迭代算子及其在可重用软件研究中的应用

ITERATORS AND ITS APPLICATION IN REUSABLE SOFTWARE STUDY

迭代算子在循环控制机制抽象和可重用软件研究中有十分重要的作用，已有１０多年研究历史，然而，至今对什么是迭代算子尚无确切和统一的定义，严重影响了对这一概念的理解，也阻碍了它的广泛应用，本文在分析研究现有各种迭代算子概念局限性的基础上，将迭代算子定义为包含于组合数据类型内部的抽象数据类型，得到了一种通用迭代算子模式，并给出了分立迭代算子和集成迭代算子的概念和模式。

Iterators act on a very important role in the abstraction of loop control mechanism and research on reusable software. Its research history is over ten years. However until now there is no precise and unified definition about it yet, which affects one to understand its meaning heavily and hinder its widespread application. Based on analyzing and studying the limitations of a variety of concepts of iterators in this paper, the authors define iterator as a abstract data type inside a combined data type and obtain a universal iterator pattern, then present the concepts and patterns of separate iterators and integrated iterators. Finally they illustrate its roles and usage by examples.