}
NS_ENSURE_TRUE(expr, NS_ERROR_OUT_OF_MEMORY);
left.forget();
right.forget();
*aResult = expr;
return NS_OK;
}
nsresult
txExprParser::createExpr(txExprLexer& lexer, txIParseContext* aContext,
Expr** aResult)
{
*aResult = nullptr;
nsresult rv = NS_OK;
bool done = false;
nsAutoPtr<Expr> expr;
txStack exprs;
txStack ops;
while (!done) {
uint16_t negations = 0;
while (lexer.peek()->mType == Token::SUBTRACTION_OP) {
negations++;
lexer.nextToken();
}
rv = createUnionExpr(lexer, aContext, getter_Transfers(expr));
if (NS_FAILED(rv)) {
break;
}
if (negations > 0) {
if (negations % 2 == 0) {
FunctionCall* fcExpr = new txCoreFunctionCall(txCoreFunctionCall::NUMBER);
rv = fcExpr->addParam(expr);
if (NS_FAILED(rv))
return rv;
expr.forget();
expr = fcExpr;
}
else {
expr = new UnaryExpr(expr.forget());
}
}
short tokPrecedence = precedence(lexer.peek());
if (tokPrecedence != 0) {
Token* tok = lexer.nextToken();
while (!exprs.isEmpty() && tokPrecedence
<= precedence(static_cast<Token*>(ops.peek()))) {
// can't use expr as argument due to order of evaluation
nsAutoPtr<Expr> left(static_cast<Expr*>(exprs.pop()));
nsAutoPtr<Expr> right(expr);
rv = createBinaryExpr(left, right,
static_cast<Token*>(ops.pop()),
getter_Transfers(expr));
if (NS_FAILED(rv)) {
done = true;
break;
}
}
exprs.push(expr.forget());
ops.push(tok);
}
else {
done = true;
}
}
while (NS_SUCCEEDED(rv) && !exprs.isEmpty()) {
nsAutoPtr<Expr> left(static_cast<Expr*>(exprs.pop()));
nsAutoPtr<Expr> right(expr);
rv = createBinaryExpr(left, right, static_cast<Token*>(ops.pop()),
getter_Transfers(expr));
}
// clean up on error
while (!exprs.isEmpty()) {
delete static_cast<Expr*>(exprs.pop());
}
NS_ENSURE_SUCCESS(rv, rv);
*aResult = expr.forget();
return NS_OK;
}
nsresult
txExprParser::createFilterOrStep(txExprLexer& lexer, txIParseContext* aContext,
Expr** aResult)
{
*aResult = nullptr;
nsresult rv = NS_OK;
Token* tok = lexer.peek();
nsAutoPtr<Expr> expr;
switch (tok->mType) {
case Token::FUNCTION_NAME_AND_PAREN:
rv = createFunctionCall(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
break;
case Token::VAR_REFERENCE :
lexer.nextToken();
{
nsCOMPtr<nsIAtom> prefix, lName;
int32_t nspace;
nsresult rv = resolveQName(tok->Value(), getter_AddRefs(prefix),
aContext, getter_AddRefs(lName),
nspace);
NS_ENSURE_SUCCESS(rv, rv);
expr = new VariableRefExpr(prefix, lName, nspace);
}
break;
case Token::L_PAREN:
lexer.nextToken();
rv = createExpr(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
if (lexer.peek()->mType != Token::R_PAREN) {
return NS_ERROR_XPATH_PAREN_EXPECTED;
}
lexer.nextToken();
break;
case Token::LITERAL :
lexer.nextToken();
expr = new txLiteralExpr(tok->Value());
break;
case Token::NUMBER:
{
lexer.nextToken();
expr = new txLiteralExpr(txDouble::toDouble(tok->Value()));
break;
}
default:
return createLocationStep(lexer, aContext, aResult);
}
if (lexer.peek()->mType == Token::L_BRACKET) {
nsAutoPtr<FilterExpr> filterExpr(new FilterExpr(expr));
expr.forget();
//-- handle predicates
rv = parsePredicates(filterExpr, lexer, aContext);
NS_ENSURE_SUCCESS(rv, rv);
expr = filterExpr.forget();
}
*aResult = expr.forget();
return NS_OK;
}
nsresult
txExprParser::createFunctionCall(txExprLexer& lexer, txIParseContext* aContext,
Expr** aResult)
{
*aResult = nullptr;
nsAutoPtr<FunctionCall> fnCall;
Token* tok = lexer.nextToken();
NS_ASSERTION(tok->mType == Token::FUNCTION_NAME_AND_PAREN,
"FunctionCall expected");
//-- compare function names
nsCOMPtr<nsIAtom> prefix, lName;
int32_t namespaceID;
nsresult rv = resolveQName(tok->Value(), getter_AddRefs(prefix), aContext,
getter_AddRefs(lName), namespaceID);
NS_ENSURE_SUCCESS(rv, rv);
txCoreFunctionCall::eType type;
if (namespaceID == kNameSpaceID_None &&
txCoreFunctionCall::getTypeFromAtom(lName, type)) {
// It is a known built-in function.
