michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:   Implementation of an XPath LocationStep
michael@0: */
michael@0: 
michael@0: #include "txExpr.h"
michael@0: #include "txIXPathContext.h"
michael@0: #include "txNodeSet.h"
michael@0: #include "txXPathTreeWalker.h"
michael@0: 
michael@0:   //-----------------------------/
michael@0:  //- Virtual methods from Expr -/
michael@0: //-----------------------------/
michael@0: 
michael@0: /**
michael@0:  * Evaluates this Expr based on the given context node and processor state
michael@0:  * @param context the context node for evaluation of this Expr
michael@0:  * @param ps the ProcessorState containing the stack information needed
michael@0:  * for evaluation
michael@0:  * @return the result of the evaluation
michael@0:  * @see Expr
michael@0: **/
michael@0: nsresult
michael@0: LocationStep::evaluate(txIEvalContext* aContext, txAExprResult** aResult)
michael@0: {
michael@0:     NS_ASSERTION(aContext, "internal error");
michael@0:     *aResult = nullptr;
michael@0: 
michael@0:     nsRefPtr<txNodeSet> nodes;
michael@0:     nsresult rv = aContext->recycler()->getNodeSet(getter_AddRefs(nodes));
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:     txXPathTreeWalker walker(aContext->getContextNode());
michael@0: 
michael@0:     switch (mAxisIdentifier) {
michael@0:         case ANCESTOR_AXIS:
michael@0:         {
michael@0:             if (!walker.moveToParent()) {
michael@0:                 break;
michael@0:             }
michael@0:             // do not break here
michael@0:         }
michael@0:         case ANCESTOR_OR_SELF_AXIS:
michael@0:         {
michael@0:             nodes->setReverse();
michael@0: 
michael@0:             do {
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0:             } while (walker.moveToParent());
michael@0: 
michael@0:             break;
michael@0:         }
michael@0:         case ATTRIBUTE_AXIS:
michael@0:         {
michael@0:             if (!walker.moveToFirstAttribute()) {
michael@0:                 break;
michael@0:             }
michael@0: 
michael@0:             do {
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0:             } while (walker.moveToNextAttribute());
michael@0:             break;
michael@0:         }
michael@0:         case DESCENDANT_OR_SELF_AXIS:
michael@0:         {
michael@0:             if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                 nodes->append(walker.getCurrentPosition());
michael@0:             }
michael@0:             // do not break here
michael@0:         }
michael@0:         case DESCENDANT_AXIS:
michael@0:         {
michael@0:             fromDescendants(walker.getCurrentPosition(), aContext, nodes);
michael@0:             break;
michael@0:         }
michael@0:         case FOLLOWING_AXIS:
michael@0:         {
michael@0:             if (txXPathNodeUtils::isAttribute(walker.getCurrentPosition())) {
michael@0:                 walker.moveToParent();
michael@0:                 fromDescendants(walker.getCurrentPosition(), aContext, nodes);
michael@0:             }
michael@0:             bool cont = true;
michael@0:             while (!walker.moveToNextSibling()) {
michael@0:                 if (!walker.moveToParent()) {
michael@0:                     cont = false;
michael@0:                     break;
michael@0:                 }
michael@0:             }
michael@0:             while (cont) {
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0: 
michael@0:                 fromDescendants(walker.getCurrentPosition(), aContext, nodes);
michael@0: 
michael@0:                 while (!walker.moveToNextSibling()) {
michael@0:                     if (!walker.moveToParent()) {
michael@0:                         cont = false;
michael@0:                         break;
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0:         case FOLLOWING_SIBLING_AXIS:
michael@0:         {
michael@0:             while (walker.moveToNextSibling()) {
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0:         case NAMESPACE_AXIS: //-- not yet implemented
michael@0: #if 0
michael@0:             // XXX DEBUG OUTPUT
michael@0:             cout << "namespace axis not yet implemented"<<endl;
michael@0: #endif
michael@0:             break;
michael@0:         case PARENT_AXIS :
michael@0:         {
michael@0:             if (walker.moveToParent() &&
michael@0:                 mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                 nodes->append(walker.getCurrentPosition());
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0:         case PRECEDING_AXIS:
michael@0:         {
michael@0:             nodes->setReverse();
michael@0: 
michael@0:             bool cont = true;
michael@0:             while (!walker.moveToPreviousSibling()) {
michael@0:                 if (!walker.moveToParent()) {
michael@0:                     cont = false;
michael@0:                     break;
michael@0:                 }
michael@0:             }
michael@0:             while (cont) {
michael@0:                 fromDescendantsRev(walker.getCurrentPosition(), aContext, nodes);
michael@0: 
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0: 
michael@0:                 while (!walker.moveToPreviousSibling()) {
michael@0:                     if (!walker.moveToParent()) {
michael@0:                         cont = false;
michael@0:                         break;
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0:         case PRECEDING_SIBLING_AXIS:
michael@0:         {
michael@0:             nodes->setReverse();
