coroutine example

examples/coroutine.cpp

@@ -0,0 +1,59 @@
+#include <string>
+#include "sol.hpp"
+
+#include <iostream>
+
+int main() {
+	std::cout << "=== coroutine example ===" << std::endl;
+
+	sol::state lua;
+	std::vector<sol::coroutine> tasks;
+
+	lua.open_libraries(sol::lib::base, sol::lib::coroutine);
+
+	sol::thread runner_thread = sol::thread::create(lua);
+
+	lua.set_function("start_task",
+		[&runner_thread, &tasks](sol::function f, sol::variadic_args va) {
+		// You must ALWAYS get the current state
+		sol::state_view runner_thread_state = runner_thread.state();
+		// Put the task in our task list to keep it alive and track it
+		std::size_t task_index = tasks.size();
+		tasks.emplace_back(runner_thread_state, f);
+		sol::coroutine& f_on_runner_thread = tasks[task_index];
+		// call coroutine with arguments that came 
+		// from main thread / other thread
+		// pusher for `variadic_args` and other sol types will transfer the
+		// arguments from the calling thread to 
+		// the runner thread automatically for you
+		// using `lua_xmove` internally
+		int wait = f_on_runner_thread(va);
+		std::cout << "First return: " << wait << std::endl;
+		// When you call it again, you don't need new arguments 
+		// (they remain the same from the first call)
+		f_on_runner_thread();
+		std::cout << "Second run complete: " << wait << std::endl;
+	});
+
+	lua.script(
+		R"(
+function main(x, y, z)
+	-- do something
+	coroutine.yield(20)
+	-- do something else
+	-- do ...
+	print(x, y, z)
+end
+
+function main2(x, y)
+	coroutine.yield(10)
+	print(x, y)
+end
+
+	start_task(main, 10, 12, 8)
+	start_task(main2, 1, 2)
+)"
+);
+
+	return 0;
+}