Implement StringIterator

Add support for String.prototype[Symbol.iterator] and the
StringIterator object.

Change-Id: I72c4f988e4f363be1af51f9cc5f8e83af43cd151
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

9 files changed, 226 insertions, 0 deletions

diff --git a/src/qml/jsruntime/jsruntime.pri b/src/qml/jsruntime/jsruntime.pri
index aa33565851..d06e505c81 100644
--- a/src/qml/jsruntime/jsruntime.pri
+++ b/src/qml/jsruntime/jsruntime.pri
@@ -31,6 +31,7 @@ SOURCES += \
     $$PWD/qv4objectproto.cpp \
     $$PWD/qv4qmlcontext.cpp \
     $$PWD/qv4regexpobject.cpp \
+    $$PWD/qv4stringiterator.cpp \
     $$PWD/qv4stringobject.cpp \
     $$PWD/qv4variantobject.cpp \
     $$PWD/qv4objectiterator.cpp \
@@ -84,6 +85,7 @@ HEADERS += \
     $$PWD/qv4qmlcontext_p.h \
     $$PWD/qv4regexpobject_p.h \
     $$PWD/qv4runtimecodegen_p.h \
+    $$PWD/qv4stringiterator_p.h \
     $$PWD/qv4stringobject_p.h \
     $$PWD/qv4variantobject_p.h \
     $$PWD/qv4property_p.h \
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index c8fb568ad1..1c3c3e7ff8 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -66,6 +66,7 @@
 #include "qv4profiling_p.h"
 #include "qv4executableallocator_p.h"
 #include "qv4iterator_p.h"
+#include "qv4stringiterator_p.h"
 
 #if QT_CONFIG(qml_sequence_object)
 #include "qv4sequenceobject_p.h"
@@ -407,6 +408,7 @@ ExecutionEngine::ExecutionEngine(QJSEngine *jsEngine)
     jsObjects[URIError_Ctor] = memoryManager->allocate<URIErrorCtor>(global);
     jsObjects[IteratorProto] = memoryManager->allocate<IteratorPrototype>();
     jsObjects[ArrayIteratorProto] = memoryManager->allocObject<ArrayIteratorPrototype>(newInternalClass(ArrayIteratorPrototype::staticVTable(), iteratorPrototype()));
+    jsObjects[StringIteratorProto] = memoryManager->allocObject<StringIteratorPrototype>(newInternalClass(StringIteratorPrototype::staticVTable(), iteratorPrototype()));
 
     static_cast<ObjectPrototype *>(objectPrototype())->init(this, objectCtor());
     static_cast<StringPrototype *>(stringPrototype())->init(this, stringCtor());
@@ -428,6 +430,8 @@ ExecutionEngine::ExecutionEngine(QJSEngine *jsEngine)
 
     static_cast<IteratorPrototype *>(iteratorPrototype())->init(this);
     static_cast<ArrayIteratorPrototype *>(arrayIteratorPrototype())->init(this);
+    static_cast<StringIteratorPrototype *>(stringIteratorPrototype())->init(this);
+
     static_cast<VariantPrototype *>(variantPrototype())->init();
 
 #if QT_CONFIG(qml_sequence_object)
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index f6ffd775ea..819481ed91 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -188,6 +188,7 @@ public:
         SignalHandlerProto,
         IteratorProto,
         ArrayIteratorProto,
+        StringIteratorProto,
 
         Object_Ctor,
         String_Ctor,
@@ -268,6 +269,7 @@ public:
     Object *signalHandlerPrototype() const { return reinterpret_cast<Object *>(jsObjects + SignalHandlerProto); }
     Object *iteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + IteratorProto); }
     Object *arrayIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + ArrayIteratorProto); }
+    Object *stringIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + StringIteratorProto); }
 
     EvalFunction *evalFunction() const { return reinterpret_cast<EvalFunction *>(jsObjects + Eval_Function); }
     FunctionObject *getStackFunction() const { return reinterpret_cast<FunctionObject *>(jsObjects + GetStack_Function); }
diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index d5ed0c0c32..bce504a4c6 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -125,6 +125,9 @@ QString Managed::className() const
     case Type_ArrayIteratorObject:
         s = "Array Iterator";
         break;
+    case Type_StringIteratorObject:
+        s = "String Iterator";
+        break;
     case Type_ForeachIteratorObject:
         s = "__ForeachIterator";
         break;
diff --git a/src/qml/jsruntime/qv4managed_p.h b/src/qml/jsruntime/qv4managed_p.h
index 454f4912c0..d404b66419 100644
--- a/src/qml/jsruntime/qv4managed_p.h
+++ b/src/qml/jsruntime/qv4managed_p.h
@@ -199,6 +199,7 @@ public:
         Type_ExecutionContext,
         Type_InternalClass,
         Type_ArrayIteratorObject,
+        Type_StringIteratorObject,
         Type_ForeachIteratorObject,
         Type_RegExp,
 
