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** This file is part of the QtXmlPatterns module of the Qt Toolkit.
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#include "qbuiltintypes_p.h"
#include "qcommonsequencetypes_p.h"
#include "qgenericsequencetype_p.h"
#include "qnodesort_p.h"
#include "qpatternistlocale_p.h"
#include "qsequencemappingiterator_p.h"
#include "qtypechecker_p.h"
#include "qpath_p.h"
QT_BEGIN_NAMESPACE
using namespace QPatternist;
Path::Path(const Expression::Ptr &operand1,
const Expression::Ptr &operand2,
const Kind kind) : PairContainer(operand1, operand2)
, m_hasCreatedSorter(kind != RegularPath)
, m_isLast(false)
, m_checkXPTY0018(kind == RegularPath)
, m_kind(kind)
{
}
Item::Iterator::Ptr Path::mapToSequence(const Item &item,
const DynamicContext::Ptr &context) const
{
/* item is the focus here. That is in /1, item is . However,
* we don't use it, since the context item is accessed through
* DynamicContext::focusIterator() and friends. */
Q_ASSERT(item);
Q_UNUSED(item); /* Needed when compiling in release mode. */
return m_operand2->evaluateSequence(context);
}
Item::Iterator::Ptr Path::evaluateSequence(const DynamicContext::Ptr &context) const
{
/* Note, we use the old context for m_operand1. */
const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));
const DynamicContext::Ptr focus(context->createFocus());
focus->setFocusIterator(source);
const Item::Iterator::Ptr result(makeSequenceMappingIterator- (ConstPtr(this), source, focus));
if(m_checkXPTY0018)
{
/* This is an expensive code path, but it should happen very rarely. */
enum FoundItem
{
FoundNone,
FoundNode,
FoundAtomicValue
} hasFound = FoundNone;
Item::List whenChecked;
Item next(result->next());
while(next)
{
const FoundItem found = next.isAtomicValue() ? FoundAtomicValue : FoundNode;
if(hasFound != FoundNone && hasFound != found)
{
/* It's an atomic value and we've already found a node. Mixed content. */
context->error(QtXmlPatterns::tr("The last step in a path must contain either nodes "
"or atomic values. It cannot be a mixture between the two."),
ReportContext::XPTY0018, this);
}
else
hasFound = found;
whenChecked.append(next);
next = result->next();
}
return makeListIterator(whenChecked);
}
else
return result;
}
Item Path::evaluateSingleton(const DynamicContext::Ptr &context) const
{
/* This function is called if both operands' cardinality is exactly-one. Therefore
* we manually go forward in the focus by calling next().
*
* We don't check for XPTY0018, only in evaluateSequence(), since if we're guaranteed
* to evaluate to one item, we can only evaluate to one node or one atomic value.
*/
/* Note, we use the old context for m_operand1. */
const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));
const DynamicContext::Ptr focus(context->createFocus());
focus->setFocusIterator(source);
/* This test is needed because if the focus is empty, we don't want to(nor can't) evaluate
* the next step. */
// TODO Why are we at all invoked then?
if(source->next())
return m_operand2->evaluateSingleton(focus);
else
return Item();
}
void Path::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
{
/* Note, we use the old context for m_operand1. */
const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));
const DynamicContext::Ptr focus(context->createFocus());
focus->setFocusIterator(source);
while(source->next())
m_operand2->evaluateToSequenceReceiver(focus);
}
Expression::Ptr Path::compress(const StaticContext::Ptr &context)
{
const Expression::Ptr me(PairContainer::compress(context));
/* "./expr" is by now equal to "expr" since we've done
* focus/type checks, and a node sorter has been inserted. */
if(m_operand1->is(IDContextItem))
return m_operand2;
/* We do this as late as we can, such that we pick up the most recent type
* from the operand. */
if(m_isLast && m_kind != XSLTForEach && m_operand2->staticType()->itemType() == BuiltinTypes::item)
m_checkXPTY0018 = true;
return me;
}
Expression::Ptr Path::typeCheck(const StaticContext::Ptr &context,
const SequenceType::Ptr &reqType)
{
m_operand2->announceFocusType(newFocusType());
/* Here we apply the function conversion first, and with the error code
* that we want -- XPTY0019 instead of XPTY0004. Unfortunately
* PairContainer::typeCheck() will do the type check again, which is
* redundant in the case of when we're not XSLTForEach.
*
* If we're XSLTForEach, it means we're a synthetic "map" expression for
* implementing various XSL-T expressions, and hence don't have the
* constraint of XPTY0019.
*
* It's important that typeCheck() is run for the operands(of course), and the call to
* PairContainer::typeCheck() ensures that below, in the case that we're XSL-T code.
*
* The type we expect, CommonSequenceTypes::ZeroOrMoreNodes() needs to be in sync with
* what we return in expectedOperandTypes(). */
if(m_kind != XSLTForEach)
{
m_operand1 = TypeChecker::applyFunctionConversion(m_operand1,
CommonSequenceTypes::ZeroOrMoreNodes,
context,
m_kind == ForApplyTemplate ? ReportContext::XTTE0520
: ReportContext::XPTY0019);
}
/* If our step ends with atomic values, we cannot sort.
*
* We must smack the NodeSortExpression ontop before calling typeCheck(), since the latter
* may insert an Atomizer, as possibly mandated by reqType. By doing it after, the Atomizer
* will be a parent to NodeSortExpression, as opposed to a child.
*/
if(!m_hasCreatedSorter)
{
m_hasCreatedSorter = true;
return NodeSortExpression::wrapAround(Expression::Ptr(this), context)->typeCheck(context, reqType);
}
else
return PairContainer::typeCheck(context, reqType);
}
SequenceType::List Path::expectedOperandTypes() const
{
SequenceType::List result;
/* This value needs to be in sync with what we pass to
* applyFunctionConversion() in typeCheck() above.
*
* We don't have the XPTY0019 restriction when we're synthetic XSL-T code.
*/
if(m_kind == XSLTForEach)
result.append(CommonSequenceTypes::ZeroOrMoreItems);
else
result.append(CommonSequenceTypes::ZeroOrMoreNodes);
result.append(CommonSequenceTypes::ZeroOrMoreItems);
return result;
}
SequenceType::Ptr Path::staticType() const
{
const SequenceType::Ptr opType(m_operand2->staticType());
/* For each parent step, we evaluate the child step. So multiply the two
* cardinalities. */
return makeGenericSequenceType(opType->itemType(),
m_operand1->staticType()->cardinality() * opType->cardinality());
}
ExpressionVisitorResult::Ptr Path::accept(const ExpressionVisitor::Ptr &visitor) const
{
return visitor->visit(this);
}
Expression::Properties Path::properties() const
{
return CreatesFocusForLast | ((m_operand1->properties() | m_operand2->properties()) & (RequiresCurrentItem | DisableElimination));
}
ItemType::Ptr Path::newFocusType() const
{
return m_operand1->staticType()->itemType();
}
Expression::ID Path::id() const
{
return IDPath;
}
QT_END_NAMESPACE