What you do today can improve all your tomorrows.
Bear in mind: S = Single Responsibility Principle
O = Opened Closed Principle
L = Liskov Substitution Principle
I = Interface Segregation Principle
D = Dependency Inversion Principle
摘要：
最近处理SGML文档时，碰到的DTD语法： <!ELEMENT name - - (#PCDATA)> 说明：- - 代表 name 元素有开始标识和结束标识 <!ELEMENT name - o (#PCDATA)> 说明：- o 代表 name 元素有开始标识，但没有结束标识 <!ELEMENT 阅读全文
