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/*
* Copyright 2019 by its authors. See AUTHORS.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef EOLIAN_CXX_ALTERNATIVE_HH
#define EOLIAN_CXX_ALTERNATIVE_HH
#include "grammar/generator.hpp"
#include "grammar/meta.hpp"
namespace efl { namespace eolian { namespace grammar {
template <typename L, typename R>
struct alternative_generator
{
template <typename OutputIterator, typename...Args, typename Context>
bool generate(OutputIterator /*sink*/, eina::variant<Args...> const& /*attribute*/, Context const& /*context*/) const
{
// return grammar::alternative_sequence(left, right, sink, attribute);
return false;
}
template <typename OutputIterator, typename Attribute, typename...Args, typename Context>
bool generate(OutputIterator sink, Attribute const& attribute, Context const& context) const
{
if(!attributes::generate(as_generator(left), sink, attribute, context))
return attributes::generate(as_generator(right), sink, attribute, context);
else
return true;
}
L left;
R right;
};
template <typename L, typename R>
struct is_eager_generator<alternative_generator<L, R> > : std::true_type {};
template <typename L, typename R>
struct is_generator<alternative_generator<L, R> > : std::true_type {};
namespace type_traits {
template <typename L, typename R>
struct attributes_needed<alternative_generator<L, R> > : std::integral_constant
<int, meta::max<attributes_needed<L>::value, attributes_needed<R>::value>::value> {};
template <typename L, typename R>
struct accepts_tuple<alternative_generator<L, R> > : std::true_type {};
}
template <typename L, typename R>
typename std::enable_if<grammar::is_generator<L>::value && grammar::is_generator<R>::value, alternative_generator<L, R>>::type
operator|(L l, R r)
{
return alternative_generator<L, R>{l, r};
}
} } }
#endif
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