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// Copyright (C) 2016 The Qt Company Ltd.
// Copyright (C) 2014 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:critical reason:data-parser
#ifndef QSTRINGITERATOR_H
#define QSTRINGITERATOR_H
//
// 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.
//
#include <QtCore/private/qglobal_p.h>
#include <QtCore/qstring.h>
QT_BEGIN_NAMESPACE
class QStringIterator
{
QString::const_iterator i, pos, e;
static_assert((std::is_same<QString::const_iterator, const QChar *>::value));
static bool less(const QChar *lhs, const QChar *rhs) noexcept
{ return std::less{}(lhs, rhs); }
public:
explicit QStringIterator(QStringView string, qsizetype idx = 0)
: i(string.begin()),
pos(i + idx),
e(string.end())
{
}
inline explicit QStringIterator(const QChar *begin, const QChar *end)
: i(begin),
pos(begin),
e(end)
{
}
explicit QStringIterator(const QChar *begin, qsizetype idx, const QChar *end)
: i(begin),
pos(begin + idx),
e(end)
{
}
inline QString::const_iterator position() const
{
return pos;
}
qsizetype index() const
{
return pos - i;
}
inline void setPosition(QString::const_iterator position)
{
Q_ASSERT_X(!less(position, i) && !less(e, position),
Q_FUNC_INFO, "position out of bounds");
pos = position;
}
// forward iteration
inline bool hasNext() const
{
return less(pos, e);
}
inline void advance()
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
if (Q_UNLIKELY((pos++)->isHighSurrogate())) {
if (Q_LIKELY(pos != e && pos->isLowSurrogate()))
++pos;
}
}
inline void advanceUnchecked()
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
if (Q_UNLIKELY((pos++)->isHighSurrogate())) {
Q_ASSERT(hasNext() && pos->isLowSurrogate());
++pos;
}
}
inline char32_t peekNextUnchecked() const
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
if (Q_UNLIKELY(pos->isHighSurrogate())) {
Q_ASSERT(less(pos + 1, e) && pos[1].isLowSurrogate());
return QChar::surrogateToUcs4(pos[0], pos[1]);
}
return pos->unicode();
}
inline char32_t peekNext(char32_t invalidAs = QChar::ReplacementCharacter) const
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
if (Q_UNLIKELY(pos->isSurrogate())) {
if (Q_LIKELY(pos->isHighSurrogate())) {
const QChar *low = pos + 1;
if (Q_LIKELY(low != e && low->isLowSurrogate()))
return QChar::surrogateToUcs4(*pos, *low);
}
return invalidAs;
}
return pos->unicode();
}
inline char32_t nextUnchecked()
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
const QChar cur = *pos++;
if (Q_UNLIKELY(cur.isHighSurrogate())) {
Q_ASSERT(hasNext() && pos->isLowSurrogate());
return QChar::surrogateToUcs4(cur, *pos++);
}
return cur.unicode();
}
inline char32_t next(char32_t invalidAs = QChar::ReplacementCharacter)
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
const QChar uc = *pos++;
if (Q_UNLIKELY(uc.isSurrogate())) {
if (Q_LIKELY(uc.isHighSurrogate() && hasNext() && pos->isLowSurrogate()))
return QChar::surrogateToUcs4(uc, *pos++);
return invalidAs;
}
return uc.unicode();
}
char32_t nextOrRawCodeUnit()
{
Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item");
const QChar uc = *pos++;
if (uc.isHighSurrogate() && hasNext() && pos->isLowSurrogate())
return QChar::surrogateToUcs4(uc, *pos++);
return uc.unicode();
}
// backwards iteration
inline bool hasPrevious() const
{
return less(i, pos);
}
inline void recede()
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
if (Q_UNLIKELY((--pos)->isLowSurrogate())) {
const QChar *high = pos - 1;
if (Q_LIKELY(high != i - 1 && high->isHighSurrogate()))
--pos;
}
}
inline void recedeUnchecked()
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
if (Q_UNLIKELY((--pos)->isLowSurrogate())) {
Q_ASSERT(hasPrevious() && pos[-1].isHighSurrogate());
--pos;
}
}
inline char32_t peekPreviousUnchecked() const
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
if (Q_UNLIKELY(pos[-1].isLowSurrogate())) {
Q_ASSERT(less(i + 1, pos) && pos[-2].isHighSurrogate());
return QChar::surrogateToUcs4(pos[-2], pos[-1]);
}
return pos[-1].unicode();
}
inline char32_t peekPrevious(char32_t invalidAs = QChar::ReplacementCharacter) const
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
if (Q_UNLIKELY(pos[-1].isSurrogate())) {
if (Q_LIKELY(pos[-1].isLowSurrogate())) {
const QChar *high = pos - 2;
if (Q_LIKELY(high != i - 1 && high->isHighSurrogate()))
return QChar::surrogateToUcs4(*high, pos[-1]);
}
return invalidAs;
}
return pos[-1].unicode();
}
inline char32_t previousUnchecked()
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
const QChar cur = *--pos;
if (Q_UNLIKELY(cur.isLowSurrogate())) {
Q_ASSERT(hasPrevious() && pos[-1].isHighSurrogate());
return QChar::surrogateToUcs4(*--pos, cur);
}
return cur.unicode();
}
inline char32_t previous(char32_t invalidAs = QChar::ReplacementCharacter)
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
const QChar uc = *--pos;
if (Q_UNLIKELY(uc.isSurrogate())) {
if (Q_LIKELY(uc.isLowSurrogate() && hasPrevious() && pos[-1].isHighSurrogate()))
return QChar::surrogateToUcs4(*--pos, uc);
return invalidAs;
}
return uc.unicode();
}
char32_t previousOrRawCodeUnit()
{
Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item");
const QChar uc = *--pos;
if (uc.isLowSurrogate() && hasPrevious() && pos[-1].isHighSurrogate())
return QChar::surrogateToUcs4(*--pos, uc);
return uc.unicode();
}
};
QT_END_NAMESPACE
#endif // QSTRINGITERATOR_H