diff --git a/src/qml/jsruntime/qv4stringiterator.cpp b/src/qml/jsruntime/qv4stringiterator.cpp
new file mode 100644
index 0000000000..abdd0ee051
--- /dev/null
+++ b/src/qml/jsruntime/qv4stringiterator.cpp
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Crimson AS <info@crimson.no>
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4iterator_p.h>
+#include <private/qv4stringiterator_p.h>
+#include <private/qv4symbol_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(StringIteratorObject);
+
+void StringIteratorPrototype::init(ExecutionEngine *e)
+{
+    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
+
+    Scope scope(e);
+    ScopedString val(scope, e->newString(QLatin1String("String Iterator")));
+    defineReadonlyConfigurableProperty(e->symbol_toStringTag(), val);
+}
+
+ReturnedValue StringIteratorPrototype::method_next(const FunctionObject *b, const Value *that, const Value *, int)
+{
+    Scope scope(b);
+    const StringIteratorObject *thisObject = that->as<StringIteratorObject>();
+    if (!thisObject)
+        return scope.engine->throwTypeError(QLatin1String("Not an String Iterator instance"));
+
+    ScopedString s(scope, thisObject->d()->iteratedString);
+    if (!s) {
+        QV4::Value undefined = Primitive::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, ScopedValue(scope, true);
+    }
+
+    quint32 index = thisObject->d()->nextIndex;
+
+    QString str = s->toQString();
+    quint32 len = str.length();
+
+    if (index >= len) {
+        thisObject->d()->iteratedString.set(scope.engine, nullptr);
+        QV4::Value undefined = Primitive::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, ScopedValue(scope, true);
+    }
+
+    QChar ch = str.at(index);
+    int num = 1;
+    if (ch.unicode() >= 0xd800 && ch.unicode() <= 0xdbff && index + 1 != len) {
+        ch = str.at(index + 1);
+        if (ch.unicode() >= 0xdc00 && ch.unicode() <= 0xdfff)
+            num = 2;
+    }
+
+    thisObject->d()->nextIndex += num;
+
+    ScopedString resultString(scope, scope.engine->newString(s->toQString().mid(index, num)));
+    return IteratorPrototype::createIterResultObject(scope.engine, resultString, ScopedValue(scope, false);
+}
+
diff --git a/src/qml/jsruntime/qv4stringiterator_p.h b/src/qml/jsruntime/qv4stringiterator_p.h
new file mode 100644
index 0000000000..672ccc9963
--- /dev/null
+++ b/src/qml/jsruntime/qv4stringiterator_p.h
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml 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 QV4STRINGITERATOR_P_H
+#define QV4STRINGITERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4string_p.h"
+
+QT_BEGIN_NAMESPACE
+
+
+namespace QV4 {
+
+namespace Heap {
+
+#define StringIteratorObjectMembers(class, Member) \
+    Member(class, Pointer, String *, iteratedString) \
+    Member(class, NoMark, quint32, nextIndex)
+
+DECLARE_HEAP_OBJECT(StringIteratorObject, Object) {
+    DECLARE_MARKOBJECTS(StringIteratorObject);
+    void init(String *str, QV4::ExecutionEngine *engine)
+    {
+        Object::init();
+        this->iteratedString.set(engine, str);
+        this->nextIndex = 0;
+    }
+};
+
+}
+
+struct StringIteratorPrototype : Object
+{
+    V4_PROTOTYPE(iteratorPrototype)
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_next(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct StringIteratorObject : Object
+{
+    V4_OBJECT2(StringIteratorObject, Object)
+    Q_MANAGED_TYPE(StringIteratorObject)
+    V4_PROTOTYPE(stringIteratorPrototype)
+
+    void init(ExecutionEngine *engine);
+};
+
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4ARRAYITERATOR_P_H
+
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index bfc7a82046..2c0d1fdbad 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -47,6 +47,7 @@
 #include "qv4symbol_p.h"
 #include "qv4alloca_p.h"
 #include "qv4jscall_p.h"
+#include "qv4stringiterator_p.h"
 #include <QtCore/QDateTime>
 #include <QtCore/QDebug>
 #include <QtCore/QStringList>
@@ -206,6 +207,7 @@ void StringPrototype::init(ExecutionEngine *engine, Object *ctor)
     defineDefaultProperty(QStringLiteral("toUpperCase"), method_toUpperCase);
     defineDefaultProperty(QStringLiteral("toLocaleUpperCase"), method_toLocaleUpperCase);
     defineDefaultProperty(QStringLiteral("trim"), method_trim);
+    defineDefaultProperty(engine->symbol_iterator(), method_iterator);
 }
 
 static Heap::String *thisAsString(ExecutionEngine *v4, const QV4::Value *thisObject)
@@ -928,3 +930,16 @@ ReturnedValue StringPrototype::method_trim(const FunctionObject *b, const Value
 
     return Encode(v4->newString(QString(chars + start, end - start + 1)));
 }
+
+
+
+ReturnedValue StringPrototype::method_iterator(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    ScopedString s(scope, thisObject->toString(scope.engine));
+    if (!s || thisObject->isNullOrUndefined())
+        return scope.engine->throwTypeError();
+
+    Scoped<StringIteratorObject> si(scope, scope.engine->memoryManager->allocate<StringIteratorObject>(s->d(), scope.engine));
+    return si->asReturnedValue();
+}
diff --git a/src/qml/jsruntime/qv4stringobject_p.h b/src/qml/jsruntime/qv4stringobject_p.h
index 7d25678b61..207e9f2781 100644
--- a/src/qml/jsruntime/qv4stringobject_p.h
+++ b/src/qml/jsruntime/qv4stringobject_p.h
@@ -139,6 +139,7 @@ struct StringPrototype: StringObject
     static ReturnedValue method_toLocaleUpperCase(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_fromCharCode(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_trim(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_iterator(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 }