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authorMarc Mutz <marc.mutz@kdab.com>2019-06-03 11:43:24 +0200
committerMarc Mutz <marc.mutz@kdab.com>2019-06-20 19:36:37 +0200
commit35431062bd7bf0d27b9bf785ab3cbc7fac5a69da (patch)
tree562a4339515e7e1db6981958e02796058012eb75
parent6f84829031f318bfda1deff5f409b5ea6c6a5c5f (diff)
QString: towards QStringView::arg() pt.3: Long live QStringView/QLatin1String::arg()
This version of arg(), unlike its QString counterpart, transparently accepts views without conversion to QString, and is also extensible to further argument types, say a future QFormattedNumber. [ChangeLog][QtCore][QStringView/QLatin1String] Added arg(), taking arbitrarily many strings. Change-Id: If40ef3c445f63383e32573f3f515fdda84c7fe3a Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
-rw-r--r--src/corelib/tools/qstring.cpp108
-rw-r--r--src/corelib/tools/qstring.h55
-rw-r--r--src/corelib/tools/qstringview.cpp18
-rw-r--r--src/corelib/tools/qstringview.h3
-rw-r--r--tests/auto/corelib/tools/qlatin1string/tst_qlatin1string.cpp42
-rw-r--r--tests/auto/corelib/tools/qstringview/tst_qstringview.cpp43
6 files changed, 246 insertions, 23 deletions
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 53513d4abb..89ab866703 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -8754,19 +8754,23 @@ QString QString::arg(double a, int fieldWidth, char fmt, int prec, QChar fillCha
return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}
-static int getEscape(const QChar *uc, qsizetype *pos, qsizetype len, int maxNumber = 999)
+static inline ushort to_unicode(const QChar c) { return c.unicode(); }
+static inline ushort to_unicode(const char c) { return QLatin1Char{c}.unicode(); }
+
+template <typename Char>
+static int getEscape(const Char *uc, qsizetype *pos, qsizetype len, int maxNumber = 999)
{
int i = *pos;
++i;
if (i < len && uc[i] == QLatin1Char('L'))
++i;
if (i < len) {
- int escape = uc[i].unicode() - '0';
+ int escape = to_unicode(uc[i]) - '0';
if (uint(escape) >= 10U)
return -1;
++i;
while (i < len) {
- int digit = uc[i].unicode() - '0';
+ int digit = to_unicode(uc[i]) - '0';
if (uint(digit) >= 10U)
break;
escape = (escape * 10) + digit;
@@ -8817,18 +8821,23 @@ static int getEscape(const QChar *uc, qsizetype *pos, qsizetype len, int maxNumb
namespace {
struct Part
{
- Q_DECL_CONSTEXPR Part() : string{}, number{0} {}
+ Part() = default; // for QVarLengthArray; do not use
Q_DECL_CONSTEXPR Part(QStringView s, int num = -1)
- : string{s}, number{num} {}
+ : tag{QtPrivate::ArgBase::U16}, number{num}, data{s.utf16()}, size{s.size()} {}
+ Q_DECL_CONSTEXPR Part(QLatin1String s, int num = -1)
+ : tag{QtPrivate::ArgBase::L1}, number{num}, data{s.data()}, size{s.size()} {}
+
+ void reset(QStringView s) noexcept { *this = {s, number}; }
+ void reset(QLatin1String s) noexcept { *this = {s, number}; }
- QStringView string;
+ QtPrivate::ArgBase::Tag tag;
int number;
+ const void *data;
+ qsizetype size;
};
} // unnamed namespace
-template <>
-class QTypeInfo<Part> : public QTypeInfoMerger<Part, QStringView, int> {}; // Q_DECLARE_METATYPE
-
+Q_DECLARE_TYPEINFO(Part, Q_PRIMITIVE_TYPE);
namespace {
@@ -8837,7 +8846,8 @@ enum { ExpectedParts = 32 };
typedef QVarLengthArray<Part, ExpectedParts> ParseResult;
typedef QVarLengthArray<int, ExpectedParts/2> ArgIndexToPlaceholderMap;
-static ParseResult parseMultiArgFormatString(QStringView s)
+template <typename StringView>
+static ParseResult parseMultiArgFormatString(StringView s)
{
ParseResult result;
