inheritance hierarchy

基本解釋

Changing the inheritance hierarchy of an object requires a declare parents tag.
改變對象的繼承層次需要一個 declare parents 標簽。
There is inheritance, though: SDO understands an inheritance hierarchy among types, and given a property expecting a given type, you can assign a subtype.
但存在繼承性：SDO 理解類型間的繼承層次結搆，給定屬性要求給定類型，可指派子類型。
Given an object (such as Foo, defined below), static crosscutting makes it quite simple to create new methods, add additional constructors, and even alter the inheritance hierarchy.
給定一個對象（比如下麪定義的 Foo ），靜態(tài)橫切使得創(chuàng)建新方法、添加附加的搆造函數(shù)，甚至改變繼承層次都變得十分簡單。