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#include "qcommonsequencetypes_p.h"

#include "qoptimizerblocks_p.h"

#include "qoptimizationpasses_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

OptimizationPass::List OptimizationPasses::comparisonPasses;

OptimizationPass::List OptimizationPasses::forPasses;

OptimizationPass::List OptimizationPasses::ifThenPasses;

OptimizationPass::List OptimizationPasses::notFN;

void OptimizationPasses::Coordinator::init()

{

    static bool isInitialized = false; // STATIC DATA

    if(isInitialized)

        return;

    isInitialized = true;

    /* Note, below is many of the building blocks re-used in several passes

     * in order to reduce memory use. Thus, when changing one building block

     * it potentially affects many passes. */

    /* ****************************************************** */

    /* Rewrite "count(<expr>) ge 1" into "exists(<expr>)" */

    OptimizationPass::ExpressionMarker firstFirstChild;

    firstFirstChild.append(0);

    firstFirstChild.append(0);

    ExpressionIdentifier::List geOpIDs;

    const ExpressionIdentifier::Ptr countFN(new ByIDIdentifier(Expression::IDCountFN));

    geOpIDs.append(countFN);

    geOpIDs.append(ExpressionIdentifier::Ptr(new IntegerIdentifier(1)));

    QVector<Expression::ID> geMatcher;

    geMatcher.append(Expression::IDValueComparison);

    geMatcher.append(Expression::IDGeneralComparison);

    const ExpressionIdentifier::Ptr ge(new ComparisonIdentifier(geMatcher,

                                                                AtomicComparator::OperatorGreaterOrEqual));

    const ExpressionCreator::Ptr existsFN(new ByIDCreator(Expression::IDExistsFN));

    const OptimizationPass::Ptr geToExists(new OptimizationPass(ge, geOpIDs, firstFirstChild, existsFN));

    comparisonPasses.append(geToExists);

    /* ****************************************************** */

    /* ****************************************************** */

    /* Rewrite "count(<expr>) gt 0" into "exists(<expr>)" */

    ExpressionIdentifier::List countAndIntZero;

    countAndIntZero.append(countFN);

    const ExpressionIdentifier::Ptr zeroInteger(new IntegerIdentifier(0));

    countAndIntZero.append(zeroInteger);

    const ExpressionIdentifier::Ptr gt(new ComparisonIdentifier(geMatcher,

                                                                AtomicComparator::OperatorGreaterThan));

    const OptimizationPass::Ptr gtToExists(new OptimizationPass(gt, countAndIntZero,

                                                                firstFirstChild, existsFN));

    comparisonPasses.append(gtToExists);

    /* ****************************************************** */

    /* ****************************************************** */

    /* Rewrite "count(<expr>) ne 0" into "exists(<expr>)" */

    const ExpressionIdentifier::Ptr ne(new ComparisonIdentifier(geMatcher,

                                                                AtomicComparator::OperatorNotEqual));

    const OptimizationPass::Ptr neToExists(new OptimizationPass(ne, countAndIntZero, firstFirstChild,

                                                                existsFN,

                                                                OptimizationPass::AnyOrder));

    comparisonPasses.append(neToExists);

    /* ****************************************************** */

    /* ****************************************************** */

    /* Rewrite "count(<expr>) eq 0" into "empty(<expr>)" */

    ExpressionIdentifier::List eqOpIDs;

    eqOpIDs.append(countFN);

    eqOpIDs.append(zeroInteger);

    const ExpressionCreator::Ptr emptyFN(new ByIDCreator(Expression::IDEmptyFN));

    const ExpressionIdentifier::Ptr eq(new ComparisonIdentifier(geMatcher,

                                                                AtomicComparator::OperatorEqual));

    const OptimizationPass::Ptr eqToEmpty(new OptimizationPass(eq, eqOpIDs, firstFirstChild,

                                                               emptyFN,

                                                               OptimizationPass::AnyOrder));

    comparisonPasses.append(eqToEmpty);

    /* ****************************************************** */

    /* ****************************************************** */

    /* Rewrite "for $var in <expr> return $var" into "<expr>" */

    ExpressionIdentifier::List forOps;

    OptimizationPass::ExpressionMarker firstChild;

    firstChild.append(0);

    forOps.append(ExpressionIdentifier::Ptr());

    forOps.append(ExpressionIdentifier::Ptr(new ByIDIdentifier(Expression::IDRangeVariableReference)));

    const OptimizationPass::Ptr simplifyFor(new OptimizationPass(ExpressionIdentifier::Ptr(), forOps,

                                                                 firstChild, ExpressionCreator::Ptr()));

    forPasses.append(simplifyFor);

    /* ****************************************************** */

    /* ****************************************************** */

    /* Rewrite "if(<expr>) then true() else false()" to "<expr>" */

    OptimizationPass::ExpressionMarker marker;

    marker.append(0);

    ExpressionIdentifier::List opIDs;

    opIDs.append(ExpressionIdentifier::Ptr(new BySequenceTypeIdentifier(

                        CommonSequenceTypes::ExactlyOneBoolean)));

    opIDs.append(ExpressionIdentifier::Ptr(new BooleanIdentifier(true)));

    opIDs.append(ExpressionIdentifier::Ptr(new BooleanIdentifier(false)));

    const OptimizationPass::Ptr pass(new OptimizationPass(ExpressionIdentifier::Ptr(), opIDs, marker));

    ifThenPasses.append(pass);

    /* ****************************************************** */

    /* ****************************************************** */

    /* Rewrite "not(exists(X))" into "empty(X)" */

    ExpressionIdentifier::List idExistsFN;

    idExistsFN.append(ExpressionIdentifier::Ptr(new ByIDIdentifier(Expression::IDExistsFN)));

    notFN.append(OptimizationPass::Ptr(new OptimizationPass(ExpressionIdentifier::Ptr(),

                                                            idExistsFN,

                                                            firstFirstChild,

                                                            emptyFN)));

    /* Rewrite "not(empty(X))" into "exists(X)" */

    ExpressionIdentifier::List idEmptyFN;

    idEmptyFN.append(ExpressionIdentifier::Ptr(new ByIDIdentifier(Expression::IDEmptyFN)));

    notFN.append(OptimizationPass::Ptr(new OptimizationPass(ExpressionIdentifier::Ptr(),

                                                            idEmptyFN,

                                                            firstFirstChild,

                                                            existsFN)));

    /* ****************************************************** */

}

QT_END_NAMESPACE