fnCall = new txCoreFunctionCall(type);
}
// check extension functions and xslt
if (!fnCall) {
rv = aContext->resolveFunctionCall(lName, namespaceID,
getter_Transfers(fnCall));
if (rv == NS_ERROR_NOT_IMPLEMENTED) {
// this should just happen for unparsed-entity-uri()
NS_ASSERTION(!fnCall, "Now is it implemented or not?");
rv = parseParameters(0, lexer, aContext);
NS_ENSURE_SUCCESS(rv, rv);
*aResult = new txLiteralExpr(tok->Value() +
NS_LITERAL_STRING(" not implemented."));
return NS_OK;
}
NS_ENSURE_SUCCESS(rv, rv);
}
//-- handle parametes
rv = parseParameters(fnCall, lexer, aContext);
NS_ENSURE_SUCCESS(rv, rv);
*aResult = fnCall.forget();
return NS_OK;
}
nsresult
txExprParser::createLocationStep(txExprLexer& lexer, txIParseContext* aContext,
Expr** aExpr)
{
*aExpr = nullptr;
//-- child axis is default
LocationStep::LocationStepType axisIdentifier = LocationStep::CHILD_AXIS;
nsAutoPtr<txNodeTest> nodeTest;
//-- get Axis Identifier or AbbreviatedStep, if present
Token* tok = lexer.peek();
switch (tok->mType) {
case Token::AXIS_IDENTIFIER:
{
//-- eat token
lexer.nextToken();
nsCOMPtr<nsIAtom> axis = do_GetAtom(tok->Value());
if (axis == nsGkAtoms::ancestor) {
axisIdentifier = LocationStep::ANCESTOR_AXIS;
}
else if (axis == nsGkAtoms::ancestorOrSelf) {
axisIdentifier = LocationStep::ANCESTOR_OR_SELF_AXIS;
}
else if (axis == nsGkAtoms::attribute) {
axisIdentifier = LocationStep::ATTRIBUTE_AXIS;
}
else if (axis == nsGkAtoms::child) {
axisIdentifier = LocationStep::CHILD_AXIS;
}
else if (axis == nsGkAtoms::descendant) {
axisIdentifier = LocationStep::DESCENDANT_AXIS;
}
else if (axis == nsGkAtoms::descendantOrSelf) {
axisIdentifier = LocationStep::DESCENDANT_OR_SELF_AXIS;
}
else if (axis == nsGkAtoms::following) {
axisIdentifier = LocationStep::FOLLOWING_AXIS;
}
else if (axis == nsGkAtoms::followingSibling) {
axisIdentifier = LocationStep::FOLLOWING_SIBLING_AXIS;
}
else if (axis == nsGkAtoms::_namespace) {
axisIdentifier = LocationStep::NAMESPACE_AXIS;
}
else if (axis == nsGkAtoms::parent) {
axisIdentifier = LocationStep::PARENT_AXIS;
}
else if (axis == nsGkAtoms::preceding) {
axisIdentifier = LocationStep::PRECEDING_AXIS;
}
else if (axis == nsGkAtoms::precedingSibling) {
axisIdentifier = LocationStep::PRECEDING_SIBLING_AXIS;
}
else if (axis == nsGkAtoms::self) {
axisIdentifier = LocationStep::SELF_AXIS;
}
else {
return NS_ERROR_XPATH_INVALID_AXIS;
}
break;
}
case Token::AT_SIGN:
//-- eat token
lexer.nextToken();
axisIdentifier = LocationStep::ATTRIBUTE_AXIS;
break;
case Token::PARENT_NODE :
//-- eat token
lexer.nextToken();
axisIdentifier = LocationStep::PARENT_AXIS;
