Expression::List TripleContainer::operands() const
{
Expression::List result;
result.append(m_operand1);
result.append(m_operand2);
result.append(m_operand3);
return result;
}
Expression::Ptr ExpressionSequence::compress(const StaticContext::Ptr &context)
{
const Expression::Ptr me(UnlimitedContainer::compress(context));
if(me != this)
return me;
Expression::List::const_iterator it(m_operands.constBegin());
const Expression::List::const_iterator end(m_operands.constEnd());
Expression::List result;
for(; it != end; ++it)
{
const ID Id = (*it)->id();
/* Remove empty sequences. This is rather important because we have some steps in the parser that
* intentionally, unconditionally and for temporary reasons create expressions like (expr, ()). Of course,
* empty sequences also occur as part of optimizations.
*
* User function call sites that are of type empty-sequence() must be avoided since
* they may contain calls to fn:error(), which we would rewrite away otherwise. */
if(Id != IDUserFunctionCallsite && (*it)->staticType()->cardinality().isEmpty())
{
/* Rewrite "(1, (), 2)" into "(1, 2)" by not
* adding (*it) to result. */
continue;
}
else if(Id == IDExpressionSequence)
{
/* Rewrite "(1, (2, 3), 4)" into "(1, 2, 3, 4)" */
Expression::List::const_iterator seqIt((*it)->operands().constBegin());
const Expression::List::const_iterator seqEnd((*it)->operands().constEnd());
for(; seqIt != seqEnd; ++seqIt)
result.append(*seqIt);
}
else
result.append(*it);
}
if(result.isEmpty())
return EmptySequence::create(this, context);
else if(result.count() == 1)
return result.first();
else
{
m_operands = result;
return me;
}
}
Expression::List PairContainer::operands() const
{
Expression::List list;
list.append(m_operand1);
list.append(m_operand2);
return list;
}
void Expression::typeCheckOperands(const StaticContext::Ptr &context)
{
const Expression::List ops(operands());
/* Check if this expression has any operands at all. */
if(ops.isEmpty())
return; /* We're done, early exit. */
const SequenceType::List opTypes(expectedOperandTypes());
Expression::List result;
/* If we create a focus, we handle the last one specially, so avoid it in the loop. */
const bool createsFocus = has(CreatesFocusForLast);
const SequenceType::List::const_iterator typeEnd(createsFocus ? --opTypes.constEnd()
: opTypes.constEnd());
const Expression::List::const_iterator end(createsFocus ? --ops.constEnd()
: ops.constEnd());
SequenceType::List::const_iterator reqType(opTypes.constBegin());
SequenceType::Ptr t(*reqType);
// TODO we assign twice to t here(also below in loop) when ops.size() > 1
Expression::List::const_iterator it(ops.constBegin());
for(; it != end; ++it)
{
/* This ensures that the last expectedOperandType stays, and is
* used for all other operands. This is used for expressions that
* have an infinite amount of operands, such as the concat() function. */
if(reqType != typeEnd)
{
t = *reqType;
++reqType;
}
/* Let the child & its children typecheck. */
result.append((*it)->typeCheck(context, t));
}
if(createsFocus)
{
const StaticContext::Ptr newContext(finalizeStaticContext(context));
result.append(ops.last()->typeCheck(newContext, opTypes.last()));
}
setOperands(result);
}
Expression::Ptr DocumentFN::typeCheck(const StaticContext::Ptr &context,
const SequenceType::Ptr &reqType)
{
/* See the class documentation for the rewrite that we're doing here. */
/* Generate type checking code for our operands such that they match. */
typeCheckOperands(context);
const QSourceLocation myLocation(context->locationFor(this));
const FunctionFactory::Ptr functions(context->functionSignatures());
Expression::Ptr uriSource;
{
Expression::List distinctValuesArgs;
distinctValuesArgs.append(m_operands.first());
uriSource = functions->createFunctionCall(QXmlName(StandardNamespaces::fn, StandardLocalNames::distinct_values),
distinctValuesArgs,
context,
this);
context->addLocation(uriSource.data(), myLocation);
}
const VariableSlotID rangeSlot = context->allocateRangeSlot();
const Expression::Ptr uriReference(new RangeVariableReference(uriSource, rangeSlot));
context->addLocation(uriReference.data(), myLocation);
Expression::List docArgs;
if(m_operands.count() == 2)
{
Expression::List baseUriArgs;
baseUriArgs.append(uriReference);
baseUriArgs.append(m_operands.at(1));
const Expression::Ptr fnBaseUri(functions->createFunctionCall(QXmlName(StandardNamespaces::fn, StandardLocalNames::resolve_uri),
baseUriArgs,
context,
this));
context->addLocation(fnBaseUri.data(), myLocation);
docArgs.append(fnBaseUri);
}
else
docArgs.append(uriReference);
