algorithm.h

/*
 *
 * algorithm
 * ledger-core
 *
 * Created by Pierre Pollastri on 25/07/2017.
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Ledger
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#ifndef LEDGER_CORE_ALGORITHM_H
#define LEDGER_CORE_ALGORITHM_H

#include "Future.hpp"
#include <utils/ImmediateExecutionContext.hpp>

namespace ledger {
    namespace core {
        namespace async {

            namespace internals {

                template <class T>
                Future<Unit> sequence_go(const std::shared_ptr<api::ExecutionContext>& context, int index, const std::vector< Future<T> >& futures, std::vector<T>* buffer) {
                if (index >= futures.size())
                return Future<Unit>::successful(unit);
                else {
                Future<T> fut = futures[index];
                return fut.template flatMap<Unit>(context, [context, buffer, index, futures](const T &r) -> Future<Unit> {
                buffer->push_back(r);
                return sequence_go(context, index + 1, futures, buffer);
            });
        }
    }

}

            template <class T>
            Future< std::vector<T> > sequence(const std::shared_ptr<api::ExecutionContext>& context, const std::vector< Future<T> >& futures) {
            auto buffer = new std::vector<T>();
            return internals::sequence_go<T>(context, 0, futures, buffer).template map< std::vector<T> >(context, [buffer] (const Unit&) -> std::vector<T> {
            auto res = *buffer;
            delete buffer;
            return res;
            });
            }

        }
    }
}

#define BEGIN_ASYNC_WHILE()

#define ASYNC_FOREACH()

#endif //LEDGER_CORE_ALGORITHM_H