main.cpp

#include <iostream>

#include "Promise.cc"

class Error{ // class for exception-handling
        std::string message;
        public:
                Error()=default;
                Error(std::string message) : message{message}{
                }
                std::string show(){
                        return message;
                }
};

std::ostream&operator<<(std::ostream&out, Error err){
        out << err.show();
        return out;
}

// some of the examples taken from <url> understanding-javascript-promises </url>
void e1(){
	auto a1 = ECMA::Promise<int, int>([](auto resolve){
                        resolve(5101);
        });

        auto a2 = ECMA::Promise<int>([](auto resolve, auto reject){
                        reject(11);
        });

        a1.then([](auto resolve, auto reject){
                        std::cout << resolve << std::endl;
        });

        a2.then([](auto resolve, auto reject){
			std::cout << reject << std::endl;
       	});

	a1.then([](auto resolve){ // not able to "resolve" a Promise a second time
			std::cout << "S: " << resolve << std::endl;
	});

	// or

        ECMA::Promise<int, int>::resolve(5101).then([](auto resolve, auto reject){
                        std::cout << resolve << std::endl;
        });

	ECMA::Promise<int>::reject(11).then([](auto resolve, auto reject){
			std::cout << reject << std::endl;
	});

	// or even
	
	ECMA::Promise<int, int>::resolve(50).await(); // 50


	// how to use async 
	
	ECMA::Promise<int>::async((std::function<int(int)>)[](auto v){
			return v;
	}, 5).then([](auto resolve){
		std::cout << resolve << std::endl;
	});
}

void e2(){ // handling errors
	ECMA::Promise<std::string, Error>([](auto resolve, auto reject){
			throw Error("Error");
	})._catch([](auto err){
		std::cout << err << std::endl;
	});

	// or
	
	ECMA::Promise<std::string>([](auto resolve, auto reject){
			reject("Error");
	})._catch([](auto err){
		std::cout << err << std::endl;
	});
}

void e3(){ // cascading errors
	ECMA::Promise<int, char*>([](auto resolve, auto reject){
			throw (char*)"ERR";
	})._catch([](auto err){
			// std::cout << err << std::endl;
			throw (char*)"SEC";
	})._catch([](auto err){
		std::cout << err << std::endl;
	});
}

int main(void){
	e1();
	e2();
	e3();
	return 0;
};