持久性在面向对象语言中的扩充

持久性是传统程序设计语言所缺乏的,它是程序设计语言中值得重视的一个要素,面向对象语言是当前表达能力和建模能力最强的一种语言,持久性与面向对象语言的结合将能够提供一个计算建模和数据建模、数据处理和数据管理的一体化语言环境。本文介绍了持久性程序设计的发展及其相关的概念,包括持久性与数据类型的正交性;讨论了持久性与面向对象语言结合中的有关问题,如对象标识及对象指针持久性等问题;同时给出了一个在面向对象语言基础上扩充持久性的实现描述,重点在其组织结构、内外存映射及其工作过程。

The Persistence Extension to Object-Oriented Programming Language

The persistence which is often absent in conventional programming languages is a property of programming language that more attention should be given. The object-oriented programming (OOP) contributes the most powerful capabilities in expression and model for software construction. To combine the persistence with OOP is meaningful in computational modelling and data modelling, and results in a good platform integrating data management with data processing. This paper introduces the persistence concepts and de velopment history including the orthogonality to data type, discusses the issues of combining persistence with OOP, such as the object identity and the persistent object pointer; de-scibes the persistence extension to OOP language, in which emphasis is given to the architecture, the map between the main and the secondary storages, and the mechanism of the process.