Source/JavaScriptCore/runtime/JSStringIterator.h

/*
 * Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
 * Copyright (C) 2021-2022 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "JSInternalFieldObjectImpl.h"

namespace JSC {

class JSStringIterator final : public JSInternalFieldObjectImpl<2> {
public:
    using Base = JSInternalFieldObjectImpl<2>;

    enum class Field : uint8_t {
        Index = 0,
        IteratedString,
    };

    DECLARE_EXPORT_INFO;

    static size_t allocationSize(Checked<size_t> inlineCapacity)
    {
        ASSERT_UNUSED(inlineCapacity, inlineCapacity == 0U);
        return sizeof(JSStringIterator);
    }

    template<typename CellType, SubspaceAccess mode>
    static GCClient::IsoSubspace* subspaceFor(VM& vm)
    {
        return vm.stringIteratorSpace<mode>();
    }

    static std::array<JSValue, numberOfInternalFields> initialValues()
    {
        return { {
            jsNumber(0),
            jsNull(),
        } };
    }

    const WriteBarrier<Unknown>& internalField(Field field) const { return Base::internalField(static_cast<uint32_t>(field)); }
    WriteBarrier<Unknown>& internalField(Field field) { return Base::internalField(static_cast<uint32_t>(field)); }

    static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
    {
        return Structure::create(vm, globalObject, prototype, TypeInfo(JSStringIteratorType, StructureFlags), info());
    }

    static JSStringIterator* create(VM& vm, Structure* structure, JSString* iteratedString)
    {
        JSStringIterator* instance = new (NotNull, allocateCell<JSStringIterator>(vm)) JSStringIterator(vm, structure);
        instance->finishCreation(vm, iteratedString);
        return instance;
    }

    JSValue iteratedString() const { return internalField(Field::IteratedString).get(); }
    JSValue index() const { return internalField(Field::Index).get(); }
    JSStringIterator* clone(JSGlobalObject*);

    DECLARE_VISIT_CHILDREN;

private:
    JSStringIterator(VM& vm, Structure* structure)
        : Base(vm, structure)
    {
    }

    void finishCreation(VM&, JSString* iteratedString);
};

} // namespace JSC