// 对co模块的简单模拟

function run(gen){

    var g = gen();

    function next(data){

        var result = g.next(data);

        if (result.done) return result.value;

        result.value.then(function(data){

            next(data);

        });

    }

    next();

}

function a(aa){

    return new Promise(function (resolve, reject){

        setTimeout(function (){

            console.log(aa);

            resolve('dataA');

        }, 1000);

    });

}

function b(bb){

    return new Promise(function (resolve, reject){

        setTimeout(function (){

            console.log(bb);

            resolve('dataB');

        }, 1000);

    });

}

function *gen(){

    console.log(yield a('aa'));

    console.log(yield b('bb'));

}

run(gen);

/*

等一秒

aa

dataA

等一秒

bb

dataB

*/

// 对co模块的简单模拟

function run(fn) {

    var gen = fn();

    function next(err, data) {

        var result = gen.next(data);

        if (result.done) return;

        result.value(next);

    }

    next();

}

var Thunk = function(fn){

    return function(...args){

        return function(callback){

            return fn.call(this, ...args, callback);

        };

    };

};

function a(aa, cb){

    setTimeout(function (){

        console.log(aa);

        cb(null, 'dataA');

    }, 1000);

}

function b(bb, cb){

    setTimeout(function (){

        console.log(bb);

        cb(null, 'dataB');

    }, 1000);

}

var aThunk = Thunk(a);

var bThunk = Thunk(b);

function *gen(){

    console.log(yield aThunk('aa'));

    console.log(yield bThunk('bb'));

}

run(gen);

/*

等一秒

aa

dataA

等一秒

bb

dataB

*/