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#include "qforclause_p.h"
#include "qfunctionfactory_p.h"
#include "qrangevariablereference_p.h"

#include "qdocumentfn_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

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);
}

QT_END_NAMESPACE