nodeTest = new txNodeTypeTest(txNodeTypeTest::NODE_TYPE);
break;
case Token::SELF_NODE :
//-- eat token
lexer.nextToken();
axisIdentifier = LocationStep::SELF_AXIS;
nodeTest = new txNodeTypeTest(txNodeTypeTest::NODE_TYPE);
break;
default:
break;
}
//-- get NodeTest unless an AbbreviatedStep was found
nsresult rv = NS_OK;
if (!nodeTest) {
tok = lexer.peek();
if (tok->mType == Token::CNAME) {
lexer.nextToken();
// resolve QName
nsCOMPtr<nsIAtom> prefix, lName;
int32_t nspace;
rv = resolveQName(tok->Value(), getter_AddRefs(prefix),
aContext, getter_AddRefs(lName),
nspace, true);
NS_ENSURE_SUCCESS(rv, rv);
nodeTest =
new txNameTest(prefix, lName, nspace,
axisIdentifier == LocationStep::ATTRIBUTE_AXIS ?
static_cast<uint16_t>(txXPathNodeType::ATTRIBUTE_NODE) :
static_cast<uint16_t>(txXPathNodeType::ELEMENT_NODE));
}
else {
rv = createNodeTypeTest(lexer, getter_Transfers(nodeTest));
NS_ENSURE_SUCCESS(rv, rv);
}
}
nsAutoPtr<LocationStep> lstep(new LocationStep(nodeTest, axisIdentifier));
nodeTest.forget();
//-- handle predicates
rv = parsePredicates(lstep, lexer, aContext);
NS_ENSURE_SUCCESS(rv, rv);
*aExpr = lstep.forget();
return NS_OK;
}
/**
* This method only handles comment(), text(), processing-instructing()
* and node()
*/
nsresult
txExprParser::createNodeTypeTest(txExprLexer& lexer, txNodeTest** aTest)
{
*aTest = 0;
nsAutoPtr<txNodeTypeTest> nodeTest;
Token* nodeTok = lexer.peek();
switch (nodeTok->mType) {
case Token::COMMENT_AND_PAREN:
lexer.nextToken();
nodeTest = new txNodeTypeTest(txNodeTypeTest::COMMENT_TYPE);
break;
case Token::NODE_AND_PAREN:
lexer.nextToken();
nodeTest = new txNodeTypeTest(txNodeTypeTest::NODE_TYPE);
break;
case Token::PROC_INST_AND_PAREN:
lexer.nextToken();
nodeTest = new txNodeTypeTest(txNodeTypeTest::PI_TYPE);
break;
case Token::TEXT_AND_PAREN:
lexer.nextToken();
nodeTest = new txNodeTypeTest(txNodeTypeTest::TEXT_TYPE);
break;
default:
return NS_ERROR_XPATH_NO_NODE_TYPE_TEST;
}
NS_ENSURE_TRUE(nodeTest, NS_ERROR_OUT_OF_MEMORY);
if (nodeTok->mType == Token::PROC_INST_AND_PAREN &&
lexer.peek()->mType == Token::LITERAL) {
Token* tok = lexer.nextToken();
nodeTest->setNodeName(tok->Value());
}
if (lexer.peek()->mType != Token::R_PAREN) {
return NS_ERROR_XPATH_PAREN_EXPECTED;
}
lexer.nextToken();
*aTest = nodeTest.forget();
return NS_OK;
}
/**
* Creates a PathExpr using the given txExprLexer
* @param lexer the txExprLexer for retrieving Tokens
*/
nsresult
txExprParser::createPathExpr(txExprLexer& lexer, txIParseContext* aContext,
Expr** aResult)
{
*aResult = nullptr;
nsAutoPtr<Expr> expr;
Token* tok = lexer.peek();
// is this a root expression?
