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Diffstat (limited to 'src/corelib/text/qstringalgorithms_p.h')
| -rw-r--r-- | src/corelib/text/qstringalgorithms_p.h | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/src/corelib/text/qstringalgorithms_p.h b/src/corelib/text/qstringalgorithms_p.h new file mode 100644 index 0000000000..64d9f2e676 --- /dev/null +++ b/src/corelib/text/qstringalgorithms_p.h @@ -0,0 +1,152 @@ +/**************************************************************************** +** +** Copyright (C) 2016 Intel Corporation. +** Contact: https://www.qt.io/licensing/ +** +** 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 The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/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 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QSTRINGALGORITHMS_P_H +#define QSTRINGALGORITHMS_P_H + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. It exists for the convenience +// of internal files. This header file may change from version to version +// without notice, or even be removed. +// +// We mean it. +// + +#include "qstring.h" +#include "qlocale_p.h" // for ascii_isspace + +QT_BEGIN_NAMESPACE + +template <typename StringType> struct QStringAlgorithms +{ + typedef typename StringType::value_type Char; + typedef typename StringType::size_type size_type; + typedef typename std::remove_cv<StringType>::type NakedStringType; + static const bool isConst = std::is_const<StringType>::value; + + static inline bool isSpace(char ch) { return ascii_isspace(ch); } + static inline bool isSpace(QChar ch) { return ch.isSpace(); } + + // Surrogate pairs are not handled in either of the functions below. That is + // not a problem because there are no space characters (Zs, Zl, Zp) outside the + // Basic Multilingual Plane. + + static inline StringType trimmed_helper_inplace(NakedStringType &str, const Char *begin, const Char *end) + { + // in-place trimming: + Char *data = const_cast<Char *>(str.cbegin()); + if (begin != data) + memmove(data, begin, (end - begin) * sizeof(Char)); + str.resize(end - begin); + return std::move(str); + } + + static inline StringType trimmed_helper_inplace(const NakedStringType &, const Char *, const Char *) + { + // can't happen + Q_UNREACHABLE(); + return StringType(); + } + + static inline void trimmed_helper_positions(const Char *&begin, const Char *&end) + { + // skip white space from end + while (begin < end && isSpace(end[-1])) + --end; + // skip white space from start + while (begin < end && isSpace(*begin)) + begin++; + } + + static inline StringType trimmed_helper(StringType &str) + { + const Char *begin = str.cbegin(); + const Char *end = str.cend(); + trimmed_helper_positions(begin, end); + + if (begin == str.cbegin() && end == str.cend()) + return str; + if (!isConst && str.isDetached()) + return trimmed_helper_inplace(str, begin, end); + return StringType(begin, end - begin); + } + + static inline StringType simplified_helper(StringType &str) + { + if (str.isEmpty()) + return str; + const Char *src = str.cbegin(); + const Char *end = str.cend(); + NakedStringType result = isConst || !str.isDetached() ? + StringType(str.size(), Qt::Uninitialized) : + std::move(str); + + Char *dst = const_cast<Char *>(result.cbegin()); + Char *ptr = dst; + bool unmodified = true; + forever { + while (src != end && isSpace(*src)) + ++src; + while (src != end && !isSpace(*src)) + *ptr++ = *src++; + if (src == end) + break; + if (*src != QChar::Space) + unmodified = false; + *ptr++ = QChar::Space; + } + if (ptr != dst && ptr[-1] == QChar::Space) + --ptr; + + int newlen = ptr - dst; + if (isConst && newlen == str.size() && unmodified) { + // nothing happened, return the original + return str; + } + result.resize(newlen); + return result; + } +}; + +QT_END_NAMESPACE + +#endif // QSTRINGALGORITHMS_P_H |