@@ -8884,16 +8894,29 @@ static ArgIndexToPlaceholderMap makeArgIndexToPlaceholderMap(const ParseResult &
return result;
}
-static qsizetype resolveStringRefsAndReturnTotalSize(ParseResult &parts, const ArgIndexToPlaceholderMap &argIndexToPlaceholderMap, const QString *args[])
+static qsizetype resolveStringRefsAndReturnTotalSize(ParseResult &parts, const ArgIndexToPlaceholderMap &argIndexToPlaceholderMap, const QtPrivate::ArgBase *args[])
{
+ using namespace QtPrivate;
qsizetype totalSize = 0;
for (Part &part : parts) {
if (part.number != -1) {
const auto it = std::find(argIndexToPlaceholderMap.begin(), argIndexToPlaceholderMap.end(), part.number);
- if (it != argIndexToPlaceholderMap.end())
- part.string = *args[it - argIndexToPlaceholderMap.begin()];
+ if (it != argIndexToPlaceholderMap.end()) {
+ const auto &arg = *args[it - argIndexToPlaceholderMap.begin()];
+ switch (arg.tag) {
+ case ArgBase::L1:
+ part.reset(static_cast<const QLatin1StringArg&>(arg).string);
+ break;
+ case ArgBase::U8:
+ Q_UNREACHABLE(); // waiting for QUtf8String...
+ break;
+ case ArgBase::U16:
+ part.reset(static_cast<const QStringViewArg&>(arg).string);
+ break;
+ }
+ }
}
- totalSize += part.string.size();
+ totalSize += part.size;
}
return totalSize;
}
@@ -8902,17 +8925,34 @@ static qsizetype resolveStringRefsAndReturnTotalSize(ParseResult &parts, const A
QString QString::multiArg(int numArgs, const QString **args) const
{
+ QVarLengthArray<QtPrivate::QStringViewArg, 9> sva;
+ sva.reserve(numArgs);
+ QVarLengthArray<const QtPrivate::ArgBase *, 9> pointers;
+ pointers.reserve(numArgs);
+ for (int i = 0; i < numArgs; ++i) {
+ sva.push_back(QtPrivate::qStringLikeToArg(*args[i]));
+ pointers.push_back(&sva.back());
+ }
+ return QtPrivate::argToQString(qToStringViewIgnoringNull(*this), static_cast<size_t>(numArgs), pointers.data());
+}
+
+Q_ALWAYS_INLINE QString to_string(QLatin1String s) noexcept { return s; }
+Q_ALWAYS_INLINE QString to_string(QStringView s) noexcept { return s.toString(); }
+
+template <typename StringView>
+static QString argToQStringImpl(StringView pattern, size_t numArgs, const QtPrivate::ArgBase **args)
+{
// Step 1-2 above
- ParseResult parts = parseMultiArgFormatString(qToStringViewIgnoringNull(*this));
+ ParseResult parts = parseMultiArgFormatString(pattern);
// 3-4
ArgIndexToPlaceholderMap argIndexToPlaceholderMap = makeArgIndexToPlaceholderMap(parts);
- if (argIndexToPlaceholderMap.size() > numArgs) // 3a
- argIndexToPlaceholderMap.resize(numArgs);
- else if (argIndexToPlaceholderMap.size() < numArgs) // 3b
- qWarning("QString::arg: %d argument(s) missing in %s",
- numArgs - argIndexToPlaceholderMap.size(), toLocal8Bit().data());
+ if (static_cast<size_t>(argIndexToPlaceholderMap.size()) > numArgs) // 3a
+ argIndexToPlaceholderMap.resize(int(numArgs));
+ else if (Q_UNLIKELY(static_cast<size_t>(argIndexToPlaceholderMap.size()) < numArgs)) // 3b
+ qWarning("QString::arg: %d argument(s) missing in %ls",
+ int(numArgs - argIndexToPlaceholderMap.size()), qUtf16Printable(to_string(pattern)));
// 5
const qsizetype totalSize = resolveStringRefsAndReturnTotalSize(parts, argIndexToPlaceholderMap, args);
@@ -8922,15 +8962,37 @@ QString QString::multiArg(int numArgs, const QString **args) const
auto out = const_cast<QChar*>(result.constData());
for (Part part : parts) {
- if (const qsizetype sz = part.string.size()) {
- memcpy(out, part.string.data(), sz * sizeof(QChar));
- out += sz;
+ switch (part.tag) {
+ case QtPrivate::ArgBase::L1:
+ if (part.size) {
+ qt_from_latin1(reinterpret_cast<ushort*>(out),
