From 8cbe52d5811a985e610aa76c3a17a75cd785fb19 Mon Sep 17 00:00:00 2001 From: Giuseppe D'Angelo Date: Thu, 23 Jun 2011 15:26:08 +0200 Subject: Long live QStringIterator! UCS-4 iterator over a QString. Kept private for now so we can still work on the API. Done-with: Thiago Change-Id: I377f8bb1921e591ee3292c08c3e097fb6bc7f0c4 Reviewed-by: Thiago Macieira --- src/corelib/tools/qstringiterator_p.h | 233 ++++++++++++++++++++++++++++++++++ 1 file changed, 233 insertions(+) create mode 100644 src/corelib/tools/qstringiterator_p.h (limited to 'src/corelib/tools/qstringiterator_p.h') diff --git a/src/corelib/tools/qstringiterator_p.h b/src/corelib/tools/qstringiterator_p.h new file mode 100644 index 0000000000..c3986f0477 --- /dev/null +++ b/src/corelib/tools/qstringiterator_p.h @@ -0,0 +1,233 @@ +/**************************************************************************** +** +** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies). +** Copyright (C) 2014 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo +** Contact: http://www.qt-project.org/legal +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and Digia. For licensing terms and +** conditions see http://qt.digia.com/licensing. For further information +** use the contact form at http://qt.digia.com/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Digia gives you certain additional +** rights. These rights are described in the Digia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QSTRINGITERATOR_H +#define QSTRINGITERATOR_H + +#include + +QT_BEGIN_NAMESPACE + +class QStringIterator +{ + QString::const_iterator i, pos, e; + +public: + inline explicit QStringIterator(const QString &string) + : i(string.constBegin()), + pos(string.constBegin()), + e(string.constEnd()) + { + } + + inline explicit QStringIterator(const QChar *begin, const QChar *end) + : i(begin), + pos(begin), + e(end) + { + } + + inline QString::const_iterator position() const + { + return pos; + } + + inline void setPosition(QString::const_iterator position) + { + Q_ASSERT_X(i <= position && position <= e, Q_FUNC_INFO, "position out of bounds"); + pos = position; + } + + // forward iteration + + inline bool hasNext() const + { + return 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())) + ++pos; + } + + inline uint peekNextUnchecked() const + { + Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item"); + + if (Q_UNLIKELY(pos->isHighSurrogate())) + return QChar::surrogateToUcs4(pos[0], pos[1]); + + return pos->unicode(); + } + + inline uint peekNext(uint 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 uint nextUnchecked() + { + Q_ASSERT_X(hasNext(), Q_FUNC_INFO, "iterator hasn't a next item"); + + const QChar cur = *pos++; + if (Q_UNLIKELY(cur.isHighSurrogate())) + return QChar::surrogateToUcs4(cur, *pos++); + return cur.unicode(); + } + + inline uint next(uint 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() && pos < e && pos->isLowSurrogate())) + return QChar::surrogateToUcs4(uc, *pos++); + return invalidAs; + } + + return uc.unicode(); + } + + // backwards iteration + + inline bool hasPrevious() const + { + return pos > i; + } + + 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())) + --pos; + } + + inline uint peekPreviousUnchecked() const + { + Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item"); + + if (Q_UNLIKELY(pos[-1].isLowSurrogate())) + return QChar::surrogateToUcs4(pos[-2], pos[-1]); + return pos[-1].unicode(); + } + + inline uint peekPrevious(uint 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 uint previousUnchecked() + { + Q_ASSERT_X(hasPrevious(), Q_FUNC_INFO, "iterator hasn't a previous item"); + + const QChar cur = *--pos; + if (Q_UNLIKELY(cur.isLowSurrogate())) + return QChar::surrogateToUcs4(*--pos, cur); + return cur.unicode(); + } + + inline uint previous(uint 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() && pos > i && pos[-1].isHighSurrogate())) + return QChar::surrogateToUcs4(*--pos, uc); + return invalidAs; + } + + return uc.unicode(); + } +}; + +QT_END_NAMESPACE + +#endif // QSTRINGITERATOR_H -- cgit v1.2.3