mirror of
https://github.com/Naios/continuable.git
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132 lines
3.2 KiB
C++
132 lines
3.2 KiB
C++
/*
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Copyright(c) 2015 - 2019 Denis Blank <denis.blank at outlook dot com>
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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**/
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#include <exception>
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#include <functional>
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#include <string>
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#include <system_error>
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template <typename... A>
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struct continuable {
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template <typename T = int>
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continuable(T&& = 0) {
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}
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template <typename T>
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continuable& then(T&&) {
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return *this;
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}
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template <typename T>
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continuable& dropped(T&&) {
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return *this;
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}
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template <typename T>
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continuable& thrown(T&&) {
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return *this;
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}
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template <typename T>
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continuable& failed(T&&) {
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return *this;
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}
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template <typename T>
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continuable& operator|(T&&) {
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return *this;
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}
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};
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template <typename... Args>
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using channel = continuable<Args...>;
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template <typename... A>
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struct promise {
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void set_value(A...) noexcept {
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}
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void operator()(A...) && noexcept {
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}
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void set_exception(std::exception_ptr exception) noexcept {
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// ...
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(void)exception;
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}
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void set_error(std::error_condition error) noexcept {
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// ...
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(void)error;
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}
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void cancel() noexcept {
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}
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bool is_canceled() const noexcept {
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return false;
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}
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};
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template <typename... Result>
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struct accumulator {
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auto accumulate() {
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return [] {};
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}
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};
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template <typename Accumulator, typename... Initial>
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auto make_accumulator(Accumulator&& /*ac*/, Initial&&... /*initial*/) {
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return std::make_tuple(continuable<>{}, accumulator<int>{});
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}
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continuable<std::string> http_request(std::string url) {
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return [url = std::move(url)](promise<std::string> result) mutable {
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// ...
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result.set_value("<html>...</html>");
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// ...
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result.set_exception(nullptr);
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// ...
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result.set_error(std::error_condition{});
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};
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}
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int main(int, char**) {
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auto accumulator = make_accumulator(std::plus<int>{}, 0);
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http_request("github.com")
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.then([](std::string response) {
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// ...
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(void)response;
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})
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.then(std::get<1>(accumulator).accumulate())
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.thrown([](std::exception_ptr exception) {
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// ...
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(void)exception;
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})
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.failed([](std::error_condition error) {
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// ...
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(void)error;
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});
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return 0;
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}
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