+ reinterpret_cast<const char*>(part.data), part.size);
+ }
+ break;
+ case QtPrivate::ArgBase::U8:
+ Q_UNREACHABLE(); // waiting for QUtf8String
+ break;
+ case QtPrivate::ArgBase::U16:
+ if (part.size)
+ memcpy(out, part.data, part.size * sizeof(QChar));
+ break;
}
+ out += part.size;
}
return result;
}
+QString QtPrivate::argToQString(QStringView pattern, size_t n, const ArgBase **args)
+{
+ return argToQStringImpl(pattern, n, args);
+}
+
+QString QtPrivate::argToQString(QLatin1String pattern, size_t n, const ArgBase **args)
+{
+ return argToQStringImpl(pattern, n, args);
+}
+
/*! \fn bool QString::isSimpleText() const
\internal
diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index 89b25821ee..6820440ca2 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -106,6 +106,9 @@ public:
Q_DECL_CONSTEXPR bool isNull() const noexcept { return !data(); }
Q_DECL_CONSTEXPR bool isEmpty() const noexcept { return !size(); }
+ template <typename...Args>
+ Q_REQUIRED_RESULT inline QString arg(Args &&...args) const;
+
Q_DECL_CONSTEXPR QLatin1Char at(int i) const
{ return Q_ASSERT(i >= 0), Q_ASSERT(i < size()), QLatin1Char(m_data[i]); }
Q_DECL_CONSTEXPR QLatin1Char operator[](int i) const { return at(i); }
@@ -1979,6 +1982,58 @@ inline const QString &asString(const QString &s) { return s; }
inline QString &&asString(QString &&s) { return std::move(s); }
}
+//
+// QStringView::arg() implementation
+//
+
+namespace QtPrivate {
+
+struct ArgBase {
+ enum Tag : uchar { L1, U8, U16 } tag;
+};
+
+struct QStringViewArg : ArgBase {
+ QStringView string;
+ QStringViewArg() = default;
+ Q_DECL_CONSTEXPR explicit QStringViewArg(QStringView v) noexcept : ArgBase{U16}, string{v} {}
+};
+
+struct QLatin1StringArg : ArgBase {
+ QLatin1String string;
+ QLatin1StringArg() = default;
+ Q_DECL_CONSTEXPR explicit QLatin1StringArg(QLatin1String v) noexcept : ArgBase{L1}, string{v} {}
+};
+
+Q_REQUIRED_RESULT Q_CORE_EXPORT QString argToQString(QStringView pattern, size_t n, const ArgBase **args);
+Q_REQUIRED_RESULT Q_CORE_EXPORT QString argToQString(QLatin1String pattern, size_t n, const ArgBase **args);
+
+template <typename StringView, typename...Args>
+Q_REQUIRED_RESULT Q_ALWAYS_INLINE QString argToQStringDispatch(StringView pattern, const Args &...args)
+{
+ const ArgBase *argBases[] = {&args..., /* avoid zero-sized array */ nullptr};
+ return QtPrivate::argToQString(pattern, sizeof...(Args), argBases);
+}
+
+Q_DECL_CONSTEXPR inline QStringViewArg qStringLikeToArg(QStringView s) noexcept { return QStringViewArg{s}; }
+ inline QStringViewArg qStringLikeToArg(const QChar &c) noexcept { return QStringViewArg{QStringView{&c, 1}}; }
+Q_DECL_CONSTEXPR inline QLatin1StringArg qStringLikeToArg(QLatin1String s) noexcept { return QLatin1StringArg{s}; }
+
+} // namespace QtPrivate
+
+template <typename...Args>
+Q_ALWAYS_INLINE
+QString QStringView::arg(Args &&...args) const
+{
+ return QtPrivate::argToQStringDispatch(*this, QtPrivate::qStringLikeToArg(args)...);
+}
+
+template <typename...Args>
+Q_ALWAYS_INLINE
+QString QLatin1String::arg(Args &&...args) const
+{
+ return QtPrivate::argToQStringDispatch(*this, QtPrivate::qStringLikeToArg(args)...);
+}
+
QT_END_NAMESPACE
#if defined(QT_USE_FAST_OPERATOR_PLUS) || defined(QT_USE_QSTRINGBUILDER)
diff --git a/src/corelib/tools/qstringview.cpp b/src/corelib/tools/qstringview.cpp
index d94ed4110e..cc852dd042 100644
--- a/src/corelib/tools/qstringview.cpp
+++ b/src/corelib/tools/qstringview.cpp
@@ -530,6 +530,24 @@ QT_BEGIN_NAMESPACE
*/
/*!