if (tok->mType == Token::PARENT_OP) {
if (!isLocationStepToken(lexer.peekAhead())) {
lexer.nextToken();
*aResult = new RootExpr();
return NS_OK;
}
}
// parse first step (possibly a FilterExpr)
nsresult rv = NS_OK;
if (tok->mType != Token::PARENT_OP &&
tok->mType != Token::ANCESTOR_OP) {
rv = createFilterOrStep(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
// is this a singlestep path expression?
tok = lexer.peek();
if (tok->mType != Token::PARENT_OP &&
tok->mType != Token::ANCESTOR_OP) {
*aResult = expr.forget();
return NS_OK;
}
}
else {
expr = new RootExpr();
#ifdef TX_TO_STRING
static_cast<RootExpr*>(expr.get())->setSerialize(false);
#endif
}
// We have a PathExpr containing several steps
nsAutoPtr<PathExpr> pathExpr(new PathExpr());
rv = pathExpr->addExpr(expr, PathExpr::RELATIVE_OP);
NS_ENSURE_SUCCESS(rv, rv);
expr.forget();
// this is ugly
while (1) {
PathExpr::PathOperator pathOp;
switch (lexer.peek()->mType) {
case Token::ANCESTOR_OP :
pathOp = PathExpr::DESCENDANT_OP;
break;
case Token::PARENT_OP :
pathOp = PathExpr::RELATIVE_OP;
break;
default:
*aResult = pathExpr.forget();
return NS_OK;
}
lexer.nextToken();
rv = createLocationStep(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
rv = pathExpr->addExpr(expr, pathOp);
NS_ENSURE_SUCCESS(rv, rv);
expr.forget();
}
NS_NOTREACHED("internal xpath parser error");
return NS_ERROR_UNEXPECTED;
}
/**
* Creates a PathExpr using the given txExprLexer
* @param lexer the txExprLexer for retrieving Tokens
*/
nsresult
txExprParser::createUnionExpr(txExprLexer& lexer, txIParseContext* aContext,
Expr** aResult)
{
*aResult = nullptr;
nsAutoPtr<Expr> expr;
nsresult rv = createPathExpr(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
if (lexer.peek()->mType != Token::UNION_OP) {
*aResult = expr.forget();
return NS_OK;
}
nsAutoPtr<UnionExpr> unionExpr(new UnionExpr());
rv = unionExpr->addExpr(expr);
NS_ENSURE_SUCCESS(rv, rv);
expr.forget();
while (lexer.peek()->mType == Token::UNION_OP) {
lexer.nextToken(); //-- eat token
rv = createPathExpr(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
rv = unionExpr->addExpr(expr.forget());
NS_ENSURE_SUCCESS(rv, rv);
}
*aResult = unionExpr.forget();
return NS_OK;
}
bool
txExprParser::isLocationStepToken(Token* aToken)
{
// We could put these in consecutive order in ExprLexer.h for speed
return aToken->mType == Token::AXIS_IDENTIFIER ||
aToken->mType == Token::AT_SIGN ||
aToken->mType == Token::PARENT_NODE ||
aToken->mType == Token::SELF_NODE ||
aToken->mType == Token::CNAME ||
aToken->mType == Token::COMMENT_AND_PAREN ||
aToken->mType == Token::NODE_AND_PAREN ||
aToken->mType == Token::PROC_INST_AND_PAREN ||
aToken->mType == Token::TEXT_AND_PAREN;
}
/**
* Using the given lexer, parses the tokens if they represent a predicate list
* If an error occurs a non-zero String pointer will be returned containing the
* error message.
