es6中的双箭头函数

原代码：

const fetchPosts = subreddit => dispatch => {

dispatch(requestPosts(subreddit));

return common.fetch({url: config.argumentSubmit, method: 'POST'})

.then(response => response.message)

.then(message => dispatch(receivePosts(subreddit, message)));

};

解析为：

const fetchPosts = function (subreddit) {

return function (dispatch) {

return common.fetch({url: config.argumentSubmit, method: 'POST'})

.then(response => response.message)

.then(message => dispatch(receivePosts(subreddit, message)));
}
}

双箭头意思是导出一个函数