+ \fn QString QStringView::arg(Args &&...args) const
+ \fn QString QLatin1String::arg(Args &&...args) const
+ \since 5.14
+
+ Replaces occurrences of \c{%N} in this string with the corresponding
+ argument from \a args. The arguments are not positional: the first of
+ the \a args replaces the \c{%N} with the lowest \c{N} (all of them), the
+ second of the \a args the \c{%N} with the next-lowest \c{N} etc.
+
+ \c Args can consist of anything that implicitly converts to QStringView
+ or QLatin1String.
+
+ In addition, the following types are also supported: QChar, QLatin1Char.
+
+ \sa QString::arg()
+*/
+
+/*!
\fn QChar QStringView::front() const
Returns the first character in the string. Same as first().
diff --git a/src/corelib/tools/qstringview.h b/src/corelib/tools/qstringview.h
index 67f5d2203c..b84b2995b9 100644
--- a/src/corelib/tools/qstringview.h
+++ b/src/corelib/tools/qstringview.h
@@ -226,6 +226,9 @@ public:
// QString API
//
+ template <typename...Args>
+ Q_REQUIRED_RESULT inline QString arg(Args &&...args) const; // defined in qstring.h
+
Q_REQUIRED_RESULT QByteArray toLatin1() const { return QtPrivate::convertToLatin1(*this); }
Q_REQUIRED_RESULT QByteArray toUtf8() const { return QtPrivate::convertToUtf8(*this); }
Q_REQUIRED_RESULT QByteArray toLocal8Bit() const { return QtPrivate::convertToLocal8Bit(*this); }
diff --git a/tests/auto/corelib/tools/qlatin1string/tst_qlatin1string.cpp b/tests/auto/corelib/tools/qlatin1string/tst_qlatin1string.cpp
index dcfb0aa042..cf46159251 100644
--- a/tests/auto/corelib/tools/qlatin1string/tst_qlatin1string.cpp
+++ b/tests/auto/corelib/tools/qlatin1string/tst_qlatin1string.cpp
@@ -45,6 +45,7 @@ class tst_QLatin1String : public QObject
private Q_SLOTS:
void at();
+ void arg() const;
void midLeftRight();
void nullString();
void emptyString();
@@ -63,6 +64,47 @@ void tst_QLatin1String::at()
QCOMPARE(l1[l1.size() - 1], QLatin1Char('d'));
}
+void tst_QLatin1String::arg() const
+{
+#define CHECK1(pattern, arg1, expected) \
+ do { \
+ auto p = QLatin1String(pattern); \
+ QCOMPARE(p.arg(QLatin1String(arg1)), expected); \
+ QCOMPARE(p.arg(QStringViewLiteral(arg1)), expected); \
+ QCOMPARE(p.arg(QStringLiteral(arg1)), expected); \
+ QCOMPARE(p.arg(QString(QLatin1String(arg1))), expected); \
+ } while (false) \
+ /*end*/
+#define CHECK2(pattern, arg1, arg2, expected) \
+ do { \
+ auto p = QLatin1String(pattern); \
+ QCOMPARE(p.arg(QLatin1String(arg1), QLatin1String(arg2)), expected); \
+ QCOMPARE(p.arg(QStringViewLiteral(arg1), QLatin1String(arg2)), expected); \
+ QCOMPARE(p.arg(QLatin1String(arg1), QStringViewLiteral(arg2)), expected); \
+ QCOMPARE(p.arg(QStringViewLiteral(arg1), QStringViewLiteral(arg2)), expected); \
+ } while (false) \
+ /*end*/
+
+ CHECK1("", "World", "");
+ CHECK1("%1", "World", "World");