michael@0: 
michael@0:             while (walker.moveToPreviousSibling()) {
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0:         case SELF_AXIS:
michael@0:         {
michael@0:             if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                 nodes->append(walker.getCurrentPosition());
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0:         default: // Children Axis
michael@0:         {
michael@0:             if (!walker.moveToFirstChild()) {
michael@0:                 break;
michael@0:             }
michael@0: 
michael@0:             do {
michael@0:                 if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) {
michael@0:                     nodes->append(walker.getCurrentPosition());
michael@0:                 }
michael@0:             } while (walker.moveToNextSibling());
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     // Apply predicates
michael@0:     if (!isEmpty()) {
michael@0:         rv = evaluatePredicates(nodes, aContext);
michael@0:         NS_ENSURE_SUCCESS(rv, rv);
michael@0:     }
michael@0: 
michael@0:     nodes->unsetReverse();
michael@0: 
michael@0:     NS_ADDREF(*aResult = nodes);
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: void LocationStep::fromDescendants(const txXPathNode& aNode,
michael@0:                                    txIMatchContext* aCs,
michael@0:                                    txNodeSet* aNodes)
michael@0: {
michael@0:     txXPathTreeWalker walker(aNode);
michael@0:     if (!walker.moveToFirstChild()) {
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     do {
michael@0:         const txXPathNode& child = walker.getCurrentPosition();
michael@0:         if (mNodeTest->matches(child, aCs)) {
michael@0:             aNodes->append(child);
michael@0:         }
michael@0:         fromDescendants(child, aCs, aNodes);
michael@0:     } while (walker.moveToNextSibling());
michael@0: }
michael@0: 
michael@0: void LocationStep::fromDescendantsRev(const txXPathNode& aNode,
michael@0:                                       txIMatchContext* aCs,
michael@0:                                       txNodeSet* aNodes)
michael@0: {
michael@0:     txXPathTreeWalker walker(aNode);
michael@0:     if (!walker.moveToLastChild()) {
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     do {
michael@0:         const txXPathNode& child = walker.getCurrentPosition();
michael@0:         fromDescendantsRev(child, aCs, aNodes);
michael@0: 
michael@0:         if (mNodeTest->matches(child, aCs)) {
michael@0:             aNodes->append(child);
michael@0:         }
michael@0: 
michael@0:     } while (walker.moveToPreviousSibling());
michael@0: }
michael@0: 
michael@0: Expr::ExprType
michael@0: LocationStep::getType()
michael@0: {
michael@0:   return LOCATIONSTEP_EXPR;
michael@0: }
michael@0: 
michael@0: 
michael@0: TX_IMPL_EXPR_STUBS_BASE(LocationStep, NODESET_RESULT)
michael@0: 
michael@0: Expr*
michael@0: LocationStep::getSubExprAt(uint32_t aPos)
michael@0: {
michael@0:     return PredicateList::getSubExprAt(aPos);
michael@0: }
michael@0: 
michael@0: void
michael@0: LocationStep::setSubExprAt(uint32_t aPos, Expr* aExpr)
michael@0: {
michael@0:     PredicateList::setSubExprAt(aPos, aExpr);
michael@0: }
michael@0: 
michael@0: bool
michael@0: LocationStep::isSensitiveTo(ContextSensitivity aContext)
michael@0: {
michael@0:     return (aContext & NODE_CONTEXT) ||
michael@0:            mNodeTest->isSensitiveTo(aContext) ||
michael@0:            PredicateList::isSensitiveTo(aContext);
michael@0: }
michael@0: 
michael@0: #ifdef TX_TO_STRING
michael@0: void
michael@0: LocationStep::toString(nsAString& str)
michael@0: {
michael@0:     switch (mAxisIdentifier) {
michael@0:         case ANCESTOR_AXIS :
michael@0:             str.AppendLiteral("ancestor::");
michael@0:             break;
michael@0:         case ANCESTOR_OR_SELF_AXIS :
michael@0:             str.AppendLiteral("ancestor-or-self::");
michael@0:             break;
michael@0:         case ATTRIBUTE_AXIS:
michael@0:             str.Append(char16_t('@'));
michael@0:             break;
michael@0:         case DESCENDANT_AXIS:
michael@0:             str.AppendLiteral("descendant::");
michael@0:             break;
michael@0:         case DESCENDANT_OR_SELF_AXIS:
michael@0:             str.AppendLiteral("descendant-or-self::");
michael@0:             break;
michael@0:         case FOLLOWING_AXIS :
michael@0:             str.AppendLiteral("following::");
michael@0:             break;
michael@0:         case FOLLOWING_SIBLING_AXIS:
michael@0:             str.AppendLiteral("following-sibling::");
michael@0:             break;
michael@0:         case NAMESPACE_AXIS:
michael@0:             str.AppendLiteral("namespace::");
michael@0:             break;
michael@0:         case PARENT_AXIS :
michael@0:             str.AppendLiteral("parent::");
michael@0:             break;
michael@0:         case PRECEDING_AXIS :
michael@0:             str.AppendLiteral("preceding::");
michael@0:             break;
michael@0:         case PRECEDING_SIBLING_AXIS :
michael@0:             str.AppendLiteral("preceding-sibling::");
michael@0:             break;
michael@0:         case SELF_AXIS :
michael@0:             str.AppendLiteral("self::");
michael@0:             break;
michael@0:         default:
michael@0:             break;
michael@0:     }
michael@0:     NS_ASSERTION(mNodeTest, "mNodeTest is null, that's verboten");
michael@0:     mNodeTest->toString(str);
michael@0: 
michael@0:     PredicateList::toString(str);
michael@0: }
michael@0: #endif