当前位置: 首页>>代码示例>>C++>>正文


C++ JSContext::wellKnownSymbols方法代码示例

本文整理汇总了C++中JSContext::wellKnownSymbols方法的典型用法代码示例。如果您正苦于以下问题:C++ JSContext::wellKnownSymbols方法的具体用法?C++ JSContext::wellKnownSymbols怎么用?C++ JSContext::wellKnownSymbols使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在JSContext的用法示例。


在下文中一共展示了JSContext::wellKnownSymbols方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: iterableObj

bool
ForOfIterator::init(HandleValue iterable, NonIterableBehavior nonIterableBehavior)
{
    JSContext* cx = cx_;
    RootedObject iterableObj(cx, ToObject(cx, iterable));
    if (!iterableObj)
        return false;

    MOZ_ASSERT(index == NOT_ARRAY);

    // Check the PIC first for a match.
    if (iterableObj->is<ArrayObject>()) {
        ForOfPIC::Chain* stubChain = ForOfPIC::getOrCreate(cx);
        if (!stubChain)
            return false;

        bool optimized;
        if (!stubChain->tryOptimizeArray(cx, iterableObj.as<ArrayObject>(), &optimized))
            return false;

        if (optimized) {
            // Got optimized stub.  Array is optimizable.
            index = 0;
            iterator = iterableObj;
            return true;
        }
    }

    MOZ_ASSERT(index == NOT_ARRAY);

    // The iterator is the result of calling obj[@@iterator]().
    InvokeArgs args(cx);
    if (!args.init(0))
        return false;
    args.setThis(ObjectValue(*iterableObj));

    RootedValue callee(cx);
    RootedId iteratorId(cx, SYMBOL_TO_JSID(cx->wellKnownSymbols().iterator));
    if (!GetProperty(cx, iterableObj, iterableObj, iteratorId, &callee))
        return false;

    // If obj[@@iterator] is undefined and we were asked to allow non-iterables,
    // bail out now without setting iterator.  This will make valueIsIterable(),
    // which our caller should check, return false.
    if (nonIterableBehavior == AllowNonIterable && callee.isUndefined())
        return true;

    // Throw if obj[@@iterator] isn't callable.
    // js::Invoke is about to check for this kind of error anyway, but it would
    // throw an inscrutable error message about |method| rather than this nice
    // one about |obj|.
    if (!callee.isObject() || !callee.toObject().isCallable()) {
        UniquePtr<char[], JS::FreePolicy> bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK,
                                                                          iterable, nullptr);
        if (!bytes)
            return false;
        JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_NOT_ITERABLE, bytes.get());
        return false;
    }

    args.setCallee(callee);
    if (!Invoke(cx, args))
        return false;

    iterator = ToObject(cx, args.rval());
    if (!iterator)
        return false;

    return true;
}
开发者ID:froydnj,项目名称:gecko-dev,代码行数:70,代码来源:ForOfIterator.cpp


注:本文中的JSContext::wellKnownSymbols方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。