* @param predicateList, the PredicateList to add predicate expressions to
* @param lexer the txExprLexer to use for parsing tokens
* @return 0 if successful, or a String pointer to the error message
*/
nsresult
txExprParser::parsePredicates(PredicateList* aPredicateList,
txExprLexer& lexer, txIParseContext* aContext)
{
nsAutoPtr<Expr> expr;
nsresult rv = NS_OK;
while (lexer.peek()->mType == Token::L_BRACKET) {
//-- eat Token
lexer.nextToken();
rv = createExpr(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
rv = aPredicateList->add(expr);
NS_ENSURE_SUCCESS(rv, rv);
expr.forget();
if (lexer.peek()->mType != Token::R_BRACKET) {
return NS_ERROR_XPATH_BRACKET_EXPECTED;
}
lexer.nextToken();
}
return NS_OK;
}
/**
* Using the given lexer, parses the tokens if they represent a parameter list
* If an error occurs a non-zero String pointer will be returned containing the
* error message.
* @param list, the List to add parameter expressions to
* @param lexer the txExprLexer to use for parsing tokens
* @return NS_OK if successful, or another rv otherwise
*/
nsresult
txExprParser::parseParameters(FunctionCall* aFnCall, txExprLexer& lexer,
txIParseContext* aContext)
{
if (lexer.peek()->mType == Token::R_PAREN) {
lexer.nextToken();
return NS_OK;
}
nsAutoPtr<Expr> expr;
nsresult rv = NS_OK;
while (1) {
rv = createExpr(lexer, aContext, getter_Transfers(expr));
NS_ENSURE_SUCCESS(rv, rv);
if (aFnCall) {
rv = aFnCall->addParam(expr.forget());
NS_ENSURE_SUCCESS(rv, rv);
}
switch (lexer.peek()->mType) {
case Token::R_PAREN :
lexer.nextToken();
return NS_OK;
case Token::COMMA: //-- param separator
lexer.nextToken();
break;
default:
return NS_ERROR_XPATH_PAREN_EXPECTED;
}
}
NS_NOTREACHED("internal xpath parser error");
return NS_ERROR_UNEXPECTED;
}
short
txExprParser::precedence(Token* aToken)
{
switch (aToken->mType) {
case Token::OR_OP:
return 1;
case Token::AND_OP:
return 2;
//-- equality
case Token::EQUAL_OP:
case Token::NOT_EQUAL_OP:
return 3;
//-- relational
case Token::LESS_THAN_OP:
case Token::GREATER_THAN_OP:
case Token::LESS_OR_EQUAL_OP:
case Token::GREATER_OR_EQUAL_OP:
return 4;
//-- additive operators
case Token::ADDITION_OP:
case Token::SUBTRACTION_OP:
return 5;
//-- multiplicative
case Token::DIVIDE_OP:
case Token::MULTIPLY_OP:
case Token::MODULUS_OP:
return 6;
default:
break;
}
return 0;
}
nsresult
txExprParser::resolveQName(const nsAString& aQName,
nsIAtom** aPrefix, txIParseContext* aContext,
nsIAtom** aLocalName, int32_t& aNamespace,
bool aIsNameTest)
{
aNamespace = kNameSpaceID_None;
int32_t idx = aQName.FindChar(':');
if (idx > 0) {
*aPrefix = NS_NewAtom(StringHead(aQName, (uint32_t)idx)).get();
if (!*aPrefix) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aLocalName = NS_NewAtom(Substring(aQName, (uint32_t)idx + 1,
aQName.Length() - (idx + 1))).get();
if (!*aLocalName) {
NS_RELEASE(*aPrefix);
return NS_ERROR_OUT_OF_MEMORY;
}
return aContext->resolveNamespacePrefix(*aPrefix, aNamespace);
}
// the lexer dealt with idx == 0
*aPrefix = 0;
if (aIsNameTest && aContext->caseInsensitiveNameTests()) {
nsAutoString lcname;
nsContentUtils::ASCIIToLower(aQName, lcname);
*aLocalName = NS_NewAtom(lcname).get();
}
else {
*aLocalName = NS_NewAtom(aQName).get();
}
if (!*aLocalName) {
return NS_ERROR_OUT_OF_MEMORY;
}
return NS_OK;
}