+ CHECK1("!%1?", "World", "!World?");
+ CHECK1("%1%1", "World", "WorldWorld");
+ CHECK1("%1%2", "World", "World%2");
+ CHECK1("%2%1", "World", "%2World");
+
+ CHECK2("", "Hello", "World", "");
+ CHECK2("%1", "Hello", "World", "Hello");
+ CHECK2("!%1, %2?", "Hello", "World", "!Hello, World?");
+ CHECK2("%1%1", "Hello", "World", "HelloHello");
+ CHECK2("%1%2", "Hello", "World", "HelloWorld");
+ CHECK2("%2%1", "Hello", "World", "WorldHello");
+
+#undef CHECK2
+#undef CHECK1
+
+ QCOMPARE(QLatin1String(" %2 %2 %1 %3 ").arg(QLatin1Char('c'), QChar::CarriageReturn, u'C'), " \r \r c C ");
+}
+
void tst_QLatin1String::midLeftRight()
{
const QLatin1String l1("Hello World");
diff --git a/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp b/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp
index e800a0d794..794f39708a 100644
--- a/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp
+++ b/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp
@@ -134,6 +134,8 @@ private Q_SLOTS:
void literals() const;
void at() const;
+ void arg() const;
+
void fromQString() const;
void fromQStringRef() const;
@@ -425,6 +427,47 @@ void tst_QStringView::at() const
QCOMPARE(sv.at(4), QChar('o')); QCOMPARE(sv[4], QChar('o'));
}
+void tst_QStringView::arg() const
+{
+#define CHECK1(pattern, arg1, expected) \
+ do { \
+ auto p = QStringViewLiteral(pattern); \
+ QCOMPARE(p.arg(QLatin1String(arg1)), expected); \
+ QCOMPARE(p.arg(QStringViewLiteral(arg1)), expected); \
+ QCOMPARE(p.arg(QStringLiteral(arg1)), expected); \
+ QCOMPARE(p.arg(QString(QLatin1String(arg1))), expected); \
+ } while (false) \
+ /*end*/
+#define CHECK2(pattern, arg1, arg2, expected) \
+ do { \
+ auto p = QStringViewLiteral(pattern); \
+ QCOMPARE(p.arg(QLatin1String(arg1), QLatin1String(arg2)), expected); \
+ QCOMPARE(p.arg(QStringViewLiteral(arg1), QLatin1String(arg2)), expected); \
+ QCOMPARE(p.arg(QLatin1String(arg1), QStringViewLiteral(arg2)), expected); \
+ QCOMPARE(p.arg(QStringViewLiteral(arg1), QStringViewLiteral(arg2)), expected); \
+ } while (false) \
+ /*end*/
+
+ CHECK1("", "World", "");
+ CHECK1("%1", "World", "World");
+ CHECK1("!%1?", "World", "!World?");
+ CHECK1("%1%1", "World", "WorldWorld");
+ CHECK1("%1%2", "World", "World%2");
+ CHECK1("%2%1", "World", "%2World");
+
+ CHECK2("", "Hello", "World", "");
+ CHECK2("%1", "Hello", "World", "Hello");
+ CHECK2("!%1, %2?", "Hello", "World", "!Hello, World?");
+ CHECK2("%1%1", "Hello", "World", "HelloHello");
+ CHECK2("%1%2", "Hello", "World", "HelloWorld");
+ CHECK2("%2%1", "Hello", "World", "WorldHello");
+
+#undef CHECK2
+#undef CHECK1
+
+ QCOMPARE(QStringViewLiteral(" %2 %2 %1 %3 ").arg(QLatin1Char('c'), QChar::CarriageReturn, u'C'), " \r \r c C ");
+}
+
void tst_QStringView::fromQString() const
{
QString null;