Add QString::splitRef functions.

The functions can be used to optimize code that do not need to use
the split results as QString directly.

[ChangeLog][QtCore] QString can now split a string to a list of
QStringRef.

Change-Id: Ic2dc929e1fba82f9a060e37c51068a301cb5b866
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

2 files changed, 75 insertions, 0 deletions

diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index e8eb04b598..fdde0955dd 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -6669,6 +6669,28 @@ QStringList QString::split(const QString &sep, SplitBehavior behavior, Qt::CaseS
 }
 
 /*!
+    Splits the string into substring references wherever \a sep occurs, and
+    returns the list of those strings. If \a sep does not match
+    anywhere in the string, splitRef() returns a single-element vector
+    containing this string reference.
+
+    \a cs specifies whether \a sep should be matched case
+    sensitively or case insensitively.
+
+    If \a behavior is QString::SkipEmptyParts, empty entries don't
+    appear in the result. By default, empty entries are kept.
+
+    \note All references are valid as long this string is alive. Destroying this
+    string will cause all references be dangling pointers.
+
+    \since 5.4
+    \sa QStringRef split()
+*/
+QVector<QStringRef> QString::splitRef(const QString &sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
+{
+    return splitString<QVector<QStringRef> >(*this, &QString::midRef, sep, behavior, cs, sep.size());
+}
+/*!
     \overload
 */
 QStringList QString::split(QChar sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
@@ -6676,6 +6698,15 @@ QStringList QString::split(QChar sep, SplitBehavior behavior, Qt::CaseSensitivit
     return splitString<QStringList>(*this, &QString::mid, sep, behavior, cs, 1);
 }
 
+/*!
+    \overload
+    \since 5.4
+*/
+QVector<QStringRef> QString::splitRef(QChar sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
+{
+    return splitString<QVector<QStringRef> >(*this, &QString::midRef, sep, behavior, cs, 1);
+}
+
 #ifndef QT_NO_REGEXP
 namespace {
 template<class ResultList, typename MidMethod>
@@ -6729,6 +6760,25 @@ QStringList QString::split(const QRegExp &rx, SplitBehavior behavior) const
 {
     return splitString<QStringList>(*this, &QString::mid, rx, behavior);
 }
+
+/*!
+    \overload
+    \since 5.4
+
+    Splits the string into substring references wherever the regular expression
+    \a rx matches, and returns the list of those strings. If \a rx
+    does not match anywhere in the string, splitRef() returns a
+    single-element vector containing this string reference.
+
+    \note All references are valid as long this string is alive. Destroying this
+    string will cause all references be dangling pointers.
+
+    \sa QStringRef split()
+*/
+QVector<QStringRef> QString::splitRef(const QRegExp &rx, SplitBehavior behavior) const
+{
+    return splitString<QVector<QStringRef> >(*this, &QString::midRef, rx, behavior);
+}
 #endif
 
 #ifndef QT_NO_REGULAREXPRESSION
@@ -6793,6 +6843,25 @@ QStringList QString::split(const QRegularExpression &re, SplitBehavior behavior)
 {
     return splitString<QStringList>(*this, &QString::mid, re, behavior);
 }
+
+/*!
+    \overload
+    \since 5.4
+
+    Splits the string into substring references wherever the regular expression
+    \a re matches, and returns the list of those strings. If \a re
+    does not match anywhere in the string, splitRef() returns a
+    single-element vector containing this string reference.
+
+    \note All references are valid as long this string is alive. Destroying this
+    string will cause all references be dangling pointers.
+
+    \sa split() QStringRef
+*/
+QVector<QStringRef> QString::splitRef(const QRegularExpression &re, SplitBehavior behavior) const
+{
+    return splitString<QVector<QStringRef> >(*this, &QString::midRef, re, behavior);
+}
 #endif // QT_BOOTSTRAPPED
 #endif // QT_NO_REGULAREXPRESSION
 
diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index 3afd68af1f..21b64f5006 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -441,13 +441,19 @@ public:
 
     QStringList split(const QString &sep, SplitBehavior behavior = KeepEmptyParts,
                       Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_REQUIRED_RESULT;
+    QVector<QStringRef> splitRef(const QString &sep, SplitBehavior behavior = KeepEmptyParts,
+                      Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_REQUIRED_RESULT;
     QStringList split(QChar sep, SplitBehavior behavior = KeepEmptyParts,
                       Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_REQUIRED_RESULT;
+    QVector<QStringRef> splitRef(QChar sep, SplitBehavior behavior = KeepEmptyParts,
+                      Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_REQUIRED_RESULT;
 #ifndef QT_NO_REGEXP
     QStringList split(const QRegExp &sep, SplitBehavior behavior = KeepEmptyParts) const Q_REQUIRED_RESULT;
+    QVector<QStringRef> splitRef(const QRegExp &sep, SplitBehavior behavior = KeepEmptyParts) const Q_REQUIRED_RESULT;
 #endif
 #ifndef QT_NO_REGULAREXPRESSION
     QStringList split(const QRegularExpression &sep, SplitBehavior behavior = KeepEmptyParts) const Q_REQUIRED_RESULT;
+    QVector<QStringRef> splitRef(const QRegularExpression &sep, SplitBehavior behavior = KeepEmptyParts) const Q_REQUIRED_RESULT;
 #endif
     enum NormalizationForm {
         NormalizationForm_D,