gecko-dev/extensions/transformiix/source/xpath/PredicateList.cpp
2001-10-03 01:27:04 +00:00

130 lines
3.8 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is TransforMiiX XSLT processor.
*
* The Initial Developer of the Original Code is The MITRE Corporation.
* Portions created by MITRE are Copyright (C) 1999 The MITRE Corporation.
*
* Portions created by Keith Visco as a Non MITRE employee,
* (C) 1999 Keith Visco. All Rights Reserved.
*
* Contributor(s):
* Keith Visco, kvisco@ziplink.net
* -- original author.
*
*/
#include "Expr.h"
/*
* Represents an ordered list of Predicates,
* for use with Step and Filter Expressions
*/
PredicateList::PredicateList()
{
} // PredicateList
/*
* Destructor, will delete all Expressions in the list
*/
PredicateList::~PredicateList()
{
txListIterator iter(&predicates);
while (iter.hasNext()) {
iter.next();
Expr* expr = (Expr*)iter.remove();
delete expr;
}
} // ~PredicateList
/*
* Adds the given Expr to the list
* @param expr the Expr to add to the list
*/
void PredicateList::add(Expr* expr)
{
predicates.add(expr);
} // add
void PredicateList::evaluatePredicates(NodeSet* nodes, ContextState* cs)
{
NS_ASSERTION(nodes, "called evaluatePredicates with NULL NodeSet");
if (!nodes)
return;
cs->getNodeSetStack()->push(nodes);
NodeSet newNodes;
// optimize; set DuplicateChecking to MB_FALSE,
// restore original state later
// we only work with |Node|s already in the NodeSet, so they
// have been checked already, no need to check again in here.
MBool ndsCheckDupl = nodes->getDuplicateChecking();
nodes->setDuplicateChecking(MB_FALSE);
newNodes.setDuplicateChecking(MB_FALSE);
txListIterator iter(&predicates);
while (iter.hasNext()) {
Expr* expr = (Expr*)iter.next();
/*
* add nodes to newNodes that match the expression
* or, if the result is a number, add the node with the right
* position
*/
newNodes.clear();
int nIdx;
for (nIdx = 0; nIdx < nodes->size(); nIdx++) {
Node* node = nodes->get(nIdx);
ExprResult* exprResult = expr->evaluate(node, cs);
if (!exprResult)
break;
switch(exprResult->getResultType()) {
case ExprResult::NUMBER :
// handle default, [position() == numberValue()]
if ((double)(nIdx+1) == exprResult->numberValue())
newNodes.add(node);
break;
default:
if (exprResult->booleanValue())
newNodes.add(node);
break;
}
delete exprResult;
}
// Move new NodeSet to the current one
nodes->clear();
newNodes.copyInto(*nodes);
}
cs->getNodeSetStack()->pop();
// restore DuplicateChecking of NodeSet
nodes->setDuplicateChecking(ndsCheckDupl);
} // evaluatePredicates
/*
* returns true if this predicate list is empty
*/
MBool PredicateList::isEmpty()
{
return (MBool)(predicates.getLength() == 0);
} // isEmpty
void PredicateList::toString(String& dest)
{
txListIterator iter(&predicates);
while (iter.hasNext()) {
Expr* expr = (Expr*) iter.next();
dest.append("[");
expr->toString(dest);
dest.append("]");
}
} // toString