mirror of
https://github.com/Naios/continuable.git
synced 2025-12-06 08:46:44 +08:00
102 lines
2.9 KiB
C++
102 lines
2.9 KiB
C++
/**
|
|
Copyright(c) 2015 - 2017 Denis Blank <denis.blank at outlook dot com>
|
|
|
|
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.
|
|
**/
|
|
|
|
#include <exception>
|
|
#include <functional>
|
|
#include <string>
|
|
#include <system_error>
|
|
|
|
template <typename... A> struct continuable {
|
|
template <typename T = int> continuable(T&& = 0) {}
|
|
|
|
template <typename T> continuable& then(T&&) { return *this; }
|
|
|
|
template <typename T> continuable& dropped(T&&) { return *this; }
|
|
|
|
template <typename T> continuable& thrown(T&&) { return *this; }
|
|
|
|
template <typename T> continuable& failed(T&&) { return *this; }
|
|
};
|
|
|
|
template <typename... A> struct promise {
|
|
void set_value(A...) noexcept {}
|
|
|
|
void operator()(A...) && noexcept {}
|
|
|
|
void set_exception(std::exception_ptr exception) noexcept {
|
|
// ...
|
|
(void)exception;
|
|
}
|
|
|
|
void set_error(std::error_code error) noexcept {
|
|
// ...
|
|
(void)error;
|
|
}
|
|
|
|
void cancel() noexcept {}
|
|
|
|
bool is_canceled() const noexcept { return false; }
|
|
};
|
|
|
|
template <typename... Result> struct accumulator {
|
|
auto accumulate() {
|
|
return [] {};
|
|
}
|
|
};
|
|
|
|
template <typename Accumulator, typename... Initial>
|
|
auto make_accumulator(Accumulator&& /*ac*/, Initial&&... /*initial*/) {
|
|
return std::make_tuple(continuable<>{}, accumulator<int>{});
|
|
}
|
|
|
|
continuable<std::string> http_request(std::string url) {
|
|
return [url = std::move(url)](promise<std::string> result) mutable {
|
|
// ...
|
|
result.set_value("<html>...</html>");
|
|
// ...
|
|
result.set_exception(nullptr);
|
|
// ...
|
|
result.set_error(std::error_code{});
|
|
};
|
|
}
|
|
|
|
int main(int, char**) {
|
|
auto accumulator = make_accumulator(std::plus<int>{}, 0);
|
|
|
|
http_request("github.com")
|
|
.then([](std::string response) {
|
|
// ...
|
|
(void)response;
|
|
})
|
|
.then(std::get<1>(accumulator).accumulate())
|
|
.thrown([](std::exception_ptr exception) {
|
|
// ...
|
|
(void)exception;
|
|
})
|
|
.failed([](std::error_code code) {
|
|
// ...
|
|
(void)code;
|
|
});
|
|
|
|
return 0;
|
|
}
|