The flexibility of object embedding and composition combined with recursion opens up a unique approach to parsing. 内嵌对象的灵活性和递归的合成，开创了一个统一的分析方法。
A member initializer that specifes an object initializer after the equals sign is an initialization of an embedded object. 成员构造者特指某个等号后面的对象构造者，是内嵌对象的初始化。