const Expression::Ptr fnDoc(functions->createFunctionCall(QXmlName(StandardNamespaces::fn, StandardLocalNames::doc),
docArgs,
context,
this));
context->addLocation(fnDoc.data(), myLocation);
Expression::Ptr newMe(new ForClause(rangeSlot,
uriSource,
fnDoc,
-1 /* We have no position variable. */));
Expression::Ptr oldMe(this);
rewrite(oldMe, newMe, context);
return newMe->typeCheck(context, reqType);
}
Expression::List SingleContainer::operands() const
{
Expression::List list;
list.append(m_operand);
return list;
}
Expression::Ptr TypeChecker::verifyType(const Expression::Ptr &operand,
const SequenceType::Ptr &reqSeqType,
const StaticContext::Ptr &context,
const ReportContext::ErrorCode code,
const Options options)
{
const ItemType::Ptr reqType(reqSeqType->itemType());
const Expression::Properties props(operand->properties());
/* If operand requires a focus, do the necessary type checking for that. */
if(props.testFlag(Expression::RequiresFocus) && options.testFlag(CheckFocus))
{
const ItemType::Ptr contextType(context->contextItemType());
if(contextType)
{
if(props.testFlag(Expression::RequiresContextItem))
{
Q_ASSERT_X(operand->expectedContextItemType(), Q_FUNC_INFO,
"When the Expression sets the RequiresContextItem property, it must "
"return a type in expectedContextItemType()");
const ItemType::Ptr expectedContextType(operand->expectedContextItemType());
/* Allow the empty sequence. We don't want to trigger XPTY0020 on ()/... . */
if(!expectedContextType->xdtTypeMatches(contextType) && contextType != CommonSequenceTypes::Empty)
{
context->error(wrongType(context->namePool(), operand->expectedContextItemType(), contextType),
ReportContext::XPTY0020, operand.data());
return operand;
}
}
}
else
{
context->error(QtXmlPatterns::tr("The focus is undefined."), ReportContext::XPDY0002, operand.data());
return operand;
}
}
SequenceType::Ptr operandSeqType(operand->staticType());
ItemType::Ptr operandType(operandSeqType->itemType());
/* This returns the operand if the types are identical or if operandType
* is a subtype of reqType. */
if(reqType->xdtTypeMatches(operandType) || *operandType == *CommonSequenceTypes::Empty)
return operand;
/* Since we haven't exited yet, it means that the operandType is a super type
* of reqType, and that there hence is a path down to it through the
* type hierachy -- but that doesn't necessarily mean that a up-cast(down the
* hierarchy) would succeed. */
Expression::Ptr result(operand);
if(reqType->isAtomicType())
{
const Expression::ID opID = operand->id();
if((opID == Expression::IDArgumentReference ||
(opID == Expression::IDCardinalityVerifier && operand->operands().first()->is(Expression::IDArgumentReference)))
&& *BuiltinTypes::item == *operandType)
return Expression::Ptr(new ArgumentConverter(result, reqType));
if(!operandType->isAtomicType())
{
result = Expression::Ptr(new Atomizer(result));
/* The atomizer might know more about the type. */
operandType = result->staticType()->itemType();
}
if(reqType->xdtTypeMatches(operandType))
{
/* Atomization was sufficient. Either the expected type is xs:anyAtomicType
* or the type the Atomizer knows it returns, matches the required type. */
return result;
}
const bool compatModeEnabled = context->compatModeEnabled();
if((options.testFlag(AutomaticallyConvert) && BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(operandType)) ||
(compatModeEnabled && BuiltinTypes::xsString->xdtTypeMatches(reqType)))
{
if(*reqType == *BuiltinTypes::numeric)
{
result = typeCheck(new UntypedAtomicConverter(result, BuiltinTypes::xsDouble, code),
context, reqSeqType);
}
else
result = typeCheck(new UntypedAtomicConverter(result, reqType, code), context, reqSeqType);
/* The UntypedAtomicConverter might know more about the type, so reload. */
operandType = result->staticType()->itemType();
}
else if(compatModeEnabled && *reqType == *BuiltinTypes::xsDouble)
{
const FunctionFactory::Ptr functions(context->functionSignatures());
Expression::List numberArgs;
numberArgs.append(operand);
result = functions->createFunctionCall(QXmlName(StandardNamespaces::fn, StandardLocalNames::number),
numberArgs,
context,
operand.data())->typeCheck(context, reqSeqType);
operandType = result->staticType()->itemType();
context->wrapExpressionWith(operand.data(), result);
}
if(reqType->xdtTypeMatches(operandType))
return result;
/* Test if promotion will solve it; the xdtTypeMatches didn't
* do that. */
if(options.testFlag(AutomaticallyConvert) && promotionPossible(operandType, reqType, context))
{
if(options.testFlag(GeneratePromotion))
return Expression::Ptr(new UntypedAtomicConverter(result, reqType));
else
return result;
}
