QRegularExpression: make escape-like functions work on QStringView

They don't store the strings.

[ChangeLog][QtCore][QRegularExpression] The escape(),
wildcardToRegularExpression() and anchoredPattern() functions
now have overloads taking a QStringView parameter.

Change-Id: Icc66ba1201ef1f1064d9565900439e78912b675c
Reviewed-by: Samuel Gaist <samuel.gaist@idiap.ch>

src/corelib/text/qregularexpression.cpp

@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 Giuseppe D'Angelo <dangelog@gmail.com>.
+** Copyright (C) 2020 Giuseppe D'Angelo <dangelog@gmail.com>.
-** Copyright (C) 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
+** Copyright (C) 2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -1829,7 +1829,19 @@ uint qHash(const QRegularExpression &key, uint seed) noexcept
     return seed;
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
+    \overload
+*/
+QString QRegularExpression::escape(const QString &str)
+{
+    return escape(QStringView(str));
+}
+#endif // QT_STRINGVIEW_LEVEL < 2
+
+/*!
+    \since 5.15
+
     Escapes all characters of \a str so that they no longer have any special
     meaning when used as a regular expression pattern string, and returns
     the escaped string. For instance:
@@ -1847,7 +1859,7 @@ uint qHash(const QRegularExpression &key, uint seed) noexcept
     inside \a str is escaped with the sequence \c{"\\0"} (backslash +
     \c{'0'}), instead of \c{"\\\0"} (backslash + \c{NUL}).
 */
-QString QRegularExpression::escape(const QString &str)
+QString QRegularExpression::escape(QStringView str)
 {
     QString result;
     const int count = str.size();
@@ -1882,8 +1894,19 @@ QString QRegularExpression::escape(const QString &str)
     return result;
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
     \since 5.12
+    \overload
+*/
+QString QRegularExpression::wildcardToRegularExpression(const QString &pattern)
+{
+    return wildcardToRegularExpression(QStringView(pattern));
+}
+#endif // QT_STRINGVIEW_LEVEL < 2
+
+/*!
+    \since 5.15
 
     Returns a regular expression representation of the given glob \a pattern.
     The transformation is targeting file path globbing, which means in particular
@@ -1928,13 +1951,13 @@ QString QRegularExpression::escape(const QString &str)
 
     \sa escape()
 */
-QString QRegularExpression::wildcardToRegularExpression(const QString &pattern)
+QString QRegularExpression::wildcardToRegularExpression(QStringView pattern)
 {
     const int wclen = pattern.length();
     QString rx;
     rx.reserve(wclen + wclen / 16);
     int i = 0;
-    const QChar *wc = pattern.unicode();
+    const QChar *wc = pattern.data();
 
 #ifdef Q_OS_WIN
     const QLatin1Char nativePathSeparator('\\');
@@ -2006,16 +2029,31 @@ QString QRegularExpression::wildcardToRegularExpression(const QString &pattern)
     return anchoredPattern(rx);
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
     \fn QRegularExpression::anchoredPattern(const QString &expression)
 
     \since 5.12
 
+    \overload
+*/
+#endif // QT_STRINGVIEW_LEVEL < 2
+
+/*!
+    \since 5.15
+
     Returns the \a expression wrapped between the \c{\A} and \c{\z} anchors to
     be used for exact matching.
 
     \sa {Porting from QRegExp's Exact Matching}
 */
+QString QRegularExpression::anchoredPattern(QStringView expression)
+{
+    return QString()
+           + QLatin1String("\\A(?:")
+           + expression
+           + QLatin1String(")\\z");
+}
 
 /*!
     \since 5.1

src/corelib/text/qregularexpression.h

@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2012 Giuseppe D'Angelo <dangelog@gmail.com>.
+** Copyright (C) 2020 Giuseppe D'Angelo <dangelog@gmail.com>.
-** Copyright (C) 2012 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
+** Copyright (C) 2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -42,9 +42,8 @@
 #define QREGULAREXPRESSION_H
 
 #include <QtCore/qglobal.h>
-
 #include <QtCore/qstring.h>
-#include <QtCore/qstringlist.h>
+#include <QtCore/qstringview.h>
 #include <QtCore/qshareddata.h>
 #include <QtCore/qvariant.h>
 
@@ -52,7 +51,8 @@ QT_REQUIRE_CONFIG(regularexpression);
 
 QT_BEGIN_NAMESPACE
 
-class QStringView;
+class QStringList;
+class QLatin1String;
 
 class QRegularExpressionMatch;
 class QRegularExpressionMatchIterator;
@@ -137,14 +137,18 @@ public:
 
     void optimize() const;
 
+#if QT_STRINGVIEW_LEVEL < 2
     static QString escape(const QString &str);
     static QString wildcardToRegularExpression(const QString &str);
     static inline QString anchoredPattern(const QString &expression)
     {
-        return QLatin1String("\\A(?:")
+        return anchoredPattern(QStringView(expression));
-               + expression
-               + QLatin1String(")\\z");
     }
+#endif
+
+    static QString escape(QStringView str);
+    static QString wildcardToRegularExpression(QStringView str);
+    static QString anchoredPattern(QStringView expression);
 
     bool operator==(const QRegularExpression &re) const;
     inline bool operator!=(const QRegularExpression &re) const { return !operator==(re); }