qcardinality_p.h

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//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.

#ifndef Patternist_Cardinality_H
#define Patternist_Cardinality_H

#include <QtCore/QtGlobal>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

class QString;

namespace QPatternist
{
    class Cardinality
    {
    public:
        typedef qint32 Count;

        enum CustomizeDisplayName
        {
            IncludeExplanation  = 1,

            ExcludeExplanation
        };

        inline Cardinality(const Cardinality &other) : m_min(other.m_min),
                                                       m_max(other.m_max)
        {
        }

        inline Cardinality() : m_min(-1), m_max(0)
        {
        }

        static inline Cardinality empty()
        {
            return Cardinality(0, 0);
        }

        static inline Cardinality exactlyOne()
        {
            return Cardinality(1, 1);
        }

        static inline Cardinality zeroOrOne()
        {
            return Cardinality(0, 1);
        }

        static inline Cardinality zeroOrMore()
        {
            return Cardinality(0, -1);
        }

        static inline Cardinality oneOrMore()
        {
            return Cardinality(1, -1);
        }

        static inline Cardinality twoOrMore()
        {
            return Cardinality(2, -1);
        }

        static inline Cardinality fromCount(const Count count)
        {
            Q_ASSERT_X(count > -1, Q_FUNC_INFO,
                       "A count smaller than 0 makes no sense.");
            return Cardinality(count, count);
        }

        static inline Cardinality fromRange(const Count minimum, const Count maximum)
        {
            Q_ASSERT_X(minimum > -1, Q_FUNC_INFO,
                       "minimum should never be less than 0.");
            Q_ASSERT_X(minimum <= maximum || maximum == -1, Q_FUNC_INFO,
                       "minimum cannot be larger than maximum.");

            return Cardinality(minimum, maximum);
        }

        static inline Cardinality fromExact(const Count count)
        {
            Q_ASSERT(count >= 0);
            return Cardinality(count, count);
        }

        inline Count minimum() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality are invalid.");
            return m_min;
        }

        inline Count maximum() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality are invalid.");
            return m_max;
        }

        inline bool allowsMany() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality are invalid.");
            return m_max == -1 || m_max > 1;
        }

        inline bool allowsEmpty() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality are invalid.");
            return m_min == 0;
        }

        inline Cardinality toWithoutMany() const
        {
            return m_min == 0 ? Cardinality(0, 1)
                              : Cardinality(1, 1);
        }

        inline bool isMatch(const Cardinality &other) const
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO, "One of the cardinalities are invalid.");
            if(other.m_min < m_min)
                return false;
            else
            { /* Ok, we now know the minimum will always be ok. */
                if(m_max == -1)
                    return true; /* We allow infinite, so anything can match. */
                else if(other.m_max == -1)
                    return false; /* other allows infinity, while we don't. */
                else
                   return m_max >= other.m_max;
            }
        }

        inline bool canMatch(const Cardinality &other) const
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO, "One of the cardinalities are invalid.");
            if(m_max == -1)
                return m_min <= other.m_min || other.m_max >= m_min || other.m_max == -1;
            else
            {
                if(m_max == other.m_min)
                    return true;
                else if(m_max > other.m_min)
                    return other.m_max >= m_min || other.m_max == -1;
                else /* m_max < other.m_min */
                    return false;
            }
        }

        inline bool isEmpty() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality is invalid.");
            return m_min == 0 && m_max == 0;
        }

        inline bool isZeroOrOne() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality is invalid.");
            return m_min == 0 && m_max == 1;
        }

        inline bool isExactlyOne() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality is invalid.");
            return m_min == 1 && m_max == 1;
        }

        inline bool isOneOrMore() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality is invalid.");
            return m_min > 0 && (m_max == -1 || m_max >= 1);
        }

        inline bool isExact() const
        {
            Q_ASSERT_X(m_min != -1, Q_FUNC_INFO, "The cardinality is invalid.");
            return m_min == m_max;
        }

        QString displayName(const CustomizeDisplayName explanation) const;

        inline Cardinality operator|(const Cardinality &other) const
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO, "One of the cardinalities are invalid.");
            if(m_max == -1 || other.m_max == -1)
                return Cardinality(qMin(m_min, other.m_min), -1);
            else
                return Cardinality(qMin(m_min, other.m_min), qMax(m_max, other.m_max));
        }

        inline Cardinality &operator|=(const Cardinality &other)
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO, "One of the cardinalities are invalid.");
            m_min = qMin(m_min, other.m_min);

            if(m_max == -1)
                return *this;
            else if(other.m_max == -1)
                m_max = -1;
            else
                m_max = qMax(m_max, other.m_max);

            return *this;
        }

        inline Cardinality operator&(const Cardinality &other) const
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO, "One of the cardinalities are invalid.");

            if(m_max < other.m_min) /* No intersection. */
                return empty();

            const Count min = qMax(m_min, other.m_min);

            if(m_max == -1)
                return Cardinality(min, other.m_max);
            else if(other.m_max == -1)
                return Cardinality(min, m_max);
            else
                return Cardinality(min, qMin(m_max, other.m_max));
        }

        inline Cardinality operator+(const Cardinality &other) const
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO, "One of the cardinalities are invalid.");
            if(m_max == -1 || other.m_max == -1)
                return Cardinality(m_min + other.m_min, -1);
            else
                return Cardinality(m_min + other.m_min, m_max + other.m_max);
        }

        inline Cardinality &operator+=(const Cardinality &other)
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO,
                       "One of the cardinalities are invalid.");
            m_min += other.m_min;

            if(m_max == -1)
                return *this;
            if(other.m_max == -1)
                m_max = -1;
            else
                m_max += other.m_max;

            return *this;
        }

        inline Cardinality operator*(const Cardinality &other) const
        {
            Q_ASSERT_X(m_min != -1 && other.m_min != -1, Q_FUNC_INFO,
                       "One of the cardinalities are invalid.");
            if(m_max == -1 || other.m_max == -1)
                return Cardinality(m_min * other.m_min, -1);
            else
                return Cardinality(m_min * other.m_min, m_max * other.m_max);
        }

        inline Cardinality &operator=(const Cardinality &other)
        {
            Q_ASSERT_X(this != &other, Q_FUNC_INFO, "Assigning to oneself makes no sense.");
            m_min = other.m_min;
            m_max = other.m_max;
            return *this;
        }

        inline bool operator==(const Cardinality &other) const
        {
            return m_min == other.m_min &&
                   m_max == other.m_max;
        }

        inline bool operator!=(const Cardinality &other) const
        {
            return m_min != other.m_min ||
                   m_max != other.m_max;
        }

    private:
        inline Cardinality(const Count min, const Count max) : m_min(min),
                                                               m_max(max)
        {
        }

        Count m_min;
        Count m_max;
    };
}

Q_DECLARE_TYPEINFO(QPatternist::Cardinality, Q_MOVABLE_TYPE);

QT_END_NAMESPACE

QT_END_HEADER

#endif