'use strict';
var Bluebird = require('bluebird');

// I do not want to wrap this in a coroutine.
function *ping(val) {
    console.log('Ping?');
    yield Bluebird.delay(500);
    pong(val + 1);
}

// I do not want to wrap this in a coroutine.
function *pong(val) {
    console.log('Pong?');
    yield Bluebird.delay(500);
    pong(val + 1);
}

// Here I want to magically convert a Generator function to a Promise.
Bluebird.coroutine.addYieldHandler(function (gen) {
    if (gen && gen.next && gen.next.call) {
        return Promise.try(function cont(a) {
            var n = gen.next(a);
            if (n.done) {
                return n.value;
            }
            if (!n.value.then) {
                return cont(n.value);
            }
            return n.value.catch(gen.throw.bind(gen)).then(cont);
        });
    }
});

// This is the main start function.
Bluebird.coroutine(function *() {
    yield ping(10);
})();