if(operandType->xdtTypeMatches(reqType))
{
/* For example, operandType is numeric, and reqType is xs:integer. */
return Expression::Ptr(new ItemVerifier(result, reqType, code));
}
else
{
context->error(wrongType(context->namePool(), reqType, operandType), code, operand.data());
return result;
}
}
else if(reqType->isNodeType())
{
ReportContext::ErrorCode myCode;
if(*reqType == *CommonSequenceTypes::EBV->itemType())
myCode = ReportContext::FORG0006;
else
myCode = code;
/* empty-sequence() is considered valid because it's ok to do
* for example nilled( () ). That is, to pass an empty sequence to a
* function requiring for example node()?. */
if(*operandType == *CommonSequenceTypes::Empty)
return result;
else if(!operandType->xdtTypeMatches(reqType))
{
context->error(wrongType(context->namePool(), reqType, operandType), myCode, operand.data());
return result;
}
/* Operand must be an item. Thus, the sequence can contain both
* nodes and atomic values: we have to verify. */
return Expression::Ptr(new ItemVerifier(result, reqType, myCode));
}
else
{
Q_ASSERT(*reqType == *CommonSequenceTypes::Empty);
/* element() doesn't match empty-sequence(), but element()* does. */
if(!reqType->xdtTypeMatches(operandType) &&
!operandSeqType->cardinality().allowsEmpty())
{
context->error(wrongType(context->namePool(), reqType, operandType),
code, operand.data());
return result;
}
}
/* This line should be reached if required type is
* EBVType, and the operand is compatible. */
return result;
}
Expression::Ptr Expression::invokeOptimizers(const Expression::Ptr &expr,
const StaticContext::Ptr &context)
{
Q_ASSERT(expr);
const OptimizationPass::List opts(expr->optimizationPasses());
if(opts.isEmpty()) /* Early exit. */
{
return expr;
}
const OptimizationPass::List::const_iterator passEnd(opts.constEnd());
const OptimizationPass::List::const_iterator end(opts.constEnd());
OptimizationPass::List::const_iterator passIt(opts.constBegin());
for(; passIt != passEnd; ++passIt) /* Invoke each optimization pass. */
{
const OptimizationPass::Ptr pass(*passIt); /* Alias, for readability. */
OptimizationPass::ExpressionMarker sourceMarker(pass->sourceExpression);
if(pass->startIdentifier && !pass->startIdentifier->matches(expr))
{
/* This pass specified a start identifier and it did
* not match -- let's try the next OptimizationPass. */
continue;
}
const ExpressionIdentifier::List::const_iterator idEnd(pass->operandIdentifiers.constEnd());
ExpressionIdentifier::List::const_iterator idIt(pass->operandIdentifiers.constBegin());
const Expression::List ops(expr->operands());
const Expression::List::const_iterator opEnd(ops.constEnd());
Expression::List::const_iterator opIt(ops.constBegin());
switch(pass->operandsMatchMethod)
{
case OptimizationPass::Sequential:
{
for(; opIt != opEnd; ++opIt)
{
const Expression::Ptr operand(*opIt); /* Alias, for readability. */
const ExpressionIdentifier::Ptr opIdentifier(*idIt); /* Alias, for readability. */
if(opIdentifier && !opIdentifier->matches(operand))
{
break;
}
++idIt;
}
if(opIt == opEnd)
break; /* All operands matched, so this pass matched. */
else
{
/* The loop above did not finish which means all operands did not match.
Therefore, this OptimizationPass did not match -- let's try the next one. */
continue;
}
}
case OptimizationPass::AnyOrder:
{
Q_ASSERT_X(ops.count() == 2, Q_FUNC_INFO,
"AnyOrder is currently only supported for Expressions with two operands.");
if(pass->operandIdentifiers.first()->matches(ops.first()) &&
pass->operandIdentifiers.last()->matches(ops.last()))
{
break;
}
else if(pass->operandIdentifiers.first()->matches(ops.last()) &&
pass->operandIdentifiers.last()->matches(ops.first()))
{
sourceMarker.first() = 1;
sourceMarker[1] = 0;
break; /* This pass matched. */
}
else
continue; /* This pass didn't match, let's loop through the next pass. */
}
}
/* Figure out the source Expression, if any. */
Expression::List operands;
Expression::Ptr sourceExpr;
if(!sourceMarker.isEmpty())
{
const OptimizationPass::ExpressionMarker::const_iterator mEnd(sourceMarker.constEnd());
OptimizationPass::ExpressionMarker::const_iterator mIt(sourceMarker.constBegin());
sourceExpr = expr;
for(; mIt != mEnd; ++mIt)
{
Q_ASSERT(*mIt >= 0);
sourceExpr = sourceExpr->operands().at(*mIt);
}
operands.append(sourceExpr);
}
if(operands.isEmpty())
{
Q_ASSERT(pass->resultCreator);
return pass->resultCreator->create(Expression::List(), context, expr.data())->compress(context);
}
else if(pass->resultCreator)
return pass->resultCreator->create(operands, context, expr.data())->compress(context);
else
{
return sourceExpr;
}
}
return expr;
}