JSDOMConvertVariadic.h   [plain text]


/*
 * Copyright (C) 2016 Apple Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions
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 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#pragma once

#include "IDLTypes.h"

namespace WebCore {

namespace Detail {

template<typename IDLType>
struct VariadicConverterBase;

template<typename IDLType> 
struct VariadicConverterBase {
    using Item = typename IDLType::ImplementationType;

    static std::optional<Item> convert(JSC::ExecState& state, JSC::JSValue value)
    {
        auto& vm = state.vm();
        auto scope = DECLARE_THROW_SCOPE(vm);

        auto result = Converter<IDLType>::convert(state, value);
        RETURN_IF_EXCEPTION(scope, std::nullopt);

        return WTFMove(result);
    }
};

template<typename T>
struct VariadicConverterBase<IDLInterface<T>> {
    using Item = std::reference_wrapper<T>;

    static std::optional<Item> convert(JSC::ExecState& state, JSC::JSValue value)
    {
        auto* result = Converter<IDLInterface<T>>::convert(state, value);
        if (!result)
            return std::nullopt;
        return std::optional<Item>(*result);
    }
};

template<typename IDLType>
struct VariadicConverter : VariadicConverterBase<IDLType> {
    using Item = typename VariadicConverterBase<IDLType>::Item;
    using Container = Vector<Item>;

    struct Result {
        size_t argumentIndex;
        std::optional<Container> arguments;
    };
};

}

template<typename IDLType> typename Detail::VariadicConverter<IDLType>::Result convertVariadicArguments(JSC::ExecState& state, size_t startIndex)
{
    size_t length = state.argumentCount();
    if (startIndex > length)
        return { 0, std::nullopt };

    typename Detail::VariadicConverter<IDLType>::Container result;
    result.reserveInitialCapacity(length - startIndex);

    for (size_t i = startIndex; i < length; ++i) {
        auto value = Detail::VariadicConverter<IDLType>::convert(state, state.uncheckedArgument(i));
        if (!value)
            return { i, std::nullopt };
        result.uncheckedAppend(WTFMove(*value));
    }

    return { length, WTFMove(result) };
}

} // namespace WebCore